use env_logger;
use std::str::FromStr;
use xmpp::{action, ClientBuilder, ClientFeature, ClientType, Event};
use xmpp_parsers::{BareJid, JidParseError};

#[derive(Debug)]
enum Error {
    Syntax(String),
    Jid(String, JidParseError),
    XMPP(tokio_xmpp::Error),
}

impl From<tokio_xmpp::Error> for Error {
    fn from(e: tokio_xmpp::Error) -> Error {
        Error::XMPP(e)
    }
}

struct Args {
    jid: BareJid,
    password: String,
    room: BareJid,
}

impl Args {
    fn from_cli() -> Result<Option<Args>, Error> {
        let mut args = std::env::args();
        let binary_name = args.next().unwrap();

        let jid = args
            .next()
            .ok_or(Error::Syntax("Missing argument: jid".into()))?;
        match jid.to_lowercase().as_str() {
            "help" | "-h" | "--help" => {
                help(&binary_name);
                return Ok(None);
            }
            _ => {}
        }
        let jid = BareJid::from_str(&jid).map_err(|e| Error::Jid(jid, e))?;

        let password = args
            .next()
            .ok_or(Error::Syntax("Missing argument: password".into()))?;

        let room = args
            .next()
            .ok_or(Error::Syntax("Missing argument: room".into()))?;
        let room = BareJid::from_str(&room).map_err(|e| Error::Jid(room, e))?;

        Ok(Some(Args {
            jid,
            password,
            room,
        }))
    }
}

fn help(name: &str) {
    println!("A bot that welcomes you when you say hello");
    println!("Usage: {} <jid> <password> <room>", name);
    println!("NOTE: Run with RUST_LOG=debug for debug logs");
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    env_logger::init();

    let args = if let Some(args) = Args::from_cli()? {
        args
    } else {
        return Ok(());
    };

    let nick = String::from("actions_bot");

    // Client instance
    let mut client = ClientBuilder::new(args.jid.clone(), &args.password)
        .set_client(ClientType::Bot, "xmpp-rs")
        .set_website("https://gitlab.com/xmpp-rs/xmpp-rs")
        .set_default_nick(&nick)
        .enable_feature(ClientFeature::JoinRooms)
        .build();

    while let Some(events) = client.wait_for_events().await {
        for event in events {
            match event {
                Event::Online => {
                    println!("Online.");
                    client
                        .action(action::room_join(args.room.clone(), &nick))
                        .await?;
                }
                Event::Disconnected => {
                    println!("Disconnected");
                }
                Event::RoomMessage(_id, room_jid, author, body) => {
                    println!(
                        "Message in room {} from {}: {}",
                        &room_jid, &author, &body.0
                    );
                    let msg = body.0.trim().to_lowercase();
                    if msg == "hello" {
                        client
                            .action(action::room_message(
                                room_jid,
                                format!("Hello, {}", &author),
                            ))
                            .await?;
                    }
                }
                Event::RoomPrivateMessage(_id, room_jid, nick, body) => {
                    println!(
                        "Private Message from room {} from {}: {}",
                        &room_jid, &nick, body.0
                    );
                    client
                        .action(action::room_private_message(
                            room_jid,
                            nick,
                            format!("You said: {}", body.0),
                        ))
                        .await?;
                }
                Event::ChatMessage(_id, jid, body) => {
                    println!("Message from {}: {}", jid, body.0);
                    client
                        .action(action::message(jid, format!("You said: {}", body.0)))
                        .await?;
                }
                Event::RoomJoined(jid) => {
                    println!("Joined room {}.", jid);
                    client
                        .action(action::room_message(jid, "Hello, world!"))
                        .await?;
                }
                _ => (),
            }
        }
    }

    Ok(())
}