use super::{common::rnd_reply, strings::*};

use crate::core::room::GameInfo;

use crate::core::server::{AddTeamError, SetTeamCountError};

use crate::{

    core::{

        room::{HwRoom, RoomFlags, MAX_TEAMS_IN_ROOM},

        server::{

            ChangeMasterError, ChangeMasterResult, HwRoomControl, HwServer, LeaveRoomResult,

            ModifyTeamError, StartGameError,

        },

        types,

        types::{ClientId, GameCfg, RoomId, VoteType, Voting, MAX_HEDGEHOGS_PER_TEAM},

    },

    protocol::messages::{

        add_flags, remove_flags, server_chat, HwProtocolMessage, HwServerMessage::*,

        ProtocolFlags as Flags,

    },

    utils::{is_name_illegal, to_engine_msg},

};

use base64::{decode, encode};

use log::*;

use std::{cmp::min, iter::once, mem::swap};

#[derive(Clone)]

struct ByMsg<'a> {

    messages: &'a [u8],

}

impl<'a> Iterator for ByMsg<'a> {

    type Item = &'a [u8];

    fn next(&mut self) -> Option<<Self as Iterator>::Item> {

        if let Some(size) = self.messages.get(0) {

            let (msg, next) = self.messages.split_at(*size as usize + 1);

            self.messages = next;

            Some(msg)

        } else {

            None

        }

    }

}

fn by_msg(source: &[u8]) -> ByMsg {

    ByMsg { messages: source }

}

const VALID_MESSAGES: &[u8] =

    b"M#+LlRrUuDdZzAaSjJ,NpPwtgfhbc12345\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8A";

const NON_TIMED_MESSAGES: &[u8] = b"M#hb";

fn is_msg_valid(msg: &[u8], team_indices: &[u8]) -> bool {

    match msg {

        [size, typ, body @ ..] => {

            VALID_MESSAGES.contains(typ)

                && match body {

                    [1..=MAX_HEDGEHOGS_PER_TEAM, team, ..] if *typ == b'h' => {

                        team_indices.contains(team)

                    }

                    _ => *typ != b'h',

                }

        }

        _ => false,

    }

}

fn is_msg_empty(msg: &[u8]) -> bool {

    msg.get(1).filter(|t| **t == b'+').is_some()

}

fn is_msg_timed(msg: &[u8]) -> bool {

    msg.get(1)

        .filter(|t| !NON_TIMED_MESSAGES.contains(t))

        .is_some()

}

fn voting_description(kind: &VoteType) -> String {

    format!(

        "New voting started: {}",

        match kind {

            VoteType::Kick(nick) => format!("kick {}", nick),

            VoteType::Map(name) => format!("map {}", name.as_ref().unwrap()),

            VoteType::Pause => "pause".to_string(),

            VoteType::NewSeed => "new seed".to_string(),

            VoteType::HedgehogsPerTeam(number) => format!("hedgehogs per team: {}", number),

        }

    )

}

fn room_message_flag(msg: &HwProtocolMessage) -> RoomFlags {

    use crate::protocol::messages::HwProtocolMessage::*;

    match msg {

        ToggleRestrictJoin => RoomFlags::RESTRICTED_JOIN,

        ToggleRestrictTeams => RoomFlags::RESTRICTED_TEAM_ADD,

        ToggleRegisteredOnly => RoomFlags::REGISTRATION_REQUIRED,

        _ => RoomFlags::empty(),

    }

}

pub fn handle(

    mut room_control: HwRoomControl,

    response: &mut super::Response,

    message: HwProtocolMessage,

) {

    let (client, room) = room_control.get();

    let (client_id, room_id) = (client.id, room.id);

    use crate::protocol::messages::HwProtocolMessage::*;

    match message {

        Part(msg) => {

            let msg = match msg {

                Some(s) => format!("part: {}", s),

                None => "part".to_string(),

            };

            let result = room_control.leave_room();

            super::common::get_room_leave_result(

                room_control.server(),

                room_control.room(),

                &msg,

                result,

                response,

            );

            room_control.cleanup_room();

