use anchor_client::{
    solana_sdk::{commitment_config::CommitmentConfig, signature::Keypair},
    Cluster,
};
use anchor_lang::prelude::Pubkey;
use client::{Client, MangoGroupContext};
use futures_channel::mpsc::{unbounded, UnboundedSender};
use futures_util::{
    future::{self, Ready},
    pin_mut, SinkExt, StreamExt, TryStreamExt,
};
use log::*;
use std::{
    collections::{HashMap, HashSet},
    fs::File,
    io::Read,
    net::SocketAddr,
    str::FromStr,
    sync::Arc,
    sync::Mutex,
    time::Duration,
};
use tokio::{
    net::{TcpListener, TcpStream},
    pin,
};
use tokio_tungstenite::tungstenite::{protocol::Message, Error};

use serde::Deserialize;
use solana_geyser_connector_lib::{
    grpc_plugin_source, metrics, websocket_source, MetricsConfig, SourceConfig,
};
use solana_geyser_connector_lib::{
    metrics::{MetricType, MetricU64},
    orderbook_filter::{self, MarketConfig, OrderbookCheckpoint, OrderbookFilterMessage},
    FilterConfig, StatusResponse,
};

type CheckpointMap = Arc<Mutex<HashMap<String, OrderbookCheckpoint>>>;
type PeerMap = Arc<Mutex<HashMap<SocketAddr, Peer>>>;

#[derive(Clone, Debug, Deserialize)]
#[serde(tag = "command")]
pub enum Command {
    #[serde(rename = "subscribe")]
    Subscribe(SubscribeCommand),
    #[serde(rename = "unsubscribe")]
    Unsubscribe(UnsubscribeCommand),
    #[serde(rename = "getMarkets")]
    GetMarkets,
}

#[derive(Clone, Debug, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SubscribeCommand {
    pub market_id: String,
}

#[derive(Clone, Debug, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct UnsubscribeCommand {
    pub market_id: String,
}

#[derive(Clone, Debug)]
pub struct Peer {
    pub sender: UnboundedSender<Message>,
    pub subscriptions: HashSet<String>,
}

#[derive(Clone, Debug, Deserialize)]
pub struct Config {
    pub source: SourceConfig,
    pub metrics: MetricsConfig,
    pub bind_ws_addr: String,
    pub rpc_http_url: String,
    pub mango_group: String,
}

async fn handle_connection_error(
    checkpoint_map: CheckpointMap,
    peer_map: PeerMap,
    market_ids: HashMap<String, String>,
    raw_stream: TcpStream,
    addr: SocketAddr,
    metrics_opened_connections: MetricU64,
    metrics_closed_connections: MetricU64,
) {
    metrics_opened_connections.clone().increment();

    let result = handle_connection(
        checkpoint_map,
        peer_map.clone(),
        market_ids,
        raw_stream,
        addr,
    )
    .await;
    if result.is_err() {
        error!("connection {} error {}", addr, result.unwrap_err());
    };

    metrics_closed_connections.clone().increment();

    peer_map.lock().unwrap().remove(&addr);
}

async fn handle_connection(
    checkpoint_map: CheckpointMap,
    peer_map: PeerMap,
    market_ids: HashMap<String, String>,
    raw_stream: TcpStream,
    addr: SocketAddr,
) -> Result<(), Error> {
    info!("ws connected: {}", addr);
    let ws_stream = tokio_tungstenite::accept_async(raw_stream).await?;
    let (ws_tx, ws_rx) = ws_stream.split();

    // 1: publish channel in peer map
    let (chan_tx, chan_rx) = unbounded();
    {
        peer_map.lock().unwrap().insert(
            addr,
            Peer {
                sender: chan_tx,
                subscriptions: HashSet::<String>::new(),
            },
        );
    }

    let receive_commands = ws_rx.try_for_each(|msg| {
        handle_commands(
            addr,
            msg,
            peer_map.clone(),
            checkpoint_map.clone(),
            market_ids.clone(),
        )
    });
    let forward_updates = chan_rx.map(Ok).forward(ws_tx);

    pin_mut!(receive_commands, forward_updates);
    future::select(receive_commands, forward_updates).await;

    peer_map.lock().unwrap().remove(&addr);
    info!("ws disconnected: {}", &addr);
    Ok(())
}

