mod backfill;
mod websocket;

use super::clock;
use crate::{
    config::{
        Config, ALPACA_CRYPTO_DATA_WEBSOCKET_URL, ALPACA_NEWS_DATA_WEBSOCKET_URL, ALPACA_SOURCE,
        ALPACA_STOCK_DATA_WEBSOCKET_URL,
    },
    create_send_await, database,
    types::{alpaca, Asset, Class},
    utils::backoff,
};
use futures_util::{future::join_all, StreamExt};
use itertools::{Either, Itertools};
use std::sync::Arc;
use tokio::{
    join, select, spawn,
    sync::{mpsc, oneshot},
};
use tokio_tungstenite::connect_async;

#[derive(Clone, Copy)]
#[allow(dead_code)]
pub enum Action {
    Add,
    Enable,
    Remove,
    Disable,
}

pub struct Message {
    pub action: Action,
    pub assets: Vec<(String, Class)>,
    pub response: oneshot::Sender<()>,
}

impl Message {
    pub fn new(action: Action, assets: Vec<(String, Class)>) -> (Self, oneshot::Receiver<()>) {
        let (sender, receiver) = oneshot::channel();
        (
            Self {
                action,
                assets,
                response: sender,
            },
            receiver,
        )
    }
}

#[derive(Clone, Copy)]
pub enum ThreadType {
    Bars(Class),
    News,
}

pub async fn run(
    config: Arc<Config>,
    mut receiver: mpsc::Receiver<Message>,
    mut clock_receiver: mpsc::Receiver<clock::Message>,
) {
    let (bars_us_equity_websocket_sender, bars_us_equity_backfill_sender) =
        init_thread(config.clone(), ThreadType::Bars(Class::UsEquity)).await;
    let (bars_crypto_websocket_sender, bars_crypto_backfill_sender) =
        init_thread(config.clone(), ThreadType::Bars(Class::Crypto)).await;
    let (news_websocket_sender, news_backfill_sender) =
        init_thread(config.clone(), ThreadType::News).await;

    loop {
        select! {
            Some(message) = receiver.recv() => {
                spawn(handle_message(
                    config.clone(),
                    bars_us_equity_websocket_sender.clone(),
                    bars_us_equity_backfill_sender.clone(),
                    bars_crypto_websocket_sender.clone(),
                    bars_crypto_backfill_sender.clone(),
                    news_websocket_sender.clone(),
                    news_backfill_sender.clone(),
                    message,
                ));
            }
            Some(_) = clock_receiver.recv() => {
                spawn(handle_clock_message(
                    config.clone(),
                    bars_us_equity_backfill_sender.clone(),
                    bars_crypto_backfill_sender.clone(),
                    news_backfill_sender.clone(),
                ));
            }
            else => panic!("Communication channel unexpectedly closed.")
        }
    }
}

async fn init_thread(
    config: Arc<Config>,
    thread_type: ThreadType,
) -> (
    mpsc::Sender<websocket::Message>,
    mpsc::Sender<backfill::Message>,
) {
    let websocket_url = match thread_type {
        ThreadType::Bars(Class::UsEquity) => {
            format!("{}/{}", ALPACA_STOCK_DATA_WEBSOCKET_URL, *ALPACA_SOURCE)
        }
        ThreadType::Bars(Class::Crypto) => ALPACA_CRYPTO_DATA_WEBSOCKET_URL.into(),
        ThreadType::News => ALPACA_NEWS_DATA_WEBSOCKET_URL.into(),
    };

    let (websocket, _) = connect_async(websocket_url).await.unwrap();
    let (mut websocket_sink, mut websocket_stream) = websocket.split();
    alpaca::websocket::data::authenticate(&mut websocket_sink, &mut websocket_stream).await;

    let (backfill_sender, backfill_receiver) = mpsc::channel(100);
    spawn(backfill::run(
        Arc::new(backfill::create_handler(thread_type, config.clone())),
        backfill_receiver,
    ));

    let (websocket_sender, websocket_receiver) = mpsc::channel(100);
    spawn(websocket::run(
        Arc::new(websocket::create_handler(thread_type, config.clone())),
        websocket_receiver,
        websocket_stream,
        websocket_sink,
    ));

