mod auth;
mod calendar;
mod config;
mod db;
mod email_theme;
mod error;
mod imap;
mod pgp;
mod realtime;
mod routes;
mod search;
mod sieve;
mod smtp;
mod ui;

use std::sync::Arc;
use std::time::Duration;

use config::AppConfig;
use tracing_subscriber::{EnvFilter, fmt, prelude::*};

use crate::auth::session::SessionStore;
use crate::imap::client::RealImapClient;
use crate::realtime::idle::IdleManager;
use crate::smtp::client::RealSmtpClient;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args: Vec<String> = std::env::args().collect();
    if args.iter().any(|arg| arg == "--version" || arg == "-V") {
        println!("rustbox {}", env!("CARGO_PKG_VERSION"));
        return Ok(());
    }

    // Initialize structured JSON logging with env filter.
    // Default to INFO level; override with RUST_LOG env var.
    tracing_subscriber::registry()
        .with(EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info")))
        .with(fmt::layer().json())
        .init();

    // Load configuration via figment (serde defaults + env vars).
    let loaded_config = AppConfig::load()?;
    loaded_config.validate().map_err(|message| {
        std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("invalid RustBox configuration: {message}"),
        )
    })?;
    if args.iter().any(|arg| arg == "--check-config") {
        println!("RustBox configuration OK");
        return Ok(());
    }
    let config = Arc::new(loaded_config);

    // Create the in-memory session store with the configured timeout.
    let store = Arc::new(SessionStore::new(Duration::from_secs(
        config.session_timeout_hours * 3600,
    )));

    // Spawn a background task that periodically purges expired sessions.
    {
        let store = Arc::clone(&store);
        tokio::spawn(async move {
            let mut interval = tokio::time::interval(Duration::from_secs(300));
            loop {
                interval.tick().await;
                store.purge_expired();
                tracing::debug!("Purged expired sessions");
            }
        });
    }

    // Create the IMAP and SMTP clients for production use.
    let imap_client: Arc<dyn imap::client::ImapClient> = Arc::new(RealImapClient::default());
    let smtp_client: Arc<dyn smtp::client::SmtpClient> = Arc::new(RealSmtpClient);

    // Create the Tantivy search engine for full-text indexing.
    let search_engine = Arc::new(search::engine::SearchEngine::new(std::path::PathBuf::from(
        &config.data_dir,
    )));

    // Create the real-time event bus and IDLE manager.
    let event_bus = Arc::new(realtime::events::EventBus::new());
    let idle_manager = Arc::new(realtime::idle::IdleManager::new());

    // Build the application router with auth, session, and static file serving.
    let app = routes::create_router(
        config.clone(),
        store,
        imap_client,
        smtp_client,
        search_engine,
        event_bus,
        idle_manager.clone(),
    );

    // Bind to the configured host and port.
    let bind_addr = format!("{}:{}", config.host, config.port);
    let listener = tokio::net::TcpListener::bind(&bind_addr).await?;

    tracing::info!(
        host = %config.host,
        port = %config.port,
        "RustBox server starting"
    );

    axum::serve(
        listener,
        app.into_make_service_with_connect_info::<std::net::SocketAddr>(),
    )
    .with_graceful_shutdown(shutdown_signal(idle_manager))
    .await?;

    tracing::info!("RustBox server stopped");
    Ok(())
}

async fn shutdown_signal(idle_manager: Arc<IdleManager>) {
    let ctrl_c = async {
        if let Err(error) = tokio::signal::ctrl_c().await {
            tracing::error!(error = %error, "Failed to install Ctrl+C handler");
        }
    };

    #[cfg(unix)]
    let terminate = async {
        match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate()) {
            Ok(mut signal) => {
                signal.recv().await;
            }
            Err(error) => {
                tracing::error!(error = %error, "Failed to install SIGTERM handler");
                std::future::pending::<()>().await;
            }
        }
    };

    #[cfg(not(unix))]
    let terminate = std::future::pending::<()>();

    tokio::select! {
        _ = ctrl_c => {},
        _ = terminate => {},
    }

    tracing::info!("Shutdown signal received; stopping IDLE tasks");
    idle_manager.stop_all();
}