/*
    Tesses.RPC A simple RPC library for .NET
    Copyright (C) 2023  Mike Nolan

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Linq;

namespace Tesses.RPC
{
    public abstract class MessageHandler
    {
        public abstract void SendMessage(string msg);

        public void OnMessageReceived(string msg)
        {
            MessageRecv?.Invoke(msg);
        }   
        internal event Action<string> MessageRecv; 
    }
    public sealed class MessageReceived<T,TType> 
    {
        Action<TType> reply;
        internal MessageReceived(T data,bool needReply,long id,Action<TType> reply)
        {
            Data = data;
            NeedReply = needReply;
            this.reply=reply;
            Id = id;
        }
        public long Id {get;private set;}
        public T Data {get;private set;}
        public bool NeedReply {get;private set;}
        public void Reply(TType msg)
        {
            reply?.Invoke(msg);
        }
    }
    public sealed class JsonMessager<TEnum,TType> where TEnum : Enum
    {
        Dictionary<TEnum,(Type type,Action<JsonMessage<TEnum>> resp)> items=new Dictionary<TEnum, (Type type,Action<JsonMessage<TEnum>> resp)>();
        MessageHandler handler;
        public JsonMessager(MessageHandler handler)
        {
            this.handler = handler;
            this.handler.MessageRecv += message_recv;
        }
        private void message_recv(string msg)
        {
          
           var res= JsonConvert.DeserializeObject<JsonMessage<TEnum>>(msg);
           if(res != null && items.ContainsKey(res.Type))
           {
               
                
                items[res.Type].resp?.Invoke(res);
           }
        }
        private event Action<JsonMessage<TEnum>> recv_res;
        public void Register<T>(TEnum val) where T : TType
        {
            Register<T>(val,(ctx)=>{});
        }
        public void Register<T>(TEnum val,Action<MessageReceived<T,TType>> recv) where T : TType
        {

            if(!items.ContainsKey(val))
            {
                Action<JsonMessage<TEnum>> msger=  (msg)=>{
                    if(recv!=null && msg.MessageState != MessageState.ResponseNoForget) 
                    {
                        
                        MessageReceived<T,TType> msg0=new MessageReceived<T,TType>(msg.Value.ToObject<T>(),msg.MessageState != MessageState.Forget ,msg.Id,(reply)=>{
                            SendMessageResponse(reply,msg.Id);
                        });
                        recv?.Invoke(msg0);
                    }else if(msg.MessageState == MessageState.ResponseNoForget){
                    
                        recv_res?.Invoke(msg);
                    }
                };
            items.Add(val,(typeof(T),msger));
            }
        }
        private void SendMessageResponse(TType msg,long msgId)
        {
             foreach(var item in items)
            {
                if(item.Value.type == msg.GetType())
                {    
                    JsonMessage<TEnum> jsonMessage = new JsonMessage<TEnum>();
                    jsonMessage.Type=item.Key;
                    jsonMessage.Value=JToken.FromObject(msg);
                    jsonMessage.Id = msgId;
                    jsonMessage.MessageState = MessageState.ResponseNoForget;

                    string text=JsonConvert.SerializeObject(jsonMessage);
                    handler.SendMessage(text);
                    return;
                }
            }
        }
        public void SendMessage(TType msg)
        {
            foreach(var item in items)
            {
                if(item.Value.type == msg.GetType())
                {    
                    JsonMessage<TEnum> jsonMessage = new JsonMessage<TEnum>();
                    jsonMessage.Type=item.Key;
                    jsonMessage.Value=JToken.FromObject(msg);
                    jsonMessage.Id = JsonMessage<TEnum>.GetNewId();
                    jsonMessage.MessageState = MessageState.Forget;

                    string text=JsonConvert.SerializeObject(jsonMessage);
                    handler.SendMessage(text);
                    return;
                }
            }
          
        }
        public void SendMessage<TResponse>(TType msg,Action<TResponse> resp)  where TResponse : TType
        {
            foreach(var item in items)
            {
                if(item.Value.type == msg.GetType())
                {    
                    JsonMessage<TEnum> jsonMessage = new JsonMessage<TEnum>();
                    jsonMessage.Type=item.Key;
                    jsonMessage.Value=JToken.FromObject(msg);
                    jsonMessage.Id = JsonMessage<TEnum>.GetNewId();
                    jsonMessage.MessageState = MessageState.RequestNoForget;

                    string text=JsonConvert.SerializeObject(jsonMessage);
                    recv_res += (e)=>{
                        if(e.Id == jsonMessage.Id && e.MessageState == MessageState.ResponseNoForget)
                        {
                            if(items.ContainsKey(e.Type) && items[e.Type].type == typeof(TResponse))
                            {
                                resp?.Invoke(e.Value.ToObject<TResponse>());
                            }
                        }
                    };
                    handler.SendMessage(text);

                    return;
                }
            }
        }

        internal enum MessageState
        {
            Forget=0,
            RequestNoForget=1,
            ResponseNoForget=2
        }
        
        private class JsonMessage<TEnum2>  where TEnum2 : Enum
        {
            private static long _curId=0;
            internal static long GetNewId()
            {
                return _curId++;
            }
            [JsonConverter(typeof(StringEnumConverter))]
            public TEnum2 Type {get;set;}

            public JToken Value {get;set;}

            public long Id {get;set;}

            public MessageState MessageState {get;set;}
        }
    }
}