v1.1.0: modo offline local-first (Room + outbox) con sincronización automática

app/build.gradle

@@ -3,6 +3,7 @@ plugins {
     id "org.jetbrains.kotlin.android"
     id "org.jetbrains.kotlin.plugin.compose"
     id "org.jetbrains.kotlin.plugin.serialization"
+    id "com.google.devtools.ksp"
 }
 
 android {
@@ -13,8 +14,8 @@ android {
         applicationId "com.conta.app"
         minSdk 24
         targetSdk 34
-        versionCode 6
+        versionCode 8
-        versionName "1.0.5"
+        versionName "1.1.0"
     }
 
     buildTypes {
@@ -67,6 +68,10 @@ dependencies {
 
     implementation("androidx.datastore:datastore-preferences:1.1.1")
 
+    implementation("androidx.room:room-runtime:2.6.1")
+    implementation("androidx.room:room-ktx:2.6.1")
+    ksp("androidx.room:room-compiler:2.6.1")
+
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.9.0")
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.7.3")
 

app/src/main/java/com/conta/app/ContaApp.kt

@@ -4,13 +4,18 @@ import android.app.Application
 import android.content.Context
 import com.conta.app.data.AppRepository
 import com.conta.app.data.SettingsRepository
+import com.conta.app.data.local.ContaDatabase
+import com.conta.app.data.local.LocalStore
 import com.conta.app.data.network.ApiService
+import com.conta.app.data.network.ConnectivityObserver
 import com.conta.app.data.network.NetworkModule
 import com.conta.app.data.network.Session
+import com.conta.app.data.sync.SyncEngine
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
 
 class ContaApp : Application() {
@@ -28,6 +33,13 @@ class ContaApp : Application() {
         scope.launch {
             Session.baseUrl = ServiceLocator.settings.baseUrl.first()
         }
+        scope.launch {
+            ServiceLocator.connectivity.hasNetwork.collectLatest { online ->
+                if (online) {
+                    ServiceLocator.repository.syncNow()
+                }
+            }
+        }
     }
 }
 
@@ -36,12 +48,21 @@ object ServiceLocator {
     lateinit var settings: SettingsRepository
         private set
 
+    lateinit var connectivity: ConnectivityObserver
+        private set
+
     val api: ApiService get() = NetworkModule.api
 
-    val repository: AppRepository by lazy { AppRepository(api) }
+    val store: LocalStore by lazy { LocalStore(ContaDatabase.get(ContaApp.instance)) }
+
+    val sync: SyncEngine by lazy { SyncEngine(api, store, connectivity, NetworkModule.json) }
+
+    val repository: AppRepository by lazy { AppRepository(api, store, sync, NetworkModule.json) }
 
     fun init(context: Context) {
         if (::settings.isInitialized) return
         settings = SettingsRepository(context.applicationContext)
+        connectivity = ConnectivityObserver(context.applicationContext)
+        connectivity.start()
     }
 }

app/src/main/java/com/conta/app/data/AppRepository.kt

@@ -1,5 +1,17 @@
 package com.conta.app.data
 
+import com.conta.app.data.local.LocalStore
+import com.conta.app.data.local.LocalTransaction
+import com.conta.app.data.local.OpType
+import com.conta.app.data.local.SyncState
+import com.conta.app.data.local.applyLocalBalances
+import com.conta.app.data.local.computeStatistics
+import com.conta.app.data.local.computeSummary
+import com.conta.app.data.local.nowIso
+import com.conta.app.data.local.toCategory
+import com.conta.app.data.local.toLocal
+import com.conta.app.data.local.toTransactionWithAccount
+import com.conta.app.data.local.withCategory
 import com.conta.app.data.model.Account
 import com.conta.app.data.model.AccountInfo
 import com.conta.app.data.model.BackupData
@@ -29,13 +41,25 @@ import com.conta.app.data.model.UpdateCategoryRequest
 import com.conta.app.data.model.UpdateRecurringTransactionRequest
 import com.conta.app.data.model.UpdateTransactionRequest
 import com.conta.app.data.network.ApiService
+import com.conta.app.data.sync.SyncEngine
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.MultipartBody
 import okhttp3.RequestBody.Companion.asRequestBody
 import java.io.File
 
-/** Convierte los errores de red/HTTP en mensajes legibles en español. */
+/**
-class AppRepository(private val api: ApiService) {
+ * Capa de datos local-first: los movimientos se guardan primero en el espejo local
+ * (outbox) y se sincronizan con el servidor. Cuentas/categorías/reglas/recurrentes
+ * se leen del espejo cuando están disponibles y se editan solo con conexión.
+ */
+class AppRepository(
+    private val api: ApiService,
+    private val store: LocalStore,
+    private val sync: SyncEngine,
+    private val json: Json,
+) {
 
     private inline fun <T> safe(block: () -> T): T {
         return try {
@@ -54,11 +78,183 @@ class AppRepository(private val api: ApiService) {
         }
     }
 
-    suspend fun listAccounts(): List<AccountInfo> = safe { api.listAccounts() }
+    // ---------- Lecturas locales ----------
+
+    suspend fun listAccounts(): List<AccountInfo> =
+        applyLocalBalances(store.snapshotAccounts(), store.snapshotTransactions())
+
+    suspend fun listAccountTransactions(id: Long): List<TransactionWithAccount> =
+        listTransactions().filter { it.accountId == id || it.toAccountId == id }
+
+    suspend fun listTransactions(): List<TransactionWithAccount> =
+        store.snapshotTransactions().map { it.toTransactionWithAccount() }
+
+    suspend fun listCategories(): List<Category> =
+        store.snapshotCategories().map { it.toCategory() }
+
+    suspend fun getSummary(): Summary = computeSummary(listAccounts())
+
+    suspend fun getStatistics(): Statistics = computeStatistics(store.snapshotTransactions())
+
+    suspend fun listRules(): List<CategorizationRule> =
+        store.getCache(CACHE_RULES)?.let { runCatching { json.decodeFromString<List<CategorizationRule>>(it) }.getOrNull() }
+            ?: emptyList()
+
+    suspend fun listRecurring(): List<RecurringTransactionWithNames> =
+        store.getCache(CACHE_RECURRING)?.let { runCatching { json.decodeFromString<List<RecurringTransactionWithNames>>(it) }.getOrNull() }
+            ?: emptyList()
+
+    suspend fun listNotices(): List<Notice> =
+        store.getCache(CACHE_NOTICES)?.let { runCatching { json.decodeFromString<List<Notice>>(it) }.getOrNull() }
+            ?: emptyList()
+
+    /** Refresca el espejo desde el servidor y cachea reglas/recurrentes/avisos. */
+    suspend fun refreshFromServer() {
+        safe {
+            sync.refreshMirror()
+            store.putCache(CACHE_RULES, json.encodeToString(api.listRules()))
+            store.putCache(CACHE_RECURRING, json.encodeToString(api.listRecurring()))
+            store.putCache(CACHE_NOTICES, json.encodeToString(api.listNotices()))
+        }
+    }
+
+    // ---------- Movimientos: local-first (outbox) ----------
+
+    suspend fun createTransaction(body: CreateTransactionRequest): Transaction {
+        val id = store.nextTempId()
+        val now = nowIso()
+        val accountName = store.snapshotAccounts().firstOrNull { it.id == body.accountId }?.name ?: ""
+        val category = store.snapshotCategories().firstOrNull { it.id == body.categoryId }
+        val local = LocalTransaction(
+            id = id,
+            accountId = body.accountId,
+            accountName = accountName,
+            transactionType = body.transactionType,
+            amount = body.amount,
+            description = body.description,
+            date = body.date,
+            categoryId = body.categoryId,
+            createdAt = now,
+            syncState = SyncState.PENDING_CREATE,
+        ).withCategory(category)
+        store.insertPendingCreate(local, json.encodeToString(body))
+        sync.requestSync()
+        return local.toTransaction()
+    }
+
+    suspend fun createTransfer(body: TransferRequest): List<Transaction> {
+        val id = store.nextTempId()
+        val now = nowIso()
+        val accounts = store.snapshotAccounts().associateBy { it.id }
+        val category = store.snapshotCategories().firstOrNull { it.id == body.categoryId }
+        val local = LocalTransaction(
+            id = id,
+            accountId = body.fromAccountId,
+            accountName = accounts[body.fromAccountId]?.name ?: "",
+            toAccountId = body.toAccountId,
+            toAccountName = accounts[body.toAccountId]?.name,
+            transactionType = "transfer",
+            amount = body.amount,
+            description = body.description,
+            date = body.date,
+            categoryId = body.categoryId,
+            createdAt = now,
+            syncState = SyncState.PENDING_CREATE,
+        ).withCategory(category)
+        store.insertPendingTransfer(local, json.encodeToString(body))
+        sync.requestSync()
+        return listOf(local.toTransaction())
+    }
+
+    suspend fun updateTransaction(id: Long, body: UpdateTransactionRequest): Transaction {
+        if (id < 0) {
+            // Aún no subida: se edita localmente (merge en el op pendiente).
+            val local = store.snapshotTransactions().firstOrNull { it.id == id } ?: return localPlaceholder(id)
+            val updated = local.copy(
+                accountId = body.accountId ?: local.accountId,
+                transactionType = body.transactionType ?: local.transactionType,
+                amount = body.amount ?: local.amount,
+                description = body.description ?: local.description,
+                date = body.date ?: local.date,
+                categoryId = body.categoryId?.value ?: local.categoryId,
+            ).withCategory(store.snapshotCategories().firstOrNull { it.id == body.categoryId?.value })
+            val opType = if (updated.transactionType == "transfer") OpType.CREATE_TRANSFER else OpType.CREATE_TRANSACTION
+            val payload = if (updated.transactionType == "transfer") {
+                json.encodeToString(
+                    TransferRequest(
+                        fromAccountId = updated.accountId,
+                        toAccountId = updated.toAccountId ?: updated.accountId,
+                        amount = updated.amount,
+                        description = updated.description,
+                        date = updated.date,
+                        categoryId = updated.categoryId,
+                    ),
+                )
+            } else {
+                json.encodeToString(
+                    CreateTransactionRequest(
+                        accountId = updated.accountId,
+                        transactionType = updated.transactionType,
+                        amount = updated.amount,
+                        description = updated.description,
+                        date = updated.date,
+                        categoryId = updated.categoryId,
+                    ),
+                )
+            }
+            store.updatePendingCreate(updated, payload, opType)
+            sync.requestSync()
+            return updated.toTransaction()
+        }
+        store.enqueueUpdate(
+            store.snapshotTransactions().firstOrNull { it.id == id } ?: return localPlaceholder(id),
+            json.encodeToString(body),
+        )
+        sync.requestSync()
+        return localPlaceholder(id)
+    }
+
+    suspend fun updateTransactionToTransfer(id: Long, body: TransferRequest): List<Transaction> {
+        if (id < 0) {
+            val local = store.snapshotTransactions().firstOrNull { it.id == id } ?: return emptyList()
+            val accounts = store.snapshotAccounts().associateBy { it.id }
+            val updated = local.copy(
+                accountId = body.fromAccountId,
+                accountName = accounts[body.fromAccountId]?.name ?: local.accountName,
+                toAccountId = body.toAccountId,
+                toAccountName = accounts[body.toAccountId]?.name,
+                transactionType = "transfer",
+                amount = body.amount,
+                description = body.description,
+                date = body.date,
+                categoryId = body.categoryId,
+            ).withCategory(store.snapshotCategories().firstOrNull { it.id == body.categoryId })
+            store.updatePendingCreate(updated, json.encodeToString(body), OpType.CREATE_TRANSFER)
+            sync.requestSync()
+            return listOf(updated.toTransaction())
+        }
+        store.enqueueUpdateToTransfer(
+            store.snapshotTransactions().firstOrNull { it.id == id } ?: return emptyList(),
+            json.encodeToString(body),
+        )
+        sync.requestSync()
+        return emptyList()
+    }
+
+    suspend fun deleteTransaction(id: Long) {
+        if (id < 0) {
+            store.removeLocal(id)
+        } else {
+            store.enqueueDelete(id)
+            sync.requestSync()
+        }
+    }
+
+    // ---------- Cuentas / categorías / reglas / recurrentes (requieren conexión) ----------
+
     suspend fun createAccount(body: CreateAccountRequest): Account = safe { api.createAccount(body) }
     suspend fun updateAccount(id: Long, body: UpdateAccountRequest): Account = safe { api.updateAccount(id, body) }
     suspend fun deleteAccount(id: Long) = safe { api.deleteAccount(id) }
-    suspend fun listAccountTransactions(id: Long): List<TransactionWithAccount> = safe { api.listAccountTransactions(id) }
 
