// Generates Store / MSIX PNG assets from assets/navis-icon.png.
package main

import (
	"fmt"
	"image"
	"image/color"
	"image/png"
	"os"
	"path/filepath"

	"golang.org/x/image/draw"
)

func main() {
	in := filepath.Join("assets", "navis-icon.png")
	outDir := filepath.Join("packaging", "msix", "Assets")
	if len(os.Args) > 1 {
		in = os.Args[1]
	}
	if len(os.Args) > 2 {
		outDir = os.Args[2]
	}
	f, err := os.Open(in)
	if err != nil {
		fatal(err)
	}
	defer f.Close()
	src, err := png.Decode(f)
	if err != nil {
		fatal(err)
	}
	if err := os.MkdirAll(outDir, 0o755); err != nil {
		fatal(err)
	}

	square := map[string]int{
		"StoreLogo.png":         50,
		"Square44x44Logo.png":   44,
		"Square71x71Logo.png":   71,
		"Square150x150Logo.png": 150,
		"Square310x310Logo.png": 310,
	}
	for name, size := range square {
		if err := writePNG(filepath.Join(outDir, name), scaleContain(src, size, size, color.RGBA{12, 22, 19, 255})); err != nil {
			fatal(err)
		}
	}
	// Wide tile + splash: brand mark centered on deep forest panel.
	if err := writePNG(filepath.Join(outDir, "Wide310x150Logo.png"), scaleContain(src, 310, 150, color.RGBA{12, 22, 19, 255})); err != nil {
		fatal(err)
	}
	if err := writePNG(filepath.Join(outDir, "SplashScreen.png"), scaleContain(src, 620, 300, color.RGBA{12, 22, 19, 255})); err != nil {
		fatal(err)
	}
	fmt.Println("Wrote Store assets to", outDir)
}

func scaleContain(src image.Image, w, h int, bg color.Color) image.Image {
	dst := image.NewRGBA(image.Rect(0, 0, w, h))
	draw.Draw(dst, dst.Bounds(), &image.Uniform{C: bg}, image.Point{}, draw.Src)
	sb := src.Bounds()
	sw, sh := sb.Dx(), sb.Dy()
	scale := float64(w) / float64(sw)
	if float64(h)/float64(sh) < scale {
		scale = float64(h) / float64(sh)
	}
	// Keep icon smaller than full tile for padding.
	scale *= 0.72
	nw, nh := int(float64(sw)*scale), int(float64(sh)*scale)
	if nw < 1 {
		nw = 1
	}
	if nh < 1 {
		nh = 1
	}
	x, y := (w-nw)/2, (h-nh)/2
	resized := image.NewRGBA(image.Rect(0, 0, nw, nh))
	draw.CatmullRom.Scale(resized, resized.Bounds(), src, sb, draw.Over, nil)
	draw.Draw(dst, image.Rect(x, y, x+nw, y+nh), resized, image.Point{}, draw.Over)
	return dst
}

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

func fatal(err error) {
	fmt.Fprintln(os.Stderr, err)
	os.Exit(1)
}