package golanghelper

import (
	"errors"
	"fmt"
	"io"
	"os"
)

type FileUtils struct {
}

func (f *FileUtils) CopyFile(srcFilePath, destFilePath string, isOverwrite bool) (err error) {
	var srcFileInfo os.FileInfo
	srcFileInfo, err = os.Stat(srcFilePath)
	if err != nil {
		return
	}
	if !srcFileInfo.Mode().IsRegular() {
		return errors.New(fmt.Sprintf("%s is not a regular file", srcFileInfo.Name()))
	}

	var isNotExist bool
	_, err = os.Stat(destFilePath)
	if err != nil {
		if os.IsNotExist(err) {
			isNotExist = true
		} else {
			return
		}
	}

	var destFile *os.File
	if isNotExist == false && isOverwrite == false {
		return errors.New("File already exists")
	}

	destFile, err = os.Create(destFilePath)
	if err != nil {
		return
	}
	defer destFile.Close()

	sourceFile, err := os.Open(srcFilePath)
	if err != nil {
		return
	}
	defer sourceFile.Close()

	_, err = io.Copy(destFile, sourceFile)

	return
}