package icon

import (
	"bytes"
	"encoding/binary"
	"image/png"
	"testing"
)

func TestTrayIsOpaqueOnTheBodyAndClearInTheKeyhole(t *testing.T) {
	img := Tray(32, Brand)
	if a := img.NRGBAAt(8, 26).A; a != 255 {
		t.Errorf("body pixel alpha %d, want 255", a)
	}
	if a := img.NRGBAAt(16, 20).A; a != 0 {
		t.Errorf("keyhole pixel alpha %d, want 0", a)
	}
	if a := img.NRGBAAt(1, 1).A; a != 0 {
		t.Errorf("corner pixel alpha %d, want 0", a)
	}
}

func TestAppHasAWhiteLockOnTheBadge(t *testing.T) {
	img := App(64)
	if c := img.NRGBAAt(32, 50); c.R != 255 || c.A != 255 {
		t.Errorf("lock body %v, want opaque white", c)
	}
	if c := img.NRGBAAt(4, 32); c != Brand {
		t.Errorf("badge edge %v, want %v", c, Brand)
	}
}

func TestICOHoldsEachSizeAsPNG(t *testing.T) {
	ico := ICO(Tray(16, Brand), Tray(256, Brand))
	var hdr [3]uint16
	if err := binary.Read(bytes.NewReader(ico), binary.LittleEndian, &hdr); err != nil {
		t.Fatal(err)
	}
	if hdr != [3]uint16{0, 1, 2} {
		t.Fatalf("header %v", hdr)
	}
	for i, want := range []int{16, 256} {
		e := ico[6+16*i:]
		size := binary.LittleEndian.Uint32(e[8:])
		off := binary.LittleEndian.Uint32(e[12:])
		img, err := png.Decode(bytes.NewReader(ico[off : off+size]))
		if err != nil {
			t.Fatalf("entry %d: %v", i, err)
		}
		if img.Bounds().Dx() != want {
			t.Errorf("entry %d is %dpx, want %d", i, img.Bounds().Dx(), want)
		}
	}
}