use mio;

use crate::{

    server::{

        server::HWServer,

        room::{HWRoom, RoomFlags},

        actions::{Action, Action::*}

    },

    protocol::messages::{

        HWProtocolMessage,

        HWServerMessage::*,

        server_chat

    },

    utils::is_name_illegal

};

use std::{

    mem::swap, fs::{File, OpenOptions},

    io::{Read, Write, Result, Error, ErrorKind}

};

use base64::{encode, decode};

use super::common::rnd_reply;

#[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";

#[cfg(canhazslicepatterns)]

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

    match msg {

        [size, typ, body..] => VALID_MESSAGES.contains(typ)

            && match body {

                _ => *typ != b'h'

            },

        _ => false

    }

}

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

    if let Some(typ) = msg.get(1) {

        VALID_MESSAGES.contains(typ)

    } else {

        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::RESTRICTED_UNREGISTERED_PLAYERS,

        _ => RoomFlags::empty()

    }

}

fn read_file(filename: &str) -> Result<String> {

    let mut reader = File::open(filename)?;

    let mut result = String::new();

    reader.read_to_string(&mut result)?;

    Ok(result)

}

fn write_file(filename: &str, content: &str) -> Result<()> {

    let mut writer = OpenOptions::new().create(true).write(true).open(filename)?;

    writer.write_all(content.as_bytes())

}

pub fn handle(server: &mut HWServer, client_id: ClientId, room_id: RoomId, message: HWProtocolMessage) {

    use crate::protocol::messages::HWProtocolMessage::*;

    match message {

        Part(None) => server.react(client_id, vec![

            MoveToLobby("part".to_string())]),

        Part(Some(msg)) => server.react(client_id, vec![

            MoveToLobby(format!("part: {}", msg))]),

        Chat(msg) => {

            let actions = {

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

                let chat_msg = ChatMsg {nick: c.nick.clone(), msg};

                vec![chat_msg.send_all().in_room(room_id).but_self().action()]

            };

            server.react(client_id, actions);

        },

        Fix => {

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

                if c.is_admin() { r.set_is_fixed(true) }

            }

        }

        Unfix => {

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

                if c.is_admin() { r.set_is_fixed(false) }

            }

        }

        Greeting(text) => {

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

                if c.is_admin() || c.is_master() && !r.is_fixed() {

                    r.greeting = text

                }

            }

        }

        RoomName(new_name) => {

            let actions =

                if is_name_illegal(&new_name) {

                    vec![Warn("Illegal room name! A room name must be between 1-40 characters long, must not have a trailing or leading space and must not have any of these characters: $()*+?[]^{|}".to_string())]

                } else if server.rooms[room_id].is_fixed() {

                    vec![Warn("Access denied.".to_string())]

                } else if server.has_room(&new_name) {

                    vec![Warn("A room with the same name already exists.".to_string())]

                } else {

                    let mut old_name = new_name.clone();

                    swap(&mut server.rooms[room_id].name, &mut old_name);

                    vec![SendRoomUpdate(Some(old_name))]

                };

            server.react(client_id, actions);

        },

        ToggleReady => {

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

                let flags = if c.is_ready() {

                    r.ready_players_number -= 1;

                    "-r"

                } else {

                    r.ready_players_number += 1;

                    "+r"

                };

                c.set_is_ready(!c.is_ready());

                let mut v =

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

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

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

                    v.push(StartRoomGame(r.id))

                }

                server.react(client_id, v);

            }

        }

        AddTeam(info) => {

            let mut actions = Vec::new();

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

                if r.teams.len() >= r.team_limit as usize {

                    actions.push(Warn("Too many teams!".to_string()))

                } else if r.addable_hedgehogs() == 0 {

                    actions.push(Warn("Too many hedgehogs!".to_string()))

                } else if r.find_team(|t| t.name == info.name) != None {

                    actions.push(Warn("There's already a team with same name in the list.".to_string()))

                } else if r.game_info.is_some() {

                    actions.push(Warn("Joining not possible: Round is in progress.".to_string()))

