package dev.plutorocks;

import net.minecraft.client.MinecraftClient;
import net.minecraft.text.MutableText;
import net.minecraft.text.Text;
import net.minecraft.util.Formatting;

import java.io.*;
import java.net.Socket;
import java.nio.charset.StandardCharsets;

public class IrcClient {

    private final String host;
    private final int port;
    private final String channel;
    private final String nick;

    private volatile boolean running = false;
    private volatile boolean connected = false;
    private volatile boolean registered = false;

    private Socket socket;
    private BufferedWriter writer;

    public IrcClient(String host, int port, String channel, String nick) {
        this.host = host;
        this.port = port;
        this.channel = channel.startsWith("#") ? channel : "#" + channel;
        this.nick = nick;
    }

    /**
     * start the IRC thread.
     */
    public void connect() {
        if (running) return;
        running = true;
        MinecraftIRC.LOGGER.info("[IRC] Connecting to {}:{} as {} in {}", host, port, nick, channel);

        Thread thread = new Thread(this::runLoop, "MinecraftIRC-Thread");
        thread.setDaemon(true);
        thread.start();
    }

    public boolean isConnected() {
        return connected;
    }

    public void disconnect() {
        running = false;
        MinecraftIRC.LOGGER.info("[IRC] Disconnect requested");
        try {
            if (socket != null && !socket.isClosed()) {
                socket.close();
            }
        } catch (IOException e) {
            MinecraftIRC.LOGGER.warn("[IRC] Error closing socket", e);
        }
        connected = false;
    }

    private void runLoop() {
        MinecraftIRC.LOGGER.info("[IRC] runLoop started");
        registered = false;
        try (Socket sock = new Socket(host, port);
             BufferedReader reader = new BufferedReader(
                     new InputStreamReader(sock.getInputStream(), StandardCharsets.UTF_8));
             BufferedWriter writer = new BufferedWriter(
                     new OutputStreamWriter(sock.getOutputStream(), StandardCharsets.UTF_8))) {

            this.socket = sock;
            this.writer = writer;
            this.connected = true;

            MinecraftIRC.LOGGER.info("[IRC] Connected TCP to {}:{}", host, port);

            sendRaw("NICK " + nick);
            sendRaw("USER " + nick + " 0 * :" + nick);

            String line;
            while (running && (line = reader.readLine()) != null) {
                MinecraftIRC.LOGGER.info("[IRC RAW] {}", line);
                handleLine(line);
            }

            if (running) {
                MinecraftIRC.LOGGER.info("[IRC] Server closed connection while running");
                sendClientChat(
                        Text.literal("[IRC] ").formatted(Formatting.AQUA)
                                .append(Text.literal("Disconnected from server. Use /irc connect to reconnect.")
                                        .formatted(Formatting.GRAY))
                );
            } else {
                MinecraftIRC.LOGGER.info("[IRC] runLoop exiting normally (running == false)");
            }

        } catch (IOException e) {
            MinecraftIRC.LOGGER.warn("[IRC] IOException in runLoop", e);
            sendClientChat(
                    Text.literal("[IRC] ").formatted(Formatting.AQUA)
                            .append(Text.literal("Connection error: " + e.getMessage()
                                            + " (use /irc connect to try again)")
                                    .formatted(Formatting.GRAY))
            );
        } finally {
            connected = false;
            running = false;
            registered = false;
            this.writer = null;
            this.socket = null;
            MinecraftIRC.LOGGER.info("[IRC] runLoop finished (connected=false, running=false)");
        }
    }

    private void handleLine(String line) {
        if (line.startsWith("ERROR")) {
            sendClientChat(
                    Text.literal("[IRC] ").formatted(Formatting.AQUA)
                            .append(Text.literal("Server ERROR: " + line)
                                    .formatted(Formatting.GRAY))
            );
            return;
        }

