use std::{

    io, io::Write,

    iter::once,

    mem::swap

};

use super::{

    server::HWServer,

    room::{RoomId, GameInfo},

    client::{ClientId, HWClient},

    room::HWRoom,

    handlers

};

use protocol::messages::{

    HWProtocolMessage,

    HWServerMessage,

    HWServerMessage::*

};

use utils::to_engine_msg;

pub enum Destination {

    ToId(ClientId),

    ToSelf,

    ToAll {

        room_id: Option<RoomId>,

        protocol: Option<u32>,

        skip_self: bool

    }

}

pub struct PendingMessage {

    pub destination: Destination,

    pub message: HWServerMessage

}

impl PendingMessage {

    pub fn send(message: HWServerMessage, client_id: ClientId) -> PendingMessage {

        PendingMessage{ destination: Destination::ToId(client_id), message}

    }

    pub fn send_self(message: HWServerMessage) -> PendingMessage {

        PendingMessage{ destination: Destination::ToSelf, message }

    }

    pub fn send_all(message: HWServerMessage) -> PendingMessage {

        let destination = Destination::ToAll {

            room_id: None,

            protocol: None,

            skip_self: false,

        };

        PendingMessage{ destination, message }

    }

    pub fn in_room(mut self, clients_room_id: RoomId) -> PendingMessage {

        if let Destination::ToAll {ref mut room_id, ..} = self.destination {

            *room_id = Some(clients_room_id)

        }

        self

    }

    pub fn with_protocol(mut self, protocol_number: u32) -> PendingMessage {

        if let Destination::ToAll {ref mut protocol, ..} = self.destination {

            *protocol = Some(protocol_number)

        }

        self

    }

    pub fn but_self(mut self) -> PendingMessage {

        if let Destination::ToAll {ref mut skip_self, ..} = self.destination {

            *skip_self = true

        }

        self

    }

    pub fn action(self) -> Action { Send(self) }

}

impl Into<Action> for PendingMessage {

    fn into(self) -> Action { self.action() }

}

impl HWServerMessage {

    pub fn send(self, client_id: ClientId) -> PendingMessage { PendingMessage::send(self, client_id) }

    pub fn send_self(self) -> PendingMessage { PendingMessage::send_self(self) }

    pub fn send_all(self) -> PendingMessage { PendingMessage::send_all(self) }

}

pub enum Action {

    Send(PendingMessage),

    RemoveClient,

    ByeClient(String),

    ReactProtocolMessage(HWProtocolMessage),

    CheckRegistered,

    JoinLobby,

    AddRoom(String, Option<String>),

    RemoveRoom(RoomId),

    MoveToRoom(RoomId),

    MoveToLobby(String),

    ChangeMaster(RoomId, Option<ClientId>),

    RemoveTeam(String),

    RemoveClientTeams,

    SendRoomUpdate(Option<String>),

    StartRoomGame(RoomId),

    SendTeamRemovalMessage(String),

    FinishRoomGame(RoomId),

    SendRoomData{to: ClientId, teams: bool, config: bool, flags: bool},

    Warn(String),

    ProtocolError(String)

}

use self::Action::*;

pub fn run_action(server: &mut HWServer, client_id: usize, action: Action) {

    match action {

        Send(msg) => server.send(client_id, msg.destination, msg.message),

        ByeClient(msg) => {

            let room_id;

            let nick;

            {

                let c = &server.clients[client_id];

                room_id = c.room_id;

                nick = c.nick.clone();

            }

            room_id.map (|id| {

                if id != server.lobby_id {

                    server.react(client_id, vec![

                        MoveToLobby(format!("quit: {}", msg.clone()))]);

                }

            });

            server.react(client_id, vec![

                LobbyLeft(nick, msg.clone()).send_all().action(),

                Bye(msg).send_self().action(),

                RemoveClient]);

        },

        RemoveClient => {

            server.removed_clients.push(client_id);

            if server.clients.contains(client_id) {

                server.clients.remove(client_id);

            }

        },

        ReactProtocolMessage(msg) =>

            handlers::handle(server, client_id, msg),

        CheckRegistered =>

            if server.clients[client_id].protocol_number > 0 && server.clients[client_id].nick != "" {

                server.react(client_id, vec![

                    JoinLobby,

                    ]);