fn handle_commands(
    addr: SocketAddr,
    msg: Message,
    peer_map: PeerMap,
    checkpoint_map: CheckpointMap,
    market_ids: HashMap<String, String>,
) -> Ready<Result<(), Error>> {
    let msg_str = msg.clone().into_text().unwrap();
    let command: Result<Command, serde_json::Error> = serde_json::from_str(&msg_str);
    let mut peers = peer_map.lock().unwrap();
    let peer = peers.get_mut(&addr).expect("peer should be in map");
    match command {
        Ok(Command::Subscribe(cmd)) => {
            let market_id = cmd.clone().market_id;
            match market_ids.get(&market_id) {
                None => {
                    let res = StatusResponse {
                        success: false,
                        message: "market not found",
                    };
                    peer.sender
                        .unbounded_send(Message::Text(serde_json::to_string(&res).unwrap()))
                        .unwrap();
                    return future::ok(());
                }
                _ => {}
            }
            let subscribed = peer.subscriptions.insert(market_id.clone());

            let res = if subscribed {
                StatusResponse {
                    success: true,
                    message: "subscribed",
                }
            } else {
                StatusResponse {
                    success: false,
                    message: "already subscribed",
                }
            };
            peer.sender
                .unbounded_send(Message::Text(serde_json::to_string(&res).unwrap()))
                .unwrap();

            if subscribed {
                let checkpoint_map = checkpoint_map.lock().unwrap();
                let checkpoint = checkpoint_map.get(&market_id);
                match checkpoint {
                    Some(checkpoint) => {
                        peer.sender
                            .unbounded_send(Message::Text(
                                serde_json::to_string(&checkpoint).unwrap(),
                            ))
                            .unwrap();
                    }
                    None => info!("no checkpoint available on client subscription"), // todo: what to do here?
                }
            }
        }
        Ok(Command::Unsubscribe(cmd)) => {
            info!("unsubscribe {}", cmd.market_id);
            let unsubscribed = peer.subscriptions.remove(&cmd.market_id);
            let res = if unsubscribed {
                StatusResponse {
                    success: true,
                    message: "unsubscribed",
                }
            } else {
                StatusResponse {
                    success: false,
                    message: "not subscribed",
                }
            };
            peer.sender
                .unbounded_send(Message::Text(serde_json::to_string(&res).unwrap()))
                .unwrap();
        }
        Ok(Command::GetMarkets) => {
            info!("getMarkets");
            peer.sender
                .unbounded_send(Message::Text(serde_json::to_string(&market_ids).unwrap()))
                .unwrap();
        }
        Err(err) => {
            info!("error deserializing user input {:?}", err);
            let res = StatusResponse {
                success: false,
                message: "invalid input",
            };
            peer.sender
                .unbounded_send(Message::Text(serde_json::to_string(&res).unwrap()))
                .unwrap();
        }
    };

    future::ok(())
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let args: Vec<String> = std::env::args().collect();

    if args.len() < 2 {
        eprintln!("Please enter a config file path argument");

        return Ok(());
    }

    let config: Config = {
        let mut file = File::open(&args[1])?;
        let mut contents = String::new();
        file.read_to_string(&mut contents)?;
        toml::from_str(&contents).unwrap()
    };

    solana_logger::setup_with_default("info");

    let metrics_tx = metrics::start(config.metrics, "orderbook".into());

    let metrics_opened_connections =
        metrics_tx.register_u64("orderbook_opened_connections".into(), MetricType::Counter);

    let metrics_closed_connections =
        metrics_tx.register_u64("orderbook_closed_connections".into(), MetricType::Counter);

    let checkpoints = CheckpointMap::new(Mutex::new(HashMap::new()));
    let peers = PeerMap::new(Mutex::new(HashMap::new()));

    let rpc_url = config.rpc_http_url;
    let ws_url = rpc_url.replace("https", "wss");
    let rpc_timeout = Duration::from_secs(10);
    let cluster = Cluster::Custom(rpc_url.clone(), ws_url.clone());
    let client = Client::new(
        cluster.clone(),
        CommitmentConfig::processed(),
        &Keypair::new(),
        Some(rpc_timeout),
    );
    let group_context = Arc::new(MangoGroupContext::new_from_rpc(
        Pubkey::from_str(&config.mango_group).unwrap(),
        client.cluster.clone(),
        client.commitment,
    )?);

