package api

import (
	"bufio"
	"encoding/base64"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

func HandleImageUpload(data *string, directory string, filename string) (string, error) {
	split := strings.Split(*data, ";base64,")
	header := split[0]
	imageData, err := base64.StdEncoding.DecodeString(split[1])
	ext, _ := strings.CutPrefix(header, "data:image/")

	switch ext {
	case "png":
	case "jpg":
	case "jpeg":
	default:
		return "", errors.New("Invalid image type. Allowed: .png, .jpg, .jpeg")
	}
    filename = fmt.Sprintf("%s.%s", filename, ext)

	// ensure directory exists
	os.MkdirAll(directory, os.ModePerm)

	imagePath := filepath.Join(directory, filename)
	file, err := os.Create(imagePath)
	if err != nil {
		return "", err
	}
	defer file.Close()

    // TODO: generate compressed versions of image (512x512?)

	buffer := bufio.NewWriter(file)
	_, err = buffer.Write(imageData)
	if err != nil {
        return "", nil
	}

	if err := buffer.Flush(); err != nil {
        return "", nil
	}

	return filename, nil
}