use crate::{

    core::{

        client::HwClient,

        room::HwRoom,

        server::{

            EndGameResult, HwRoomControl, HwServer, JoinRoomError, LeaveRoomResult, StartGameError,

            VoteError, VoteResult,

        },

    },

        add_flags, remove_flags, server_chat,

        HwProtocolMessage::{self, Rnd},

        HwServerMessage::{self, *},

        ProtocolFlags as Flags,

    },

};

use rand::{self, seq::SliceRandom, thread_rng, Rng};

use std::{iter::once, mem::replace};

pub fn rnd_reply(options: &[String]) -> HwServerMessage {

    let mut rng = thread_rng();

    let reply = if options.is_empty() {

        (*&["heads", "tails"].choose(&mut rng).unwrap()).to_string()

    } else {

        options.choose(&mut rng).unwrap().clone()

    };

    ChatMsg {

        nick: "[random]".to_string(),

        msg: reply,

    }

}

pub fn get_lobby_join_data(server: &HwServer, response: &mut Response) {

    let client_id = response.client_id();

    let client = server.client(client_id);

    let nick = vec![client.nick.clone()];

    let mut flags = vec![];

    if client.is_registered() {

        flags.push(Flags::Registered)

    }

    if client.is_admin() {

        flags.push(Flags::Admin)

    }

    if client.is_contributor() {

        flags.push(Flags::Contributor)

    }

    let all_nicks: Vec<_> = server.collect_nicks(|_| true);

    let mut flag_selectors = [

        (

            Flags::Registered,

            server.collect_nicks(|(_, c)| c.is_registered()),

        ),

        (Flags::Admin, server.collect_nicks(|(_, c)| c.is_admin())),

        (

            Flags::Contributor,

            server.collect_nicks(|(_, c)| c.is_contributor()),

        ),

        (

            Flags::InRoom,

            server.collect_nicks(|(_, c)| c.room_id.is_some()),

        ),

    ];

    let server_msg = ServerMessage(server.get_greetings(client).to_string());

    let rooms_msg = Rooms(

        server

            .iter_rooms()

            .filter(|r| r.protocol_number == client.protocol_number)

            .flat_map(|r| r.info(r.master_id.map(|id| server.client(id))))

            .collect(),

    );

    response.add(LobbyJoined(nick).send_all().but_self());

    response.add(

        ClientFlags(add_flags(&flags), all_nicks.clone())

            .send_all()

            .but_self(),

    );

    response.add(LobbyJoined(all_nicks).send_self());

    for (flag, nicks) in &mut flag_selectors {

        if !nicks.is_empty() {

            response.add(ClientFlags(add_flags(&[*flag]), replace(nicks, vec![])).send_self());

        }

    }

    response.add(server_msg.send_self());

    response.add(rooms_msg.send_self());

}

pub fn get_room_join_data<'a, I: Iterator<Item = &'a HwClient> + Clone>(

    client: &HwClient,

    room: &HwRoom,

    room_clients: I,

    response: &mut Response,

) {

    #[inline]

    fn partition_nicks<'a, I, F>(clients: I, f: F) -> (Vec<String>, Vec<String>)

    where

        I: Iterator<Item = &'a HwClient> + Clone,

        F: Fn(&&'a HwClient) -> bool,

    {

        (

            clients

                .clone()

                .filter(|c| f(c))

                .map(|c| &c.nick)

                .cloned()

                .collect(),

            clients

                .filter(|c| !f(c))

                .map(|c| &c.nick)

                .cloned()

                .collect(),

        )

    }

    let nick = client.nick.clone();

    response.add(

        RoomJoined(vec![nick.clone()])

            .send_all()

            .in_room(room.id)

            .but_self(),

    );

    response.add(ClientFlags(add_flags(&[Flags::InRoom]), vec![nick.clone()]).send_all());

    let nicks = room_clients.clone().map(|c| c.nick.clone()).collect();

    response.add(RoomJoined(nicks).send_self());

    let mut flag_selectors = [

        (

            Flags::RoomMaster,

            partition_nicks(room_clients.clone(), |c| c.is_master()),

        ),

        (

            Flags::Ready,

            partition_nicks(room_clients.clone(), |c| c.is_ready()),

        ),

        (

            Flags::InGame,

            partition_nicks(room_clients.clone(), |c| c.is_in_game()),

        ),

    ];

    for (flag, (set_nicks, cleared_nicks)) in &mut flag_selectors {

        if !set_nicks.is_empty() {

            response.add(ClientFlags(add_flags(&[*flag]), replace(set_nicks, vec![])).send_self());

