use std::{env, process::exit, time::Duration};

use matrix_sdk::{
    config::SyncSettings,
    room::Room,
    ruma::events::room::{
        member::StrippedRoomMemberEvent,
        message::{
            MessageType, OriginalSyncRoomMessageEvent, RoomMessageEventContent,
            TextMessageEventContent,
        },
    },
    store::StateStore,
    Client,
};
use tokio::time::sleep;

async fn on_room_message(event: OriginalSyncRoomMessageEvent, room: Room) {
    if let Room::Joined(room) = room {
        let msg_body = match event.content.msgtype {
            MessageType::Text(TextMessageEventContent { body, .. }) => body,
            _ => return,
        };

        if msg_body.contains("!party") {
            let content = RoomMessageEventContent::text_plain("🎉🎊🥳 let's PARTY!! 🥳🎊🎉");

            println!("sending");

            // send our message to the room we found the "!party" command in
            // the last parameter is an optional transaction id which we don't
            // care about.
            room.send(content, None).await.unwrap();

            println!("message sent");
        }
    }
}

async fn on_stripped_state_member(
    room_member: StrippedRoomMemberEvent,
    client: Client,
    room: Room,
) {
    if room_member.state_key != client.user_id().await.unwrap() {
        return;
    }

    if let Room::Invited(room) = room {
        println!("Autojoining room {}", room.room_id());
        let mut delay = 2;

        while let Err(err) = room.accept_invitation().await {
            // retry autojoin due to synapse sending invites, before the
            // invited user can join for more information see
            // https://github.com/matrix-org/synapse/issues/4345
            eprintln!(
                "Failed to join room {} ({:?}), retrying in {}s",
                room.room_id(),
                err,
                delay
            );

            sleep(Duration::from_secs(delay)).await;
            delay *= 2;

            if delay > 3600 {
                eprintln!("Can't join room {} ({:?})", room.room_id(), err);
                break;
            }
        }
        println!("Successfully joined room {}", room.room_id());
    }
}

async fn login_and_sync(
    homeserver_url: String,
    username: String,
    password: String,
) -> anyhow::Result<()> {
    let mut client_builder = Client::builder().homeserver_url(homeserver_url);

    // The location to save files to
    let proj_dirs = directories::ProjectDirs::from("de", "Entropia",  "Matrix Rust Example Bot").unwrap();
    let state_store = StateStore::open_with_path(proj_dirs.data_dir())?;
    client_builder = client_builder.state_store(Box::new(state_store));

    let client = client_builder.build().await.unwrap();
    client
        .login(&username, &password, None, Some("command bot"))
        .await?;

    println!("logged in as {}", username);

    // An initial sync to set up state and so our bot doesn't respond to old
    // messages. If the `StateStore` finds saved state in the location given the
    // initial sync will be skipped in favor of loading state from the store
    client.sync_once(SyncSettings::default()).await.unwrap();
    // add our CommandBot to be notified of incoming messages, we do this after the
    // initial sync to avoid responding to messages before the bot was running.
    client.register_event_handler(on_room_message).await;
    client
        .register_event_handler(on_stripped_state_member)
        .await;

    // since we called `sync_once` before we entered our sync loop we must pass
    // that sync token to `sync`
    let settings = SyncSettings::default().token(client.sync_token().await.unwrap());
    // this keeps state from the server streaming in to CommandBot via the
    // EventHandler trait
    client.sync(settings).await;

    Ok(())
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    tracing_subscriber::fmt::init();

    let (homeserver_url, username, password) =
        match (env::args().nth(1), env::args().nth(2), env::args().nth(3)) {
            (Some(a), Some(b), Some(c)) => (a, b, c),
            _ => {
                eprintln!(
                    "Usage: {} <homeserver_url> <username> <password>",
                    env::args().next().unwrap()
                );
                exit(1)
            }
        };

    login_and_sync(homeserver_url, username, password).await?;
    Ok(())
}