//! Requires the "client", "standard_framework", and "voice" features be enabled in your
//! Cargo.toml, like so:
//!
//! ```toml
//! [dependencies.serenity]
//! git = "https://github.com/serenity-rs/serenity.git"
//! features = ["client", "standard_framework", "voice"]
//! ```
use std::env;

// This trait adds the `register_songbird` and `register_songbird_with` methods
// to the client builder below, making it easy to install this voice client.
// The voice client can be retrieved in any command using `songbird::get(ctx).await`.
use songbird::SerenityInit;

// Event related imports to detect track creation failures.
use songbird::events::{Event, EventContext, EventHandler as VoiceEventHandler, TrackEvent};

// To turn user URLs into playable audio, we'll use yt-dlp.
use songbird::input::YoutubeDl;

// YtDl requests need an HTTP client to operate -- we'll create and store our own.
use reqwest::Client as HttpClient;

// Import the `Context` to handle commands.
use serenity::client::Context;

use serenity::{
    async_trait,
    client::{Client, EventHandler},
    framework::{
        standard::{
            macros::{command, group},
            Args,
            CommandResult,
        },
        StandardFramework,
    },
    model::{channel::Message, gateway::Ready},
    prelude::{GatewayIntents, TypeMapKey},
    Result as SerenityResult,
};

struct HttpKey;

impl TypeMapKey for HttpKey {
    type Value = HttpClient;
}

struct Handler;

#[async_trait]
impl EventHandler for Handler {
    async fn ready(&self, _: Context, ready: Ready) {
        println!("{} is connected!", ready.user.name);
    }
}

#[group]
#[commands(deafen, join, leave, mute, play, ping, undeafen, unmute)]
struct General;

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt::init();

    // Configure the client with your Discord bot token in the environment.
    let token = env::var("DISCORD_TOKEN").expect("Expected a token in the environment");

    let framework = StandardFramework::new().group(&GENERAL_GROUP);
    framework.configure(|c| c.prefix("~"));

    let intents = GatewayIntents::non_privileged() | GatewayIntents::MESSAGE_CONTENT;

    let mut client = Client::builder(&token, intents)
        .event_handler(Handler)
        .framework(framework)
        .register_songbird()
        // We insert our own HTTP client here to make use of in
        // `~play`. If we wanted, we could supply cookies and auth
        // details ahead of time.
        //
        // Generally, we don't want to make a new Client for every request!
        .type_map_insert::<HttpKey>(HttpClient::new())
        .await
        .expect("Err creating client");

    tokio::spawn(async move {
        let _ = client
            .start()
            .await
            .map_err(|why| println!("Client ended: {:?}", why));
    });

    let _signal_err = tokio::signal::ctrl_c().await;
    println!("Received Ctrl-C, shutting down.");
}

#[command]
#[only_in(guilds)]
async fn deafen(ctx: &Context, msg: &Message) -> CommandResult {
    let guild_id = msg.guild_id.unwrap();

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();

    let handler_lock = match manager.get(guild_id) {
        Some(handler) => handler,
        None => {
            check_msg(msg.reply(ctx, "Not in a voice channel").await);

            return Ok(());
        },
    };

    let mut handler = handler_lock.lock().await;

    if handler.is_deaf() {
        check_msg(msg.channel_id.say(&ctx.http, "Already deafened").await);
    } else {
        if let Err(e) = handler.deafen(true).await {
            check_msg(
                msg.channel_id
                    .say(&ctx.http, format!("Failed: {:?}", e))
                    .await,
            );
        }

        check_msg(msg.channel_id.say(&ctx.http, "Deafened").await);
    }

    Ok(())
}

#[command]
#[only_in(guilds)]
async fn join(ctx: &Context, msg: &Message) -> CommandResult {
    let (guild_id, channel_id) = {
        let guild = msg.guild(&ctx.cache).unwrap();
        let channel_id = guild
            .voice_states
            .get(&msg.author.id)
            .and_then(|voice_state| voice_state.channel_id);

        (guild.id, channel_id)
    };

    let connect_to = match channel_id {
        Some(channel) => channel,
        None => {
            check_msg(msg.reply(ctx, "Not in a voice channel").await);

            return Ok(());
        },
    };

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();

    if let Ok(handler_lock) = manager.join(guild_id, connect_to).await {
        // Attach an event handler to see notifications of all track errors.
        let mut handler = handler_lock.lock().await;
        handler.add_global_event(TrackEvent::Error.into(), TrackErrorNotifier);
    }

    Ok(())
}

struct TrackErrorNotifier;

#[async_trait]
impl VoiceEventHandler for TrackErrorNotifier {
    async fn act(&self, ctx: &EventContext<'_>) -> Option<Event> {
        if let EventContext::Track(track_list) = ctx {
            for (state, handle) in *track_list {
                println!(
                    "Track {:?} encountered an error: {:?}",
                    handle.uuid(),
                    state.playing
                );
            }
        }