            },

        JoinLobby => {

            server.clients[client_id].room_id = Some(server.lobby_id);

            let joined_msg;

            {

                let mut lobby_nicks = Vec::new();

                for (_, c) in server.clients.iter() {

                    if c.room_id.is_some() {

                        lobby_nicks.push(c.nick.clone());

                    }

                }

                joined_msg = LobbyJoined(lobby_nicks);

            }

            let everyone_msg = LobbyJoined(vec![server.clients[client_id].nick.clone()]);

            let flags_msg = ClientFlags(

                "+i".to_string(),

                server.clients.iter()

                    .filter(|(_, c)| c.room_id.is_some())

                    .map(|(_, c)| c.nick.clone())

                    .collect());

            let server_msg = ServerMessage("\u{1f994} is watching".to_string());

            let rooms_msg = Rooms(server.rooms.iter()

                .filter(|(id, _)| *id != server.lobby_id)

                .flat_map(|(_, r)|

                    r.info(r.master_id.map(|id| &server.clients[id])))

                .collect());

            server.react(client_id, vec![

                everyone_msg.send_all().but_self().action(),

                joined_msg.send_self().action(),

                flags_msg.send_self().action(),

                server_msg.send_self().action(),

                rooms_msg.send_self().action(),

                ]);

        },

        AddRoom(name, password) => {

            let room_id = server.add_room();;

            let actions = {

                let r = &mut server.rooms[room_id];

                let c = &mut server.clients[client_id];

                r.master_id = Some(c.id);

                r.name = name;

                r.password = password;

                r.protocol_number = c.protocol_number;

                vec![

                    RoomAdd(r.info(Some(&c))).send_all()

                        .with_protocol(r.protocol_number).action(),

                    MoveToRoom(room_id)]

            };

            server.react(client_id, actions);

        },

        RemoveRoom(room_id) => {

            let actions = {

                let r = &mut server.rooms[room_id];

                vec![RoomRemove(r.name.clone()).send_all()

                        .with_protocol(r.protocol_number).action()]

            };

            server.rooms.remove(room_id);

            server.react(client_id, actions);

        }

        MoveToRoom(room_id) => {

            let actions = {

                let r = &mut server.rooms[room_id];

                let c = &mut server.clients[client_id];

                r.players_number += 1;

                c.room_id = Some(room_id);

                c.is_joined_mid_game = false;

                if r.master_id == Some(c.id) {

                    r.ready_players_number += 1;

                    c.is_master = true;

                    c.is_ready = true;

                } else {

                    c.is_ready = false;

                    c.is_master = false;

                }

                let mut v = vec![

                    RoomJoined(vec![c.nick.clone()]).send_all().in_room(room_id).action(),

                    ClientFlags("+i".to_string(), vec![c.nick.clone()]).send_all().action(),

                    SendRoomUpdate(None)];

                if !c.is_master {

                    let team_names: Vec<_>;

                    if let Some(ref mut info) = r.game_info {

                        c.is_in_game = true;

                        c.is_joined_mid_game = true;

                        {

                            let teams = info.client_teams(c.id);

                            c.teams_in_game = teams.clone().count() as u8;

                            c.clan = teams.clone().next().map(|t| t.color);

                            team_names = teams.map(|t| t.name.clone()).collect();

                        }

                        if !team_names.is_empty() {

                            info.left_teams.retain(|name|

                                !team_names.contains(&name));

                            info.teams_in_game += team_names.len() as u8;

                            r.teams = info.teams_at_start.iter()

                                .filter(|(_, t)| !team_names.contains(&t.name))

                                .cloned().collect();

                        }

                    } else {

                        team_names = Vec::new();

                    }

                    v.push(SendRoomData{ to: client_id, teams: true, config: true, flags: true});

                    if let Some(ref info) = r.game_info {

                        v.push(RunGame.send_self().action());

                        v.push(ClientFlags("+g".to_string(), vec![c.nick.clone()])

                            .send_all().in_room(r.id).action());

