package net.lax1dude.eaglercraft.sp;

import net.minecraft.server.MinecraftServer;
import net.minecraft.src.EntityPlayerMP;
import net.minecraft.src.Packet250CustomPayload;

import java.io.*;
import java.util.*;
import java.util.function.Predicate;

public class VoiceChatPlugin {

    private static final Map<String, EntityPlayerMP> voicePlayers = new HashMap<>();
    private static final Map<String, ExpiringSet<String>> voiceRequests = new HashMap<>();
    private static final Set<String[]> voicePairs = new HashSet<>();

    private static final List<String> iceServers = new ArrayList();

    private static final int VOICE_SIGNAL_ALLOWED = 0;
    private static final int VOICE_SIGNAL_REQUEST = 0;
    private static final int VOICE_SIGNAL_CONNECT = 1;
    private static final int VOICE_SIGNAL_DISCONNECT = 2;
    private static final int VOICE_SIGNAL_ICE = 3;
    private static final int VOICE_SIGNAL_DESC = 4;
    private static final int VOICE_SIGNAL_GLOBAL = 5;

    public static boolean handleMessage(EntityPlayerMP player, Packet250CustomPayload payload) {
        if ("EAG|Voice".equals(payload.channel) && payload.data.length > 0) {
            deev:
            {
                String user = player.username;
                byte[] msg = payload.data;
                try {
                    DataInputStream streamIn = new DataInputStream(new ByteArrayInputStream(msg));
                    int sig = streamIn.read();
                    switch (sig) {
                        case VOICE_SIGNAL_CONNECT:
                            if (voicePlayers.containsKey(user))
                                break deev; // user is already using voice chat
                            // send out packet for player joined voice
                            // notice: everyone on the server can see this packet!! however, it doesn't do
                            // anything but let clients know that the player has turned on voice chat
                            ByteArrayOutputStream baos = new ByteArrayOutputStream();
                            DataOutputStream dos = new DataOutputStream(baos);
                            dos.write(VOICE_SIGNAL_CONNECT);
                            dos.writeUTF(user);
                            byte[] out = baos.toByteArray();
                            for (EntityPlayerMP conn : voicePlayers.values())
                                conn.playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", out));
                            voicePlayers.put(user, player);
                            for (String username : voicePlayers.keySet())
                                sendVoicePlayers(username);
                            break;
                        case VOICE_SIGNAL_DISCONNECT:
                            if (!voicePlayers.containsKey(user))
                                break deev; // user is not using voice chat
                            try {
                                String user2 = streamIn.readUTF();
                                if (!voicePlayers.containsKey(user2))
                                    break deev;
                                if (removeIf(voicePairs, pair -> (pair[0].equals(user) && pair[1].equals(user2))
                                        || (pair[0].equals(user2) && pair[1].equals(user)))) {
                                    ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
                                    DataOutputStream dos2 = new DataOutputStream(baos2);
                                    dos2.write(VOICE_SIGNAL_DISCONNECT);
                                    dos2.writeUTF(user);
                                    voicePlayers.get(user2).playerNetServerHandler.sendPacket(
                                            new Packet250CustomPayload("EAG|Voice", baos2.toByteArray()));
                                    baos2 = new ByteArrayOutputStream();
                                    dos2 = new DataOutputStream(baos2);
                                    dos2.write(VOICE_SIGNAL_DISCONNECT);
                                    dos2.writeUTF(user2);
                                    player.playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", baos2.toByteArray()));
                                }
                            } catch (EOFException e) {
                                removeUser(user);
                            }
                            break;
                        case VOICE_SIGNAL_REQUEST:
                            if (!voicePlayers.containsKey(user))
                                break deev; // user is not using voice chat
                            String targetUser = streamIn.readUTF();
                            if (user.equals(targetUser))
                                break deev; // prevent duplicates
                            if (checkVoicePair(user, targetUser))
                                break deev; // already paired
                            if (!voicePlayers.containsKey(targetUser))
                                break deev; // target user is not using voice chat
                            if (!voiceRequests.containsKey(user))
                                voiceRequests.put(user, new ExpiringSet<>(2000));
                            if (voiceRequests.get(user).contains(targetUser))
                                break deev;
                            voiceRequests.get(user).add(targetUser);