     suspend fun importStatement(accountId: Long, file: File): StatementImportResult =
         safe { api.importStatement(accountId, file.toMultipart("statement.pdf")) }
@@ -66,34 +262,20 @@ class AppRepository(private val api: ApiService) {
     suspend fun importSavingsStatement(accountId: Long, file: File): StatementImportResult =
         safe { api.importSavingsStatement(accountId, file.toMultipart("statement.pdf")) }
 
-    suspend fun listTransactions(): List<TransactionWithAccount> = safe { api.listTransactions() }
-    suspend fun createTransaction(body: CreateTransactionRequest): Transaction = safe { api.createTransaction(body) }
-    suspend fun createTransfer(body: TransferRequest): List<Transaction> = safe { api.createTransfer(body) }
-    suspend fun updateTransaction(id: Long, body: UpdateTransactionRequest): Transaction = safe { api.updateTransaction(id, body) }
-    suspend fun updateTransactionToTransfer(id: Long, body: TransferRequest): List<Transaction> =
-        safe { api.updateTransactionToTransfer(id, body) }
-    suspend fun deleteTransaction(id: Long) = safe { api.deleteTransaction(id) }
-
-    suspend fun listCategories(): List<Category> = safe { api.listCategories() }
     suspend fun createCategory(body: CreateCategoryRequest): Category = safe { api.createCategory(body) }
     suspend fun updateCategory(id: Long, body: UpdateCategoryRequest): Category = safe { api.updateCategory(id, body) }
     suspend fun deleteCategory(id: Long) = safe { api.deleteCategory(id) }
 
-    suspend fun listRules(): List<CategorizationRule> = safe { api.listRules() }
     suspend fun createRule(body: CreateCategorizationRuleRequest): CategorizationRuleCreated = safe { api.createRule(body) }
     suspend fun updateRule(id: Long, body: UpdateCategorizationRuleRequest): CategorizationRule = safe { api.updateRule(id, body) }
     suspend fun deleteRule(id: Long) = safe { api.deleteRule(id) }
 
-    suspend fun getSummary(): Summary = safe { api.getSummary() }
+    suspend fun createRecurring(body: CreateRecurringTransactionRequest): RecurringTransactionWithNames = safe { api.createRecurring(body) }
-    suspend fun getStatistics(): Statistics = safe { api.getStatistics() }
+    suspend fun updateRecurring(id: Long, body: UpdateRecurringTransactionRequest): RecurringTransactionWithNames = safe { api.updateRecurring(id, body) }
-
-    suspend fun listRecurring(): List<RecurringTransactionWithNames> = safe { api.listRecurring() }
-    suspend fun createRecurring(body: CreateRecurringTransactionRequest): RecurringTransactionWithNames =
-        safe { api.createRecurring(body) }
-    suspend fun updateRecurring(id: Long, body: UpdateRecurringTransactionRequest): RecurringTransactionWithNames =
-        safe { api.updateRecurring(id, body) }
     suspend fun deleteRecurring(id: Long) = safe { api.deleteRecurring(id) }
 
+    // ---------- Otros ----------
+
     suspend fun exportBackup(): BackupData = safe { api.exportBackup() }
     suspend fun importBackup(body: BackupData) = safe { api.importBackup(body) }
 
@@ -101,11 +283,40 @@ class AppRepository(private val api: ApiService) {
     suspend fun saveNtfySettings(body: NtfySettingsRequest): NtfySettings = safe { api.saveNtfySettings(body) }
     suspend fun testNtfy(): NtfyTestResult = safe { api.testNtfy() }
 
-    suspend fun listNotices(): List<Notice> = safe { api.listNotices() }
     suspend fun dismissNotice(fingerprint: String) = safe { api.dismissNotice(DismissNoticeRequest(fingerprint)) }
 
+    suspend fun syncNow(): Boolean = sync.syncNow()
+
+    private fun localPlaceholder(id: Long): Transaction = Transaction(
+        id = id,
+        accountId = 0,
+        transactionType = "expense",
+        amount = 0.0,
+        description = "",
+        date = "",
+        createdAt = "",
+    )
+
+    private fun LocalTransaction.toTransaction(): Transaction = Transaction(
+        id = id,
+        accountId = accountId,
+        toAccountId = toAccountId,
+        transactionType = transactionType,
+        amount = amount,
+        description = description,
+        date = date,
+        categoryId = categoryId,
+        createdAt = createdAt,
+    )
+
     private fun File.toMultipart(name: String): MultipartBody.Part =
         MultipartBody.Part.createFormData("file", name, asRequestBody("application/pdf".toMediaType()))
+
+    private companion object {
+        const val CACHE_RULES = "rules"
+        const val CACHE_RECURRING = "recurring"
+        const val CACHE_NOTICES = "notices"
+    }
 }
 
 class ApiError(message: String) : Exception(message)

app/src/main/java/com/conta/app/data/local/ContaDatabase.kt

@@ -0,0 +1,39 @@
+package com.conta.app.data.local
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+
+@Database(
+    entities = [
+        LocalAccount::class,
+        LocalCategory::class,
+        LocalTransaction::class,
+        PendingOp::class,
+        SyncMeta::class,
+    ],
+    version = 1,
+    exportSchema = false,
+)
+abstract class ContaDatabase : RoomDatabase() {
+    abstract fun accountDao(): AccountDao
+    abstract fun categoryDao(): CategoryDao
+    abstract fun transactionDao(): TransactionDao
+    abstract fun pendingOpDao(): PendingOpDao
+    abstract fun metaDao(): MetaDao
+
+    companion object {
+        @Volatile
+        private var instance: ContaDatabase? = null
+
+        fun get(context: Context): ContaDatabase =
+            instance ?: synchronized(this) {
+                instance ?: Room.databaseBuilder(
+                    context.applicationContext,
+                    ContaDatabase::class.java,
+                    "conta_local.db",
+                ).build().also { instance = it }
+            }
+    }
+}

app/src/main/java/com/conta/app/data/local/Daos.kt

@@ -0,0 +1,100 @@
+package com.conta.app.data.local
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface AccountDao {
+    @Query("SELECT * FROM accounts ORDER BY accountType, name")
+    fun observeAll(): Flow<List<LocalAccount>>
+
+    @Query("SELECT * FROM accounts ORDER BY accountType, name")
+    suspend fun getAll(): List<LocalAccount>
+
+    @Query("SELECT * FROM accounts WHERE id = :id")
+    suspend fun findById(id: Long): LocalAccount?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun upsertAll(accounts: List<LocalAccount>)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun upsert(account: LocalAccount)
+
+    @Query("DELETE FROM accounts")
+    suspend fun clear()
+}
+
+@Dao
+interface CategoryDao {
+    @Query("SELECT * FROM categories ORDER BY name")
+    fun observeAll(): Flow<List<LocalCategory>>
+
+    @Query("SELECT * FROM categories ORDER BY name")
+    suspend fun getAll(): List<LocalCategory>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun upsertAll(categories: List<LocalCategory>)
+
+    @Query("DELETE FROM categories")
+    suspend fun clear()
+}
+
+@Dao
+interface TransactionDao {
+    @Query("SELECT * FROM transactions ORDER BY date DESC, id DESC")
+    fun observeAll(): Flow<List<LocalTransaction>>
+
+    @Query("SELECT * FROM transactions ORDER BY date DESC, id DESC")
+    suspend fun getAll(): List<LocalTransaction>
+
+    @Query("SELECT * FROM transactions WHERE id = :id")
+    suspend fun findById(id: Long): LocalTransaction?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun upsertAll(transactions: List<LocalTransaction>)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun upsert(transaction: LocalTransaction)
+
+    @Query("DELETE FROM transactions")
+    suspend fun clear()
+
+    @Query("DELETE FROM transactions WHERE id = :id")
+    suspend fun deleteById(id: Long)
+
+    @Query("SELECT COUNT(*) FROM transactions WHERE syncState != :state")
+    suspend fun countPending(state: String = SyncState.SYNCED): Int
+}
+
+@Dao
+interface PendingOpDao {
+    @Query("SELECT * FROM pending_ops ORDER BY opId ASC")
+    fun observeAll(): Flow<List<PendingOp>>
+
+    @Query("SELECT * FROM pending_ops ORDER BY opId ASC")
+    suspend fun getAll(): List<PendingOp>
+
+    @Query("SELECT COUNT(*) FROM pending_ops")
+    fun observeCount(): Flow<Int>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insert(op: PendingOp): Long
+
+    @Query("DELETE FROM pending_ops WHERE opId = :opId")
+    suspend fun deleteById(opId: Long)
+
+    @Query("UPDATE pending_ops SET retryCount = :retry, lastError = :error WHERE opId = :opId")
+    suspend fun updateRetry(opId: Long, retry: Int, error: String?)
+}
+
+@Dao
+interface MetaDao {
+    @Query("SELECT value FROM sync_meta WHERE `key` = :key")
+    suspend fun get(key: String): String?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun put(entry: SyncMeta)
+}