                        v.push(ForwardEngineMessage(

                            vec![to_engine_msg("e$spectate 1".bytes())])

                            .send_self().action());

                        v.push(ForwardEngineMessage(info.msg_log.clone())

                            .send_self().action());

                        for name in team_names.iter() {

                            v.push(ForwardEngineMessage(

                                vec![to_engine_msg(once(b'G').chain(name.bytes()))])

                                .send_all().in_room(r.id).action());

                        }

                        if info.is_paused {

                            v.push(ForwardEngineMessage(vec![to_engine_msg(once(b'I'))])

                                .send_all().in_room(r.id).action())

                        }

                    }

                }

                v

            };

            server.react(client_id, actions);

        }

        SendRoomData {to, teams, config, flags} => {

            let mut actions = Vec::new();

            let room_id = server.clients[client_id].room_id;

            if let Some(r) = room_id.and_then(|id| server.rooms.get(id)) {

                if config {

                    actions.push(ConfigEntry("FULLMAPCONFIG".to_string(), r.map_config())

                        .send(to).action());

                    for cfg in r.game_config().into_iter() {

                        actions.push(cfg.to_server_msg().send(to).action());

                    }

                }

                if teams {

                    let current_teams = match r.game_info {

                        Some(ref info) => &info.teams_at_start,

                        None => &r.teams

                    };

                    for (owner_id, team) in current_teams.iter() {

                        actions.push(TeamAdd(HWRoom::team_info(&server.clients[*owner_id], &team))

                            .send(to).action());

                        actions.push(TeamColor(team.name.clone(), team.color)

                            .send(to).action());

                        actions.push(HedgehogsNumber(team.name.clone(), team.hedgehogs_number)

                            .send(to).action());

                    }

                }

                if flags {

                    if let Some(id) = r.master_id {

                        actions.push(ClientFlags("+h".to_string(), vec![server.clients[id].nick.clone()])

                            .send(to).action());

                    }

                    let nicks: Vec<_> = server.clients.iter()

                        .filter(|(_, c)| c.room_id == Some(r.id) && c.is_ready)

                        .map(|(_, c)| c.nick.clone()).collect();

                    if !nicks.is_empty() {

                        actions.push(ClientFlags("+r".to_string(), nicks)

                            .send(to).action());

                    }

                }

            }

            server.react(client_id, actions);

        }

        MoveToLobby(msg) => {

            let mut actions = Vec::new();

            let lobby_id = server.lobby_id;

            if let (c, Some(r)) = server.client_and_room(client_id) {

                r.players_number -= 1;

                if c.is_ready && r.ready_players_number > 0 {

                    r.ready_players_number -= 1;

                }

                if r.players_number > 0 && c.is_master {

                    actions.push(ChangeMaster(r.id, None));

                }

                actions.push(RemoveClientTeams);

                actions.push(RoomLeft(c.nick.clone(), msg)

                    .send_all().in_room(r.id).but_self().action());

                actions.push(ClientFlags("-i".to_string(), vec![c.nick.clone()])

                    .send_all().action());

                actions.push(SendRoomUpdate(Some(r.name.clone())));

            }

            server.react(client_id, actions);

            actions = Vec::new();

            if let (c, Some(r)) = server.client_and_room(client_id) {

                c.room_id = Some(lobby_id);

                if r.players_number == 0 {

                    actions.push(RemoveRoom(r.id));

                }

            }

            server.react(client_id, actions)

        }

        ChangeMaster(room_id, new_id) => {

            let mut actions = Vec::new();

            let room_client_ids = server.room_clients(room_id);

            let new_id = new_id.or_else(||

                room_client_ids.iter().find(|id| **id != client_id).map(|id| *id));

            let new_nick = new_id.map(|id| server.clients[id].nick.clone());

            if let (c, Some(r)) = server.client_and_room(client_id) {

                match r.master_id {

                    Some(id) if id == c.id => {

                        c.is_master = false;

                        r.master_id = None;

                        actions.push(ClientFlags("-h".to_string(), vec![c.nick.clone()])

                            .send_all().in_room(r.id).action());

