package services

import (
	"bytes"
	"fmt"
	"image/png"
	"slices"

	"github.com/boombuler/barcode"
	"github.com/boombuler/barcode/code128"
	"github.com/boombuler/barcode/ean"
	"github.com/boombuler/barcode/qr"
)

type BarcodeGenerator interface {
	GenerateBarcode(format string, content string) (bytes.Buffer, error)
	IsTypeSupported(format string) bool
}

type DefaultBarcodeGenerator struct {
}

func (b *DefaultBarcodeGenerator) GenerateBarcode(format string, content string, width int, height int) (bytes.Buffer, error) {
	if !b.IsTypeSupported(format) {
		return bytes.Buffer{}, fmt.Errorf("unsupported barcode type: %s", format)
	}

	var generatedCode barcode.Barcode
	var err error

	switch format {
	case "ean13":
		generatedCode, err = ean.Encode(content)
		if err != nil {
			return bytes.Buffer{}, err
		}
		break
	case "code128":
		generatedCode, err = code128.Encode(content)
		if err != nil {
			return bytes.Buffer{}, err
		}
		break
	case "qr":
		generatedCode, err = qr.Encode(content, qr.M, qr.AlphaNumeric)
		if err != nil {
			return bytes.Buffer{}, err
		}
		break
	}

	scaledCode, err := barcode.Scale(generatedCode, width, height)
	if err != nil {
		return bytes.Buffer{}, err
	}

	var buf bytes.Buffer
	err = png.Encode(&buf, scaledCode)
	if err != nil {
		return bytes.Buffer{}, err
	}

	return buf, nil
}

func (b *DefaultBarcodeGenerator) IsTypeSupported(format string) bool {
	supportedTypes := []string{"ean13", "code128", "qr"}
	return slices.Contains(supportedTypes, format)
}