                } else if r.is_team_add_restricted() {

                    actions.push(Warn("This room currently does not allow adding new teams.".to_string()));

                } else {

                    let team = r.add_team(c.id, *info);

                    c.teams_in_game += 1;

                    c.clan = Some(team.color);

                    actions.push(TeamAccepted(team.name.clone())

                        .send_self().action());

                    actions.push(TeamAdd(HWRoom::team_info(&c, team))

                        .send_all().in_room(room_id).but_self().action());

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

                        .send_all().in_room(room_id).action());

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

                        .send_all().in_room(room_id).action());

                    actions.push(SendRoomUpdate(None));

                }

            }

            server.react(client_id, actions);

        },

        RemoveTeam(name) => {

            let mut actions = Vec::new();

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

                match r.find_team_owner(&name) {

                    None =>

                        actions.push(Warn("Error: The team you tried to remove does not exist.".to_string())),

                    Some((id, _)) if id != client_id =>

                        actions.push(Warn("You can't remove a team you don't own.".to_string())),

                    Some((_, name)) => {

                        c.teams_in_game -= 1;

                        c.clan = r.find_team_color(c.id);

                        actions.push(Action::RemoveTeam(name.to_string()));

                    }

                }

            };

            server.react(client_id, actions);

        },

        SetHedgehogsNumber(team_name, number) => {

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

                let addable_hedgehogs = r.addable_hedgehogs();

                let actions = if let Some((_, team)) = r.find_team_and_owner_mut(|t| t.name == team_name) {

                    if !c.is_master() {

                        vec![ProtocolError("You're not the room master!".to_string())]

                           || number > addable_hedgehogs + team.hedgehogs_number {

                        vec![HedgehogsNumber(team.name.clone(), team.hedgehogs_number)

                            .send_self().action()]

                    } else {

                        team.hedgehogs_number = number;

                        vec![HedgehogsNumber(team.name.clone(), number)

                            .send_all().in_room(room_id).but_self().action()]

                    }

                } else {

                    vec![(Warn("No such team.".to_string()))]

                };

                server.react(client_id, actions);

            }

        },

        SetTeamColor(team_name, color) => {

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

                let mut owner_id = None;

                let actions = if let Some((owner, team)) = r.find_team_and_owner_mut(|t| t.name == team_name) {

                    if !c.is_master() {

                        vec![ProtocolError("You're not the room master!".to_string())]

                    } else if false  {

                        Vec::new()

                    } else {

                        owner_id = Some(owner);

                        team.color = color;

                        vec![TeamColor(team.name.clone(), color)

                            .send_all().in_room(room_id).but_self().action()]

                    }

                } else {

                    vec![(Warn("No such team.".to_string()))]

                };

                if let Some(id) = owner_id {

                    server.clients[id].clan = Some(color);

                }

                server.react(client_id, actions);

            };

        },

        Cfg(cfg) => {

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

                let actions = if r.is_fixed() {

                    vec![Warn("Access denied.".to_string())]

                } else if !c.is_master() {

                    vec![ProtocolError("You're not the room master!".to_string())]

                } else {

                    let v = vec![cfg.to_server_msg()

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

                    r.set_config(cfg);

                    v

                };

                server.react(client_id, actions);

            }

        }

        Save(name, location) => {

            let actions = vec![server_chat(format!("Room config saved as {}", name))

                .send_all().in_room(room_id).action()];

            server.rooms[room_id].save_config(name, location);

            server.react(client_id, actions);

        }

        SaveRoom(filename) => {

            if server.clients[client_id].is_admin() {

                let actions = match server.rooms[room_id].get_saves() {

                    Ok(text) => match write_file(&filename, &text) {

                        Ok(_) => vec![server_chat("Room configs saved successfully.".to_string())

                            .send_self().action()],

                        Err(e) => {

                            warn!("Error while writing the config file \"{}\": {}", filename, e);

                            vec![Warn("Unable to save the room configs.".to_string())]

                        }

                    }

                    Err(e) => {

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

                        vec![Warn("Unable to serialize the room configs.".to_string())]

                    }

                };

                server.react(client_id, actions);