                    }

                    Some(_) => unreachable!(),

                    None => {}

                }

                r.master_id = new_id;

                if let Some(nick) = new_nick {

                    actions.push(ClientFlags("+h".to_string(), vec![nick])

                        .send_all().in_room(r.id).action());

                }

            }

            new_id.map(|id| server.clients[id].is_master = true);

            server.react(client_id, actions);

        }

        RemoveTeam(name) => {

            let mut actions = Vec::new();

            if let (c, Some(r)) = server.client_and_room(client_id) {

                r.remove_team(&name);

                if let Some(ref mut info) = r.game_info {

                    info.left_teams.push(name.clone());

                }

                actions.push(TeamRemove(name.clone()).send_all().in_room(r.id).action());

                actions.push(SendRoomUpdate(None));

                if r.game_info.is_some() && c.is_in_game {

                    actions.push(SendTeamRemovalMessage(name));

                }

            }

            server.react(client_id, actions);

        },

        RemoveClientTeams => {

            let actions = if let (c, Some(r)) = server.client_and_room(client_id) {

                r.client_teams(c.id).map(|t| RemoveTeam(t.name.clone())).collect()

            } else {

                Vec::new()

            };

            server.react(client_id, actions);

        }

        SendRoomUpdate(old_name) => {

            let actions = if let (c, Some(r)) = server.client_and_room(client_id) {

                let name = old_name.unwrap_or_else(|| r.name.clone());

                vec![RoomUpdated(name, r.info(Some(&c)))

                    .send_all().with_protocol(r.protocol_number).action()]

            } else {

                Vec::new()

            };

            server.react(client_id, actions);

        },

        StartRoomGame(room_id) => {

            let actions = {

                let (room_clients, room_nicks): (Vec<_>, Vec<_>) = server.clients.iter()

                    .map(|(id, c)| (id, c.nick.clone())).unzip();

                let room = &mut server.rooms[room_id];

                if !room.has_multiple_clans() {

                    vec![Warn("The game can't be started with less than two clans!".to_string())]

                } else if room.game_info.is_some() {

                    vec![Warn("The game is already in progress".to_string())]

                } else {

                    room.start_round();

                    for id in room_clients {

                        let c = &mut server.clients[id];

                        c.is_in_game = true;

                        c.team_indices = room.client_team_indices(c.id);

                    }

                    vec![RunGame.send_all().in_room(room.id).action(),

                         SendRoomUpdate(None),

                         ClientFlags("+g".to_string(), room_nicks)

                             .send_all().in_room(room.id).action()]

                }

            };

            server.react(client_id, actions);

        }

        SendTeamRemovalMessage(team_name) => {

            let mut actions = Vec::new();

            if let (c, Some(r)) = server.client_and_room(client_id) {

                if let Some(ref mut info) = r.game_info {

                    let msg = once(b'F').chain(team_name.bytes());

                    actions.push(ForwardEngineMessage(vec![to_engine_msg(msg)]).

                        send_all().in_room(r.id).but_self().action());

                    info.teams_in_game -= 1;

                    if info.teams_in_game == 0 {

                        actions.push(FinishRoomGame(r.id));

                    }

                    let remove_msg = to_engine_msg(once(b'F').chain(team_name.bytes()));

                    }

                    actions.push(ForwardEngineMessage(vec![remove_msg])

                        .send_all().in_room(r.id).but_self().action());

                }

            }

            server.react(client_id, actions);

        }

        FinishRoomGame(room_id) => {

            let mut actions = Vec::new();

            let mut old_info = None;

            {

                let r = &mut server.rooms[room_id];

                swap(&mut old_info, &mut r.game_info);

                r.game_info = None;

                r.ready_players_number = 1;

                actions.push(SendRoomUpdate(None));

                actions.push(RoundFinished.send_all().in_room(r.id).action());

            }

            if let Some(info) = old_info {

                for (_, c) in server.clients.iter() {

                    if c.room_id == Some(room_id) && c.is_joined_mid_game {

                        actions.push(SendRoomData{

                            to: c.id, teams: false,

                            config: true, flags: false});

                        for name in info.left_teams.iter() {

                            actions.push(TeamRemove(name.clone())

                                .send(c.id).action());

                        }

                    }

                }