    // todo: reload markets at intervals
    let market_configs: Vec<(Pubkey, MarketConfig)> = group_context
        .perp_markets
        .iter()
        .map(|(_, context)| {
            let quote_decimals = match group_context.tokens.get(&context.market.settle_token_index) {
                Some(token) => token.decimals,
                None => panic!("token not found for market") // todo: default to 6 for usdc?
            };
            (
                context.address,
                MarketConfig {
                    name: context.market.name().to_owned(),
                    bids: context.market.bids,
                    asks: context.market.asks,
                    base_decimals: context.market.base_decimals,
                    quote_decimals,
                },
            )
        })
        .collect();

    let serum_market_configs: Vec<(Pubkey, MarketConfig)> = group_context
        .serum3_markets
        .iter()
        .map(|(_, context)| {
            let base_decimals = match group_context.tokens.get(&context.market.base_token_index) {
                Some(token) => token.decimals,
                None => panic!("token not found for market") // todo: default?
            };
            let quote_decimals = match group_context.tokens.get(&context.market.quote_token_index) {
                Some(token) => token.decimals,
                None => panic!("token not found for market") // todo: default to 6 for usdc?
            };
            (
                context.address,
                MarketConfig {
                    name: context.market.name().to_owned(),
                    bids: context.bids,
                    asks: context.asks,
                    base_decimals,
                    quote_decimals,
                },
            )
        })
        .collect();

    let market_pubkey_strings: HashMap<String, String> = [market_configs.clone(), serum_market_configs.clone()]
        .concat()
        .iter()
        .map(|market| (market.0.to_string(), market.1.name.clone()))
        .collect::<Vec<(String, String)>>()
        .into_iter()
        .collect();

    let (account_write_queue_sender, slot_queue_sender, orderbook_receiver) =
        orderbook_filter::init(market_configs, serum_market_configs, metrics_tx.clone()).await?;

    let checkpoints_ref_thread = checkpoints.clone();
    let peers_ref_thread = peers.clone();

    tokio::spawn(async move {
        pin!(orderbook_receiver);
        loop {
            let message = orderbook_receiver.recv().await.unwrap();
            match message {
                OrderbookFilterMessage::Update(update) => {
                    debug!("ws update {} {:?}", update.market, update.side);
                    let mut peer_copy = peers_ref_thread.lock().unwrap().clone();
                    for (addr, peer) in peer_copy.iter_mut() {
                        let json = serde_json::to_string(&update).unwrap();

                        // only send updates if the peer is subscribed
                        if peer.subscriptions.contains(&update.market) {
                            let result = peer.sender.send(Message::Text(json)).await;
                            if result.is_err() {
                                error!(
                                    "ws update {} {:?} fill could not reach {}",
                                    update.market, update.side, addr
                                );
                            }
                        }
                    }
                }
                OrderbookFilterMessage::Checkpoint(checkpoint) => {
                    checkpoints_ref_thread
                        .lock()
                        .unwrap()
                        .insert(checkpoint.market.clone(), checkpoint);
                }
            }
        }
    });

    info!("ws listen: {}", config.bind_ws_addr);
    let try_socket = TcpListener::bind(&config.bind_ws_addr).await;
    let listener = try_socket.expect("Failed to bind");
    tokio::spawn(async move {
        // Let's spawn the handling of each connection in a separate task.
        while let Ok((stream, addr)) = listener.accept().await {
            tokio::spawn(handle_connection_error(
                checkpoints.clone(),
                peers.clone(),
                market_pubkey_strings.clone(),
                stream,
                addr,
                metrics_opened_connections.clone(),
                metrics_closed_connections.clone(),
            ));
        }
    });

    info!(
        "rpc connect: {}",
        config
            .source
            .grpc_sources
            .iter()
            .map(|c| c.connection_string.clone())
            .collect::<String>()
    );
    let use_geyser = true;
    if use_geyser {
        let filter_config = FilterConfig {
            program_ids: vec![
                "4MangoMjqJ2firMokCjjGgoK8d4MXcrgL7XJaL3w6fVg".into(),
                "srmqPvymJeFKQ4zGQed1GFppgkRHL9kaELCbyksJtPX".into(),
            ],
        };
        grpc_plugin_source::process_events(
            &config.source,
            &filter_config,
            account_write_queue_sender,
            slot_queue_sender,
            metrics_tx.clone(),
        )
        .await;
    } else {
        websocket_source::process_events(
            &config.source,
            account_write_queue_sender,
            slot_queue_sender,
        )
        .await;
    }

    Ok(())
}