        }

        Chat(msg) => {

            response.add(

                ChatMsg {

                    nick: client.nick.clone(),

                    msg,

                }

                .send_all()

                .in_room(room_id),

            );

        }

        TeamChat(msg) => {

            if room.game_info.is_some() {

                if let Some(clan_color) = room.find_team_color(client_id) {

                    let engine_msg =

                        to_engine_msg(format!("b{}]{}\x20\x20", client.nick, msg).bytes());

                    let team = room.clan_team_owners(clan_color).collect();

                    response.add(ForwardEngineMessage(vec![engine_msg]).send_many(team))

                }

            }

        }

        Fix => {

            if let Err(_) = room_control.fix_room() {

                response.warn(ACCESS_DENIED)

            }

        }

        Unfix => {

            if let Err(_) = room_control.unfix_room() {

                response.warn(ACCESS_DENIED)

            }

        }

        Greeting(text) => {

            if let Err(_) = room_control.set_room_greeting(text) {

                response.warn(ACCESS_DENIED)

            }

        }

        MaxTeams(count) => {

            use crate::core::server::SetTeamCountError;

            match room_control.set_room_max_teams(count) {

                Ok(()) => {}

                Err(SetTeamCountError::NotMaster) => response.warn(NOT_MASTER),

                Err(SetTeamCountError::InvalidNumber) => {

                    response.warn("/maxteams: specify number from 2 to 8")

                }

            };

        }

        RoomName(new_name) => {

            use crate::core::server::ModifyRoomNameError;

            match room_control.set_room_name(new_name) {

                Ok(old_name) => {

                    let (client, room) = room_control.get();

                    super::common::get_room_update(Some(old_name), room, Some(client), response)

                }

                Err(ModifyRoomNameError::AccessDenied) => response.warn(ACCESS_DENIED),

                Err(ModifyRoomNameError::InvalidName) => response.warn(ILLEGAL_ROOM_NAME),

                Err(ModifyRoomNameError::DuplicateName) => response.warn(ROOM_EXISTS),

            }

        }

        ToggleReady => {

            let flags = if room_control.toggle_ready() {

                add_flags(&[Flags::Ready])

            } else {

                remove_flags(&[Flags::Ready])

            };

            let (client, room) = room_control.get();

            let msg = if client.protocol_number < 38 {

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

            } else {

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

            };

            response.add(msg.send_all().in_room(room_id));

            if room.is_fixed() && room.ready_players_number == room.players_number {

                let result = room_control.start_game();

                super::common::get_start_game_data(

                    room_control.server(),

                    room_id,

                    result,

                    response,

                );

            }

        }

        AddTeam(info) => {

            use crate::core::server::AddTeamError;

            match room_control.add_team(info) {

                Ok(team) => {

                    response.add(TeamAccepted(team.name.clone()).send_self());

                    response.add(

                        TeamAdd(team.to_protocol())

                            .send_all()

                            .in_room(room_id)

                            .but_self(),

                    );

                    response.add(

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

                            .send_all()

                            .in_room(room_id),

                    );

                    response.add(

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

                            .send_all()

                            .in_room(room_id),

                    );

                    let room = room_control.room();

                    let room_master = room.master_id.map(|id| room_control.server().client(id));

                    super::common::get_room_update(None, room, room_master, response);

                }

                Err(AddTeamError::TooManyTeams) => response.warn(TOO_MANY_TEAMS),

                Err(AddTeamError::TooManyHedgehogs) => response.warn(TOO_MANY_HEDGEHOGS),

                Err(AddTeamError::TeamAlreadyExists) => response.warn(TEAM_EXISTS),

                Err(AddTeamError::GameInProgress) => response.warn(ROUND_IN_PROGRESS),

                Err(AddTeamError::Restricted) => response.warn(TEAM_ADD_RESTRICTED),

            }

        }

        RemoveTeam(name) => {

            use crate::core::server::RemoveTeamError;

            match room_control.remove_team(&name) {

                Ok(()) => {

                    let (client, room) = room_control.get();

                    let removed_teams = vec![name];

                    super::common::get_remove_teams_data(room_id, false, removed_teams, response);

