package main

import (
	"fmt"
	"image"
	"image/jpeg"
	"image/png"
	"log"
	"net/http"
	"os"
	"path/filepath"

	"github.com/labstack/echo/v4"
	"github.com/nfnt/resize"
	"github.com/nickalie/go-webpbin"
)

func Conversion(input string) error {
	var width uint = 1920
	output := filepath.Base(input)
	outputdir := filepath.Dir(input)
	ext := filepath.Ext(output)
	output = output[0 : len(output)-len(ext)] // Remove file extension	            // Add .webp extension
	log.Println("Converting", input, "to", output+".webp")
	f, err := os.Open(input)
	if err != nil {
		return err
	}
	defer f.Close()
	var img image.Image

	switch ext {
	case ".webp":
		log.Println("Image already in WebP format")
		img, err = webpbin.Decode(f)
		if err != nil {
			return err
		}
	case ".png", ".PNG":
		// Convert from PNG
		img, err = png.Decode(f)
		if err != nil {
			return err
		}
	case ".jpeg", ".jpg", ".JPG", ".JPEG":
		// Convert from JPEG
		img, err = jpeg.Decode(f)
		if err != nil {
			return err
		}
	default:
		return fmt.Errorf("error: Unsupported file type: %s", ext)
	}

	err = image_creation(img, width, output, outputdir)
	if err != nil {
		return err
	}

	err = thumbnail_creation(img, output, outputdir)
	if err != nil {
		return err
	}

	fmt.Println("Conversion completed successfully")

	return nil
}

func image_creation(img image.Image, width uint, output string, outputdir string) error {
	// Resize the image
	resizedImg := resize.Resize(width, 0, img, resize.Lanczos3)

	// Create the output file
	outputPath := fmt.Sprintf("%s/%s.webp", outputdir, output)
	log.Println("Creating", outputPath)
	out, err := os.Create(outputPath)
	if err != nil {
		return err
	}
	defer out.Close()

	// Encode the resized image to the output file
	err = webpbin.Encode(out, resizedImg)
	if err != nil {
		return err
	}
	return nil
}

func thumbnail_creation(img image.Image, output string, outputdir string) error {
	// Resize the image
	resizedImg := resize.Resize(32, 0, img, resize.Lanczos3)

	// Create the output file
	outputPath := fmt.Sprintf("%s/thumbnail-%s.webp", outputdir, output)
	log.Println("Creating", outputPath)
	out, err := os.Create(outputPath)
	if err != nil {
		return err
	}
	defer out.Close()

	// Encode the resized image to the output file
	err = webpbin.Encode(out, resizedImg)
	if err != nil {
		return err
	}
	return nil
}

func FallbackImage(c echo.Context) error {
	// Serve a fallback image if the requested image is not found
	fallbackPath := "fallback.webp" // Path to your fallback image
	if _, err := os.Stat(fallbackPath); os.IsNotExist(err) {
		return c.String(http.StatusNotFound, "Fallback image not found")
	}
	return c.File(fallbackPath)
}