        }

        if !cleared_nicks.is_empty() {

            response.add(

                ClientFlags(remove_flags(&[*flag]), replace(cleared_nicks, vec![])).send_self(),

            );

        }

    }

    get_active_room_teams(room, Destination::ToSelf, response);

    get_active_room_config(room, Destination::ToSelf, response);

    if !room.greeting.is_empty() {

        response.add(

            ChatMsg {

                nick: "[greeting]".to_string(),

                msg: room.greeting.clone(),

            }

            .send_self(),

        );

    }

    if let Some(info) = &room.game_info {

        response.add(

            ClientFlags(add_flags(&[Flags::Ready, Flags::InGame]), vec![nick])

                .send_all()

                .in_room(room.id),

        );

        response.add(RunGame.send_self());

        response.add(

            ForwardEngineMessage(

                once(to_engine_msg("e$spectate 1".bytes()))

                    .chain(info.msg_log.iter().cloned())

                    .collect(),

            )

            .send_self(),

        );

        for team in info.client_teams(client.id) {

            response.add(

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

                    .send_all()

                    .in_room(room.id),

            );

        }

        if info.is_paused {

            response.add(ForwardEngineMessage(vec![to_engine_msg(once(b'I'))]).send_self());

        }

        for (_, original_team) in &info.original_teams {

            if let Some(team) = room.find_team(|team| team.name == original_team.name) {

                if team != original_team {

                    response.add(TeamRemove(original_team.name.clone()).send_self());

                    response.add(TeamAdd(team.to_protocol()).send_self());

                }

            } else {

                response.add(TeamRemove(original_team.name.clone()).send_self());

            }

        }

        for (_, team) in &room.teams {

            if !info.original_teams.iter().any(|(_, t)| t.name == team.name) {

                response.add(TeamAdd(team.to_protocol()).send_self());

            }

        }

        get_room_config_impl(room.config(), Destination::ToSelf, response);

    }

}

pub fn get_room_join_error(error: JoinRoomError, response: &mut Response) {

    use super::strings::*;

    match error {

        JoinRoomError::DoesntExist => response.warn(NO_ROOM),

        JoinRoomError::WrongProtocol => response.warn(INCOMPATIBLE_ROOM_PROTOCOL),

        JoinRoomError::WrongPassword => {

            response.add(Notice("WrongPassword".to_string()).send_self())

        }

        JoinRoomError::Full => response.warn(ROOM_FULL),

        JoinRoomError::Restricted => response.warn(ROOM_JOIN_RESTRICTED),

        JoinRoomError::RegistrationRequired => response.warn(ROOM_REGISTRATION_REQUIRED),

    }

}

pub fn get_remove_teams_data(

    room_id: RoomId,

    was_in_game: bool,

    removed_teams: Vec<String>,

    response: &mut Response,

) {

    if was_in_game {

        for team_name in &removed_teams {

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

            response.add(

                ForwardEngineMessage(vec![remove_msg])

                    .send_all()

                    .in_room(room_id)

                    .but_self(),

            );

        }

    } else {

        for team_name in removed_teams {

            response.add(TeamRemove(team_name).send_all().in_room(room_id));

        }

    }

}

pub fn get_room_leave_result(

    server: &HwServer,

    room: &HwRoom,

    leave_message: &str,

    result: LeaveRoomResult,

    response: &mut Response,

) {

    let client = server.client(response.client_id);

    response.add(ClientFlags(remove_flags(&[Flags::InRoom]), vec![client.nick.clone()]).send_all());

    match result {

        LeaveRoomResult::RoomRemoved => {

            response.add(

                RoomRemove(room.name.clone())

                    .send_all()

                    .with_protocol(room.protocol_number),

            );

        }

        LeaveRoomResult::RoomRemains {

            is_empty,

            was_master,

            new_master,

            was_in_game,

            removed_teams,

        } => {

            if !is_empty {

                response.add(

                    RoomLeft(client.nick.clone(), leave_message.to_string())

                        .send_all()

                        .in_room(room.id)

                        .but_self(),

                );

            }

            if was_master {

                response.add(

                    ClientFlags(

                        remove_flags(&[Flags::RoomMaster]),

                        vec![client.nick.clone()],

                    )

                    .send_all()

                    .in_room(room.id),

                );

                if let Some(new_master_id) = new_master {

                    let new_master_nick = server.client(new_master_id).nick.clone();

                    response.add(

                        ClientFlags(add_flags(&[Flags::RoomMaster]), vec![new_master_nick])

                            .send_all()

                            .in_room(room.id),

                    );

