Docmost-App/app/src/main/java/com/docmost/app/data/SessionManager.kt

package com.docmost.app.data

import android.content.Context
import android.content.SharedPreferences
import androidx.security.crypto.EncryptedSharedPreferences
import androidx.security.crypto.MasterKeys
import com.google.gson.Gson
import com.google.gson.JsonParser


data class Credentials(
    val url: String,
    val email: String,
    val password: String,
    val authToken: String = "",
    val avatarUrl: String? = null
)

class SessionManager(private val context: Context) {

    private val gson = Gson()

    private val prefs: SharedPreferences by lazy {
        createEncryptedPrefs(context, PREFS_NAME)
    }

    private val savedAccountsPrefs: SharedPreferences by lazy {
        createEncryptedPrefs(context, SAVED_ACCOUNTS_PREFS)
    }

    private fun createEncryptedPrefs(context: Context, prefsName: String): SharedPreferences {
        val masterKeyAlias = MasterKeys.getOrCreate(MasterKeys.AES256_GCM_SPEC)
        return try {
            EncryptedSharedPreferences.create(
                prefsName,
                masterKeyAlias,
                context,
                EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
                EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
            )
        } catch (e: Exception) {
            context.getSharedPreferences(prefsName, Context.MODE_PRIVATE).edit().clear().apply()
            EncryptedSharedPreferences.create(
                prefsName,
                masterKeyAlias,
                context,
                EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
                EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
            )
        }
    }

    fun saveCredentials(credentials: Credentials) {
        try {
            val json = gson.toJson(credentials)
            prefs.edit().putString(KEY_CREDENTIALS, json).apply()
        } catch (e: Exception) {
            clear()
        }
    }

    fun getCredentials(): Credentials? {
        val json = try {
            prefs.getString(KEY_CREDENTIALS, null)
        } catch (e: Exception) {
            clear()
            null
        } ?: return null
        return try {
            gson.fromJson(json, Credentials::class.java)
        } catch (e: Exception) {
            null
        }
    }

    fun saveAuthToken(token: String) {
        val current = getCredentials() ?: return
        saveCredentials(current.copy(authToken = token))
    }

    fun clear() {
        try {
            prefs.edit().clear().apply()
        } catch (_: Exception) {}
    }

    fun hasSession(): Boolean {
        val creds = getCredentials() ?: return false
        return creds.url.isNotBlank() && creds.email.isNotBlank() && creds.authToken.isNotBlank()
    }

    fun saveAccount(credentials: Credentials) {
        try {
            val accounts = getSavedAccounts().toMutableList()
            accounts.removeAll { it.email == credentials.email && it.url == credentials.url }
            accounts.add(credentials)
            val json = gson.toJson(accounts)
            savedAccountsPrefs.edit().putString(KEY_SAVED_ACCOUNTS, json).apply()
        } catch (e: Exception) {
            context.getSharedPreferences(SAVED_ACCOUNTS_PREFS, Context.MODE_PRIVATE).edit().clear().commit()
            val json = gson.toJson(listOf(credentials))
            savedAccountsPrefs.edit().putString(KEY_SAVED_ACCOUNTS, json).commit()
        }
    }

    fun getSavedAccounts(): List<Credentials> {
        val json = try {
            savedAccountsPrefs.getString(KEY_SAVED_ACCOUNTS, null)
        } catch (e: Exception) {
            context.getSharedPreferences(SAVED_ACCOUNTS_PREFS, Context.MODE_PRIVATE).edit().clear().commit()
            null
        } ?: return emptyList()
        return try {
            val array = JsonParser.parseString(json).asJsonArray
            array.map { gson.fromJson(it, Credentials::class.java) }
        } catch (e: Exception) {
            emptyList()
        }
    }

    fun removeAccount(email: String, url: String) {
        try {
            val accounts = getSavedAccounts().toMutableList()
            accounts.removeAll { it.email == email && it.url == url }
            val json = gson.toJson(accounts)
            savedAccountsPrefs.edit().putString(KEY_SAVED_ACCOUNTS, json).apply()
        } catch (_: Exception) {}
    }

    fun hasAccount(email: String, url: String): Boolean {
        return getSavedAccounts().any { it.email == email && it.url == url }
    }

    companion object {
        private const val PREFS_NAME = "docmost_session"
        private const val KEY_CREDENTIALS = "credentials"
        private const val SAVED_ACCOUNTS_PREFS = "docmost_saved_accounts"
        private const val KEY_SAVED_ACCOUNTS = "saved_accounts"
    }
}