use mio;

use protocol::messages::{

    HWProtocolMessage,

    HWServerMessage::*

};

use server::{

    server::HWServer,

    client::ClientId,

    room::HWRoom,

    actions::{Action, Action::*}

};

use utils::is_name_illegal;

use std::mem::swap;

use base64::{encode, decode};

#[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: &Vec<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 {

                [1...8, team, ..] if *typ == b'h' => team_indices.contains(team),

                _ => *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()

}

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

    use 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];

                if let Some(room_id) = c.room_id {

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

                } else {

                    Vec::new()

                }

            };

            server.react(client_id, actions);

        },

        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.has_room(&new_name) {

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

                } else {

                    let mut old_name = new_name.clone();

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

                        swap(&mut r.name, &mut old_name);

                        vec![SendRoomUpdate(Some(old_name))]

                    } else {

                        Vec::new()

                    }

                };

            server.react(client_id, actions);

        },

        ToggleReady => {

            let actions = 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.is_ready = !c.is_ready;

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

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

            } else {

                Vec::new()

            };

            server.react(client_id, actions);

        }

        AddTeam(info) => {

            let mut actions = Vec::new();

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

                let room_id = r.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 {

                    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) => {

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

                let room_id = r.id;

                let addable_hedgehogs = r.addable_hedgehogs();

                if let Some((_, mut 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 number < 1 || number > 8

                           || 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()))]

                }

            } else {

                Vec::new()

            };

            server.react(client_id, actions);

        },

        SetTeamColor(team_name, color) => {

            let mut owner_id = None;

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

                let room_id = r.id;

                if let Some((owner, mut 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()))]

                }

            } else {

                Vec::new()

            };

            if let Some(id) = owner_id {

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

            }

            server.react(client_id, actions);

        },

        Cfg(cfg) => {

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

                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

                }

            } else {

                Vec::new()

            };

            server.react(client_id, actions);

        }

        StartGame => {

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

                vec![StartRoomGame(r.id)]

            } else {

                Vec::new()

            };

            server.react(client_id, actions);

        }

        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.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)

        _ => warn!("Unimplemented!")

    }

}