mod app;
mod news;
mod ui;

use std::io;

use crossterm::{
    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode},
    execute,
    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
};
use ratatui::{backend::CrosstermBackend, Terminal};
use tokio::sync::mpsc;

use app::{App, AppMessage, Tab};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    enable_raw_mode()?;
    let mut stdout = io::stdout();
    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;

    let backend = CrosstermBackend::new(stdout);
    let mut terminal = Terminal::new(backend)?;

    let result = run_app(&mut terminal).await;

    // Always restore terminal even on error
    disable_raw_mode()?;
    execute!(
        terminal.backend_mut(),
        LeaveAlternateScreen,
        DisableMouseCapture
    )?;
    terminal.show_cursor()?;

    result
}

async fn run_app(
    terminal: &mut Terminal<CrosstermBackend<io::Stdout>>,
) -> Result<(), Box<dyn std::error::Error>> {
    let (tx, mut rx) = mpsc::channel::<AppMessage>(100);
    let mut app = App::new();

    // Kick off the initial story fetch
    app.load_stories(tx.clone());

    loop {
        // Drain all pending async messages before drawing
        while let Ok(msg) = rx.try_recv() {
            app.handle_message(msg, tx.clone());
        }

        terminal.draw(|f| ui::draw(f, &mut app))?;

        // Poll for keyboard input with a short timeout so messages keep flowing
        if event::poll(std::time::Duration::from_millis(200))? {
            if let Event::Key(key) = event::read()? {
                match key.code {
                    KeyCode::Char('q') | KeyCode::Esc => break,
                    KeyCode::Down | KeyCode::Char('j') => app.next_story(tx.clone()),
                    KeyCode::Up | KeyCode::Char('k') => app.prev_story(tx.clone()),
                    KeyCode::PageDown => app.scroll_content_down(),
                    KeyCode::PageUp => app.scroll_content_up(),
                    KeyCode::Char('r') => app.load_stories(tx.clone()),
                    KeyCode::Char('s') => app.toggle_save(tx.clone()),
                    KeyCode::Char('1') => app.switch_tab(Tab::TopStories, tx.clone()),
                    KeyCode::Char('2') => app.switch_tab(Tab::Saved, tx.clone()),
                    KeyCode::Right => app.next_source(tx.clone()),
                    KeyCode::Left => app.prev_source(tx.clone()),
                    _ => {}
                }
            }
        }
    }

    Ok(())
}