gopaper/files.go

package main

import (
	"fmt"
	"math/rand"
	"os"
	"regexp"
)

func getRandomFile(dir string) (path string, filename string, error error) {
	files, err := os.ReadDir(dir)
	if err != nil {
		return "", "", err
	}

	var randomIndex int
	var randomImg os.DirEntry
	for {
		randomIndex = rand.Intn(len(files))
		randomImg = files[randomIndex]
		//re-roll if you get a directory
		if files[randomIndex].IsDir() {
			fmt.Printf("%v is a directory\n", randomImg.Name())
			continue
		}
		//re-roll if not a recognised image type
		isImage, _ := regexp.Match(".jpg$|.jpeg$|.png$|.bmp$|.webp$", []byte(randomImg.Name()))
		if !isImage {
			fmt.Printf("%v is not a recognised image format\n", randomImg.Name())
			continue
		}
		return dir + "/" + randomImg.Name(), randomImg.Name(), nil
	}
}

func fileExistsInCache(filename string) (bool, error) {
	files, err := os.ReadDir("images")
	if err != nil {
		return false, err
	}
	for _, file := range files {
		if file.Name() == filename {
			return true, nil
		}
	}
	return false, nil
}