            }

        }

        LoadRoom(filename) => {

            if server.clients[client_id].is_admin() {

                let actions = match read_file(&filename) {

                    Ok(text) => match server.rooms[room_id].set_saves(&text) {

                        Ok(_) => vec![server_chat("Room configs loaded successfully.".to_string())

                            .send_self().action()],

                        Err(e) => {

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

                            vec![Warn("Unable to deserialize the room configs.".to_string())]

                        }

                    }

                    Err(e) => {

                        warn!("Error while reading the config file \"{}\": {}", filename, e);

                        vec![Warn("Unable to load the room configs.".to_string())]

                    }

                };

                server.react(client_id, actions);

            }

        }

        Delete(name) => {

            let actions = if !server.rooms[room_id].delete_config(&name) {

                vec![Warn(format!("Save doesn't exist: {}", name))]

            } else {

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

                    .send_all().in_room(room_id).action()]

            };

            server.react(client_id, actions);

        }

        CallVote(None) => {

            server.react(client_id, vec![

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

                    .send_self().action()])

        }

        CallVote(Some(kind)) => {

            let is_in_game = server.rooms[room_id].game_info.is_some();

            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<_> = server.rooms[room_id].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 server.rooms[room_id].saves.get(&name[..]).is_some() {

                        None

                    } else {

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

                    }

                },

                VoteType::Pause => {

                    if is_in_game {

                        None

                    } else {

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

                    }

                },

                VoteType::NewSeed => {

                    None

                },

                VoteType::HedgehogsPerTeam(number) => {

                    match number {

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

                    }

                },

            };

            match error {

                None => {

                    let msg = voting_description(&kind);

                    let voting = Voting::new(kind, server.room_clients(client_id));

                    server.rooms[room_id].voting = Some(voting);

                    server.react(client_id, vec![

                        server_chat(msg).send_all().in_room(room_id).action(),

                        AddVote{ vote: true, is_forced: false}]);

                }

                Some(msg) => {

                    server.react(client_id, vec![

                        server_chat(msg).send_self().action()])

                }

            }

        }

        Vote(vote) => {

            server.react(client_id, vec![AddVote{ vote, is_forced: false }]);

        }

        ForceVote(vote) => {

            let is_forced = server.clients[client_id].is_admin();

            server.react(client_id, vec![AddVote{ vote, is_forced }]);

        }

        ToggleRestrictJoin | ToggleRestrictTeams | ToggleRegisteredOnly  => {

            if server.clients[client_id].is_master() {

                server.rooms[room_id].flags.toggle(room_message_flag(&message));

            }

            server.react(client_id, vec![SendRoomUpdate(None)]);

        }

        StartGame => {

            server.react(client_id, vec![StartRoomGame(room_id)]);

        }

        EngineMessage(em) => {

            let mut actions = Vec::new();

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

                if c.teams_in_game > 0 {

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

                    let messages = by_msg(&decoding);

                    let valid = messages.filter(|m| is_msg_valid(m, &c.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() {

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

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

                    }

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

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

                        if !em_log.is_empty() {

                            info.msg_log.push(em_log);

                        }

                        if let Some(msg) = sync_msg {

                            info.sync_msg = msg;

                        }

                    }

                }

            }

            server.react(client_id, actions)

        }

        RoundFinished => {

            let mut actions = Vec::new();

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

                if c.is_in_game() {

                    c.set_is_in_game(false);

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

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

                    if r.game_info.is_some() {

                        for team in r.client_teams(c.id) {

                            actions.push(SendTeamRemovalMessage(team.name.clone()));

                        }

                    }

                }

            }

            server.react(client_id, actions)

        },

        Rnd(v) => {

            let result = rnd_reply(&v);

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

            echo.extend(v.into_iter());

            let chat_msg = ChatMsg {

                nick: server.clients[client_id].nick.clone(),

                msg: echo.join(" ")

            };

            server.react(client_id, vec![

                chat_msg.send_all().in_room(room_id).action(),

                result.send_all().in_room(room_id).action()])

        },

        _ => warn!("Unimplemented!")

    }

}