#![feature(exit_status_error)]
pub mod api;
pub mod check;
pub mod log;
pub mod mail;
pub mod web;

use ::log::error;
use anyhow::{anyhow, Result};
use api::make_json_response;
use axum::{
    http::HeaderMap,
    response::{Html, IntoResponse},
    routing::get,
    Json, Router,
};
use check::{check_loop, Check};
use chrono::{DateTime, Utc};
use mail::MailConfig;
use reqwest::{
    header::{CACHE_CONTROL, CONTENT_TYPE, REFRESH},
    StatusCode,
};
use serde::Deserialize;
use std::{collections::BTreeMap, net::SocketAddr, process::exit, sync::Arc};
use tokio::{fs::read_to_string, sync::RwLock};
use web::make_html_page;

pub static GLOBAL_ERROR: RwLock<Option<anyhow::Error>> = RwLock::const_new(None);

#[tokio::main]
async fn main() {
    env_logger::init_from_env("LOG");
    if let Err(e) = run().await {
        error!("{e:?}");
        exit(1);
    }
}

#[derive(Debug, Deserialize)]
pub struct Config {
    mail: Option<MailConfig>,
    title: String,
    bind: SocketAddr,
    interval: u64,
    services: Vec<Service>,
}

#[derive(Debug, Deserialize)]
pub struct Service {
    title: String,
    url: Option<String>,
    checks: Vec<Check>,
    #[serde(default)]
    mail_to: Vec<String>,
}

#[derive(Debug, Clone)]
pub struct Status {
    pub time: DateTime<Utc>,
    pub status: Result<String, String>,
}

static STATUS: RwLock<BTreeMap<(usize, usize), Status>> = RwLock::const_new(BTreeMap::new());

async fn run() -> anyhow::Result<()> {
    let config = std::env::args()
        .nth(1)
        .ok_or(anyhow!("expected config path as first argument"))?;
    let config = read_to_string(config).await?;
    let config = Arc::<Config>::new(serde_yaml::from_str(&config)?);

    for i in 0..config.services.len() {
        tokio::task::spawn(check_loop(config.clone(), i));
    }

    let app = Router::new()
        .route(
            "/",
            get({
                let config = config.clone();
                move |headers: HeaderMap| async move {
                    (
                        [
                            (
                                CACHE_CONTROL,
                                format!("max-age={}, public", config.interval),
                            ),
                            (REFRESH, format!("{}", config.interval)),
                        ],
                        if headers
                            .get("accept")
                            .map_or(false, |s| s == "application/json")
                        {
                            Json(make_json_response(config.clone()).await).into_response()
                        } else {
                            Html(make_html_page(config.clone()).await).into_response()
                        },
                    )
                }
            }),
        )
        .route(
            "/font.woff2",
            get(|| async {
                (
                    [
                        (CONTENT_TYPE, "font/woff2"),
                        (CACHE_CONTROL, "public, immutable"),
                    ],
                    include_bytes!("cantarell.woff2"),
                )
            }),
        )
        .route("/favicon.ico", get(|| async { StatusCode::NO_CONTENT }));
    let listener = tokio::net::TcpListener::bind(config.bind).await?;
    axum::serve(listener, app).await?;
    Ok(())
}