use crate::server::client::HWClient;

use crate::server::coretypes::ClientId;

use crate::server::room::HWRoom;

use crate::utils::to_engine_msg;

use crate::{

    protocol::messages::{

        HWProtocolMessage::{self, Rnd},

        HWServerMessage::{

            self, Bye, ChatMsg, ClientFlags, ForwardEngineMessage, LobbyJoined, LobbyLeft, Notice,

            RoomLeft, RoomRemove, RoomUpdated, Rooms, ServerMessage, TeamRemove,

        },

    },

    server::{actions::Action, core::HWServer},

};

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

use std::iter::once;

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

    let mut rng = thread_rng();

    let reply = if options.is_empty() {

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

    } else {

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

    };

    ChatMsg {

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

        msg: reply.clone(),

    }

}

pub fn process_login(server: &mut HWServer, response: &mut super::Response) {

    let client_id = response.client_id();

    let nick = server.clients[client_id].nick.clone();

    let has_nick_clash = server

        .clients

        .iter()

        .any(|(id, c)| id != client_id && c.nick == nick);

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

    if !client.is_checker() && has_nick_clash {

        if client.protocol_number < 38 {

            remove_client(server, response, "Nickname is already in use".to_string());

        } else {

            client.nick.clear();

            response.add(Notice("NickAlreadyInUse".to_string()).send_self());

        }

    } else {

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

        let lobby_nicks: Vec<_> = server

            .clients

            .iter()

            .filter_map(|(_, c)| c.room_id.and(Some(c.nick.clone())))

            .collect();

        let 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(),

        );

        response.add(everyone_msg.send_all().but_self());

        response.add(joined_msg.send_self());

        response.add(flags_msg.send_self());

        response.add(server_msg.send_self());

        response.add(rooms_msg.send_self());

    }

}

pub fn remove_teams(

    room: &mut HWRoom,

    team_names: Vec<String>,

    is_in_game: bool,

    response: &mut super::Response,

) {

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

        for team_name in &team_names {

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

            if is_in_game {

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

                response.add(

                    ForwardEngineMessage(vec![to_engine_msg(msg)])

                        .send_all()

                        .in_room(room.id)

                        .but_self(),

                );

                info.teams_in_game -= 1;

                if info.teams_in_game == 0 {

                    //FinishRoomGame(room.id)

                }

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

                if let Some(m) = &info.sync_msg {

                    info.msg_log.push(m.clone());

                    info.sync_msg = None

                }

                info.msg_log.push(remove_msg.clone());

                response.add(

                    ForwardEngineMessage(vec![remove_msg])

                        .send_all()

                        .in_room(room.id)

                        .but_self(),

                );

            }

        }

    }

    for team_name in team_names {

        room.remove_team(&team_name);

        response.add(TeamRemove(team_name).send_all().in_room(room.id));

    }

}

pub fn exit_room(client: &HWClient, room: &mut HWRoom, response: &mut super::Response, msg: &str) {

    if room.players_number > 1 || room.is_fixed() {

        room.players_number -= 1;

        if client.is_ready() && room.ready_players_number > 0 {

            room.ready_players_number -= 1;

        }

        let team_names: Vec<_> = room

            .client_teams(client.id)

            .map(|t| t.name.clone())

            .collect();

        remove_teams(room, team_names, client.is_in_game(), response);

        if room.players_number > 0 {

            response.add(

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

                    .send_all()

                    .in_room(room.id)

                    .but_self(),

            );

        }

        //ChangeMaster(room.id, None));

    }

    let update_msg = if room.players_number == 0 && !room.is_fixed() {

        RoomRemove(room.name.clone())

    } else {

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

    };

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

    response.add(ClientFlags("-i".to_string(), vec![client.nick.clone()]).send_all());

}

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

    let client_id = response.client_id();

    let lobby_id = server.lobby_id;

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

    let (nick, room_id) = (client.nick.clone(), client.room_id);

    if let Some(room_id) = room_id {

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

        exit_room(client, room, response, &msg);

        client.room_id = Some(lobby_id);

    }

    server.remove_client(client_id);

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

    response.add(Bye("User quit: ".to_string() + &msg).send_self());

}

#[cfg(test)]

mod tests {

    use super::*;

    use crate::protocol::messages::HWServerMessage::ChatMsg;

    use crate::server::actions::PendingMessage;

    fn reply2string(r: HWServerMessage) -> String {

        match r {

            ChatMsg { msg: p, .. } => String::from(p),

            _ => panic!("expected a ChatMsg"),

        }

    }

    fn run_handle_test(opts: Vec<String>) {

        let opts2 = opts.clone();

        for opt in opts {

            while reply2string(rnd_reply(&opts2)) != opt {}

        }

    }

    /// This test terminates almost surely.

    #[test]

    fn test_handle_rnd_empty() {

        run_handle_test(vec![])

    }

    /// This test terminates almost surely.

    #[test]

    fn test_handle_rnd_nonempty() {

        run_handle_test(vec!["A".to_owned(), "B".to_owned(), "C".to_owned()])

    }

    /// This test terminates almost surely (strong law of large numbers)

    #[test]

    fn test_distribution() {

        let eps = 0.000001;

        let lim = 0.5;

        let opts = vec![0.to_string(), 1.to_string()];

        let mut ones = 0;

        let mut tries = 0;

        while tries < 1000 || ((ones as f64 / tries as f64) - lim).abs() >= eps {

            tries += 1;

            if reply2string(rnd_reply(&opts)) == 1.to_string() {

                ones += 1;

            }

        }

    }

}