                            // check if other has requested earlier
                            if (voiceRequests.containsKey(targetUser) && voiceRequests.get(targetUser).contains(user)) {
                                if (voiceRequests.containsKey(targetUser)) {
                                    voiceRequests.get(targetUser).remove(user);
                                    if (voiceRequests.get(targetUser).isEmpty())
                                        voiceRequests.remove(targetUser);
                                }
                                if (voiceRequests.containsKey(user)) {
                                    voiceRequests.get(user).remove(targetUser);
                                    if (voiceRequests.get(user).isEmpty())
                                        voiceRequests.remove(user);
                                }
                                // send each other add data
                                voicePairs.add(new String[]{user, targetUser});
                                ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
                                DataOutputStream dos2 = new DataOutputStream(baos2);
                                dos2.write(VOICE_SIGNAL_CONNECT);
                                dos2.writeUTF(user);
                                dos2.writeBoolean(false);
                                voicePlayers.get(targetUser).playerNetServerHandler.sendPacket(
                                        new Packet250CustomPayload("EAG|Voice", baos2.toByteArray()));
                                baos2 = new ByteArrayOutputStream();
                                dos2 = new DataOutputStream(baos2);
                                dos2.write(VOICE_SIGNAL_CONNECT);
                                dos2.writeUTF(targetUser);
                                dos2.writeBoolean(true);
                                player.playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", baos2.toByteArray()));
                            }
                            break;
                        case VOICE_SIGNAL_ICE:
                        case VOICE_SIGNAL_DESC:
                            if (!voicePlayers.containsKey(user))
                                break deev; // user is not using voice chat
                            String targetUser2 = streamIn.readUTF();
                            if (checkVoicePair(user, targetUser2)) {
                                String data = streamIn.readUTF();
                                ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
                                DataOutputStream dos2 = new DataOutputStream(baos2);
                                dos2.write(sig);
                                dos2.writeUTF(user);
                                dos2.writeUTF(data);
                                voicePlayers.get(targetUser2).playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", baos2.toByteArray()));
                            }
                            break;
                        default:
                            break;
                    }
                } catch (Throwable t) {
                    // hacker
                    // t.printStackTrace(); // todo: remove in production
                    removeUser(user);
                }
            }
            return true;
        }
        return false;
    }

    public static void activate(List<String> ice) {
        if (iceServers.size() == 0) {
            iceServers.addAll(ice);
            for (Object o : MinecraftServer.getServer().getConfigurationManager().playerEntityList) {
                handleConnect((EntityPlayerMP) o);
            }
        }
    }

    public static void handleConnect(EntityPlayerMP player) {
        if (iceServers.size() > 0) {
            try {
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                DataOutputStream dos = new DataOutputStream(baos);
                dos.write(VOICE_SIGNAL_ALLOWED);
                dos.writeBoolean(true);
                dos.write(iceServers.size());
                for (String str : iceServers) {
                    dos.writeUTF(str);
                }
                player.playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", baos.toByteArray()));
                sendVoicePlayers(player.username);
            } catch (IOException ignored) {
            }
        }
    }

    public static void handleDisconnect(EntityPlayerMP player) {
        removeUser(player.username);
    }

    private static void removeUser(String name) {
        voicePlayers.remove(name);
        for (String username : voicePlayers.keySet()) {
            if (!name.equals(username))
                sendVoicePlayers(username);
        }
        for (String[] voicePair : voicePairs) {
            String target = null;
            if (voicePair[0].equals(name)) {
                target = voicePair[1];
            } else if (voicePair[1].equals(name)) {
                target = voicePair[0];
            }
            if (target != null && voicePlayers.containsKey(target)) {
                try {
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    DataOutputStream dos = new DataOutputStream(baos);
                    dos.write(VOICE_SIGNAL_DISCONNECT);
                    dos.writeUTF(name);
                    voicePlayers.get(target).playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", baos.toByteArray()));
                } catch (IOException ignored) {
                }
            }
        }
        removeIf(voicePairs, pair -> pair[0].equals(name) || pair[1].equals(name));
    }

    public static void reset() {
        voicePlayers.clear();
        voiceRequests.clear();
        voicePairs.clear();
        iceServers.clear();
    }

    private static void sendVoicePlayers(String name) {
        if (!voicePlayers.containsKey(name))
            return;
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            DataOutputStream dos = new DataOutputStream(baos);
            dos.write(VOICE_SIGNAL_GLOBAL);
            Set<String> mostlyGlobalPlayers = new HashSet<>();
            for (String username : voicePlayers.keySet()) {
                if (username.equals(name))
                    continue;
                if (anyMatch(voicePairs, pair -> (pair[0].equals(name) && pair[1].equals(username))
                        || (pair[0].equals(username) && pair[1].equals(name))))
                    continue;
                mostlyGlobalPlayers.add(username);
            }
            if (mostlyGlobalPlayers.size() > 0) {
                dos.writeInt(mostlyGlobalPlayers.size());
                for (String username : mostlyGlobalPlayers)
                    dos.writeUTF(username);
                voicePlayers.get(name).playerNetServerHandler.sendPacket(new Packet250CustomPayload("EAG|Voice", baos.toByteArray()));
            }
        } catch (IOException ignored) {
        }
    }

    private static boolean checkVoicePair(String user1, String user2) {
        return anyMatch(voicePairs, pair -> (pair[0].equals(user1) && pair[1].equals(user2))
                || (pair[0].equals(user2) && pair[1].equals(user1)));
    }

    /**
     * JDK 8 function not available in TeaVM
     */
    private static <T> boolean removeIf(Collection<T> collection, Predicate<T> pre) {
        boolean ret = false;
        Iterator<T> itr = collection.iterator();
        while (itr.hasNext()) {
            if (pre.test(itr.next())) {
                itr.remove();
                ret = true;
            }
        }
        return ret;
    }

    /**
     * JDK 8 function not available in TeaVM
     */
    private static <T> boolean anyMatch(Collection<T> collection, Predicate<T> pre) {
        boolean ret = false;
        Iterator<T> itr = collection.iterator();
        while (itr.hasNext()) {
            if (pre.test(itr.next())) {
                return true;
            }
        }
        return false;
    }

}