        None
    }
}

#[command]
#[only_in(guilds)]
async fn leave(ctx: &Context, msg: &Message) -> CommandResult {
    let guild_id = msg.guild_id.unwrap();

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();
    let has_handler = manager.get(guild_id).is_some();

    if has_handler {
        if let Err(e) = manager.remove(guild_id).await {
            check_msg(
                msg.channel_id
                    .say(&ctx.http, format!("Failed: {:?}", e))
                    .await,
            );
        }

        check_msg(msg.channel_id.say(&ctx.http, "Left voice channel").await);
    } else {
        check_msg(msg.reply(ctx, "Not in a voice channel").await);
    }

    Ok(())
}

#[command]
#[only_in(guilds)]
async fn mute(ctx: &Context, msg: &Message) -> CommandResult {
    let guild_id = msg.guild_id.unwrap();

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();

    let handler_lock = match manager.get(guild_id) {
        Some(handler) => handler,
        None => {
            check_msg(msg.reply(ctx, "Not in a voice channel").await);

            return Ok(());
        },
    };

    let mut handler = handler_lock.lock().await;

    if handler.is_mute() {
        check_msg(msg.channel_id.say(&ctx.http, "Already muted").await);
    } else {
        if let Err(e) = handler.mute(true).await {
            check_msg(
                msg.channel_id
                    .say(&ctx.http, format!("Failed: {:?}", e))
                    .await,
            );
        }

        check_msg(msg.channel_id.say(&ctx.http, "Now muted").await);
    }

    Ok(())
}

#[command]
async fn ping(ctx: &Context, msg: &Message) -> CommandResult {
    check_msg(msg.channel_id.say(&ctx.http, "Pong!").await);
    Ok(())
}

#[command]
#[only_in(guilds)]
async fn play(ctx: &Context, msg: &Message, mut args: Args) -> CommandResult {
    let url = match args.single::<String>() {
        Ok(url) => url,
        Err(_) => {
            check_msg(
                msg.channel_id
                    .say(&ctx.http, "Must provide a URL to a video or audio")
                    .await,
            );

            return Ok(());
        },
    };

    if !url.starts_with("http") {
        check_msg(
            msg.channel_id
                .say(&ctx.http, "Must provide a valid URL")
                .await,
        );

        return Ok(());
    }

    let guild_id = msg.guild_id.unwrap();

    let http_client = {
        let data = ctx.data.read().await;
        data.get::<HttpKey>()
            .cloned()
            .expect("Guaranteed to exist in the typemap.")
    };

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();

    if let Some(handler_lock) = manager.get(guild_id) {
        let mut handler = handler_lock.lock().await;

        let src = YoutubeDl::new(http_client, url);
        let _ = handler.play_input(src.into());

        check_msg(msg.channel_id.say(&ctx.http, "Playing song").await);
    } else {
        check_msg(
            msg.channel_id
                .say(&ctx.http, "Not in a voice channel to play in")
                .await,
        );
    }

    Ok(())
}

#[command]
#[only_in(guilds)]
async fn undeafen(ctx: &Context, msg: &Message) -> CommandResult {
    let guild_id = msg.guild_id.unwrap();

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();

    if let Some(handler_lock) = manager.get(guild_id) {
        let mut handler = handler_lock.lock().await;
        if let Err(e) = handler.deafen(false).await {
            check_msg(
                msg.channel_id
                    .say(&ctx.http, format!("Failed: {:?}", e))
                    .await,
            );
        }

        check_msg(msg.channel_id.say(&ctx.http, "Undeafened").await);
    } else {
        check_msg(
            msg.channel_id
                .say(&ctx.http, "Not in a voice channel to undeafen in")
                .await,
        );
    }

    Ok(())
}

#[command]
#[only_in(guilds)]
async fn unmute(ctx: &Context, msg: &Message) -> CommandResult {
    let guild_id = msg.guild_id.unwrap();

    let manager = songbird::get(ctx)
        .await
        .expect("Songbird Voice client placed in at initialisation.")
        .clone();

    if let Some(handler_lock) = manager.get(guild_id) {
        let mut handler = handler_lock.lock().await;
        if let Err(e) = handler.mute(false).await {
            check_msg(
                msg.channel_id
                    .say(&ctx.http, format!("Failed: {:?}", e))
                    .await,
            );
        }

        check_msg(msg.channel_id.say(&ctx.http, "Unmuted").await);
    } else {
        check_msg(
            msg.channel_id
                .say(&ctx.http, "Not in a voice channel to unmute in")
                .await,
        );
    }

    Ok(())
}

/// Checks that a message successfully sent; if not, then logs why to stdout.
fn check_msg(result: SerenityResult<Message>) {
    if let Err(why) = result {
        println!("Error sending message: {:?}", why);
    }
}