package response

import (
	"compress/gzip"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"strings"
)

// JSON makes a JSON response
func JSON(writer http.ResponseWriter, status int, data interface{}) {
	jsonData, err := json.Marshal(data)

	if err != nil {
		log.Println("JSON Marshal failed: ", err.Error())

		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
		writer.WriteHeader(503)
		fmt.Fprint(writer, "JSON marshalling failed:", err.Error())
		return
	}

	writer.Header().Set("Content-Type", "application/json")
	writer.WriteHeader(status)

	writer.Write(jsonData)
}

// CompressedJSON makes a compressed JSON response, but only if the client supports it and the.
// payload exceeds 1024 bytes.
func CompressedJSON(writer http.ResponseWriter, request *http.Request, status int, data interface{}) {
	jsonData, err := json.Marshal(data)

	if err != nil {
		log.Println("JSON Marshal failed: ", err.Error())

		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
		writer.WriteHeader(503)
		fmt.Fprint(writer, "JSON marshalling failed:", err.Error())
		return
	}

	writer.Header().Set("Content-Type", "application/json")

	if len(jsonData) > 1024 && strings.Contains(request.Header.Get("Accept-Encoding"), "gzip") {
		writer.Header().Set("Content-Encoding", "gzip")
		writer.WriteHeader(status)

		gz := gzip.NewWriter(writer)
		gz.Write(jsonData)
		gz.Close()
	} else {
		writer.WriteHeader(status)
		writer.Write(jsonData)
	}
}