use consumer::indexing as relay;
use deadpool_postgres::Runtime;
use eyre::OptionExt as _;
use metrics_exporter_prometheus::PrometheusBuilder;
use tokio::signal::ctrl_c;
use tokio_postgres::NoTls;

/// Custom time formatter for tracing - shows only HH:MM:SS in local time
struct SimpleTime;

impl tracing_subscriber::fmt::time::FormatTime for SimpleTime {
    fn format_time(&self, w: &mut tracing_subscriber::fmt::format::Writer<'_>) -> std::fmt::Result {
        let now = chrono::Local::now();
        write!(w, "{}", now.format("%H:%M:%S"))
    }
}

#[tokio::main]
async fn main() -> eyre::Result<()> {
    // Install color-eyre for beautiful error reports
    color_eyre::install()?;

    // Initialize tracing with structured, concise output
    // RUST_LOG env var controls verbosity (default: info)
    tracing_subscriber::fmt()
        .with_timer(SimpleTime)
        .with_max_level(
            std::env::var("RUST_LOG")
                .ok()
                .and_then(|s| s.parse().ok())
                .unwrap_or(tracing::Level::INFO)
        )
        .compact()
        .with_target(false)
        .with_file(true)
        .with_line_number(true)
        .with_thread_ids(true)
        .init();
    PrometheusBuilder::new().install()?;

    let cli = consumer::parse();
    let mut conf = consumer::load_config()?;


    // Configure database connection pool for 30-worker database writer architecture
    // 30 workers + 15 headroom for burst traffic + other operations = 45 connections
    conf.database.pool = Some(deadpool_postgres::PoolConfig {
        max_size: 45,
        ..Default::default()
    });
    tracing::info!(
        "Database connection pool configured with max_size=45 for 30-worker database writer"
    );

    let pool = conf.database.create_pool(Some(Runtime::Tokio1), NoTls)?;

    // Note: DID/handle resolution is now handled by Tap

    let tracker = tokio_util::task::TaskTracker::new();
    let (stop_tx, stop) = tokio::sync::watch::channel(false);

    // Calculate retention cutoff from config if retention_days is set
    let _retention_cutoff = conf.retention_days.map(|days| {
        let cutoff = chrono::Utc::now() - chrono::Duration::days(i64::from(days));
        tracing::info!(
            retention_days = days,
            cutoff_date = %cutoff.format("%Y-%m-%d"),
            "Retention enabled: only processing records newer than cutoff"
        );
        cutoff
    });

    // Create shared database writer infrastructure if indexer mode is enabled
    let shared_database_writer = if cli.indexer {
        // Create channel for database writer (bounded to provide backpressure)
        // When channel fills up, workers will block, propagating backpressure
        let (tap_tx, tap_rx) = tokio::sync::mpsc::channel::<consumer::database_writer::WriterEvent>(10_000);

        // Spawn single database writer task
        let batch_events_processed = std::sync::Arc::new(std::sync::atomic::AtomicU64::new(0));
        let batch_operations_processed = std::sync::Arc::new(std::sync::atomic::AtomicU64::new(0));

        // Create unified ID cache for fast DID→actor_id and URI→post_id lookups
        // Actor cache: 5min TTL, 50k capacity
        // Post cache: 10min TTL, 50k capacity
        let id_cache = parakeet_db::id_cache::IdCache::new();
        tracing::info!("ID cache initialized (actors: 5min TTL/50k capacity, posts: 10min TTL/50k capacity)");

        // Spawn database writer with Tap as primary source
        let database_writer_handle = consumer::spawn_database_writer_tap(
            pool.clone(),
            tap_rx,
            batch_events_processed.clone(),
            batch_operations_processed.clone(),
            id_cache,
            stop.clone(),
        );
        drop(tracker.spawn(database_writer_handle));

        // Create worker supervisor (shared for all supervised workers)
        let worker_supervisor = consumer::worker_core::WorkerSupervisor::new();

        // Note: Handle resolution is now managed by Tap
        // Worker supervisor manages its own tasks via TaskTracker
        // We don't need to explicitly track it in the main tracker

        Some((
            tap_tx,
            batch_events_processed,
            batch_operations_processed,
            worker_supervisor,
        ))
    } else {
        None
    };

    if cli.indexer {
        let indexer_cfg = conf
            .indexer
            .ok_or_eyre("Config item [indexer] must be specified when using --indexer")?;

        // Get the shared infrastructure from the database writer setup
        let (
            tap_tx,
            batch_events_processed,
            batch_operations_processed,
            worker_supervisor,
        ) = shared_database_writer.as_ref().unwrap();

        // Create Tap configuration
        let tap_config = consumer::streaming::sources::tap::consumer::TapConfig {
            websocket_url: indexer_cfg.tap_websocket_url.clone(),
            admin_url: indexer_cfg.tap_admin_url.clone(),
            admin_password: indexer_cfg.tap_admin_password.clone(),
            max_pending_acks: indexer_cfg.max_pending_acks,
            reconnect_backoff_ms: 1000,
            reconnect_max_backoff_ms: 60000,
        };

        // Create Tap indexer factory and spawn with supervision
        let tap_indexer_factory = relay::TapIndexerFactory::new(
            pool.clone(),
            tap_config,
            indexer_cfg.workers,
            tap_tx.clone(),
            batch_events_processed.clone(),
            batch_operations_processed.clone(),
        );

        worker_supervisor.spawn(
            tap_indexer_factory,
            stop.clone(),
            consumer::worker_core::RestartPolicy::Always, // Critical worker - always restart
        );
    }

    // Wait for Control+C
    tokio::select! {
        _ = ctrl_c() => {
            tracing::info!("Received SIGINT (Control+C), initiating shutdown...");
        }
    }

    // Step 1: Signal all tasks to stop
    tracing::info!("Sending stop signal to all tasks...");
    stop_tx.send(true).unwrap();

    // Step 2: Drop the shared database writer senders to close the channels
    // This must happen BEFORE we wait, so tasks can see the channels close
    // Tasks will drop their clones as they exit, and once all are dropped,
    // the database writer will drain and exit
    if let Some((
        tap_tx,
        _batch_events_processed,
        _batch_operations_processed,
        _worker_supervisor,
    )) = shared_database_writer
    {
        tracing::info!("Closing database writer channels...");
        drop(tap_tx);
    }

    // Step 3: Close the tracker to prevent new tasks
    tracker.close();

    // Step 4: Wait for all tasks to complete
    // Tasks should respect the stop signal and exit cleanly
    // The database writer will drain its queue before exiting
    tracing::info!("Waiting for all tasks to complete...");
    tracker.wait().await;

    tracing::info!("Consumer shutdown complete");
    Ok(())
}