package json

import ( 
	"net/http"
	json "github.com/json-iterator/go"
	"bytes" 
	"io"
	"errors"
)

var (
	jsonContentType = []string{"application/json; charset=utf-8"}
	JSONConfig = json.ConfigFastest 
	errorJsonEncoderEmpty = errors.New("empty json encoder")
)
func DumpJSON(w http.ResponseWriter, code int, serializable interface{}) {
	// Encode
	header := w.Header()
	if val := header["Content-Type"]; len(val) == 0 {
		header["Content-Type"] = jsonContentType
	}
	w.WriteHeader(code)
	stream := JSONConfig.BorrowStream(w)
	if stream == nil {
		panic(errorJsonEncoderEmpty)
	}
	defer JSONConfig.ReturnStream(stream) 
	stream.WriteVal(serializable) 
	stream.Flush()
	if stream.Error != nil {
		panic(stream.Error)
	}
}
func DumpJSONData(serializable interface{}) ([]byte, error) {
	buf := bytes.Buffer{}
	stream := JSONConfig.BorrowStream(&buf)
	if stream == nil {
		panic(errors.New("empty json encoder"))
	}
	defer JSONConfig.ReturnStream(stream) 
	stream.WriteVal(serializable)
	stream.Flush() 
	return buf.Bytes(), stream.Error
}
func LoadJSON(data []byte, deserializable interface{}) (err error) {
	iterator := JSONConfig.BorrowIterator(data)
	if iterator == nil {
		err = errors.New("empty json data")
		return
	}
	defer JSONConfig.ReturnIterator(iterator) 
	iterator.ReadVal(deserializable)
	return iterator.Error
}
func LoadJSONReader(r io.Reader, deserializable interface{}) (err error) {
	decoder := JSONConfig.NewDecoder(r) 
	return decoder.Decode(deserializable)
}