#![feature(proc_macro_hygiene, decl_macro)]

use anyhow::{anyhow, bail, Result};
use log::{debug, info, trace};
use regex::Regex;
use rocket::{fairing::AdHoc, get, post, routes, State};
use rocket_contrib::json::Json;
use serde::{Deserialize, Serialize};

use std::{collections::HashMap, fs::File, io::BufReader, net::SocketAddr, process::Command};

#[derive(Debug, Deserialize, Serialize)]
struct Config {
    hooks: HashMap<String, Hook>,
}

#[derive(Debug, Deserialize, Serialize)]
struct Hook {
    action: Option<String>,
    filters: HashMap<String, Filter>,
}

#[derive(Debug, Deserialize, Serialize)]
struct Filter {
    pointer: String,
    regex: String,
}

#[derive(Debug, Deserialize, Serialize)]
struct Data(serde_json::Value);

#[get("/")]
fn index() -> &'static str {
    "Hello, webhookey!"
}

fn execute_hook(name: &str, hook: &Hook, data: &serde_json::Value) -> Result<()> {
    debug!("Running hook `{}`", name);

    for (filter_name, filter) in hook.filters.iter() {
        debug!("Matching filter `{}`", filter_name);

        if let Some(value) = data.pointer(&filter.pointer) {
            let regex = Regex::new(&filter.regex)?;

            if let Some(value) = value.as_str() {
                if !regex.is_match(value) {
                    info!("Filter `{}` in hook `{}` did not match", filter_name, name);
                    return Ok(());
                }
            } else {
                anyhow!(
                    "Could not parse pointer in hook `{}` from filter `{}`",
                    name,
                    filter_name
                );
            }
        }
    }

    if let Some(action) = &hook.action {
        info!("Execute `{}` from hook `{}`", action, name);

        Command::new(action).spawn()?;
    }

    Ok(())
}

#[post("/", format = "json", data = "<data>")]
fn receive_hook(address: SocketAddr, config: State<Config>, data: Json<Data>) -> Result<String> {
    info!("POST request received from: {}", address);

    let data = serde_json::to_value(data.0)?;

    trace!("Data received from: {}\n{}", address, data);

    for (hook_name, hook) in config.hooks.iter() {
        execute_hook(&hook_name, &hook, &data)?;
    }

    Ok("Request received.".to_string())
}

fn get_config() -> Result<File> {
    if let Ok(config) = File::open("/etc/webhookey/config.yml") {
        info!("Loading configuration from `/etc/webhookey/config.yml`");

        return Ok(config);
    }

    if let Some(mut path) = dirs::config_dir() {
        path.push("webhookey/config.yml");

        if let Ok(config) = File::open(&path) {
            info!(
                "Loading configuration from `{}`",
                path.to_str().unwrap_or("path not printable"),
            );

            return Ok(config);
        }
    }

    if let Ok(config) = File::open("config.yml") {
        info!("Loading configuration from `./config.yml`");

        return Ok(config);
    }

    bail!("No configuration files found.");
}

fn main() -> Result<()> {
    env_logger::init();

    let config = get_config()?;

    let config: Config = serde_yaml::from_reader(BufReader::new(config))?;

    trace!("Parsed configuration:\n{}", serde_yaml::to_string(&config)?);

    rocket::ignite()
        .mount("/", routes![index, receive_hook])
        .attach(AdHoc::on_attach("webhookey config", move |rocket| {
            Ok(rocket.manage(config))
        }))
        .launch();

    Ok(())
}