package main

import (
	"errors"
	"image"
	"io/ioutil"
	"os"

	"github.com/golang/freetype"

	"github.com/nfnt/resize"

	"image/color"
	"image/draw"
	_ "image/gif"
	_ "image/jpeg"
	"image/png"
	_ "image/png"

	"b612.me/starainrt"
)

func OpenImage(name string) (image.Image, error) {
	if !starainrt.Exists(name) {
		return nil, errors.New("File Not Exists")
	}
	fso, err := os.Open(name)
	if err != nil {
		return nil, err
	}
	img, _, err := image.Decode(fso)
	if err != nil {
		return nil, err
	}
	return img, nil
}

func MergePhoto(big, small image.Image, bigsize, smallsize uint, x, y int) image.Image {
	big = resize.Resize(bigsize, bigsize, big, resize.Lanczos3)
	small = resize.Resize(smallsize, smallsize, small, resize.Lanczos3)
	offset := image.Pt(x, y)
	b := big.Bounds()
	nimg := image.NewRGBA(b)
	draw.Draw(nimg, b, big, image.ZP, draw.Src)
	draw.Draw(nimg, small.Bounds(), small, offset, draw.Over)
	return nimg
}

func SavePhoto(path string, img image.Image) error {
	imgf, err := os.Create(path)
	if err != nil {
		return err
	}
	defer imgf.Close()
	return png.Encode(imgf, img)
}

func SetAlpha(img image.Image, alpha uint8) image.Image {
	size := img.Bounds()
	nimg := image.NewRGBA(size)
	for x := 0; x < size.Dx(); x++ {
		for y := 0; y < size.Dy(); y++ {
			r, g, b, a := img.At(x, y).RGBA()
			r = r >> 8
			g = g >> 8
			b = b >> 8
			a = a >> 8
			nimg.Set(x, y, color.NRGBA{uint8(r), uint8(g), uint8(b), alpha})
			//nimg.Set(x, y, color.Alpha{alpha})
			//nimg.Set(x, y, img.At(x, y))
		}
	}
	return nimg
}

func AddText(text string, img image.Image, x, y int, dpi, size float64, colors color.RGBA, ttf string) (image.Image, error) {
	if !starainrt.Exists(ttf) {
		return nil, errors.New("File Not Exists")
	}
	fontbyte, err := ioutil.ReadFile(ttf)
	if err != nil {
		return nil, err
	}
	font, err := freetype.ParseFont(fontbyte)
	if err != nil {
		return nil, err
	}
	nimg, ok := img.(draw.Image)
	if !ok {
		size := img.Bounds()
		nimg = image.NewRGBA(img.Bounds())
		for x := 0; x < size.Dx(); x++ {
			for y := 0; y < size.Dy(); y++ {
				r, g, b, a := img.At(x, y).RGBA()
				nimg.Set(x, y, color.NRGBA{uint8(r), uint8(g), uint8(b), uint8(a)})
			}
		}
	}
	f := freetype.NewContext()
	f.SetDPI(dpi)
	f.SetFontSize(size)
	f.SetFont(font)
	f.SetClip(nimg.Bounds())
	f.SetDst(nimg)
	f.SetSrc(image.NewUniform(colors))
	_, err = f.DrawString(text, freetype.Pt(x, y))
	if err != nil {
		return nil, err
	}
	return nimg, nil
}

type TextImg struct {
	Text  string
	X     int
	Y     int
	Dpi   float64
	Size  float64
	Color color.NRGBA
}

type TextList struct {
	List []TextImg
	TTF  []byte
}

func AddListTests(list TextList, img image.Image) (image.Image, error) {
	font, err := freetype.ParseFont(list.TTF)
	if err != nil {
		return nil, err
	}
	nimg, ok := img.(draw.Image)
	if !ok {
		size := img.Bounds()
		nimg = image.NewRGBA(img.Bounds())
		for x := 0; x < size.Dx(); x++ {
			for y := 0; y < size.Dy(); y++ {
				r, g, b, a := img.At(x, y).RGBA()
				nimg.Set(x, y, color.NRGBA{uint8(r), uint8(g), uint8(b), uint8(a)})
			}
		}
	}
	for _, v := range list.List {
		f := freetype.NewContext()
		f.SetDPI(v.Dpi)
		f.SetFontSize(v.Size)
		f.SetFont(font)
		f.SetClip(nimg.Bounds())
		f.SetDst(nimg)
		f.SetSrc(image.NewUniform(v.Color))
		_, err = f.DrawString(v.Text, freetype.Pt(v.X, v.Y))
		if err != nil {
			return nil, err
		}
	}
	return nimg, nil
}

func AddTexts(text string, img image.Image, x, y int, dpi, size float64, colors color.NRGBA, ttf string) (image.Image, error) {
	if !starainrt.Exists(ttf) {
		return nil, errors.New("File Not Exists")
	}
	fontbyte, err := ioutil.ReadFile(ttf)
	if err != nil {
		return nil, err
	}
	font, err := freetype.ParseFont(fontbyte)
	if err != nil {
		return nil, err
	}
	nimg, ok := img.(draw.Image)
	if !ok {
		size := img.Bounds()
		nimg = image.NewRGBA(img.Bounds())
		for x := 0; x < size.Dx(); x++ {
			for y := 0; y < size.Dy(); y++ {
				r, g, b, a := img.At(x, y).RGBA()
				nimg.Set(x, y, color.NRGBA{uint8(r), uint8(g), uint8(b), uint8(a)})
			}
		}
	}
	f := freetype.NewContext()
	f.SetDPI(dpi)
	f.SetFontSize(size)
	f.SetFont(font)
	f.SetClip(nimg.Bounds())
	f.SetDst(nimg)
	f.SetSrc(image.NewUniform(colors))
	_, err = f.DrawString(text, freetype.Pt(x, y))
	if err != nil {
		return nil, err
	}
	return nimg, nil
}