extern crate termion;

use clichess::{ClientRequest, GameInfo, RecvPositionError, UserRole, EXIT_MSG};
use shakmaty::{fen, Chess, Color, Outcome, Position, Setup};
use std::io;
use std::os::unix::net::UnixStream;
use std::sync::mpsc::{channel, Receiver, Sender};
use std::sync::{Arc, Mutex};
use std::thread;
use std::time;
use termion::event::{parse_event, Event, Key};

use std::io::{stdin, stdout, Read, Write};
use termion::raw::{IntoRawMode, RawTerminal};

struct Client {
    player: clichess::Player,
    side: Color,
    display_sender: Sender<DisplayMessage>,
    waiting_server_msg_receiver: Receiver<WaitingServerMsg>,
    keyboard_input_recv: Receiver<String>,
    server_message_recv: Receiver<String>,
    opponent_name: Option<String>,
    last_move: Option<String>,
    is_player_turn: Arc<Mutex<bool>>,
}

fn main() {
    let version = env!("CARGO_PKG_VERSION");
    println!("Running clichess version {}", version);
    let username = std::env::args().nth(1).expect("no name given");
    let public_key = std::env::args().nth(2).expect("no public key given");
    //send username and public key to server
    let mut stream = match UnixStream::connect("/tmp/clichess.socket") {
        Ok(sock) => sock,
        Err(_) => {
            println!("clichess daemon is not running.");
            return;
        }
    };

    let is_player_turn = Arc::new(Mutex::new(true));
    let (display_sender, display_receiver) = channel();
    let (waiting_server_msg_sender, waiting_server_msg_receiver) = channel();
    let keyboard_input_recv = start_keyboard_input_thread(
        display_sender.clone(),
        waiting_server_msg_sender.clone(),
        is_player_turn.clone(),
    );
    start_display_thread(display_receiver);
    //start a thread to listen to server messages
    let server_message_recv =
        setup_server_message_recv(&stream, waiting_server_msg_sender.clone()).unwrap();

    let mut client = Client {
        player: clichess::Player {
            role: UserRole::Spectator,
            username,
            public_key,
        },
        side: Color::White,
        display_sender: display_sender.clone(),
        waiting_server_msg_receiver,
        keyboard_input_recv,
        server_message_recv,
        opponent_name: Option::None,
        last_move: Option::None,
        is_player_turn,
    };

    let login_result = login(&mut client, &mut stream);
    if login_result == LoginResult::UserExited {
        send_request(&client, &mut stream, ClientRequest::Exit);
        client.display_sender.send(DisplayMessage::Exit).unwrap();
        return;
    }
    client.display_sender.send(DisplayMessage::Clear).unwrap();
    if client.player.role == UserRole::Black {
        client.side = Color::Black;
    }
    if client.player.role == UserRole::Spectator {
        client
            .display_sender
            .send(DisplayMessage::Information(format!(
                "Hello, {} !\n\r You're spectating !",
                client.player.username
            )))
            .unwrap();
    } else {
        client
            .display_sender
            .send(DisplayMessage::Information(format!(
                "Hello, {} !\n\r You're playing with the {} pieces",
                client.player.username,
                client.player.role.to_string()
            )))
            .unwrap();
    }

    loop {
        client.display_sender.send(DisplayMessage::Help).unwrap();
        if !game_loop(&mut client, &mut stream) {
            break;
        }
        client.display_sender.send(DisplayMessage::Clear).unwrap();
    }
    client.display_sender.send(DisplayMessage::Clear).unwrap();
    send_request(&client, &mut stream, ClientRequest::Exit);
    client.display_sender.send(DisplayMessage::Exit).unwrap();
}