app/src/main/java/com/conta/app/data/local/LocalCalculations.kt

@@ -0,0 +1,116 @@
+package com.conta.app.data.local
+
+import com.conta.app.data.model.AccountInfo
+import com.conta.app.data.model.CategoryStat
+import com.conta.app.data.model.MonthlyStat
+import com.conta.app.data.model.Statistics
+import com.conta.app.data.model.Summary
+import java.time.LocalDate
+import java.util.TreeMap
+
+/** Cálculos locales que replican la lógica del backend (saldos, resumen, estadísticas). */
+
+fun transactionEffect(tx: LocalTransaction): Map<Long, Double> = when (tx.transactionType) {
+    "income" -> mapOf(tx.accountId to tx.amount)
+    "expense" -> mapOf(tx.accountId to -tx.amount)
+    "transfer" -> buildMap {
+        put(tx.accountId, -tx.amount)
+        tx.toAccountId?.let { put(it, tx.amount) }
+    }
+    else -> emptyMap()
+}
+
+/** Saldo efectivo por cuenta = saldo inicial + efectos de todas las transacciones. */
+fun computeBalances(accounts: List<LocalAccount>, transactions: List<LocalTransaction>): Map<Long, Double> {
+    val balances = HashMap<Long, Double>()
+    for (a in accounts) {
+        val base = if (a.accountType == "credit_card") -a.initialBalance else a.initialBalance
+        balances[a.id] = base
+    }
+    for (tx in transactions) {
+        for ((accountId, delta) in transactionEffect(tx)) {
+            balances[accountId] = (balances[accountId] ?: 0.0) + delta
+        }
+    }
+    return balances
+}
+
+/** Aplica los saldos locales a los espejos, manteniendo los campos avanzados del servidor. */
+fun applyLocalBalances(accounts: List<LocalAccount>, transactions: List<LocalTransaction>): List<AccountInfo> {
+    val balances = computeBalances(accounts, transactions)
+    return accounts.map { a ->
+        val balance = balances[a.id] ?: a.balance
+        val debt = (-balance).coerceAtLeast(0.0)
+        val saldoAFavor = balance.coerceAtLeast(0.0)
+        val creditAvailable = if (a.accountType == "credit_card" && a.creditLimit != null) {
+            (a.creditLimit - debt).coerceAtLeast(0.0)
+        } else {
+            a.creditAvailable
+        }
+        a.toAccountInfo().copy(
+            balance = balance,
+            debt = debt,
+            saldoAFavor = saldoAFavor,
+            creditAvailable = creditAvailable,
+        )
+    }
+}
+
+fun computeSummary(accounts: List<AccountInfo>): Summary = Summary(
+    totalBalance = accounts.sumOf { it.balance },
+    totalSavings = accounts.filter { it.accountType == "savings" }.sumOf { it.balance },
+    totalCredit = accounts.filter { it.accountType == "credit_card" }.sumOf { it.debt },
+    totalTimeDeposits = accounts.filter { it.accountType == "time_deposit" }.sumOf { it.balance },
+    accounts = accounts,
+)
+
+fun lastMonthLabels(count: Int, today: String): List<String> {
+    val parts = today.split("-")
+    val year = parts.getOrNull(0)?.toIntOrNull() ?: LocalDate.now().year
+    val month = parts.getOrNull(1)?.toIntOrNull() ?: 1
+    val total = year * 12 + (month - 1)
+    return (0 until count)
+        .map { i ->
+            val t = total - (count - 1 - i)
+            "%04d-%02d".format(t / 12, t % 12 + 1)
+        }
+}
+
+fun computeStatistics(transactions: List<LocalTransaction>, today: String = LocalDate.now().toString()): Statistics {
+    val labels = lastMonthLabels(6, today)
+    val currentMonth = labels.last()
+
+    val monthly = labels.map { month ->
+        var income = 0.0
+        var expense = 0.0
+        for (tx in transactions) {
+            if (!tx.date.startsWith(month)) continue
+            when (tx.transactionType) {
+                "income" -> income += tx.amount
+                "expense" -> expense += tx.amount
+            }
+        }
+        MonthlyStat(month = month, income = income, expense = expense)
+    }
+
+    val byCategory = TreeMap<Long?, CategoryStat> { a, b -> (a ?: Long.MIN_VALUE).compareTo(b ?: Long.MIN_VALUE) }
+    for (tx in transactions) {
+        if (tx.transactionType != "expense" || !tx.date.startsWith(currentMonth)) continue
+        val existing = byCategory[tx.categoryId]
+        if (existing == null) {
+            byCategory[tx.categoryId] = CategoryStat(
+                categoryId = tx.categoryId,
+                name = tx.categoryName ?: "Sin categoría",
+                color = tx.categoryColor,
+                icon = tx.categoryIcon,
+                total = tx.amount,
+            )
+        } else {
+            byCategory[tx.categoryId] = existing.copy(total = existing.total + tx.amount)
+        }
+    }
+
+    val expensesByCategory = byCategory.values.sortedByDescending { it.total }
+
+    return Statistics(expensesByCategory = expensesByCategory, monthly = monthly)
+}

app/src/main/java/com/conta/app/data/local/LocalEntities.kt

@@ -0,0 +1,100 @@
+package com.conta.app.data.local
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+object SyncState {
+    const val SYNCED = "SYNCED"
+    const val PENDING_CREATE = "PENDING_CREATE"
+    const val PENDING_UPDATE = "PENDING_UPDATE"
+    const val PENDING_DELETE = "PENDING_DELETE"
+    const val FAILED = "FAILED"
+}
+
+/** Espejo local de AccountInfo (solo lectura: se actualiza desde el servidor). */
+@Entity(tableName = "accounts")
+data class LocalAccount(
+    @PrimaryKey val id: Long,
+    val name: String,
+    val accountType: String,
+    val balance: Double,
+    val initialBalance: Double = 0.0,
+    val creditLimit: Double? = null,
+    val interestRate: Double? = null,
+    val maturityDate: String? = null,
+    val paymentAccountId: Long? = null,
+    val cutDay: Int? = null,
+    val paymentDay: Int? = null,
+    val minPaymentPct: Double? = null,
+    val minPaymentMin: Double? = null,
+    val lateFee: Double? = null,
+    val createdAt: String,
+    val debt: Double = 0.0,
+    val creditAvailable: Double? = null,
+    val saldoAFavor: Double = 0.0,
+    val statementBalance: Double? = null,
+    val minPayment: Double? = null,
+    val nextCutDate: String? = null,
+    val nextPaymentDate: String? = null,
+    val overdue: Boolean = false,
+)
+
+/** Espejo local de Category (solo lectura). */
+@Entity(tableName = "categories")
+data class LocalCategory(
+    @PrimaryKey val id: Long,
+    val name: String,
+    val categoryType: String,
+    val icon: String? = null,
+    val color: String? = null,
+    val createdAt: String,
+)
+
+/** Espejo local de TransactionWithAccount + estado de sincronización. */
+@Entity(tableName = "transactions")
+data class LocalTransaction(
+    @PrimaryKey val id: Long,
+    val accountId: Long,
+    val accountName: String = "",
+    val toAccountId: Long? = null,
+    val toAccountName: String? = null,
+    val transactionType: String,
+    val amount: Double,
+    val description: String,
+    val date: String,
+    val categoryId: Long? = null,
+    val categoryName: String? = null,
+    val categoryIcon: String? = null,
+    val categoryColor: String? = null,
+    val createdAt: String,
+    val syncState: String = SyncState.SYNCED,
+    /** Identificador del servidor; null mientras el registro es local (id negativo). */
+    val clientRef: String? = null,
+    val lastError: String? = null,
+)
+
+/** Operación pendiente de subir al servidor (outbox). */
+@Entity(tableName = "pending_ops")
+data class PendingOp(
+    @PrimaryKey(autoGenerate = true) val opId: Long = 0,
+    val type: String,
+    val txId: Long,
+    val payloadJson: String,
+    val createdAt: String,
+    val retryCount: Int = 0,
+    val lastError: String? = null,
+)
+
+@Entity(tableName = "sync_meta")
+data class SyncMeta(
+    @PrimaryKey val key: String,
+    val value: String,
+)
+
+object OpType {
+    const val CREATE_TRANSACTION = "CREATE_TRANSACTION"
+    const val CREATE_TRANSFER = "CREATE_TRANSFER"
+    const val UPDATE_TRANSACTION = "UPDATE_TRANSACTION"
+    const val UPDATE_TO_TRANSFER = "UPDATE_TO_TRANSFER"
+    const val DELETE_TRANSACTION = "DELETE_TRANSACTION"
+}

