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

use anyhow::{Context, Result};
use axum::routing::{get, post};
use axum::Router;
use tokio::sync::Mutex;
use tracing::info;

mod api;
mod db;
mod poller;
mod types;
mod webhook;

use types::WebhookTarget;

#[tokio::main]
async fn main() -> Result<()> {
    tracing_subscriber::fmt()
        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
        .init();

    let port: u16 = std::env::var("NOISEBELL_CACHE_PORT")
        .unwrap_or_else(|_| "3000".into())
        .parse()
        .context("NOISEBELL_CACHE_PORT must be a valid u16")?;

    let pi_address = std::env::var("NOISEBELL_CACHE_PI_ADDRESS")
        .context("NOISEBELL_CACHE_PI_ADDRESS is required")?;

    let pi_api_key = std::env::var("NOISEBELL_CACHE_PI_API_KEY")
        .context("NOISEBELL_CACHE_PI_API_KEY is required")?;

    let inbound_api_key = std::env::var("NOISEBELL_CACHE_INBOUND_API_KEY")
        .context("NOISEBELL_CACHE_INBOUND_API_KEY is required")?;

    let data_dir =
        std::env::var("NOISEBELL_CACHE_DATA_DIR").unwrap_or_else(|_| "/var/lib/noisebell-cache".into());

    let status_poll_interval_secs: u64 = std::env::var("NOISEBELL_CACHE_STATUS_POLL_INTERVAL_SECS")
        .unwrap_or_else(|_| "60".into())
        .parse()
        .context("NOISEBELL_CACHE_STATUS_POLL_INTERVAL_SECS must be a valid u64")?;

    let info_poll_interval_secs: u64 = std::env::var("NOISEBELL_CACHE_INFO_POLL_INTERVAL_SECS")
        .unwrap_or_else(|_| "300".into())
        .parse()
        .context("NOISEBELL_CACHE_INFO_POLL_INTERVAL_SECS must be a valid u64")?;

    let offline_threshold: u32 = std::env::var("NOISEBELL_CACHE_OFFLINE_THRESHOLD")
        .unwrap_or_else(|_| "3".into())
        .parse()
        .context("NOISEBELL_CACHE_OFFLINE_THRESHOLD must be a valid u32")?;

    let retry_attempts: u32 = std::env::var("NOISEBELL_CACHE_RETRY_ATTEMPTS")
        .unwrap_or_else(|_| "3".into())
        .parse()
        .context("NOISEBELL_CACHE_RETRY_ATTEMPTS must be a valid u32")?;

    let retry_base_delay_secs: u64 = std::env::var("NOISEBELL_CACHE_RETRY_BASE_DELAY_SECS")
        .unwrap_or_else(|_| "1".into())
        .parse()
        .context("NOISEBELL_CACHE_RETRY_BASE_DELAY_SECS must be a valid u64")?;

    let http_timeout_secs: u64 = std::env::var("NOISEBELL_CACHE_HTTP_TIMEOUT_SECS")
        .unwrap_or_else(|_| "10".into())
        .parse()
        .context("NOISEBELL_CACHE_HTTP_TIMEOUT_SECS must be a valid u64")?;

    // Parse outbound webhooks from NOISEBELL_CACHE_WEBHOOK_<n>_URL and _SECRET env vars
    let mut webhooks = Vec::new();
    for i in 0.. {
        let url_key = format!("NOISEBELL_CACHE_WEBHOOK_{i}_URL");
        match std::env::var(&url_key) {
            Ok(url) => {
                let secret_key = format!("NOISEBELL_CACHE_WEBHOOK_{i}_SECRET");
                let secret = std::env::var(&secret_key).ok();
                webhooks.push(WebhookTarget { url, secret });
            }
            Err(_) => break,
        }
    }

    info!(
        port,
        %pi_address,
        webhook_count = webhooks.len(),
        "starting noisebell-cache"
    );

    let db_path = format!("{data_dir}/noisebell.db");
    let conn = db::init(&db_path)?;
    let db = Arc::new(Mutex::new(conn));

    let client = reqwest::Client::builder()
        .timeout(Duration::from_secs(http_timeout_secs))
        .build()
        .context("failed to build HTTP client")?;

    let poller_config = Arc::new(poller::PollerConfig {
        pi_address,
        pi_api_key,
        status_poll_interval: Duration::from_secs(status_poll_interval_secs),
        info_poll_interval: Duration::from_secs(info_poll_interval_secs),
        offline_threshold,
        retry_attempts,
        retry_base_delay_secs,
        http_timeout_secs,
        webhooks: webhooks.clone(),
    });

    poller::spawn_status_poller(poller_config.clone(), db.clone(), client.clone());
    poller::spawn_info_poller(poller_config, db.clone(), client.clone());

    let app_state = Arc::new(api::AppState {
        db,
        client,
        inbound_api_key,
        webhooks,
        retry_attempts,
        retry_base_delay_secs,
    });

    let app = Router::new()
        .route("/webhook", post(api::post_webhook))
        .route("/status", get(api::get_status))
        .route("/info", get(api::get_info))
        .route("/history", get(api::get_history))
        .with_state(app_state);

    let listener = tokio::net::TcpListener::bind(("0.0.0.0", port))
        .await
        .context(format!("failed to bind to 0.0.0.0:{port}"))?;

    info!(port, "listening");

    let mut sigterm = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
        .context("failed to register SIGTERM handler")?;
    axum::serve(listener, app)
        .with_graceful_shutdown(async move {
            sigterm.recv().await;
        })
        .await
        .context("server error")?;

    info!("shutdown complete");
    Ok(())
}