use axum::{
    middleware::{from_fn_with_state},
    routing::get,
    Router,
};
use axum_prometheus::PrometheusMetricLayer;
use common::{init_pool, Config};
use crate::state::AppState;
use crate::middleware;
use sqlx::PgPool;
use std::collections::HashMap;
use std::net::SocketAddr;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::RwLock;
use tower_http::cors::{AllowOrigin, CorsLayer};
use axum::http::{HeaderValue, Method};
use axum::http::header;
use tower_http::trace::TraceLayer;

fn parse_allowed_origins() -> AllowOrigin {
    let origins_str = std::env::var("ALLOWED_ORIGINS")
        .unwrap_or_else(|_| "http://localhost:3000,http://localhost:8000,http://localhost:8001".to_string());
    let origins: Vec<HeaderValue> = origins_str
        .split(',')
        .filter_map(|s| s.trim().parse().ok())
        .collect();
    AllowOrigin::list(origins)
}

async fn wait_for_db(db_url: &str) -> PgPool {
    loop {
        match init_pool(db_url).await {
            Ok(pool) => return pool,
            Err(e) => {
                tracing::warn!("Database not ready yet, retrying in 2s: {}", e);
                tokio::time::sleep(Duration::from_secs(2)).await;
            }
        }
    }
}

pub async fn run() -> anyhow::Result<()> {
    let config = Config::new().expect("Failed to load configuration");

    tracing::info!("Starting MadBase Worker...");

    let pool = wait_for_db(&config.database_url).await;
    
    let app_state = AppState {
        control_db: pool.clone(),
        tenant_pools: Arc::new(RwLock::new(HashMap::new())),
    };

    let auth_state = auth::AuthState {
        db: pool.clone(),
        config: config.clone(),
    };

    let data_state = data_api::handlers::DataState {
        db: pool.clone(),
        config: config.clone(),
    };

    let default_tenant_db_url = std::env::var("DEFAULT_TENANT_DB_URL")
        .expect("DEFAULT_TENANT_DB_URL must be set");
    let tenant_pool = wait_for_db(&default_tenant_db_url).await;

    let mut tenant_config = config.clone();
    tenant_config.database_url = default_tenant_db_url.clone();

    // Realtime Init
    let (realtime_router, realtime_state) = realtime::init(tenant_pool.clone(), tenant_config.clone());

    // Replication Listener
    let repl_config = tenant_config.clone();
    let repl_tx = realtime_state.broadcast_tx.clone();
    tokio::spawn(async move {
        if let Err(e) = realtime::replication::start_replication_listener(repl_config, repl_tx).await {
            tracing::error!("Replication listener failed: {}", e);
        }
    });

    // Storage Init
    let storage_router = storage::init(pool.clone(), config.clone()).await;

    // Functions Init
    let functions_runtime = Arc::new(
        functions::runtime::WasmRuntime::new()
            .expect("Failed to initialize WASM runtime")
    );
    let deno_runtime = Arc::new(functions::deno_runtime::DenoRuntime::new());
    let functions_state = functions::FunctionsState {
        db: pool.clone(),
        config: config.clone(),
        runtime: functions_runtime,
        deno_runtime,
    };

    // Auth Middleware State
    let auth_middleware_state = auth::AuthMiddlewareState {
        config: config.clone(),
    };

    // Project Middleware State
    let project_middleware_state = middleware::ProjectMiddlewareState {
        control_db: app_state.control_db.clone(),
        tenant_pools: app_state.tenant_pools.clone(),
        project_cache: moka::future::Cache::new(100),
    };

    // Construct Worker Routes
    let tenant_routes = Router::new()
        .nest("/auth/v1", auth::router().with_state(auth_state))
        .nest("/rest/v1", data_api::router().with_state(data_state))
        .nest("/realtime/v1", realtime_router)
        .nest("/storage/v1", storage_router)
        .nest("/functions/v1", functions::router(functions_state))
        .layer(from_fn_with_state(
            auth_middleware_state,
            auth::auth_middleware,
        ))
        .layer(from_fn_with_state(
            project_middleware_state.clone(),
            middleware::inject_tenant_pool,
        ))
        .layer(from_fn_with_state(
            project_middleware_state,
            middleware::resolve_project,
        ));

    let (prometheus_layer, metric_handle) = PrometheusMetricLayer::pair();

    let app = Router::new()
        .route("/health", get(|| async { "OK" }))
        .route("/metrics", get(|| async move { metric_handle.render() }))
        .route("/ready", get(|| async { "Ready" }))
        .nest("/", tenant_routes)
        .layer(
            CorsLayer::new()
                .allow_origin(parse_allowed_origins())
                .allow_methods([Method::GET, Method::POST, Method::PUT, Method::PATCH, Method::DELETE, Method::OPTIONS])
                .allow_headers([header::CONTENT_TYPE, header::AUTHORIZATION, axum::http::HeaderName::from_static("apikey")])
                .allow_credentials(true),
        )
        .layer(TraceLayer::new_for_http())
        .layer(prometheus_layer);

    let port = std::env::var("WORKER_PORT")
        .unwrap_or_else(|_| "8002".to_string())
        .parse::<u16>()?;
    
    let addr = SocketAddr::from(([0, 0, 0, 0], port));
    tracing::info!("Worker listening on {}", addr);

    let listener = tokio::net::TcpListener::bind(addr).await?;
    axum::serve(listener, app.into_make_service_with_connect_info::<SocketAddr>()).await?;

    Ok(())
}