using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Dynamic;
using System.Linq;
using System.Reflection.Metadata;
using System.Reflection.Metadata.Ecma335;
using System.Text;
using System.Threading.Tasks;
public class TwitchChatMessage
{
    public static readonly string Delimter = "\r\n";
    public TwitchChatMessageType MessageType { get; protected set; }
    public string Prefix { get; protected set; }
    public string Source { get; protected set; }
    public List<string> Parameters { get; } = new();
    public string RawParameters { get; protected set; }
    public string RawText { get; protected set; }
    public TwitchMessageTags MessageTags { get; protected set; } = new();

    protected TwitchChatMessage()
    {

    }
    protected TwitchChatMessage(TwitchChatMessage other)
    {
        MessageType = other.MessageType;
        Prefix = other.Prefix;
        Source = other.Source;
        Parameters = new(other.Parameters);
        RawParameters = other.RawParameters;
        RawText = other.RawText;
        MessageTags = new(other.MessageTags);
    }
    public static TwitchChatMessage Parse(string s)
    {
        TwitchChatMessage message = new();
        message.RawText = s;
        //message has tags
        if (s.StartsWith('@'))
        {
            s = s[1..];
            //first ' ' acts as the delimeter
            var split = s.Split(' ', 2);
            Debug.Assert(split.Length == 2, "no space found to end tag section");
            string tagString = split[0];
            s = split[1].TrimStart(' ');
            message.MessageTags = TwitchMessageTags.Parse(tagString);
        }
        //message has source
        if (s.StartsWith(':'))
        {
            s = s[1..];
            var split = s.Split(' ', 2);
            Debug.Assert(split.Length == 2, "no space found to end prefix");
            message.Prefix = split[0];
            s = split[1].TrimStart(' ');
        }
        var spl_command = s.Split(' ', 2);
        message.MessageType = TwitchChatMessageTypeHelper.Parse(spl_command[0]);
        //message has parameters
        if (spl_command.Length >= 2)
        {
            s = spl_command[1];
            message.RawParameters = s;
            //message has single parameter marked as the final parameter
            //this needs to be handled specially because the leading ' '
            //is stripped
            if (s.StartsWith(':'))
            {
                message.Parameters.Add(s[1..]);
            }
            else
            {
                var spl_final = s.Split(" :", 2);
                var spl_initial = spl_final[0].Split(' ', StringSplitOptions.RemoveEmptyEntries
                    | StringSplitOptions.TrimEntries);
                message.Parameters.AddRange(spl_initial);
                if (spl_final.Length >= 2)
                    message.Parameters.Add(spl_final[1]);
            }
        }
        return message.MessageType switch
        {
            TwitchChatMessageType.PRIVMSG => new Privmsg(message),
            _ => message,
        };
    }
    protected string TryGetTag(string s)
    {
        if (!MessageTags.TryGetValue(s, out string value))
            return "";
        return value ?? "";
    }
    public static TwitchChatMessage MakePong(TwitchChatMessage ping)
    {
        var pong = new TwitchChatMessage(ping);
        pong.MessageType = TwitchChatMessageType.PONG;
        return pong;
    }
}