#[derive(PartialEq)]
enum LoginResult {
    Success,
    UserExited,
}

fn login(client: &mut Client, stream: &mut UnixStream) -> LoginResult {
    let mut response = String::from("KO");
    while &response != "OK" {
        match prompt_user_for_role(client, stream) {
            PromptedRoleResponse::Role(role) => {
                client.player.role = role.clone();
                response = send_request(
                    client,
                    stream,
                    ClientRequest::Login {
                        username: client.player.username.clone(),
                        pubkey: client.player.public_key.clone(),
                        role,
                    },
                );
            }
            PromptedRoleResponse::Exit => return LoginResult::UserExited,
            PromptedRoleResponse::Retry => continue,
        };
    }
    LoginResult::Success
}

fn game_loop(client: &mut Client, stream: &mut UnixStream) -> bool {
    let mut replay = false;
    let mut current_position = fetch_initial_chess_position(client, stream);

    loop {
        let is_player_turn_loop = clichess::is_player_turn(&client.player, current_position.turn());
        {
            let mut is_player_turn = client.is_player_turn.lock().unwrap();
            *is_player_turn = is_player_turn_loop;
        }
        if is_player_turn_loop || client.player.role == UserRole::Spectator {
            let mut message = String::from("");
            let opponent_name = client.opponent_name.clone();
            if opponent_name.is_some() {
                message.push_str(&format!("{} played", opponent_name.expect("is some")));
                client
                    .last_move
                    .clone()
                    .map(|chessmove| message.push_str(&format!(" {}", chessmove)));
            }
            if message.len() > 0 {
                client
                    .display_sender
                    .send(DisplayMessage::Information(message))
                    .unwrap();
            }
        }
        client
            .display_sender
            .send(DisplayMessage::Chessboard {
                fen: fen::fen(&current_position),
                side: client.side.clone(),
            })
            .unwrap();
        //check if game is over.
        if current_position.is_game_over() {
            break;
        }
        if is_player_turn_loop {
            //it's the user turn, taking user input
            let mut input = client.keyboard_input_recv.recv().unwrap();
            input = String::from(input.trim());
            if input == EXIT_MSG {
                client.waiting_server_msg_receiver.recv().unwrap();
                break;
            }
            let response = send_request(client, stream, ClientRequest::Play(input.clone()));
            if response == String::from("KO") {
                client
                    .display_sender
                    .send(DisplayMessage::Message(format!("Invalid move: {}", input)))
                    .unwrap();
                //go back to taking user input
                continue;
            }
            client.last_move = Some(input);
            match get_current_position(client, stream) {
                Ok(position) => current_position = position,
                Err(_) => break,
            };
            //clear message
            client
                .display_sender
                .send(DisplayMessage::Message(String::default()))
                .unwrap();
        } else {
            match wait_for_next_move(client, stream) {
                Ok(position) => current_position = position,
                Err(_) => break,
            };
        }
    }
    let end_message = match current_position.outcome() {
        None => "",
        Some(Outcome::Draw) => "Draw game.",
        Some(Outcome::Decisive { winner }) => {
            if winner == Color::White {
                "White has won the game."
            } else {
                "Black has won the game."
            }
        }
    }
    .to_string();
    if !end_message.is_empty() {
        //accept input
        if client.player.role != UserRole::Spectator {
            client
                .display_sender
                .send(DisplayMessage::Message(format!(
                    "{}\n\rPress enter to rematch.",
                    end_message
                )))
                .unwrap();
            let mut is_player_turn = client.is_player_turn.lock().unwrap();
            *is_player_turn = true;
        } else {
            client
                .display_sender
                .send(DisplayMessage::Message(format!("{}", end_message)))
                .unwrap();
            thread::sleep(time::Duration::from_secs(5));
            return false;
        }
        let buffer = client.keyboard_input_recv.recv().unwrap();

        if buffer == EXIT_MSG {
            client.waiting_server_msg_receiver.recv().unwrap();
        } else {
            replay = true;
            client
                .display_sender
                .send(DisplayMessage::Message(format!(
                    "{}\n\rWaiting for your opponent to restart...",
                    end_message
                )))
                .unwrap();
            send_request(client, stream, ClientRequest::Reset);
        }
    }
    replay
}

fn send_request(client: &Client, stream: &mut UnixStream, request: ClientRequest) -> String {
    let response: String;
    match serde_json::to_string(&request) {
        Ok(request_str) => {
            clichess::write_to_stream(stream, request_str).unwrap();
            response = fetch_message_from_server(client);
        }

