package kk_image

import (
	"bytes"
	"errors"
	"gitee.com/cruvie/kk_go_kit/kk_file"
	"gitee.com/cruvie/kk_go_kit/kk_stage"
	"log/slog"
	"mime/multipart"
	"os"
)

type TargetSize string

const (
	Small    TargetSize = "small"
	Medium   TargetSize = "medium"
	Original TargetSize = "original"
)

type Image struct {
	TargetSize TargetSize
	TargetType kk_file.FileType
	SourceType kk_file.FileType
	data       []byte
}

func NewImageFromFile(fileStream *os.File) (img *Image, err error) {
	img = &Image{}
	err = img.loadDataFromFile(fileStream)
	if err != nil {
		return nil, err
	}
	support, sourceType := img.checkType()
	if !support {
		return nil, errors.New("unsupported image type")
	}
	img.SourceType = sourceType
	return img, nil
}
func NewImageFromFileHeader(fileHeader multipart.FileHeader) (img *Image, err error) {
	img = &Image{}
	err = img.loadDataFromFileHeader(fileHeader)
	if err != nil {
		return nil, err
	}
	support, sourceType := img.checkType()
	if !support {
		return nil, errors.New("unsupported image type")
	}
	img.SourceType = sourceType
	return img, nil
}

func NewImageFromBuffer(buf []byte) (img *Image, err error) {
	img = &Image{
		data: buf,
	}
	support, sourceType := img.checkType()
	if !support {
		return nil, errors.New("unsupported image type")
	}
	img.SourceType = sourceType
	return img, nil
}

func (img *Image) Copy() *Image {
	newImg := &Image{
		TargetSize: img.TargetSize,
		TargetType: img.TargetType,
		SourceType: img.SourceType,
	}
	newImg.data = make([]byte, len(img.data))
	copy(newImg.data, img.data)
	return newImg
}

func (img *Image) SetTargetSizeType(targetSize TargetSize, targetType kk_file.FileType) *Image {
	img.TargetSize = targetSize
	img.TargetType = targetType
	return img
}

// Resize 生成文件流
func (img *Image) Resize() ([]byte, error) {
	if img.TargetType == img.SourceType && img.TargetSize == Original {
		return img.data, nil
	}
	switch img.TargetType {
	case kk_file.Jpeg:
		return img.resizeToJPEG()
	case kk_file.Avif:
		return img.resizeToAvif()
	case kk_file.Gif:
		return img.resizeToGif()
	default:
		return nil, errors.New("不支持的目标图片类型")
	}
}

// GetResizedImage 获取压缩后用于上传的图片数据
func (img *Image) GetResizedImage() (uploadDataReader *bytes.Reader, err error) {

	imageReader, err := img.Resize()
	if err != nil {
		return nil, err
	}

	uploadDataReader = bytes.NewReader(imageReader)

	return uploadDataReader, nil
}

func (img *Image) CheckSize(maxSize kk_file.FileSize) (support bool) {
	if len(img.data) > maxSize.Int() {
		slog.Error("file size too large", kk_stage.NewLog(nil).
			Any("size(MB)", kk_file.ConvertFileSizeMB(int64(len(img.data)))).
			Any("limit(MB)", kk_file.ConvertFileSizeMB(maxSize.Int64())).Args()...)
		return false
	}
	return true
}