app/src/main/java/com/conta/app/data/local/LocalStore.kt

@@ -0,0 +1,336 @@
+package com.conta.app.data.local
+
+import android.content.Context
+import androidx.room.withTransaction
+import com.conta.app.data.model.AccountInfo
+import com.conta.app.data.model.Category
+import com.conta.app.data.model.Transaction
+import com.conta.app.data.model.TransactionWithAccount
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * Capa de persistencia local: espejo de cuentas/categorías/transacciones
+ * más el outbox de operaciones pendientes de subir al servidor.
+ */
+class LocalStore(private val db: ContaDatabase) {
+
+    val accounts: Flow<List<LocalAccount>> = db.accountDao().observeAll()
+    val categories: Flow<List<LocalCategory>> = db.categoryDao().observeAll()
+    val transactions: Flow<List<LocalTransaction>> = db.transactionDao().observeAll()
+    val pendingCount: Flow<Int> = db.pendingOpDao().observeCount()
+
+    suspend fun snapshotAccounts(): List<LocalAccount> = db.accountDao().getAll()
+    suspend fun snapshotTransactions(): List<LocalTransaction> = db.transactionDao().getAll()
+    suspend fun snapshotCategories(): List<LocalCategory> = db.categoryDao().getAll()
+
+    suspend fun pendingOps(): List<PendingOp> = db.pendingOpDao().getAll()
+
+    suspend fun lastSyncedAt(): String? = db.metaDao().get(MetaKeys.LAST_SYNCED_AT)
+    suspend fun setLastSyncedAt(iso: String) = db.metaDao().put(SyncMeta(MetaKeys.LAST_SYNCED_AT, iso))
+
+    suspend fun getCache(key: String): String? = db.metaDao().get("cache_$key")
+    suspend fun putCache(key: String, json: String) = db.metaDao().put(SyncMeta("cache_$key", json))
+
+    /** Reemplaza todo el espejo con datos frescos del servidor. */
+    suspend fun replaceAll(
+        accounts: List<LocalAccount>,
+        categories: List<LocalCategory>,
+        transactions: List<LocalTransaction>,
+    ) {
+        db.withTransaction {
+            db.accountDao().clear()
+            if (accounts.isNotEmpty()) db.accountDao().upsertAll(accounts)
+            db.categoryDao().clear()
+            if (categories.isNotEmpty()) db.categoryDao().upsertAll(categories)
+            db.transactionDao().clear()
+            if (transactions.isNotEmpty()) db.transactionDao().upsertAll(transactions)
+        }
+    }
+
+    /** Inserta una transacción nueva (id negativo) junto con su op pendiente. */
+    suspend fun insertPendingCreate(tx: LocalTransaction, payloadJson: String) {
+        db.withTransaction {
+            db.transactionDao().upsert(tx)
+            db.pendingOpDao().insert(
+                PendingOp(
+                    type = OpType.CREATE_TRANSACTION,
+                    txId = tx.id,
+                    payloadJson = payloadJson,
+                    createdAt = tx.createdAt,
+                ),
+            )
+        }
+    }
+
+    /** Inserta una transferencia nueva junto con su op pendiente. */
+    suspend fun insertPendingTransfer(tx: LocalTransaction, payloadJson: String) {
+        db.withTransaction {
+            db.transactionDao().upsert(tx)
+            db.pendingOpDao().insert(
+                PendingOp(
+                    type = OpType.CREATE_TRANSFER,
+                    txId = tx.id,
+                    payloadJson = payloadJson,
+                    createdAt = tx.createdAt,
+                ),
+            )
+        }
+    }
+
+    /** Actualiza una transacción que aún no se ha subido (merge en el op existente). */
+    suspend fun updatePendingCreate(tx: LocalTransaction, payloadJson: String, opType: String = OpType.CREATE_TRANSACTION) {
+        db.withTransaction {
+            val oldOp = db.pendingOpDao().getAll().firstOrNull { it.txId == tx.id }
+            if (oldOp != null) {
+                db.pendingOpDao().deleteById(oldOp.opId)
+                db.pendingOpDao().insert(
+                    oldOp.copy(
+                        type = opType,
+                        payloadJson = payloadJson,
+                        retryCount = 0,
+                        lastError = null,
+                    ),
+                )
+            }
+            db.transactionDao().upsert(tx)
+        }
+    }
+
+    /** Marca una transacción ya sincronizada para editar: PENDING_UPDATE + op. */
+    suspend fun enqueueUpdate(tx: LocalTransaction, payloadJson: String) {
+        db.withTransaction {
+            db.transactionDao().upsert(tx.copy(syncState = SyncState.PENDING_UPDATE, lastError = null))
+            db.pendingOpDao().insert(
+                PendingOp(
+                    type = OpType.UPDATE_TRANSACTION,
+                    txId = tx.id,
+                    payloadJson = payloadJson,
+                    createdAt = nowIso(),
+                ),
+            )
+        }
+    }
+
+    /** Marca una transacción para convertirla en transferencia. */
+    suspend fun enqueueUpdateToTransfer(tx: LocalTransaction, payloadJson: String) {
+        db.withTransaction {
+            db.transactionDao().upsert(tx.copy(syncState = SyncState.PENDING_UPDATE, lastError = null))
+            db.pendingOpDao().insert(
+                PendingOp(
+                    type = OpType.UPDATE_TO_TRANSFER,
+                    txId = tx.id,
+                    payloadJson = payloadJson,
+                    createdAt = nowIso(),
+                ),
+            )
+        }
+    }
+
+    /** Marca una transacción sincronizada para borrar: PENDING_DELETE + op. */
+    suspend fun enqueueDelete(id: Long) {
+        db.withTransaction {
+            val tx = db.transactionDao().findById(id) ?: return@withTransaction
+            db.transactionDao().upsert(tx.copy(syncState = SyncState.PENDING_DELETE, lastError = null))
+            db.pendingOpDao().insert(
+                PendingOp(
+                    type = OpType.DELETE_TRANSACTION,
+                    txId = id,
+                    payloadJson = "",
+                    createdAt = nowIso(),
+                ),
+            )
+        }
+    }
+
+    /**
+     * Elimina una transacción que aún no se ha subido (junto con su op pendiente).
+     * Si ya estaba marcada como PENDING_DELETE de algo no subido, simplemente se quita.
+     */
+    suspend fun removeLocal(id: Long) {
+        db.withTransaction {
+            db.transactionDao().deleteById(id)
+            db.pendingOpDao().getAll().filter { it.txId == id }.forEach { db.pendingOpDao().deleteById(it.opId) }
+        }
+    }
+
+    /** Reemplaza una fila temp (id negativo) por la fila servida real y borra su op. */
+    suspend fun resolveSyncedCreate(tempId: Long, serverTx: LocalTransaction) {
+        db.withTransaction {
+            db.transactionDao().deleteById(tempId)
+            db.transactionDao().upsert(serverTx.copy(syncState = SyncState.SYNCED, lastError = null))
+            db.pendingOpDao().getAll().filter { it.txId == tempId }.forEach { db.pendingOpDao().deleteById(it.opId) }
+        }
+    }
+
+    /** Marca una transacción como sincronizada y borra su op (usado tras un update exitoso). */
+    suspend fun markSynced(id: Long) {
+        db.withTransaction {
+            val tx = db.transactionDao().findById(id) ?: return@withTransaction
+            db.transactionDao().upsert(tx.copy(syncState = SyncState.SYNCED, lastError = null))
+            db.pendingOpDao().getAll().filter { it.txId == id }.forEach { db.pendingOpDao().deleteById(it.opId) }
+        }
+    }
+
+    /** Borra la fila local de una transacción (p. ej. borrado confirmado o descartado por 404). */
+    suspend fun dropTransaction(id: Long) {
+        db.withTransaction {
+            db.transactionDao().deleteById(id)
+            db.pendingOpDao().getAll().filter { it.txId == id }.forEach { db.pendingOpDao().deleteById(it.opId) }
+        }
+    }
+
+    suspend fun markFailed(op: PendingOp, error: String) {
+        db.withTransaction {
+            db.pendingOpDao().deleteById(op.opId)
+            val tx = db.transactionDao().findById(op.txId)
+            if (tx != null) db.transactionDao().upsert(tx.copy(syncState = SyncState.FAILED, lastError = error))
+        }
+    }
+
+    suspend fun nextTempId(): Long {
+        val key = MetaKeys.NEXT_TEMP_ID
+        val current = db.metaDao().get(key)?.toLongOrNull() ?: 0L
+        val next = current - 1
+        db.metaDao().put(SyncMeta(key, next.toString()))
+        return next
+    }
+
+    private object MetaKeys {
+        const val LAST_SYNCED_AT = "last_synced_at"
+        const val NEXT_TEMP_ID = "next_temp_id"
+    }
+}
+
+fun nowIso(): String = java.time.LocalDateTime.now().toString()
+
+// -------- Conversión modelo <-> entidad --------
+
+fun AccountInfo.toLocal(): LocalAccount = LocalAccount(
+    id = id,
+    name = name,
+    accountType = accountType,
+    balance = balance,
+    initialBalance = initialBalance,
+    creditLimit = creditLimit,
+    interestRate = interestRate,
+    maturityDate = maturityDate,
+    paymentAccountId = paymentAccountId,
+    cutDay = cutDay,
+    paymentDay = paymentDay,
+    minPaymentPct = minPaymentPct,
+    minPaymentMin = minPaymentMin,
+    lateFee = lateFee,
+    createdAt = createdAt,
+    debt = debt,
+    creditAvailable = creditAvailable,
+    saldoAFavor = saldoAFavor,
+    statementBalance = statementBalance,
+    minPayment = minPayment,
+    nextCutDate = nextCutDate,
+    nextPaymentDate = nextPaymentDate,
+    overdue = overdue,
+)
+
+fun LocalAccount.toAccountInfo(): AccountInfo = AccountInfo(
+    id = id,
+    name = name,
+    accountType = accountType,
+    balance = balance,
+    initialBalance = initialBalance,
+    creditLimit = creditLimit,
+    interestRate = interestRate,
+    maturityDate = maturityDate,
+    paymentAccountId = paymentAccountId,
+    cutDay = cutDay,
+    paymentDay = paymentDay,
+    minPaymentPct = minPaymentPct,
+    minPaymentMin = minPaymentMin,
+    lateFee = lateFee,
+    createdAt = createdAt,
+    debt = debt,
+    creditAvailable = creditAvailable,
+    saldoAFavor = saldoAFavor,
+    statementBalance = statementBalance,
+    minPayment = minPayment,
+    nextCutDate = nextCutDate,
+    nextPaymentDate = nextPaymentDate,
+    overdue = overdue,
+)
+
+fun Category.toLocal(): LocalCategory = LocalCategory(
+    id = id,
+    name = name,
+    categoryType = categoryType,
+    icon = icon,
+    color = color,
+    createdAt = createdAt,
+)
+
+fun LocalCategory.toCategory(): Category = Category(
+    id = id,
+    name = name,
+    categoryType = categoryType,
+    icon = icon,
+    color = color,
+    createdAt = createdAt,
+)
+
+fun TransactionWithAccount.toLocal(syncState: String = SyncState.SYNCED, clientRef: String? = null): LocalTransaction =
+    LocalTransaction(
+        id = id,
+        accountId = accountId,
+        accountName = accountName,
+        toAccountId = toAccountId,
+        toAccountName = toAccountName,
+        transactionType = transactionType,
+        amount = amount,
+        description = description,
+        date = date,
+        categoryId = categoryId,
+        categoryName = categoryName,
+        categoryIcon = categoryIcon,
+        categoryColor = categoryColor,
+        createdAt = createdAt,
+        syncState = syncState,
+        clientRef = clientRef,
+    )
+
+fun Transaction.toLocal(syncState: String = SyncState.SYNCED, clientRef: String? = null): LocalTransaction =
+    LocalTransaction(
+        id = id,
+        accountId = accountId,
+        toAccountId = toAccountId,
+        transactionType = transactionType,
+        amount = amount,
+        description = description,
+        date = date,
+        categoryId = categoryId,
+        createdAt = createdAt,
+        syncState = syncState,
+        clientRef = clientRef,
+    )
+
+fun LocalTransaction.toTransactionWithAccount(): TransactionWithAccount = TransactionWithAccount(
+    id = id,
+    accountId = accountId,
+    accountName = accountName,
+    toAccountId = toAccountId,
+    toAccountName = toAccountName,
+    transactionType = transactionType,
+    amount = amount,
+    description = description,
+    date = date,
+    categoryId = categoryId,
+    categoryName = categoryName,
+    categoryIcon = categoryIcon,
+    categoryColor = categoryColor,
+    createdAt = createdAt,
+)
+
+fun LocalTransaction.withAccountName(name: String): LocalTransaction = copy(accountName = name)
+fun LocalTransaction.withCategory(cat: LocalCategory?): LocalTransaction = copy(
+    categoryId = cat?.id ?: categoryId,
+    categoryName = cat?.name,
+    categoryIcon = cat?.icon,
+    categoryColor = cat?.color,
+)

