package imaging

import (
	domain "RenewCMS/internal/domain/image"
	"bytes"
	"image"
	"image/jpeg"
	"image/png"

	"github.com/gen2brain/webp"
)

type encoder interface {
	contentType() string
	flattensTransparency() bool
	encode(output *bytes.Buffer, source image.Image, quality int) error
}

type jpegEncoder struct{}

func (jpegEncoder) contentType() string { return "image/jpeg" }

func (jpegEncoder) flattensTransparency() bool { return true }

func (jpegEncoder) encode(output *bytes.Buffer, source image.Image, quality int) error {
	return jpeg.Encode(output, source, &jpeg.Options{Quality: quality})
}

type pngEncoder struct{}

func (pngEncoder) contentType() string { return "image/png" }

func (pngEncoder) flattensTransparency() bool { return false }

func (pngEncoder) encode(output *bytes.Buffer, source image.Image, _ int) error {
	return png.Encode(output, source)
}

type webpEncoder struct{}

func (webpEncoder) contentType() string { return "image/webp" }

func (webpEncoder) flattensTransparency() bool { return false }

func (webpEncoder) encode(output *bytes.Buffer, source image.Image, quality int) error {
	return webp.Encode(output, source, webp.Options{Quality: quality})
}

var knownEncoders = map[domain.VariantFormat]encoder{
	domain.FormatJPEG: jpegEncoder{},
	domain.FormatPNG:  pngEncoder{},
	domain.FormatWebP: webpEncoder{},
}

var sourceFormats = map[string]domain.VariantFormat{
	"jpeg": domain.FormatJPEG,
	"png":  domain.FormatPNG,
	"webp": domain.FormatWebP,
	"gif":  domain.FormatPNG,
}