        Err(e) => {
            client
                .display_sender
                .send(DisplayMessage::Message(format!(
                    "Error when parsing client request: {}",
                    e
                )))
                .unwrap();
            response = String::from("KO");
        }
    };
    response
}

#[derive(PartialEq, Clone)]
pub enum DisplayMessage {
    Chessboard { fen: String, side: Color },
    Message(String),
    Information(String),
    Debug(String),
    Help,
    Input(Key),
    RemoveLastInput,
    SwitchAsciiMode,
    Enter,
    Clear,
    Exit,
}

fn start_display_thread(request_recv: Receiver<DisplayMessage>) {
    thread::spawn(move || {
        let stdout = stdout();
        let mut stdout = stdout.lock().into_raw_mode().unwrap();
        write!(
            stdout,
            "{}{}",
            termion::clear::All,
            termion::cursor::Goto(3, 17)
        )
        .unwrap();
        stdout.flush().unwrap();
        let mut ascii_mode = false;
        let mut last_fen_position = String::default();
        let mut last_side = Color::White;
        loop {
            let msg = request_recv.recv().unwrap();
            match msg {
                DisplayMessage::Chessboard { fen, side } => {
                    let current_position = clichess::parse_position(&fen);
                    last_fen_position = fen.clone();
                    last_side = side.clone();
                    clichess::print_board_representation(
                        &current_position,
                        side,
                        &mut stdout,
                        ascii_mode,
                    );
                }
                DisplayMessage::SwitchAsciiMode => {
                    ascii_mode = !ascii_mode;
                    write!(stdout, "{}", termion::cursor::Save,).unwrap();

                    clichess::print_board_representation(
                        &clichess::parse_position(&last_fen_position),
                        last_side,
                        &mut stdout,
                        ascii_mode,
                    );
                    write!(stdout, "{}", termion::cursor::Restore).unwrap();
                }
                DisplayMessage::Message(s) => write!(
                    stdout,
                    "{}{}{}{}{}",
                    termion::cursor::Save,
                    termion::cursor::Goto(3, 18),
                    termion::clear::CurrentLine,
                    s,
                    termion::cursor::Restore
                )
                .unwrap(),
                DisplayMessage::Information(s) => write!(
                    stdout,
                    "{}{}{}{}{}",
                    termion::cursor::Save,
                    termion::cursor::Goto(3, 3),
                    termion::clear::CurrentLine,
                    s,
                    termion::cursor::Restore
                )
                .unwrap(),
                DisplayMessage::Clear => write!(stdout, "{}", termion::clear::All).unwrap(),
                DisplayMessage::Enter => write!(
                    stdout,
                    "{}{}",
                    termion::clear::CurrentLine,
                    termion::cursor::Goto(3, 17)
                )
                .unwrap(),
                DisplayMessage::Input(k) => display_key(&mut stdout, k),
                DisplayMessage::RemoveLastInput => write!(
                    stdout,
                    "{}{}",
                    termion::cursor::Left(1),
                    termion::clear::UntilNewline
                )
                .unwrap(),
                DisplayMessage::Help => print_help(&mut stdout),
                DisplayMessage::Debug(s) => write!(
                    stdout,
                    "{}{}{}{}{}",
                    termion::cursor::Save,
                    termion::cursor::Goto(3, 30),
                    termion::clear::CurrentLine,
                    s,
                    termion::cursor::Restore
                )
                .unwrap(),
                DisplayMessage::Exit => break,
            }
            stdout.flush().unwrap();
        }
        write!(stdout, "{}", termion::clear::All,).unwrap();
        stdout.flush().unwrap();
    });
}

