files.go

package main

import (
	"errors"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
)

func readDirectory(currentDirectory string, targetDirectory string) ([]picture, error) {
	var pictures []picture
	//Get list of files
	files, err := ioutil.ReadDir(currentDirectory)
	if err != nil {
		return pictures, err
	}
	//Prepare slice of pictures
	for _, file := range files {
		var fullSourcePath = filepath.Join(currentDirectory, file.Name())
		var fullTargetPath = filepath.Join(targetDirectory, file.Name())
		var extension = strings.ToLower(filepath.Ext(file.Name()))
		var temp rgbHistogram
		if extension == ".jpg" || extension == ".png" {
			pictures = append(pictures, picture{fullSourcePath, fullTargetPath, temp, temp})
		}
	}
	if len(pictures) < 1 {
		return pictures, errors.New("the source directory does not contain any compatible images (JPG or PNG)")
	}
	return pictures, nil
}

func testForDirectory(directory string) bool {
	if _, err := os.Stat(directory); os.IsNotExist(err) {
		return false
	}
	return true
}