using System.Data;
using System.Net.Sockets;
using System.Text;
using System.Text.Json;

namespace riff;

public abstract class IRCBot
{
    public string Host;
    public int Port;
    public string Nick;
    public string RealName;
    public List<string> JoinedChannels = new();
    public List<string> PermanentChannels;
    public List<string> UserChannels;
    public string UserChannelStoragePath;
    public List<Action<PRIVMSG>> Listeners = new();
    private List<CommandRunner> CommandRunners = new();
    private List<PollRunner> PollRunners = new();
    private TcpClient Client;
    private NetworkStream Stream;

    public IRCBot(string host, int port, string nick, string realname, List<string> permanentChannels)
    {
        Host = host;
        Port = port;
        Nick = nick;
        RealName = realname;
        PermanentChannels = permanentChannels;
        UserChannelStoragePath = $"data/{Nick}_user_channels.json";
        UserChannels = LoadUserChannels();
        Client = new TcpClient(Host, Port);
        Stream = Client.GetStream();
        SendLine($"NICK {Nick}");
        SendLine($"USER {Nick} 0 * :{RealName}");
        foreach (string channel in PermanentChannels)
            JoinChannel(channel);
        foreach (string channel in UserChannels)
            JoinChannel(channel);
    }

    public void HookCommands((string, Action<PRIVMSG>)[] commands)
    {
        foreach ((string, Action<PRIVMSG>) command in commands)
        {
            CommandRunners.Add(new CommandRunner(command.Item1, command.Item2));
        }
    }

    public void HookPollRunners((int, Action)[] runners)
    {
        foreach ((int, Action) runner in runners)
        {
            PollRunners.Add(new PollRunner(runner.Item1, runner.Item2));
        }
    }

    public void HookListeners(Action<PRIVMSG>[] listeners)
    {
        foreach (Action<PRIVMSG> listener in listeners)
        {
            Listeners.Add(listener);
        }
    }

    private void SendLine(string line)
    {
        Byte[] bytes = Encoding.UTF8.GetBytes(line + "\r\n");
        Stream.Write(bytes, 0, bytes.Length);
    }

    public void SendPrivmsg(string destination, string message)
    {
        if (message != string.Empty)
            SendLine($"PRIVMSG {destination} :{message}");
    }

    public void JoinChannel(string channel)
    {
        SendLine($"JOIN {channel}");
        JoinedChannels.Add(channel);
    }

    public void JoinChannels(List<string> channels)
    {
        foreach (string channel in channels)
            JoinChannel(channel);
    }

    public void PartChannel(string channel)
    {
        SendLine($"PART {channel}");
        JoinedChannels.Remove(channel);
    }

    public List<string> LoadUserChannels()
    {
        List<string> channels;
        try
        {
            using (FileStream stream = File.OpenRead(UserChannelStoragePath))
            {
                channels = JsonSerializer.Deserialize<List<string>>(stream)!;
                if (channels == null)
                    throw new NoNullAllowedException();
                return channels;
            }
        }
        catch (FileNotFoundException)
        {
            channels = [];
            return channels;
        }
    }

    public void AddUserChannel(string channel)
    {
        UserChannels.Add(channel);
        JoinChannel(channel);
        WriteUserChannels();
    }

    public void RemoveUserChannel(string channel)
    {
        UserChannels.Remove(channel);
        PartChannel(channel);
        WriteUserChannels();
    }

    public void WriteUserChannels()
    {
        File.WriteAllText(UserChannelStoragePath, JsonSerializer.Serialize(UserChannels));
    }

    public void MainLoop()
    {
        foreach (PollRunner runner in PollRunners)
            runner.Start();
        using var reader = new StreamReader(Stream, Encoding.UTF8);
        while (true)
        {
            string? line = reader.ReadLine();
            if (line == null)
            {
                Console.WriteLine($"{Nick} disconnected");
                break;
            }
            Console.WriteLine(line);
            IRCMessage msg = new(line);
            switch (msg.Command)
            {
                case "PING":
                    if (msg.Arguments.Count == 0)
                        SendLine("PONG");
                    else
                        SendLine("PONG " + msg.Arguments[0]);
                    break;
                case "INVITE":
                    AddUserChannel(msg.Arguments[1]);
                    break;
                case "KICK":
                    string channel = msg.Arguments[0];
                    UserChannels.Remove(channel);
                    JoinedChannels.Remove(channel);
                    WriteUserChannels();
                    break;
                case "PRIVMSG":
                    PRIVMSG privmsg = new(msg);
                    foreach (Action<PRIVMSG> listener in Listeners)
                        listener(privmsg);
                    foreach (CommandRunner command in CommandRunners)
                        if (command.Run(privmsg))
                            break;
                    break;
            }
        }
    }
}