                }

            }

            get_remove_teams_data(room.id, was_in_game, removed_teams, response);

            response.add(

                RoomUpdated(room.name.clone(), room.info(Some(&client)))

                    .send_all()

                    .with_protocol(room.protocol_number),

            );

        }

    }

}

pub fn remove_client(server: &mut HwServer, response: &mut Response, msg: String) {

    let client_id = response.client_id();

    let client = server.client(client_id);

    let nick = client.nick.clone();

    if let Some(mut room_control) = server.get_room_control(client_id) {

        let room_id = room_control.room().id;

        let result = room_control.leave_room();

        get_room_leave_result(server, server.room(room_id), &msg, result, response);

    }

    server.remove_client(client_id);

    response.add(LobbyLeft(nick, msg.clone()).send_all());

    response.add(Bye(msg).send_self());

    response.remove_client(client_id);

}

pub fn get_room_update(

    room_name: Option<String>,

    room: &HwRoom,

    master: Option<&HwClient>,

    response: &mut Response,

) {

    let update_msg = RoomUpdated(room_name.unwrap_or(room.name.clone()), room.info(master));

    response.add(update_msg.send_all().with_protocol(room.protocol_number));

}

pub fn get_room_config_impl(

    config: &RoomConfig,

    destination: Destination,

    response: &mut Response,

) {

    response.add(

        ConfigEntry("FULLMAPCONFIG".to_string(), config.to_map_config())

            .send_to_destination(destination.clone()),

    );

    for cfg in config.to_game_config() {

        response.add(cfg.to_server_msg().send_to_destination(destination.clone()));

    }

}

pub fn get_active_room_config(room: &HwRoom, destination: Destination, response: &mut Response) {

    get_room_config_impl(room.active_config(), destination, response);

}

pub fn get_teams<'a, I>(teams: I, destination: Destination, response: &mut Response)

where

    I: Iterator<Item = &'a TeamInfo>,

{

    for team in teams {

        response.add(TeamAdd(team.to_protocol()).send_to_destination(destination.clone()));

        response

            .add(TeamColor(team.name.clone(), team.color).send_to_destination(destination.clone()));

        response.add(

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

                .send_to_destination(destination.clone()),

        );

    }

}

pub fn get_active_room_teams(room: &HwRoom, destination: Destination, response: &mut Response) {

    let current_teams = match room.game_info {

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

        None => &room.teams,

    };

    get_teams(current_teams.iter().map(|(_, t)| t), destination, response);

}

pub fn get_room_flags(

    server: &HwServer,

    room_id: RoomId,

    destination: Destination,

    response: &mut Response,

) {

    let room = server.room(room_id);

    if let Some(id) = room.master_id {

        response.add(

            ClientFlags(

                add_flags(&[Flags::RoomMaster]),

                vec![server.client(id).nick.clone()],

            )

            .send_to_destination(destination.clone()),

        );

    }

    let nicks = server.collect_nicks(|(_, c)| c.room_id == Some(room_id) && c.is_ready());

    if !nicks.is_empty() {

        response

            .add(ClientFlags(add_flags(&[Flags::Ready]), nicks).send_to_destination(destination));

    }

}

pub fn check_vote(

    server: &HwServer,

    room: &HwRoom,

    kind: &VoteType,

    response: &mut Response,

) -> bool {

    let error = match &kind {

        VoteType::Kick(nick) => {

            if server

                .find_client(&nick)

                .filter(|c| c.room_id == Some(room.id))

                .is_some()

            {

                None

            } else {

                Some("/callvote kick: No such user!".to_string())

            }

        }

        VoteType::Map(None) => {

            let names: Vec<_> = room.saves.keys().cloned().collect();

            if names.is_empty() {

                Some("/callvote map: No maps saved in this room!".to_string())

            } else {

                Some(format!("Available maps: {}", names.join(", ")))

            }

        }

        VoteType::Map(Some(name)) => {

            if room.saves.get(&name[..]).is_some() {

                None

            } else {

                Some("/callvote map: No such map!".to_string())

            }

        }

        VoteType::Pause => {

            if room.game_info.is_some() {

                None

            } else {

                Some("/callvote pause: No game in progress!".to_string())

            }

        }

        VoteType::NewSeed => None,

        VoteType::HedgehogsPerTeam(number) => match number {

            1..=MAX_HEDGEHOGS_PER_TEAM => None,

            _ => Some("/callvote hedgehogs: Specify number from 1 to 8.".to_string()),

        },

    };

    match error {

        None => true,

        Some(msg) => {

            response.add(server_chat(msg).send_self());

            false

        }