                }

                Err(RemoveTeamError::NoTeam) => response.warn(NO_TEAM_TO_REMOVE),

                Err(RemoveTeamError::TeamNotOwned) => response.warn(TEAM_NOT_OWNED),

            }

        }

        SetHedgehogsNumber(team_name, number) => {

            use crate::core::server::SetHedgehogsError;

            match room_control.set_team_hedgehogs_number(&team_name, number) {

                Ok(()) => {

                    response.add(

                        HedgehogsNumber(team_name.clone(), number)

                            .send_all()

                            .in_room(room_id)

                            .but_self(),

                    );

                }

                Err(SetHedgehogsError::NotMaster) => response.error(NOT_MASTER),

                Err(SetHedgehogsError::NoTeam) => response.warn(NO_TEAM),

                Err(SetHedgehogsError::InvalidNumber(previous_number)) => {

                    response.add(HedgehogsNumber(team_name.clone(), previous_number).send_self())

                }

            }

        }

        SetTeamColor(team_name, color) => match room_control.set_team_color(&team_name, color) {

            Ok(()) => response.add(

                TeamColor(team_name, color)

                    .send_all()

                    .in_room(room_id)

                    .but_self(),

            ),

            Err(ModifyTeamError::NoTeam) => response.warn(NO_TEAM),

            Err(ModifyTeamError::NotMaster) => response.error(NOT_MASTER),

        },

        Cfg(cfg) => {

            use crate::core::server::SetConfigError;

            let msg = cfg.to_server_msg();

            match room_control.set_config(cfg) {

                Ok(()) => {

                    response.add(msg.send_all().in_room(room_control.room().id).but_self());

                }

                Err(SetConfigError::NotMaster) => response.error(NOT_MASTER),

                Err(SetConfigError::RoomFixed) => response.warn(ACCESS_DENIED),

            }

        }

        Save(name, location) => {

            response.add(

                server_chat(format!("Room config saved as {}", name))

                    .send_all()

                    .in_room(room_id),

            );

            room_control.save_config(name, location);

        }

        #[cfg(feature = "official-server")]

        SaveRoom(filename) => {

            if client.is_admin() {

                match room.get_saves() {

                    Ok(contents) => response.request_io(super::IoTask::SaveRoom {

                        room_id,

                        filename,

                        contents,

                    }),

                    Err(e) => {

                        warn!("Error while serializing the room configs: {}", e);

                        response.warn("Unable to serialize the room configs.")

                    }

                }

            }

        }

        #[cfg(feature = "official-server")]

        LoadRoom(filename) => {

            if client.is_admin() {

                response.request_io(super::IoTask::LoadRoom { room_id, filename });

            }

        }

        Delete(name) => {

            if !room_control.delete_config(&name) {

                response.add(Warning(format!("Save doesn't exist: {}", name)).send_self());

            } else {

                response.add(

                    server_chat(format!("Room config {} has been deleted", name))

                        .send_all()

                        .in_room(room_id),

                );

            }

        }

        CallVote(None) => {

            response.add(server_chat("Available callvote commands: kick <nickname>, map <name>, pause, newseed, hedgehogs <number>".to_string())

                .send_self());

        }

        CallVote(Some(kind)) => {

            use crate::core::server::StartVoteError;

            let room_id = room_control.room().id;

            if super::common::check_vote(

                room_control.server(),

                room_control.room(),

                &kind,

                response,

            ) {

                match room_control.start_vote(kind.clone()) {

                    Ok(()) => {

                        let msg = voting_description(&kind);

