use actix_cors::Cors;
use actix_web::cookie::time::Duration;
use actix_web::middleware::Logger;
use actix_web::{App, HttpResponse, HttpServer, cookie::Key, web};
use clap::Parser;
use db::cache::AppCache;
use db::database::AppDatabase;
use sea_orm::ConnectionTrait;
use service::AppService;
use session::SessionMiddleware;
use session::config::{PersistentSession, SessionLifecycle, TtlExtensionPolicy};
use session::storage::RedisClusterSessionStore;
use slog::Drain;

mod args;
mod logging;

use args::ServerArgs;
use config::AppConfig;
use migrate::{Migrator, MigratorTrait};

#[derive(Clone)]
pub struct AppState {
    pub db: AppDatabase,
    pub cache: AppCache,
}

fn build_slog_logger(level: &str) -> slog::Logger {
    let level_filter = match level {
        "trace" => 0usize,
        "debug" => 1usize,
        "info" => 2usize,
        "warn" => 3usize,
        "error" => 4usize,
        _ => 2usize,
    };

    struct StderrDrain(usize);

    impl Drain for StderrDrain {
        type Ok = ();
        type Err = ();
        #[inline]
        fn log(&self, record: &slog::Record, _logger: &slog::OwnedKVList) -> Result<(), ()> {
            let slog_level = match record.level() {
                slog::Level::Trace => 0,
                slog::Level::Debug => 1,
                slog::Level::Info => 2,
                slog::Level::Warning => 3,
                slog::Level::Error => 4,
                slog::Level::Critical => 5,
            };
            if slog_level < self.0 {
                return Ok(());
            }
            let _ = eprintln!(
                "{} [{}] {}:{} - {}",
                chrono::Utc::now().format("%Y-%m-%dT%H:%M:%S%.3fZ"),
                record.level().to_string(),
                record
                    .file()
                    .rsplit_once('/')
                    .map(|(_, s)| s)
                    .unwrap_or(record.file()),
                record.line(),
                record.msg(),
            );
            Ok(())
        }
    }

    let drain = StderrDrain(level_filter);
    let drain = std::sync::Mutex::new(drain);
    let drain = slog::Fuse::new(drain);
    slog::Logger::root(drain, slog::o!())
}

fn build_session_key(cfg: &AppConfig) -> anyhow::Result<Key> {
    if let Some(secret) = cfg.env.get("APP_SESSION_SECRET") {
        let bytes: Vec<u8> = secret.as_bytes().iter().cycle().take(64).copied().collect();
        return Ok(Key::from(&bytes));
    }
    Ok(Key::generate())
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let cfg = AppConfig::load();
    let log_level = cfg.log_level().unwrap_or_else(|_| "info".to_string());
    let log = build_slog_logger(&log_level);
    slog::info!(
        log,
        "Starting {} {}",
        cfg.app_name().unwrap_or_default(),
        cfg.app_version().unwrap_or_default()
    );
    let db = AppDatabase::init(&cfg).await?;
    slog::info!(log, "Database connected");
    let redis_urls = cfg.redis_urls()?;
    let store: RedisClusterSessionStore = RedisClusterSessionStore::new(redis_urls).await?;
    slog::info!(log, "Redis connected");
    let cache = AppCache::init(&cfg).await?;
    slog::info!(log, "Cache initialized");
    run_migrations(&db, &log).await?;
    let session_key = build_session_key(&cfg)?;
    let args = ServerArgs::parse();
    let service = AppService::new(cfg.clone()).await?;
    slog::info!(log, "AppService initialized");

    let (shutdown_tx, shutdown_rx) = tokio::sync::broadcast::channel::<()>(1);
    let worker_service = service.clone();
    let log_for_http = log.clone();
    let log_for_worker = log.clone();
    let worker_handle = tokio::spawn(async move {
        worker_service
            .start_room_workers(shutdown_rx, log_for_worker)
            .await
    });

    let bind_addr = args.bind.unwrap_or_else(|| "127.0.0.1:8080".to_string());
    slog::info!(log, "Listening on {}", bind_addr);
    HttpServer::new(move || {
        let cors = Cors::default()
            .allow_any_origin()
            .allow_any_method()
            .allow_any_header()
            .supports_credentials()
            .max_age(3600);

        let session_mw = SessionMiddleware::builder(store.clone(), session_key.clone())
            .cookie_name("id".to_string())
            .cookie_path("/".to_string())
            .cookie_secure(false)
            .cookie_http_only(true)
            .session_lifecycle(SessionLifecycle::PersistentSession(
                PersistentSession::default()
                    .session_ttl(Duration::days(30))
                    .session_ttl_extension_policy(TtlExtensionPolicy::OnEveryRequest),
            ))
            .build();

        App::new()
            .wrap(cors)
            .wrap(session_mw)
            .wrap(Logger::default().exclude("/health"))
            .app_data(web::Data::new(AppState {
                db: db.clone(),
                cache: cache.clone(),
            }))
            .app_data(web::Data::new(service.clone()))
            .app_data(web::Data::new(cfg.clone()))
            .app_data(web::Data::new(db.clone()))
            .app_data(web::Data::new(cache.clone()))
            .wrap(logging::RequestLogger::new(log_for_http.clone()))
            .route("/health", web::get().to(health_check))
            .configure(api::route::init_routes)
    })
    .bind(&bind_addr)?
    .run()
    .await?;

    slog::info!(log, "Server stopped, shutting down room workers");
    let _ = shutdown_tx.send(());
    let _ = worker_handle.await;
    slog::info!(log, "Room workers stopped");

    Ok(())
}

async fn run_migrations(db: &AppDatabase, log: &slog::Logger) -> anyhow::Result<()> {
    slog::info!(log, "Running database migrations...");
    Migrator::up(db.writer(), None)
        .await
        .map_err(|e| anyhow::anyhow!("Migration failed: {:?}", e))?;
    slog::info!(log, "Migrations completed");
    Ok(())
}

async fn health_check(state: web::Data<AppState>) -> HttpResponse {
    let db_ok = db_ping(&state.db).await;
    let cache_ok = cache_ping(&state.cache).await;

    let healthy = db_ok && cache_ok;
    if healthy {
        HttpResponse::Ok().json(serde_json::json!({
            "status": "ok",
            "db": "ok",
            "cache": "ok",
        }))
    } else {
        HttpResponse::ServiceUnavailable().json(serde_json::json!({
            "status": "unhealthy",
            "db": if db_ok { "ok" } else { "error" },
            "cache": if cache_ok { "ok" } else { "error" },
        }))
    }
}

async fn db_ping(db: &AppDatabase) -> bool {
    db.query_one_raw(sea_orm::Statement::from_string(
        sea_orm::DbBackend::Postgres,
        "SELECT 1",
    ))
    .await
    .is_ok()
}

async fn cache_ping(cache: &AppCache) -> bool {
    cache.conn().await.is_ok()
}