package api

import (
	"encoding/json"
	"fmt"
	"net/http"
)

// Response is a JSON encoded HTTP response body
type Response struct {
	Error *Error      `json:",omitempty"`
	Data  interface{} `json:",omitempty"`
}

type ErrorCode string

// Error is a JSON encoded error
type Error struct {
	Code ErrorCode
	Data interface{} `json:",omitempty"`
}

func (e *Error) Error() string {
	return fmt.Sprintf("%s: %v", e.Code, e.Data)
}

func DataResponse(w http.ResponseWriter, status int, data interface{}) {
	response(w, status, &Response{
		Data: data,
	})
}

func ErrorResponse(w http.ResponseWriter, status int, code ErrorCode, data interface{}) {
	response(w, status, &Response{
		Error: &Error{code, data},
	})
}

func response(w http.ResponseWriter, status int, res *Response) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	encoder := json.NewEncoder(w)
	encoder.SetIndent("", "  ")
	if err := encoder.Encode(res); err != nil {
		panic(err)
	}
}