app/src/main/java/com/conta/app/data/network/ConnectivityObserver.kt

@@ -0,0 +1,46 @@
+package com.conta.app.data.network
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.Network
+import android.net.NetworkCapabilities
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/** Observa si el dispositivo tiene una conexión de red activa con acceso a Internet. */
+class ConnectivityObserver(private val context: Context) {
+
+    private val _hasNetwork = MutableStateFlow(false)
+    val hasNetwork: StateFlow<Boolean> = _hasNetwork
+
+    private val callback = object : ConnectivityManager.NetworkCallback() {
+        override fun onAvailable(network: Network) = update()
+        override fun onLost(network: Network) = update()
+        override fun onCapabilitiesChanged(network: Network, capabilities: NetworkCapabilities) = update()
+    }
+
+    fun start() {
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+        update()
+        try {
+            cm.registerDefaultNetworkCallback(callback)
+        } catch (_: Exception) {
+        }
+    }
+
+    fun stop() {
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+        try {
+            cm.unregisterNetworkCallback(callback)
+        } catch (_: Exception) {
+        }
+    }
+
+    private fun update() {
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+        val network = cm.activeNetwork ?: run { _hasNetwork.value = false; return }
+        val caps = cm.getNetworkCapabilities(network)
+        val online = caps?.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) == true
+        _hasNetwork.value = online
+    }
+}

app/src/main/java/com/conta/app/data/sync/SyncEngine.kt

@@ -0,0 +1,228 @@
+package com.conta.app.data.sync
+
+import com.conta.app.data.local.LocalAccount
+import com.conta.app.data.local.LocalStore
+import com.conta.app.data.local.LocalTransaction
+import com.conta.app.data.local.OpType
+import com.conta.app.data.local.SyncState
+import com.conta.app.data.local.toLocal
+import com.conta.app.data.model.CreateTransactionRequest
+import com.conta.app.data.model.TransactionWithAccount
+import com.conta.app.data.model.TransferRequest
+import com.conta.app.data.model.UpdateTransactionRequest
+import com.conta.app.data.network.ApiService
+import com.conta.app.data.network.ConnectivityObserver
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import kotlinx.serialization.json.Json
+import java.io.IOException
+import java.time.LocalDateTime
+import java.util.concurrent.atomic.AtomicBoolean
+import kotlin.math.roundToLong
+
+/**
+ * Sincroniza el outbox local con el servidor y refresca el espejo.
+ * Dedupe de creaciones por clave (cuenta + fecha + monto + tipo + descripción):
+ * si ya existe en el servidor, se omite la subida y se mapea el id.
+ */
+class SyncEngine(
+    private val api: ApiService,
+    private val store: LocalStore,
+    private val connectivity: ConnectivityObserver,
+    private val json: Json,
+    private val scope: CoroutineScope = CoroutineScope(SupervisorJob() + Dispatchers.IO),
+) {
+    private val _isSyncing = MutableStateFlow(false)
+    val isSyncing: StateFlow<Boolean> = _isSyncing.asStateFlow()
+
+    private val _serverReachable = MutableStateFlow(false)
+    val serverReachable: StateFlow<Boolean> = _serverReachable.asStateFlow()
+
+    private val _lastSyncedAt = MutableStateFlow<String?>(null)
+    val lastSyncedAt: StateFlow<String?> = _lastSyncedAt.asStateFlow()
+
+    private val syncQueued = AtomicBoolean(false)
+
+    /** Pide una sincronización (no bloqueante, debounced). */
+    fun requestSync() {
+        if (!connectivity.hasNetwork.value) return
+        if (!syncQueued.compareAndSet(false, true)) return
+        scope.launch {
+            kotlinx.coroutines.delay(1500)
+            syncQueued.set(false)
+            syncNow()
+        }
+    }
+
+    /** Sincroniza el outbox y refresca el espejo. Devuelve true si pudo conectarse. */
+    suspend fun syncNow(): Boolean {
+        if (_isSyncing.value) return _serverReachable.value
+        _isSyncing.value = true
+        try {
+            if (!connectivity.hasNetwork.value) {
+                _serverReachable.value = false
+                return false
+            }
+            val serverTx = try {
+                api.listTransactions()
+            } catch (e: IOException) {
+                _serverReachable.value = false
+                return false
+            } catch (e: Exception) {
+                _serverReachable.value = false
+                return false
+            }
+
+            val accounts = store.snapshotAccounts().associateBy { it.id }
+            val serverKeySet = serverTx.map { dedupeKey(it.accountId, it.date, it.amount, it.transactionType, it.description) }.toSet()
+
+            val ops = store.pendingOps()
+            for (op in ops) {
+                when (op.type) {
+                    OpType.CREATE_TRANSACTION, OpType.CREATE_TRANSFER -> {
+                        val local = store.snapshotTransactions().firstOrNull { it.id == op.txId } ?: continue
+                        val key = dedupeKey(local.accountId, local.date, local.amount, local.transactionType, local.description)
+                        if (key in serverKeySet) {
+                            val existing = serverTx.first { dedupeKey(it.accountId, it.date, it.amount, it.transactionType, it.description) == key }
+                            store.resolveSyncedCreate(op.txId, fillNames(existing.toLocal(), accounts))
+                            continue
+                        }
+                        try {
+                            val created: LocalTransaction = if (op.type == OpType.CREATE_TRANSACTION) {
+                                val body = json.decodeFromString<CreateTransactionRequest>(op.payloadJson)
+                                api.createTransaction(body).toLocal()
+                            } else {
+                                val body = json.decodeFromString<TransferRequest>(op.payloadJson)
+                                api.createTransfer(body).first().toLocal()
+                            }
+                            store.resolveSyncedCreate(op.txId, fillNames(created, accounts))
+                        } catch (e: IOException) {
+                            _serverReachable.value = false
+                            return false
+                        } catch (e: Exception) {
+                            if (isHttpError(e)) store.markFailed(op, friendlyError(e)) else {
+                                _serverReachable.value = false
+                                return false
+                            }
+                        }
+                    }
+
+                    OpType.UPDATE_TRANSACTION -> {
+                        try {
+                            val body = json.decodeFromString<UpdateTransactionRequest>(op.payloadJson)
+                            api.updateTransaction(op.txId, body)
+                            store.markSynced(op.txId)
+                        } catch (e: IOException) {
+                            _serverReachable.value = false
+                            return false
+                        } catch (e: Exception) {
+                            if (isHttpError(e)) {
+                                if (is404(e)) store.dropTransaction(op.txId) else store.markFailed(op, friendlyError(e))
+                            } else {
+                                _serverReachable.value = false
+                                return false
+                            }
+                        }
+                    }
+
+                    OpType.UPDATE_TO_TRANSFER -> {
+                        try {
+                            val body = json.decodeFromString<TransferRequest>(op.payloadJson)
+                            api.updateTransactionToTransfer(op.txId, body)
+                            store.markSynced(op.txId)
+                        } catch (e: IOException) {
+                            _serverReachable.value = false
+                            return false
+                        } catch (e: Exception) {
+                            if (isHttpError(e)) {
+                                if (is404(e)) store.dropTransaction(op.txId) else store.markFailed(op, friendlyError(e))
+                            } else {
+                                _serverReachable.value = false
+                                return false
+                            }
+                        }
+                    }
+
+                    OpType.DELETE_TRANSACTION -> {
+                        try {
+                            api.deleteTransaction(op.txId)
+                            store.dropTransaction(op.txId)
+                        } catch (e: IOException) {
+                            _serverReachable.value = false
+                            return false
+                        } catch (e: Exception) {
+                            if (isHttpError(e)) {
+                                if (is404(e)) store.dropTransaction(op.txId) else store.markFailed(op, friendlyError(e))
+                            } else {
+                                _serverReachable.value = false
+                                return false
+                            }
+                        }
+                    }
+                }
+            }
+
+            // Si quedaron ops (no se pudieron procesar todas), no refrescamos el espejo para no perder pendientes.
+            if (store.pendingOps().isEmpty()) {
+                refreshMirror()
+                _serverReachable.value = true
+                _lastSyncedAt.value = LocalDateTime.now().toString()
+                store.setLastSyncedAt(LocalDateTime.now().toString())
+            }
+            return _serverReachable.value
+        } finally {
+            _isSyncing.value = false
+        }
+    }
+
+    /** Actualiza el espejo de cuentas/categorías/transacciones desde el servidor, conservando pendientes. */
+    suspend fun refreshMirror() {
+        val serverAccounts = api.listAccounts()
+        val serverCategories = api.listCategories()
+        val serverTx = api.listTransactions()
+
+        val pending = store.snapshotTransactions().filter { it.syncState != SyncState.SYNCED }
+        val accountsByName = serverAccounts.associateBy { it.id }.mapValues { it.value.name }
+
+        store.replaceAll(
+            accounts = serverAccounts.map { it.toLocal() },
+            categories = serverCategories.map { it.toLocal() },
+            transactions = pending + serverTx.map {
+                it.toLocal().let { t ->
+                    t.copy(
+                        accountName = accountsByName[t.accountId] ?: t.accountName,
+                        toAccountName = t.toAccountId?.let { id -> accountsByName[id] },
+                    )
+                }
+            },
+        )
+        _serverReachable.value = true
+        _lastSyncedAt.value = LocalDateTime.now().toString()
+        store.setLastSyncedAt(LocalDateTime.now().toString())
+    }
+
+    private fun fillNames(tx: LocalTransaction, accounts: Map<Long, LocalAccount>): LocalTransaction = tx.copy(
+        accountName = accounts[tx.accountId]?.name ?: tx.accountName,
+        toAccountName = tx.toAccountId?.let { accounts[it]?.name } ?: tx.toAccountName,
+    )
+
+    private fun dedupeKey(accountId: Long, date: String, amount: Double, type: String, description: String): String =
+        "$accountId|$date|${amount.round()}|$type|${description.trim()}".lowercase()
+
+    private fun Double.round(): Long = (this * 100).roundToLong()
+
+    private fun isHttpError(e: Exception): Boolean = e is retrofit2.HttpException
+    private fun is404(e: Exception): Boolean = (e as? retrofit2.HttpException)?.code() == 404
+
+    private fun friendlyError(e: Exception): String = when {
+        e is retrofit2.HttpException && e.code() == 400 -> "Solicitud inválida (verifica los datos)"
+        e is retrofit2.HttpException && e.code() == 404 -> "Ya no existe en el servidor"
+        e is retrofit2.HttpException -> "Error del servidor (${e.code()})"
+        else -> e.message ?: "Error"
+    }
+}

