using JsonRPC.Protocol;
using Newtonsoft.Json;

namespace JsonRPC.RPC
{
    public class Receiver : AbsSingle<Receiver>
    {
        Dictionary<string, Func<JsonRPCRequest, JsonRPCResponse>> handlers = new();

        public void RegHandler(string methodSig, Func<JsonRPCRequest, JsonRPCResponse> func)
        {
            handlers.Add(methodSig, func);
        }

        public string OnReceive(string msg)
        {
            JsonRPCResponse response;
            var req = JsonConvert.DeserializeObject<JsonRPCRequest>(msg);
            if(req == null)
            {
                response = new JsonRPCResponse()
                {
                    Error = new JsonRPCError()
                    {
                        Code = (int)EErrorCode.ParseError,
                        Message = msg,
                        Data = "invalid json."
                    }
                };
                
                return JsonConvert.SerializeObject(response);
            }

            if (handlers.TryGetValue(req.Method, out var handler))
            {
                try
                {
                    response = handler!(req);
                }
                catch (Exception e)
                {
                    response = new JsonRPCResponse()
                    {
                        Id = req.Id,
                        Error = new JsonRPCError()
                        {
                            Code = (int)EErrorCode.InternalError,
                            Message = msg,
                            Data = e.ToString()
                        }
                    };
                }
            }
            else
            {
                response = new JsonRPCResponse()
                {
                    Id = req.Id,
                    Error = new JsonRPCError()
                    {
                        Code = (int)EErrorCode.MethodNotFound,
                        Message = msg,
                    }
                };
            }
            
            return JsonConvert.SerializeObject(response);
        }

    }
}