        if (line.startsWith(":")) {
            String[] parts = line.split(" ");
            if (parts.length >= 2) {
                String code = parts[1];
                if ("001".equals(code)) {
                    registered = true;
                    MinecraftIRC.LOGGER.info("[IRC] Registration complete (001), joining {}", channel);
                    sendRaw("JOIN " + channel);
                    sendClientChat(
                            Text.literal("[IRC] ").formatted(Formatting.AQUA)
                                    .append(Text.literal("Connected to " + host + " " + channel + " as " + nick)
                                            .formatted(Formatting.GRAY))
                    );
                    return;
                }
                if ("432".equals(code)) {
                    sendClientChat(
                            Text.literal("[IRC] ").formatted(Formatting.AQUA)
                                    .append(Text.literal("Nick " + nick + " is invalid on this server (e.g. too long).")
                                            .formatted(Formatting.GRAY))
                    );
                    MinecraftIRC.LOGGER.warn("[IRC] Nick {} rejected with 432", nick);
                    running = false;
                    return;
                }
                if ("433".equals(code)) {
                    sendClientChat(
                            Text.literal("[IRC] ").formatted(Formatting.AQUA)
                                    .append(Text.literal("Nick " + nick + " is already in use on this server.")
                                            .formatted(Formatting.GRAY))
                    );
                    MinecraftIRC.LOGGER.warn("[IRC] Nick {} already in use (433)", nick);
                    running = false;
                    return;
                }
                if ("451".equals(code)) {
                    sendClientChat(
                            Text.literal("[IRC] ").formatted(Formatting.AQUA)
                                    .append(Text.literal("Server says connection is not registered (451).")
                                            .formatted(Formatting.GRAY))
                    );
                    MinecraftIRC.LOGGER.warn("[IRC] Received 451 (connection not registered)");
                    return;
                }
            }
        }

        if (line.startsWith("PING")) {
            String payload = line.length() > 5 ? line.substring(5) : "";
            sendRaw("PONG " + payload);
            return;
        }

        if (!line.contains(" PRIVMSG ")) {
            return;
        }

        int prefixEnd = line.indexOf(' ');
        if (!line.startsWith(":") || prefixEnd <= 1) {
            return;
        }

        String prefix = line.substring(1, prefixEnd);

        String nick = prefix;
        int bang = prefix.indexOf('!');
        if (bang != -1) {
            nick = prefix.substring(0, bang);
        }

        String[] split = line.split(" :", 2);
        if (split.length < 2) {
            return;
        }

        String trailing = split[1];
        String commandPart = split[0];

        String[] cmdParts = commandPart.split(" ");
        if (cmdParts.length < 3) {
            return;
        }

        String target = cmdParts[2];

        if (!target.equalsIgnoreCase(this.channel)
                && !target.equalsIgnoreCase(this.nick)) {
            return;
        }

        MutableText prefixText = Text.literal("[IRC] ")
                .formatted(Formatting.AQUA);
        MutableText nickText = Text.literal("<" + nick + "> ")
                .formatted(Formatting.WHITE);
        MutableText msgText = Text.literal(trailing)
                .formatted(Formatting.WHITE);

        sendClientChat(prefixText.append(nickText).append(msgText));
    }

    /**
     * sends a message to the configured channel
     */
    public void sendChannelMessage(String message) {
        if (!connected) {
            MinecraftIRC.LOGGER.info("[IRC] Ignoring sendChannelMessage while not connected: {}", message);
            return;
        }
        if (!registered) {
            MinecraftIRC.LOGGER.info("[IRC] Ignoring sendChannelMessage while not registered: {}", message);
            sendClientChat(
                    Text.literal("[IRC] ").formatted(Formatting.AQUA)
                            .append(Text.literal("Cannot send message yet; IRC connection is not fully registered.")
                                    .formatted(Formatting.GRAY))
            );
            return;
        }
        sendRaw("PRIVMSG " + channel + " :" + message);
    }

    /**
     * low-level raw IRC send
     */
    private synchronized void sendRaw(String line) {
        if (writer == null) {
            MinecraftIRC.LOGGER.info("[IRC] sendRaw called but writer is null: {}", line);
            return;
        }
        try {
            MinecraftIRC.LOGGER.debug("[IRC SEND] {}", line);
            writer.write(line);
            writer.write("\r\n");
            writer.flush();
        } catch (IOException e) {
            MinecraftIRC.LOGGER.warn("[IRC] IOException in sendRaw", e);
            sendClientChat(
                    Text.literal("[IRC] ").formatted(Formatting.AQUA)
                            .append(Text.literal("Send error: " + e.getMessage())
                                    .formatted(Formatting.GRAY))
            );
            disconnect();
        }
    }

    private void sendClientChat(Text text) {
        MinecraftClient client = MinecraftClient.getInstance();
        if (client == null) return;

        client.execute(() -> {
            if (client.inGameHud != null) {
                client.inGameHud.getChatHud().addMessage(text);
            }
        });
    }
}