app/src/main/java/com/conta/app/ui/AppRoot.kt

@@ -5,6 +5,7 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.AccountBalance
+import androidx.compose.material.icons.filled.BarChart
 import androidx.compose.material.icons.filled.Home
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material.icons.filled.SwapHoriz
@@ -42,12 +43,14 @@ import com.conta.app.ui.screens.categories.CategoriesScreen
 import com.conta.app.ui.screens.dashboard.DashboardScreen
 import com.conta.app.ui.screens.recurring.RecurringFormScreen
 import com.conta.app.ui.screens.recurring.RecurringScreen
+import com.conta.app.ui.screens.reports.ReportsScreen
 import com.conta.app.ui.screens.rules.RuleFormScreen
 import com.conta.app.ui.screens.rules.RulesScreen
 import com.conta.app.ui.screens.settings.BackupScreen
 import com.conta.app.ui.screens.settings.NtfyScreen
 import com.conta.app.ui.screens.settings.SettingsScreen
 import com.conta.app.ui.screens.settings.ThemeScreen
+import com.conta.app.ui.components.OfflineBanner
 import com.conta.app.ui.screens.transactions.TransactionFormScreen
 import com.conta.app.ui.screens.transactions.TransactionsScreen
 
@@ -58,6 +61,7 @@ object Routes {
     const val ACCOUNT_FORM = "account_form"
     const val TRANSACTIONS = "transactions"
     const val TRANSACTION_FORM = "transaction_form"
+    const val REPORTS = "reports"
     const val CATEGORIES = "categories"
     const val CATEGORY_FORM = "category_form"
     const val RULES = "rules"
@@ -93,6 +97,7 @@ private val bottomItems = listOf(
     BottomNavItem(Routes.DASHBOARD, "Inicio", Icons.Filled.Home),
     BottomNavItem(Routes.ACCOUNTS, "Cuentas", Icons.Filled.AccountBalance),
     BottomNavItem(Routes.TRANSACTIONS, "Movimientos", Icons.Filled.SwapHoriz),
+    BottomNavItem(Routes.REPORTS, "Reportes", Icons.Filled.BarChart),
     BottomNavItem(Routes.SETTINGS, "Ajustes", Icons.Filled.Settings),
 )
 
@@ -102,9 +107,13 @@ fun AppRoot(viewModel: AppViewModel = viewModel()) {
     val snackbarHostState = remember { SnackbarHostState() }
     val message by viewModel.message.collectAsStateWithLifecycle()
     val busy by viewModel.busy.collectAsStateWithLifecycle()
+    val isOnline by viewModel.isOnline.collectAsStateWithLifecycle()
+    val isSyncing by viewModel.isSyncing.collectAsStateWithLifecycle()
+    val pendingCount by viewModel.pendingCount.collectAsStateWithLifecycle()
     val backStackEntry by navController.currentBackStackEntryAsState()
     val currentRoute = backStackEntry?.destination?.route
     val showBottomBar = bottomItems.any { it.route == currentRoute }
+    val showOfflineBanner = !isOnline || pendingCount > 0
 
     LaunchedEffect(message) {
         message?.let {
@@ -115,6 +124,16 @@ fun AppRoot(viewModel: AppViewModel = viewModel()) {
 
     Scaffold(
         snackbarHost = { SnackbarHost(snackbarHostState) },
+        topBar = {
+            if (showOfflineBanner) {
+                OfflineBanner(
+                    pendingCount = pendingCount,
+                    isOnline = isOnline,
+                    isSyncing = isSyncing,
+                    onSync = { viewModel.forceSync() },
+                )
+            }
+        },
         bottomBar = {
             if (showBottomBar) {
                 NavigationBar {
@@ -147,6 +166,7 @@ fun AppRoot(viewModel: AppViewModel = viewModel()) {
                 composable(Routes.DASHBOARD) { DashboardScreen(viewModel, navController) }
                 composable(Routes.ACCOUNTS) { AccountsScreen(viewModel, navController) }
                 composable(Routes.TRANSACTIONS) { TransactionsScreen(viewModel, navController) }
+                composable(Routes.REPORTS) { ReportsScreen(viewModel, navController) }
                 composable(Routes.SETTINGS) { SettingsScreen(viewModel, navController) }
                 composable(Routes.CATEGORIES) { CategoriesScreen(viewModel, navController) }
                 composable(Routes.RULES) { RulesScreen(viewModel, navController) }

app/src/main/java/com/conta/app/ui/AppViewModel.kt

@@ -30,32 +30,53 @@ import com.conta.app.data.model.UpdateCategorizationRuleRequest
 import com.conta.app.data.model.UpdateCategoryRequest
 import com.conta.app.data.model.UpdateRecurringTransactionRequest
 import com.conta.app.data.model.UpdateTransactionRequest
+import com.conta.app.data.local.applyLocalBalances
+import com.conta.app.data.local.computeStatistics
+import com.conta.app.data.local.computeSummary
+import com.conta.app.data.local.toCategory
+import com.conta.app.data.local.toTransactionWithAccount
 import com.conta.app.data.network.Session
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import java.io.File
 
 class AppViewModel : ViewModel() {
 
     private val repo = ServiceLocator.repository
+    private val store = ServiceLocator.store
 
-    private val _summary = MutableStateFlow<Summary?>(null)
+    // ---------- Flujos desde el espejo local (Room) ----------
-    val summary: StateFlow<Summary?> = _summary.asStateFlow()
 
-    private val _statistics = MutableStateFlow<Statistics?>(null)
+    val accounts: StateFlow<List<AccountInfo>> = combine(store.accounts, store.transactions) { acc, tx ->
-    val statistics: StateFlow<Statistics?> = _statistics.asStateFlow()
+        applyLocalBalances(acc, tx)
+    }.stateIn(viewModelScope, SharingStarted.Eagerly, emptyList())
 
-    private val _accounts = MutableStateFlow<List<AccountInfo>>(emptyList())
+    val transactions: StateFlow<List<TransactionWithAccount>> = store.transactions.map { list ->
-    val accounts: StateFlow<List<AccountInfo>> = _accounts.asStateFlow()
+        list.map { it.toTransactionWithAccount() }
+    }.stateIn(viewModelScope, SharingStarted.Eagerly, emptyList())
 
-    private val _transactions = MutableStateFlow<List<TransactionWithAccount>>(emptyList())
+    val categories: StateFlow<List<Category>> = store.categories.map { list ->
-    val transactions: StateFlow<List<TransactionWithAccount>> = _transactions.asStateFlow()
+        list.map { it.toCategory() }
+    }.stateIn(viewModelScope, SharingStarted.Eagerly, emptyList())
 
-    private val _categories = MutableStateFlow<List<Category>>(emptyList())
+    /** Null mientras no hay datos ni conexión (se usa para la pantalla de "No conectado"). */
-    val categories: StateFlow<List<Category>> = _categories.asStateFlow()
+    private val _connected = MutableStateFlow(false)
+    val hasConnected: StateFlow<Boolean> = _connected.asStateFlow()
+
+    val summary: StateFlow<Summary?> = combine(store.accounts, store.transactions, _connected) { acc, tx, connected ->
+        if (!connected && acc.isEmpty() && tx.isEmpty()) null
+        else computeSummary(applyLocalBalances(acc, tx))
+    }.stateIn(viewModelScope, SharingStarted.Eagerly, null)
+
+    val statistics: StateFlow<Statistics?> = store.transactions.map { computeStatistics(it) }
+        .stateIn(viewModelScope, SharingStarted.Eagerly, null)
 
     private val _rules = MutableStateFlow<List<CategorizationRule>>(emptyList())
     val rules: StateFlow<List<CategorizationRule>> = _rules.asStateFlow()
@@ -75,6 +96,21 @@ class AppViewModel : ViewModel() {
     private val _message = MutableStateFlow<String?>(null)
     val message: StateFlow<String?> = _message.asStateFlow()
 
