package transport

import "encoding/json"

const jsonRPCVersion = "2.0"

// JSON-RPC 2.0 standard error codes (https://www.jsonrpc.org/specification).
const (
	errParse          = -32700
	errInvalidRequest = -32600
	errMethodNotFound = -32601
	errInvalidParams  = -32602
	errInternal       = -32603
)

type rpcRequest struct {
	JSONRPC string          `json:"jsonrpc"`
	ID      json.RawMessage `json:"id,omitempty"`
	Method  string          `json:"method"`
	Params  json.RawMessage `json:"params,omitempty"`
}

type rpcResponse struct {
	JSONRPC string          `json:"jsonrpc"`
	ID      json.RawMessage `json:"id,omitempty"`
	Result  interface{}     `json:"result,omitempty"`
	Error   *rpcError       `json:"error,omitempty"`
}

type rpcError struct {
	Code    int         `json:"code"`
	Message string      `json:"message"`
	Data    interface{} `json:"data,omitempty"`
}

func resultResponse(id json.RawMessage, result interface{}) rpcResponse {
	return rpcResponse{JSONRPC: jsonRPCVersion, ID: id, Result: result}
}

func errorResponse(id json.RawMessage, code int, message string) rpcResponse {
	return rpcResponse{JSONRPC: jsonRPCVersion, ID: id, Error: &rpcError{Code: code, Message: message}}
}