/*
 * tmtd - Suckless To Do list
 * Copyright (C) 2022 lemon.sh & karx
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of  MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

use crate::web::App;
use crate::{config::Config, database::Database};
use async_sqlx_session::PostgresSessionStore;
use std::str::FromStr;
use std::time::Duration;
use std::{env, sync::Arc};
use tokio::sync::broadcast;
use tokio::task::JoinHandle;
use tokio::time::sleep;
use tracing::{debug, error, info, Level};

mod config;
mod database;
mod web;

#[cfg(unix)]
async fn terminate_signal() {
    use tokio::signal::unix::{signal, SignalKind};
    let mut sigterm = signal(SignalKind::terminate()).unwrap();
    let mut sigint = signal(SignalKind::interrupt()).unwrap();
    debug!("Installed ctrl+c handler");
    tokio::select! {
        _ = sigterm.recv() => {},
        _ = sigint.recv() => {}
    }
}

#[cfg(windows)]
async fn terminate_signal() {
    use tokio::signal::windows::ctrl_c;
    let mut ctrlc = ctrl_c().unwrap();
    debug!("Installed ctrl+c handler");
    let _ = ctrlc.recv().await;
}

#[tokio::main(flavor = "current_thread")]
async fn main() -> anyhow::Result<()> {
    let config_var = env::var("TMTD_CONFIG");
    let config_path = config_var.as_deref().unwrap_or("tmtd.toml");
    println!("Loading config from '{}'...", config_path);
    let cfg = Arc::new(Config::load_from_file(config_path).await?);

    tracing_subscriber::fmt::fmt()
        .with_max_level({
            if let Some(o) = cfg.log_level.as_deref() {
                Level::from_str(o)?
            } else {
                Level::INFO
            }
        })
        .init();

    info!(concat!("Initializing - tmtd ", env!("CARGO_PKG_VERSION")));
    let (ctx, _) = broadcast::channel(1);
    let database = Arc::new(Database::connect(&cfg.connection_string).await?);
    let session_store =
        PostgresSessionStore::from_client(database.pool()).with_table_name("sessions");
    session_store.migrate().await?;

    let cleanup_task =
        spawn_session_cleanup_task(&session_store, Duration::from_secs(600), ctx.subscribe());
    info!("Started session cleanup task");

    let web_app = App::new(cfg.clone(), database.clone(), session_store)?;
    let web_task = tokio::spawn(web_app.run(ctx.subscribe()));
    info!("Started the web app at http://{}", cfg.listen_addr);

    terminate_signal().await;
    ctx.send(()).unwrap();

    cleanup_task
        .await
        .unwrap_or_else(|e| error!("Couldn't join cleanup task: {}", e));
    web_task
        .await
        .unwrap_or_else(|e| error!("Couldn't join web task: {}", e));
    database.close().await;

    Ok(())
}

fn spawn_session_cleanup_task(
    store: &PostgresSessionStore,
    period: Duration,
    mut cancel: broadcast::Receiver<()>,
) -> JoinHandle<()> {
    let store = store.clone();
    tokio::spawn(async move {
        loop {
            tokio::select! {
                _ = sleep(period) => {
                    if let Err(error) = store.cleanup().await {
                        error!("Error in cleanup task: {}", error);
                    }
                }
                _ = cancel.recv() => break
            }
        }
        info!("Cleanup task has been shut down");
    })
}