// Copyright 2015-2018 trivago N.V.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package tlog

import (
	"bytes"
	"fmt"
	"io"
	"os"
)

type logReferrer struct {
	writer io.Writer
}

// Write sends the message to the io.Writer passed to Configure
func (log logReferrer) Write(message []byte) (int, error) {
	length := len(message)
	if length == 0 {
		return 0, nil
	}

	logMessage := bytes.TrimRight(message, "\r\n\t ")
	switch {
	case log.writer == nil:
		fmt.Println(string(logMessage))
		return length, nil

	case log.writer == os.Stdout || log.writer == os.Stderr:
		fmt.Fprintln(log.writer, string(logMessage))
		return length, nil

	default:
		return log.writer.Write(logMessage)
	}
}