package web

import (
	"fmt"
	"io/fs"
	"math/rand"
	"net/http"
	"os"
)

func imageHandler() http.Handler {
	fs := http.FS(os.DirFS(config.imageDir))
	hfs := http.FileServer(fs)
	return hfs
}

func chooseRandomFile(imageDir string) (filepath string, err error) {
	validEntries := make([]string, 0)
	log := config.logger.Sugar()
	err = fs.WalkDir(os.DirFS(imageDir), ".", func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			log.Errorw("Error walking directory", "imageDir", imageDir, "error", err)
			return err
		}
		if d.Type().IsRegular() {
			validEntries = append(validEntries, fmt.Sprintf("%s/%s", imageDir, d.Name()))
		}
		return nil
	})

	chosen := rand.Intn(len(validEntries))
	filepath = validEntries[chosen]
	return
}

func randomImageFunc(w http.ResponseWriter, r *http.Request) {
	log := config.logger.Sugar()
	path, err := chooseRandomFile(config.imageDir)
	if err != nil {
		log.Errorw("Couldn't choose a random file", "error", err)
		w.WriteHeader(http.StatusInternalServerError)
		fmt.Fprint(w, "Error selecting a file.")
		return
	}
	log.Infow("serving image file", "path", path)
	http.ServeFile(w, r, path)
}