// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

package notify

import (
	"bytes"
	"image"
	"image/color"
	"image/png"
	"testing"

	"github.com/godbus/dbus/v5"
)

// rawVariant builds the (iiibiiay) struct the bus delivers for image-data.
func rawVariant(w, h, stride int, alpha bool, ch int, data []byte) dbus.Variant {
	return dbus.MakeVariant([]interface{}{
		int32(w), int32(h), int32(stride), alpha, int32(8), int32(ch), data,
	})
}

func TestImageDataFromHints(t *testing.T) {
	// 2x1 RGBA: red, green.
	rgba := []byte{255, 0, 0, 255, 0, 255, 0, 255}
	cases := []struct {
		name  string
		hints map[string]dbus.Variant
		wantW int
		want  bool
	}{
		{"image-data wins", map[string]dbus.Variant{
			"image-data": rawVariant(2, 1, 8, true, 4, rgba),
			"icon_data":  rawVariant(9, 9, 8, true, 4, rgba),
			"image-path": dbus.MakeVariant("/tmp/x.png"),
		}, 2, true},
		{"image_data alias", map[string]dbus.Variant{
			"image_data": rawVariant(2, 1, 8, true, 4, rgba),
		}, 2, true},
		{"icon_data is not tier 1", map[string]dbus.Variant{
			"icon_data": rawVariant(2, 1, 8, true, 4, rgba),
		}, 0, false},
		{"absent", map[string]dbus.Variant{}, 0, false},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			got, ok := ImageDataFromHints(c.hints)
			if ok != c.want {
				t.Fatalf("ok = %v, want %v", ok, c.want)
			}
			if ok && got.Width != c.wantW {
				t.Fatalf("width = %d, want %d", got.Width, c.wantW)
			}
		})
	}
}

func TestIconDataFromHints(t *testing.T) {
	rgba := []byte{255, 0, 0, 255, 0, 255, 0, 255}
	if got, ok := IconDataFromHints(map[string]dbus.Variant{
		"icon_data": rawVariant(2, 1, 8, true, 4, rgba),
	}); !ok || got.Width != 2 {
		t.Fatalf("icon_data got %v ok=%v", got, ok)
	}
	if _, ok := IconDataFromHints(map[string]dbus.Variant{
		"image-data": rawVariant(2, 1, 8, true, 4, rgba),
	}); ok {
		t.Fatal("image-data must not be read as icon_data")
	}
}

func TestImagePathFromHints(t *testing.T) {
	got, ok := ImagePathFromHints(map[string]dbus.Variant{"image-path": dbus.MakeVariant("/tmp/shot.png")})
	if !ok || got != "/tmp/shot.png" {
		t.Fatalf("got %q ok=%v", got, ok)
	}
	if _, ok := ImagePathFromHints(map[string]dbus.Variant{}); ok {
		t.Fatal("empty hints must not report a path")
	}
}

// checkPixel asserts the RGBA of img at (x,y) matches want.
func checkPixel(t *testing.T, img image.Image, x, y int, want color.RGBA) {
	t.Helper()
	r, g, b, a := img.At(x, y).RGBA()
	if r>>8 != uint32(want.R) || g>>8 != uint32(want.G) || b>>8 != uint32(want.B) || a>>8 != uint32(want.A) {
		t.Fatalf("pixel (%d,%d) = %d %d %d %d, want %v", x, y, r>>8, g>>8, b>>8, a>>8, want)
	}
}

func TestRawImagePNG(t *testing.T) {
	// 2x2 RGBA with a rowstride wider than Width*Channels. The second row is
	// the point: if stride were ignored, row 1 would read the row-0 padding.
	r := &RawImage{Width: 2, Height: 2, RowStride: 12, HasAlpha: true, BitsPerSample: 8, Channels: 4,
		Data: []byte{
			255, 0, 0, 255, 0, 255, 0, 255, 9, 9, 9, 9, // row 0: red, green, pad
			0, 0, 255, 255, 255, 255, 255, 255, 9, 9, 9, 9, // row 1: blue, white, pad
		}}
	data, err := r.PNG()
	if err != nil {
		t.Fatalf("PNG: %v", err)
	}
	img, err := png.Decode(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("decode: %v", err)
	}
	if img.Bounds().Dx() != 2 || img.Bounds().Dy() != 2 {
		t.Fatalf("bounds = %v", img.Bounds())
	}
	checkPixel(t, img, 0, 0, color.RGBA{255, 0, 0, 255})
	checkPixel(t, img, 1, 0, color.RGBA{0, 255, 0, 255})
	checkPixel(t, img, 0, 1, color.RGBA{0, 0, 255, 255})
	checkPixel(t, img, 1, 1, color.RGBA{255, 255, 255, 255})
}

func TestRawImagePNGThreeChannel(t *testing.T) {
	// 2x1 RGB, no alpha byte: PNG() must force opaque.
	r := &RawImage{Width: 2, Height: 1, RowStride: 6, HasAlpha: false, BitsPerSample: 8, Channels: 3,
		Data: []byte{255, 0, 0, 0, 255, 0}}
	data, err := r.PNG()
	if err != nil {
		t.Fatalf("PNG: %v", err)
	}
	img, err := png.Decode(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("decode: %v", err)
	}
	if img.Bounds().Dx() != 2 || img.Bounds().Dy() != 1 {
		t.Fatalf("bounds = %v", img.Bounds())
	}
	checkPixel(t, img, 0, 0, color.RGBA{255, 0, 0, 255})
	checkPixel(t, img, 1, 0, color.RGBA{0, 255, 0, 255})
}

func TestRawImagePNGRejectsBadData(t *testing.T) {
	if _, err := (&RawImage{Width: 0, Height: 1, Channels: 4, BitsPerSample: 8}).PNG(); err == nil {
		t.Fatal("zero width must error")
	}
	if _, err := (&RawImage{Width: 1, Height: 1, Channels: 2, BitsPerSample: 8}).PNG(); err == nil {
		t.Fatal("channels 2 must error")
	}
	// 2x2 RGBA needs 16 bytes; the slice holds one row.
	if _, err := (&RawImage{Width: 2, Height: 2, RowStride: 8, BitsPerSample: 8, Channels: 4,
		Data: []byte{0, 0, 0, 255, 255, 255, 255, 255}}).PNG(); err == nil {
		t.Fatal("short data must error")
	}
	// Dimensions straight off the bus: with RowStride 0 the stride*(Height-1)
	// product overflows to negative and used to slip past the guard into
	// image.NewRGBA. Must error, not panic.
	if _, err := (&RawImage{
		Width: 1<<31 - 1, Height: 1<<31 - 1, RowStride: 0,
		BitsPerSample: 8, Channels: 4, Data: []byte{0, 0, 0, 255},
	}).PNG(); err == nil {
		t.Fatal("oversized dimensions must error")
	}
}