package core

import (
	"backend/util"
	"errors"
	"image"
	"image/jpeg"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/disintegration/imaging"
)

func CompressImage(path string) (string, error) {
	name := strings.TrimSuffix(filepath.Base(path), filepath.Ext(filepath.Base(path))) + "_compressed.jpeg"
	basedir := filepath.Join(util.GetConfig().PhotoPath, ".compressed", name)

	// Creating folder
	if err := os.MkdirAll(filepath.Join(util.GetConfig().PhotoPath, ".compressed"), 0755); err != nil {
		return "", err
	}

	// Checking output file
	if _, err := os.Stat(basedir); err == nil {
		return name, errors.New("file already created")
	}
	// Create file
	outputFile, err := os.Create(basedir)
	if err != nil {
		return "", err
	}
	defer outputFile.Close()

	// Opening image + Reducing its size and quality
	img, err := imaging.Open(path)
	if err != nil {
		return "", err
	}
	width := float64(img.Bounds().Dx())
	height := float64(img.Bounds().Dy())
	ratio := float64(0)
	var imgOutput *image.NRGBA
	if width < height {
		ratio = height / width
		imgOutput = imaging.Resize(img, 320, int(320*ratio), imaging.Lanczos)
	} else {
		ratio = width / height
		imgOutput = imaging.Resize(img, int(320*ratio), 320, imaging.Lanczos)
	}

	// Encoding to jpeg afterwards
	if err := jpeg.Encode(outputFile, imgOutput, &jpeg.Options{Quality: 100}); err != nil {
		return "", err
	}
	return name, nil
}

func CompressFiles() {
	picd := GetPictureData()
	cfg := util.GetConfig()
	count := 0
	start := time.Now()
	for i := range picd {
		path := filepath.Join(cfg.PhotoPath, picd[i].Album, picd[i].Name)
		compressed_name, err := CompressImage(path)
		if err != nil {
			if strings.Compare(err.Error(), "file already created") != 0 {
				util.Logformat(util.WARNING, "Failed to compress '%s' : (%v)\n", picd[i].Name, err)
			} else {
				picd[i].URLCompressed = util.GetURL() + "/.compressed/" + compressed_name
			}
		} else {
			util.Logformatrn(util.INFO, "Compressing %d files...", count)
			picd[i].URLCompressed = util.GetURL() + "/.compressed/" + compressed_name
			count++
		}
	}
	if count > 0 {
		elapsed := time.Since(start)
		util.Logformatrn(util.CORRECT, "Compressed %d files in %dms.\n", count, elapsed.Milliseconds())
	}
}