                        response.add(server_chat(msg).send_all().in_room(room_id));

                        let vote_result = room_control.vote(types::Vote {

                            is_pro: true,

                            is_forced: false,

                        });

                        super::common::handle_vote(room_control, vote_result, response);

                    }

                    Err(StartVoteError::VotingInProgress) => {

                        response.add(

                            server_chat("There is already voting in progress".to_string())

                                .send_self(),

                        );

                    }

                }

            }

        }

        Vote(vote) => {

            let vote_result = room_control.vote(types::Vote {

                is_pro: vote,

                is_forced: false,

            });

            super::common::handle_vote(room_control, vote_result, response);

        }

        ForceVote(vote) => {

            let is_forced = client.is_admin();

            let vote_result = room_control.vote(types::Vote {

                is_pro: vote,

                is_forced,

            });

            super::common::handle_vote(room_control, vote_result, response);

        }

        ToggleRestrictJoin | ToggleRestrictTeams | ToggleRegisteredOnly => {

            if room_control.toggle_flag(room_message_flag(&message)) {

                let (client, room) = room_control.get();

                super::common::get_room_update(None, room, Some(&client), response);

            }

        }

        StartGame => {

            let result = room_control.start_game();

            super::common::get_start_game_data(room_control.server(), room_id, result, response);

        }

        EngineMessage(em) => {

            if client.teams_in_game > 0 {

                let decoding = decode(&em[..]).unwrap();

                let messages = by_msg(&decoding);

                let valid = messages.filter(|m| is_msg_valid(m, &client.team_indices));

                let non_empty = valid.clone().filter(|m| !is_msg_empty(m));

                let sync_msg = valid.clone().filter(|m| is_msg_timed(m)).last().map(|m| {

                    if is_msg_empty(m) {

                        Some(encode(m))

                    } else {

                        None

                    }

                });

                let em_response = encode(&valid.flat_map(|msg| msg).cloned().collect::<Vec<_>>());

                if !em_response.is_empty() {

                    response.add(

                        ForwardEngineMessage(vec![em_response])

                            .send_all()

                            .in_room(room.id)

                            .but_self(),

                    );

                }

                let em_log = encode(&non_empty.flat_map(|msg| msg).cloned().collect::<Vec<_>>());

                room_control.log_engine_msg(em_log, sync_msg);

            }

        }

        RoundFinished => {

            if let Some(team_names) = room_control.leave_game() {

                let (client, room) = room_control.get();

                response.add(

                    ClientFlags(remove_flags(&[Flags::InGame]), vec![client.nick.clone()])

                        .send_all()

                        .in_room(room.id),

                );

                for team_name in team_names {

                    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(),

                    );

                }

                if let Some(0) = room.teams_in_game() {

                    if let Some(result) = room_control.end_game() {

                        super::common::get_end_game_result(

                            room_control.server(),

                            room_id,

                            result,

                            response,

                        );

                    }

                }

            }

        }

        Rnd(v) => {

            let result = rnd_reply(&v);

            let mut echo = vec!["/rnd".to_string()];

            echo.extend(v.into_iter());

            let chat_msg = ChatMsg {

                nick: client.nick.clone(),

                msg: echo.join(" "),

            };

            response.add(chat_msg.send_all().in_room(room_id));

            response.add(result.send_all().in_room(room_id));

        }

        Delegate(nick) => match room_control.change_master(nick) {

            Ok(ChangeMasterResult {

                old_master_id,

                new_master_id,

            }) => {

                if let Some(master_id) = old_master_id {

                    response.add(

                        ClientFlags(

                            remove_flags(&[Flags::RoomMaster]),

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

                        )

                        .send_all()

                        .in_room(room_id),

                    );

                }

                response.add(

                    ClientFlags(

                        add_flags(&[Flags::RoomMaster]),

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

                    )

                    .send_all()

                    .in_room(room_id),

                );