+    val isOnline: StateFlow<Boolean> = combine(
+        ServiceLocator.connectivity.hasNetwork,
+        ServiceLocator.sync.serverReachable,
+    ) { hasNetwork, reachable -> hasNetwork && reachable }
+        .stateIn(viewModelScope, SharingStarted.Eagerly, false)
+
+    val isSyncing: StateFlow<Boolean> = ServiceLocator.sync.isSyncing
+        .stateIn(viewModelScope, SharingStarted.Eagerly, false)
+
+    val pendingCount: StateFlow<Int> = store.pendingCount
+        .stateIn(viewModelScope, SharingStarted.Eagerly, 0)
+
+    val lastSyncAt: StateFlow<String?> = ServiceLocator.sync.lastSyncedAt
+        .stateIn(viewModelScope, SharingStarted.Eagerly, null)
+
     fun consumeMessage() {
         _message.value = null
     }
@@ -87,6 +123,7 @@ class AppViewModel : ViewModel() {
         viewModelScope.launch {
             val saved = ServiceLocator.settings.baseUrl.first()
             Session.baseUrl = saved
+            refreshCached()
             if (saved.isNotBlank()) refreshAll()
         }
     }
@@ -101,60 +138,56 @@ class AppViewModel : ViewModel() {
         }
     }
 
+    private suspend fun refreshCached() {
+        _rules.value = repo.listRules()
+        _recurring.value = repo.listRecurring()
+        _notices.value = repo.listNotices()
+    }
+
+    /** Trae datos del servidor al espejo local y cachea reglas/recurrentes/avisos. */
+    private suspend fun pullFromServer() {
+        try {
+            repo.refreshFromServer()
+            _connected.value = true
+            refreshCached()
+        } catch (_: Exception) {
+        }
+    }
+
     fun refreshAll() {
         viewModelScope.launch {
             _loading.value = true
-            runRequest { _summary.value = repo.getSummary() }
+            pullFromServer()
-            runRequest { _transactions.value = repo.listTransactions() }
+            repo.syncNow()
-            runRequest { _accounts.value = repo.listAccounts() }
+            refreshCached()
-            runRequest { _categories.value = repo.listCategories() }
-            runRequest { _rules.value = repo.listRules() }
-            runRequest { _recurring.value = repo.listRecurring() }
-            runRequest { _notices.value = repo.listNotices() }
-            runRequest { _statistics.value = repo.getStatistics() }
             _loading.value = false
         }
     }
 
     fun refreshDashboard() {
         viewModelScope.launch {
-            runRequest { _summary.value = repo.getSummary() }
+            pullFromServer()
-            runRequest { _transactions.value = repo.listTransactions() }
+            repo.syncNow()
-            runRequest { _accounts.value = repo.listAccounts() }
+            refreshCached()
-            runRequest { _notices.value = repo.listNotices() }
-            runRequest { _statistics.value = repo.getStatistics() }
         }
     }
 
-    fun refreshAccounts() {
+    fun refreshAccounts() = refreshDashboard()
+    fun refreshCategories() = refreshDashboard()
+    fun refreshRules() = refreshDashboard()
+    fun refreshRecurring() = refreshDashboard()
+
+    /** Sincronización manual (botón en Ajustes). */
+    fun forceSync() {
         viewModelScope.launch {
-            runRequest { _summary.value = repo.getSummary() }
+            pullFromServer()
-            runRequest { _accounts.value = repo.listAccounts() }
+            repo.syncNow()
-            runRequest { _transactions.value = repo.listTransactions() }
+            refreshCached()
-            runRequest { _statistics.value = repo.getStatistics() }
+            if (isOnline.value) showMessage("Sincronizado")
-            runRequest { _notices.value = repo.listNotices() }
         }
     }
 
-    fun refreshCategories() {
+    // ---------- Cuentas (requieren conexión) ----------
-        viewModelScope.launch {
-            runRequest { _categories.value = repo.listCategories() }
-        }
-    }
-
-    fun refreshRules() {
-        viewModelScope.launch {
-            runRequest { _rules.value = repo.listRules() }
-        }
-    }
-
-    fun refreshRecurring() {
-        viewModelScope.launch {
-            runRequest { _recurring.value = repo.listRecurring() }
-        }
-    }
-
-    // ---------- Cuentas ----------
 
     fun createAccount(body: CreateAccountRequest, onDone: () -> Unit = {}) {
         viewModelScope.launch {
@@ -220,7 +253,7 @@ class AppViewModel : ViewModel() {
         }
     }
 
-    // ---------- Transacciones ----------
+    // ---------- Movimientos (local-first) ----------
 
     fun createTransaction(body: CreateTransactionRequest, onDone: () -> Unit = {}) {
         viewModelScope.launch {
@@ -277,7 +310,7 @@ class AppViewModel : ViewModel() {
         }
     }
 
-    // ---------- Categorías ----------
+    // ---------- Categorías / Reglas / Recurrentes (requieren conexión) ----------
 
     fun createCategory(body: CreateCategoryRequest, onDone: () -> Unit = {}) {
         viewModelScope.launch {
@@ -313,8 +346,6 @@ class AppViewModel : ViewModel() {
         }
     }
 
-    // ---------- Reglas ----------
-
     fun createRule(body: CreateCategorizationRuleRequest, onDone: (CategorizationRuleCreated?) -> Unit) {
         viewModelScope.launch {
             _busy.value = true
@@ -356,8 +387,6 @@ class AppViewModel : ViewModel() {
         }
     }
 
-    // ---------- Recurrentes ----------
-
     fun createRecurring(body: CreateRecurringTransactionRequest, onDone: () -> Unit = {}) {
         viewModelScope.launch {
             _busy.value = true

app/src/main/java/com/conta/app/ui/components/Charts.kt

@@ -28,6 +28,7 @@ import com.conta.app.ui.util.formatMonth
 import com.conta.app.ui.util.formatMoneyCompact
 import com.conta.app.ui.util.resolveCategoryColor
 import kotlin.math.max
+import kotlin.math.roundToInt
 
 @Composable
 fun MonthlyBarChart(stats: List<MonthlyStat>, modifier: Modifier = Modifier) {
@@ -193,3 +194,71 @@ fun CategoryBars(stats: List<CategoryStat>, modifier: Modifier = Modifier) {
         }
     }
 }
+
+/** Barras de gasto por día del mes (espejo del "Gasto Diario" del frontend). */
+@Composable
+fun DailyExpenseChart(values: List<Double>, modifier: Modifier = Modifier) {
+    val barColor = MaterialTheme.colorScheme.error
+    val textColor = MaterialTheme.colorScheme.onSurfaceVariant
+    val chartHeight = 220.dp
+
+    Column(modifier) {
+        Canvas(
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(chartHeight),
+        ) {
+            val gridColor = textColor.copy(alpha = 0.15f)
+            val maxValue = values.maxOrNull() ?: 0.0
+            val scale = if (maxValue <= 0.0) 1.0 else maxValue
+
+            // Líneas de referencia (0, 25, 50, 75, 100 %)
+            for (frac in listOf(0f, 0.25f, 0.5f, 0.75f, 1f)) {
+                val y = size.height * (1f - frac)
+                drawLine(
+                    color = gridColor,
+                    start = Offset(0f, y),
+                    end = Offset(size.width, y),
+                    strokeWidth = 1f,
+                )
+            }
+
+            if (values.isEmpty()) return@Canvas
+
+            val slotWidth = size.width / values.size
+            val barWidth = (slotWidth * 0.55f).coerceAtLeast(2f)
+            val gap = slotWidth * 0.15f
+
+            values.forEachIndexed { i, total ->
+                if (total <= 0.0) return@forEachIndexed
+                val barH = (total / scale).toFloat() * size.height
+                val top = size.height - barH
+                drawRoundRect(
+                    color = barColor,
+                    topLeft = Offset(i * slotWidth + gap, top),
+                    size = Size(barWidth, barH),
+                    cornerRadius = CornerRadius(3f, 3f),
+                )
+            }
+        }
+        // Etiquetas de días (cada 5 para no saturar)
+        Row(modifier = Modifier.fillMaxWidth()) {
+            val step = max(1, (values.size.toDouble() / 7.0).roundToInt())
+            values.forEachIndexed { i, _ ->
+                Box(
+                    modifier = Modifier.weight(1f),
+                    contentAlignment = Alignment.Center,
+                ) {
+                    if (i % step == 0 || i == values.size - 1) {
+                        Text(
+                            text = "${i + 1}",
+                            style = MaterialTheme.typography.labelSmall,
+                            color = textColor,
+                            maxLines = 1,
+                        )
+                    }
+                }
+            }
+        }
+    }
+}

app/src/main/java/com/conta/app/ui/components/SyncStatus.kt

@@ -0,0 +1,130 @@
+package com.conta.app.ui.components
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.CloudOff
+import androidx.compose.material.icons.filled.Sync
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+
+/** Banner superior mostrado cuando hay cambios pendientes o no hay conexión. */
+@Composable
+fun OfflineBanner(pendingCount: Int, isOnline: Boolean, isSyncing: Boolean, onSync: () -> Unit) {
+    val text = when {
+        isSyncing -> "Sincronizando cambios..."
+        pendingCount > 0 -> "Modo offline · $pendingCount cambios pendientes de sincronizar"
+        else -> "Sin conexión · los cambios se guardarán localmente"
+    }
+    Surface(
+        color = if (pendingCount > 0) MaterialTheme.colorScheme.tertiaryContainer
+        else MaterialTheme.colorScheme.surfaceVariant,
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 16.dp, vertical = 4.dp),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            Icon(
+                imageVector = if (pendingCount > 0) Icons.Filled.CloudOff else Icons.Filled.Sync,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.size(16.dp),
+            )
+            Text(
+                text = text,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.weight(1f),
+            )
+            if (pendingCount > 0 && !isSyncing) {
+                TextButton(onClick = onSync) {
+                    Text("Sincronizar")
+                }
+            }
+        }
+    }
+}
+
+/** Tarjeta de estado de sincronización (Ajustes). */
+@Composable
+fun SyncStatusCard(
+    isOnline: Boolean,
+    isSyncing: Boolean,
+    pendingCount: Int,
+    lastSyncAt: String?,
+    onSync: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    Card(
+        modifier = modifier.fillMaxWidth(),
+        shape = RoundedCornerShape(16.dp),
+        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface),
+    ) {
+        Column(modifier = Modifier.padding(14.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                Icon(
+                    imageVector = if (isOnline) Icons.Filled.Sync else Icons.Filled.CloudOff,
+                    contentDescription = null,
+                    tint = if (isOnline) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.error,
+                )
+                Text(
+                    "Sincronización",
+                    style = MaterialTheme.typography.titleSmall,
+                    fontWeight = FontWeight.Bold,
+                )
+            }
+            androidx.compose.foundation.layout.Spacer(Modifier.padding(bottom = 8.dp))
+            Text(
+                text = if (isOnline) "En línea" else "Sin conexión",
+                style = MaterialTheme.typography.bodySmall,
+                color = if (isOnline) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.error,
+            )
+            Text(
+                text = if (pendingCount > 0) "$pendingCount cambios pendientes"
+                else "Al día",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            lastSyncAt?.let {
+                Text(
+                    text = "Última sincronización: ${formatSyncTime(it)}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+            if (pendingCount > 0) {
+                androidx.compose.foundation.layout.Spacer(Modifier.padding(bottom = 8.dp))
+                androidx.compose.material3.Button(onClick = onSync, enabled = !isSyncing) {
+                    Icon(Icons.Filled.Sync, contentDescription = null, modifier = Modifier.padding(end = 6.dp))
+                    Text(if (isSyncing) "Sincronizando..." else "Sincronizar ahora")
+                }
+            }
+        }
+    }
+}
+
+private fun formatSyncTime(iso: String): String {
+    val dt = runCatching { LocalDateTime.parse(iso) }.getOrNull() ?: return iso
+    return dt.format(DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm", Locale.getDefault()))
+}