fn print_help(stdout: &mut RawTerminal<io::StdoutLock>) {
    write!(stdout, "{}", termion::cursor::Save).unwrap();
    let help = [
        "move are parsed using SAN (Nc3) or UCI (b1c3)",
        "@ to toggle ascii mode",
        "Ctrl-C to quit",
    ];
    for (i, h) in help.iter().enumerate() {
        write!(stdout, "{}{}", termion::cursor::Goto(3, 22 + (i as u16)), h).unwrap();
    }
    write!(stdout, "{}", termion::cursor::Restore).unwrap();
}

fn start_keyboard_input_thread(
    display_sender: Sender<DisplayMessage>,
    waiting_server_msg_sender: Sender<WaitingServerMsg>,
    is_player_turn: Arc<Mutex<bool>>,
) -> Receiver<String> {
    let (sender, receiver) = channel();
    thread::spawn(move || {
        let mut buffer = String::new();
        let stdin = stdin();
        let stdin = stdin.lock();
        let mut bytes = stdin.bytes();
        loop {
            let b = bytes.next().unwrap().unwrap();
            let e = parse_event(b, &mut bytes).unwrap();
            let is_player_turn = is_player_turn.lock().unwrap();
            if !*is_player_turn
                && e != Event::Key(Key::Ctrl('c'))
                && e != Event::Key(Key::Char('@'))
            {
                //ignore input when it's not the client turn
                continue;
            }
            match e {
                Event::Key(Key::Ctrl('c')) => {
                    sender.send(String::from(EXIT_MSG)).unwrap();
                    waiting_server_msg_sender
                        .send(WaitingServerMsg::UserCanceled)
                        .unwrap();
                    break;
                }
                Event::Key(Key::Char('\n')) => {
                    display_sender.send(DisplayMessage::Enter).unwrap();
                    sender.send(buffer.clone()).unwrap();
                    if buffer == EXIT_MSG {
                        waiting_server_msg_sender
                            .send(WaitingServerMsg::UserCanceled)
                            .unwrap();
                    }
                    buffer.clear();
                }
                Event::Key(Key::Char('@')) => {
                    display_sender
                        .send(DisplayMessage::SwitchAsciiMode)
                        .unwrap();
                }
                Event::Key(Key::Char(c)) => {
                    if buffer.len() < 10 {
                        buffer.push_str(&c.to_string());
                        display_sender
                            .send(DisplayMessage::Input(Key::Char(c)))
                            .unwrap();
                    }
                }
                Event::Key(Key::Backspace) => {
                    if buffer.len() > 0 {
                        buffer.pop();
                        display_sender
                            .send(DisplayMessage::RemoveLastInput)
                            .unwrap();
                    }
                }
                Event::Key(_) => continue,
                Event::Mouse(_) => continue,
                Event::Unsupported(_) => continue,
            };
        }
    });
    receiver
}

fn display_key(stdout: &mut RawTerminal<io::StdoutLock>, key: Key) {
    match key {
        Key::Char(c) => write!(stdout, "{}", c).unwrap(),
        _ => {}
    };
}

enum WaitingServerMsg {
    MsgReceived,
    UserCanceled,
}

fn setup_server_message_recv(
    stream: &UnixStream,
    waiting_server_msg_sender: Sender<WaitingServerMsg>,
) -> io::Result<Receiver<String>> {
    let (sender, receiver) = channel();
    let thread_stream = stream.try_clone()?;

    thread::spawn(move || {
        loop {
            //wait for server message
            let buffer =
                clichess::read_line_from_stream(&thread_stream).expect("Error message from server");
            sender.send(buffer).unwrap();
            waiting_server_msg_sender
                .send(WaitingServerMsg::MsgReceived)
                .unwrap();
        }
    });
    Ok(receiver)
}