    (websocket_sender, backfill_sender)
}

#[allow(clippy::too_many_arguments)]
#[allow(clippy::too_many_lines)]
async fn handle_message(
    config: Arc<Config>,
    bars_us_equity_websocket_sender: mpsc::Sender<websocket::Message>,
    bars_us_equity_backfill_sender: mpsc::Sender<backfill::Message>,
    bars_crypto_websocket_sender: mpsc::Sender<websocket::Message>,
    bars_crypto_backfill_sender: mpsc::Sender<backfill::Message>,
    news_websocket_sender: mpsc::Sender<websocket::Message>,
    news_backfill_sender: mpsc::Sender<backfill::Message>,
    message: Message,
) {
    let (us_equity_symbols, crypto_symbols): (Vec<_>, Vec<_>) = message
        .assets
        .clone()
        .into_iter()
        .partition_map(|asset| match asset.1 {
            Class::UsEquity => Either::Left(asset.0),
            Class::Crypto => Either::Right(asset.0),
        });

    let symbols = message
        .assets
        .into_iter()
        .map(|(symbol, _)| symbol)
        .collect::<Vec<_>>();

    let bars_us_equity_future = async {
        if us_equity_symbols.is_empty() {
            return;
        }

        create_send_await!(
            bars_us_equity_websocket_sender,
            websocket::Message::new,
            message.action.into(),
            us_equity_symbols.clone()
        );

        create_send_await!(
            bars_us_equity_backfill_sender,
            backfill::Message::new,
            message.action.into(),
            us_equity_symbols
        );
    };

    let bars_crypto_future = async {
        if crypto_symbols.is_empty() {
            return;
        }

        create_send_await!(
            bars_crypto_websocket_sender,
            websocket::Message::new,
            message.action.into(),
            crypto_symbols.clone()
        );

        create_send_await!(
            bars_crypto_backfill_sender,
            backfill::Message::new,
            message.action.into(),
            crypto_symbols
        );
    };

    let news_future = async {
        create_send_await!(
            news_websocket_sender,
            websocket::Message::new,
            message.action.into(),
            symbols.clone()
        );

        create_send_await!(
            news_backfill_sender,
            backfill::Message::new,
            message.action.into(),
            symbols.clone()
        );
    };

    join!(bars_us_equity_future, bars_crypto_future, news_future);

    match message.action {
        Action::Add => {
            let assets = join_all(symbols.into_iter().map(|symbol| {
                let config = config.clone();
                async move {
                    let asset_future = async {
                        alpaca::api::incoming::asset::get_by_symbol(
                            &config.alpaca_client,
                            &config.alpaca_rate_limiter,
                            &symbol,
                            Some(backoff::infinite()),
                        )
                        .await
                        .unwrap()
                    };

                    let position_future = async {
                        alpaca::api::incoming::position::get_by_symbol(
                            &config.alpaca_rate_limiter,
                            &config.alpaca_client,
                            &symbol,
                            Some(backoff::infinite()),
                        )
                        .await
                        .unwrap()
                    };

                    let (asset, position) = join!(asset_future, position_future);
                    Asset::from((asset, position))
                }
            }))
            .await;

            database::assets::upsert_batch(&config.clickhouse_client, &assets)
                .await
                .unwrap();
        }
        Action::Remove => {
            database::assets::delete_where_symbols(&config.clickhouse_client, &symbols)
                .await
                .unwrap();
        }
        _ => {}
    }

    message.response.send(()).unwrap();
}

async fn handle_clock_message(
    config: Arc<Config>,
    bars_us_equity_backfill_sender: mpsc::Sender<backfill::Message>,
    bars_crypto_backfill_sender: mpsc::Sender<backfill::Message>,
    news_backfill_sender: mpsc::Sender<backfill::Message>,
) {
    database::cleanup_all(&config.clickhouse_client)
        .await
        .unwrap();

    let assets = database::assets::select(&config.clickhouse_client)
        .await
        .unwrap();

    let (us_equity_symbols, crypto_symbols): (Vec<_>, Vec<_>) = assets
        .clone()
        .into_iter()
        .partition_map(|asset| match asset.class {
            Class::UsEquity => Either::Left(asset.symbol),
            Class::Crypto => Either::Right(asset.symbol),
        });

    let symbols = assets
        .into_iter()
        .map(|asset| asset.symbol)
        .collect::<Vec<_>>();

    let bars_us_equity_future = async {
        create_send_await!(
            bars_us_equity_backfill_sender,
            backfill::Message::new,
            Some(backfill::Action::Backfill),
            us_equity_symbols.clone()
        );
    };

    let bars_crypto_future = async {
        create_send_await!(
            bars_crypto_backfill_sender,
            backfill::Message::new,
            Some(backfill::Action::Backfill),
            crypto_symbols.clone()
        );
    };

    let news_future = async {
        create_send_await!(
            news_backfill_sender,
            backfill::Message::new,
            Some(backfill::Action::Backfill),
            symbols
        );
    };

    join!(bars_us_equity_future, bars_crypto_future, news_future);
}