app/src/main/java/com/conta/app/ui/screens/reports/ReportsScreen.kt

@@ -0,0 +1,161 @@
+package com.conta.app.ui.screens.reports
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowLeft
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.navigation.NavController
+import com.conta.app.ui.AppViewModel
+import com.conta.app.ui.components.DailyExpenseChart
+import com.conta.app.ui.components.EmptyState
+import com.conta.app.ui.components.LoadingScreen
+import com.conta.app.ui.util.currentMonthIso
+import com.conta.app.ui.util.daysInMonthIso
+import com.conta.app.ui.util.formatMoney
+import com.conta.app.ui.util.formatMonthFull
+import com.conta.app.ui.util.shiftMonthIso
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ReportsScreen(viewModel: AppViewModel, navController: NavController) {
+    val transactions by viewModel.transactions.collectAsStateWithLifecycle()
+    val summary by viewModel.summary.collectAsStateWithLifecycle()
+    val loading by viewModel.loading.collectAsStateWithLifecycle()
+
+    var month by remember { mutableStateOf(currentMonthIso()) }
+    val isCurrentMonth = month == currentMonthIso()
+
+    val days = daysInMonthIso(month)
+    val values = remember(transactions, month) {
+        val sums = DoubleArray(days)
+        for (tx in transactions) {
+            if (tx.transactionType != "expense" || !tx.date.startsWith(month)) continue
+            val day = tx.date.substringAfterLast('-', "").toIntOrNull() ?: continue
+            if (day in 1..days) sums[day - 1] += tx.amount
+        }
+        sums.toList()
+    }
+    val totalMonth = values.sum()
+
+    Scaffold(
+        contentWindowInsets = WindowInsets(0.dp, 0.dp, 0.dp, 0.dp),
+    ) { padding ->
+        when {
+            summary == null && loading -> LoadingScreen(Modifier.padding(padding))
+            summary == null -> {
+                Column(
+                    modifier = Modifier
+                        .fillMaxSize()
+                        .padding(padding),
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                    verticalArrangement = Arrangement.Center,
+                ) {
+                    EmptyState("No conectado. Configura la URL del servidor en Ajustes.")
+                    Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                        androidx.compose.material3.Button(onClick = { viewModel.refreshAll() }) {
+                            Text("Reintentar")
+                        }
+                        androidx.compose.material3.OutlinedButton(onClick = { navController.navigate(com.conta.app.ui.Routes.SETTINGS) }) {
+                            Text("Ir a Ajustes")
+                        }
+                    }
+                }
+            }
+            else -> Column(
+                modifier = Modifier
+                    .padding(padding)
+                    .verticalScroll(rememberScrollState())
+                    .padding(horizontal = 16.dp),
+            ) {
+                Text(
+                    "Reportes",
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold,
+                )
+                androidx.compose.foundation.layout.Spacer(Modifier.size(12.dp))
+
+                Card(
+                    modifier = Modifier.fillMaxWidth(),
+                    shape = RoundedCornerShape(16.dp),
+                    colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface),
+                    elevation = CardDefaults.cardElevation(defaultElevation = 1.dp),
+                ) {
+                    Column(modifier = Modifier.padding(16.dp)) {
+                        Row(
+                            modifier = Modifier.fillMaxWidth(),
+                            horizontalArrangement = Arrangement.SpaceBetween,
+                            verticalAlignment = Alignment.CenterVertically,
+                        ) {
+                            Text(
+                                "Gasto Diario del Mes",
+                                style = MaterialTheme.typography.titleSmall,
+                                fontWeight = FontWeight.Bold,
+                            )
+                            Row(verticalAlignment = Alignment.CenterVertically) {
+                                IconButton(onClick = { month = shiftMonthIso(month, -1) }) {
+                                    Icon(Icons.AutoMirrored.Filled.KeyboardArrowLeft, contentDescription = "Mes anterior")
+                                }
+                                Text(
+                                    text = formatMonthFull(month),
+                                    style = MaterialTheme.typography.labelLarge,
+                                    modifier = Modifier.padding(horizontal = 4.dp),
+                                    maxLines = 1,
+                                )
+                                IconButton(
+                                    onClick = { month = shiftMonthIso(month, 1) },
+                                    enabled = !isCurrentMonth,
+                                ) {
+                                    Icon(Icons.AutoMirrored.Filled.KeyboardArrowRight, contentDescription = "Mes siguiente")
+                                }
+                            }
+                        }
+                        androidx.compose.foundation.layout.Spacer(Modifier.size(8.dp))
+                        Text(
+                            text = "Total del mes: ${formatMoney(totalMonth)}",
+                            style = MaterialTheme.typography.labelMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+
+                        if (transactions.isEmpty() && !loading) {
+                            EmptyState("Sin transacciones")
+                        } else if (totalMonth == 0.0 && !loading) {
+                            EmptyState("Sin gastos en ${formatMonthFull(month)}")
+                        } else {
+                            androidx.compose.foundation.layout.Spacer(Modifier.size(16.dp))
+                            DailyExpenseChart(values, modifier = Modifier.fillMaxWidth())
+                        }
+                    }
+                }
+                androidx.compose.foundation.layout.Spacer(Modifier.size(24.dp))
+            }
+        }
+    }
+}

app/src/main/java/com/conta/app/ui/screens/settings/SettingsScreen.kt

@@ -48,6 +48,7 @@ import com.conta.app.ServiceLocator
 import com.conta.app.ui.AppViewModel
 import com.conta.app.ui.Routes
 import com.conta.app.ui.components.SectionHeader
+import com.conta.app.ui.components.SyncStatusCard
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -62,6 +63,10 @@ fun SettingsScreen(viewModel: AppViewModel, navController: NavController) {
     }
 
     val summary by viewModel.summary.collectAsStateWithLifecycle()
+    val isOnline by viewModel.isOnline.collectAsStateWithLifecycle()
+    val isSyncing by viewModel.isSyncing.collectAsStateWithLifecycle()
+    val pendingCount by viewModel.pendingCount.collectAsStateWithLifecycle()
+    val lastSyncAt by viewModel.lastSyncAt.collectAsStateWithLifecycle()
 
     Scaffold(
         contentWindowInsets = WindowInsets(0.dp, 0.dp, 0.dp, 0.dp),
@@ -117,6 +122,16 @@ fun SettingsScreen(viewModel: AppViewModel, navController: NavController) {
                 }
             }
 
+            androidx.compose.foundation.layout.Spacer(Modifier.padding(bottom = 20.dp))
+            SectionHeader("Sincronización")
+            SyncStatusCard(
+                isOnline = isOnline,
+                isSyncing = isSyncing,
+                pendingCount = pendingCount,
+                lastSyncAt = lastSyncAt,
+                onSync = { viewModel.forceSync() },
+            )
+
             androidx.compose.foundation.layout.Spacer(Modifier.padding(bottom = 20.dp))
             SectionHeader("Notificaciones")
             SettingsItemCard(

app/src/main/java/com/conta/app/ui/util/Formatters.kt

@@ -35,6 +35,37 @@ fun formatMonth(monthStr: String): String {
     return "$label $year"
 }
 
+/** "2024-01" -> "Enero 2024" */
+fun formatMonthFull(monthStr: String): String {
+    val parts = monthStr.split("-")
+    if (parts.size != 2) return monthStr
+    val month = parts[1].toIntOrNull() ?: return monthStr
+    val year = parts[0]
+    val label = LocalDate.of(year.toIntOrNull() ?: 1970, month, 1)
+        .month.getDisplayName(TextStyle.FULL, Locale.getDefault())
+    return "$label $year"
+}
+
+/** "2024-01" -> año y mes en forma "2024-01" (igual pero validado). */
+fun currentMonthIso(): String = LocalDate.now().toString().substring(0, 7)
+
+/** Desplaza un mes "yyyy-MM" por delta y devuelve "yyyy-MM". */
+fun shiftMonthIso(month: String, delta: Int): String {
+    val parts = month.split("-")
+    val year = parts.getOrNull(0)?.toIntOrNull() ?: LocalDate.now().year
+    val m = parts.getOrNull(1)?.toIntOrNull() ?: (LocalDate.now().monthValue)
+    val date = LocalDate.of(year, m, 1).plusMonths(delta.toLong())
+    return "${date.year}-${date.monthValue.toString().padStart(2, '0')}"
+}
+
+/** Número de días de un mes "yyyy-MM". */
+fun daysInMonthIso(month: String): Int {
+    val parts = month.split("-")
+    val year = parts.getOrNull(0)?.toIntOrNull() ?: LocalDate.now().year
+    val m = parts.getOrNull(1)?.toIntOrNull() ?: 1
+    return LocalDate.of(year, m, 1).lengthOfMonth()
+}
+
 /** Formatea la cantidad con el prefijo de tipo de transacción: +, -, o sin signo. */
 fun signedAmount(amount: Double, type: String): String = when (type) {
     "income" -> "+${formatMoney(amount)}"

build.gradle

@@ -3,4 +3,5 @@ plugins {
     id "org.jetbrains.kotlin.android" version "2.0.21" apply false
     id "org.jetbrains.kotlin.plugin.compose" version "2.0.21" apply false
     id "org.jetbrains.kotlin.plugin.serialization" version "2.0.21" apply false
+    id "com.google.devtools.ksp" version "2.0.21-1.0.28" apply false
 }