//get current position from server
fn get_current_position(
    client: &mut Client,
    stream: &mut UnixStream,
) -> Result<Chess, RecvPositionError> {
    let response = send_request(client, stream, ClientRequest::GetGameInfo);
    if response.is_empty() {
        Err(RecvPositionError::UserCanceledError)
    } else {
        let game_info: GameInfo = serde_json::from_str(&response).unwrap();
        update_client(&game_info, client);
        Ok(clichess::parse_position(&game_info.game_fen))
    }
}

fn wait_for_next_move(
    client: &mut Client,
    stream: &mut UnixStream,
) -> Result<Chess, RecvPositionError> {
    client
        .display_sender
        .send(DisplayMessage::Information(String::from(
            "Waiting for opponent move...",
        )))
        .unwrap();
    send_request(client, stream, ClientRequest::WaitForNextMove);
    let response = fetch_message_from_server(client);
    if response == EXIT_MSG {
        Err(RecvPositionError::UserCanceledError)
    } else {
        let game_info: GameInfo = serde_json::from_str(&response).unwrap();
        update_client(&game_info, client);
        Ok(clichess::parse_position(&game_info.game_fen))
    }
}

fn update_client(game_info: &GameInfo, client: &mut Client) {
    if game_info.opponent_name != "" {
        client.opponent_name = Some(game_info.opponent_name.clone());
    }
    if game_info.last_move != "" {
        client.last_move = Some(game_info.last_move.clone());
    }
}

fn fetch_message_from_server(client: &Client) -> String {
    match client.waiting_server_msg_receiver.recv().unwrap() {
        WaitingServerMsg::MsgReceived => client.server_message_recv.recv().unwrap(),
        WaitingServerMsg::UserCanceled => client.keyboard_input_recv.recv().unwrap(),
    }
}

enum PromptedRoleResponse {
    Role(UserRole),
    Exit,
    Retry,
}

fn prompt_user_for_role(client: &Client, stream: &mut UnixStream) -> PromptedRoleResponse {
    let response = send_request(client, stream, ClientRequest::FetchAvailableRoles);
    let available_roles = roles_from_str(&response).unwrap();
    let mut prompt = String::new();
    if !available_roles.contains(&UserRole::White) && !available_roles.contains(&UserRole::Black) {
        prompt.push_str("You can only spectate this game. Press enter to start spectating.");
    } else if available_roles.contains(&UserRole::White) {
        prompt = String::from("Do you want to play as White (W)");
        if available_roles.contains(&UserRole::Black) {
            prompt.push_str(", Black (B)");
        }
        prompt.push_str(" or Spectate (S)?");
    } else {
        prompt = String::from("Do you want to play as Black (B) or Spectate (S)?");
    }
    client
        .display_sender
        .send(DisplayMessage::Information(prompt))
        .unwrap();
    let mut input = client.keyboard_input_recv.recv().unwrap();
    input = String::from(input.trim());
    if input == EXIT_MSG {
        client.waiting_server_msg_receiver.recv().unwrap();
        return PromptedRoleResponse::Exit;
    }

    if !available_roles.contains(&UserRole::White) && !available_roles.contains(&UserRole::Black) {
        //we can only spectate
        input = String::from("S");
    }
    match clichess::parse_to_role(&input) {
        Ok(r) => {
            if !available_roles.contains(&r) {
                client
                    .display_sender
                    .send(DisplayMessage::Message(String::from(
                        "Sorry, this side is not available.",
                    )))
                    .unwrap();
                return PromptedRoleResponse::Retry;
            }
            return PromptedRoleResponse::Role(r);
        }
        Err(e) => {
            client
                .display_sender
                .send(DisplayMessage::Message(format!("{}", e)))
                .unwrap();
            return PromptedRoleResponse::Retry;
        }
    };
}

fn fetch_initial_chess_position(client: &Client, stream: &mut UnixStream) -> Chess {
    let response = send_request(client, stream, ClientRequest::GetGameInfo);
    let game_info: GameInfo = serde_json::from_str(&response).unwrap();
    clichess::parse_position(&game_info.game_fen)
}

fn roles_from_str(s: &str) -> Result<Vec<UserRole>, String> {
    s.split(',').map(clichess::parse_to_role).collect()
}