package rpc

import (
	"context"
	"encoding/json"
	"fmt"

	"nhooyr.io/websocket"
)

const ERROR_JRPC2_PARSE_ERROR = -32700
const ERROR_JRPC2_METHOD_NOT_FOUND = -32601
const ERROR_JRPC2_INTERNAL = -32603

func NewServer() *server {
	return &server{
		methods:  make(map[string]func(context.Context, Request) (any, error)),
		requests: make(map[string]chan *Response, 1),
	}
}

func (s *server) RegisterMethod(name string, method func(context.Context, Request) (any, error)) {
	s.methods[name] = method
}

// TODO Method With Multiple Responses

func (s *server) HandleMessage(ctx context.Context, c *websocket.Conn, data []byte) {
	var message Message
	err := json.Unmarshal(data, &message)
	if err != nil {
		respondError(ctx, c, "", ERROR_JRPC2_PARSE_ERROR, fmt.Errorf("Error Parsing Message: %w", err), nil)
		return
	}

	// Check if this is a Request or a Response with the Existance of the Method field
	if message.Method != nil {
		s.handleRequest(ctx, c, data)
	} else {
		s.handleResponse(ctx, data)
	}
}