package display

import (
	"errors"
	"strings"
	"testing"

	"github.com/BurntSushi/xgb/shape"
	"github.com/BurntSushi/xgb/xproto"
)

func TestX11FullscreenArgsOrderByRole(t *testing.T) {
	below := strings.Join(x11FullscreenArgs(0x1a2b, RoleBelow), " ")
	if !strings.Contains(below, "add,fullscreen,below") {
		t.Fatalf("args %q must request fullscreen with below stacking", below)
	}
	if !strings.Contains(below, "0x00001a2b") {
		t.Fatalf("args %q must reference the kiosk window id", below)
	}

	above := strings.Join(x11FullscreenArgs(0x1a2b, RoleAbove), " ")
	if strings.Contains(above, "below") {
		t.Fatalf("args %q must never stack the OSD overlay below video", above)
	}
	if !strings.Contains(above, "add,fullscreen,above") {
		t.Fatalf("args %q must request fullscreen with above stacking", above)
	}
}

func TestX11SessionRedrawsOnlyOnExpose(t *testing.T) {
	if !x11WantsRedraw(xproto.ExposeEvent{}) {
		t.Fatal("expose events must trigger a redraw")
	}
	if x11WantsRedraw(xproto.MapNotifyEvent{}) {
		t.Fatal("map notify events must not trigger a redraw")
	}
}

func TestX11OpenerAppliesFullscreenArgsThroughHook(t *testing.T) {
	var got [][]string
	opener := X11Opener{Fullscreen: func(args []string) error {
		got = append(got, args)
		return errors.New("wmctrl missing")
	}}

	if err := opener.applyFullscreen(x11FullscreenArgs(0x42, RoleBelow)); err == nil {
		t.Fatal("hook error must propagate for logging")
	}
	if len(got) != 1 || !strings.Contains(strings.Join(got[0], " "), "add,fullscreen,below") {
		t.Fatalf("hook args %v must request fullscreen with below stacking", got)
	}
}

func TestClassifyVideoChangeTracksVideoWindowLifecycle(t *testing.T) {
	const own = xproto.Window(0x10)
	const video = xproto.Window(0x20)
	const other = xproto.Window(0x30)

	change, w := classifyVideoChange(xproto.MapNotifyEvent{Window: video}, own)
	if change != videoAppeared || w != video {
		t.Fatalf("map of a foreign window must announce video, got %v %v", change, w)
	}

	change, _ = classifyVideoChange(xproto.MapNotifyEvent{Window: own}, own)
	if change != videoUnrelated {
		t.Fatalf("map of the kiosk window must be unrelated, got %v", change)
	}

	change, w = classifyVideoChange(xproto.UnmapNotifyEvent{Window: video}, own)
	if change != videoDisappeared || w != video {
		t.Fatalf("unmap must announce a video end candidate, got %v %v", change, w)
	}

	change, _ = classifyVideoChange(xproto.UnmapNotifyEvent{Window: own}, own)
	if change != videoUnrelated {
		t.Fatalf("unmap of the kiosk window must be unrelated, got %v", change)
	}

	change, w = classifyVideoChange(xproto.UnmapNotifyEvent{Window: other}, own)
	if change != videoDisappeared || w != other {
		t.Fatalf("unmap of a foreign window must be an end candidate, got %v %v", change, w)
	}

	change, w = classifyVideoChange(xproto.DestroyNotifyEvent{Window: video}, own)
	if change != videoDisappeared || w != video {
		t.Fatalf("destroy must announce a video end candidate, got %v %v", change, w)
	}

	change, _ = classifyVideoChange(xproto.ExposeEvent{}, own)
	if change != videoUnrelated {
		t.Fatalf("expose must not change video presence, got %v", change)
	}
}

func TestAddAndRemoveVideoWindowTrackPresenceTransitions(t *testing.T) {
	const video = xproto.Window(0x20)
	const second = xproto.Window(0x30)
	windows := make(map[xproto.Window]struct{})

	if !addVideoWindow(windows, video) {
		t.Fatal("first video window must change presence")
	}
	if addVideoWindow(windows, video) {
		t.Fatal("re-adding the tracked window must not change presence")
	}
	if addVideoWindow(windows, second) {
		t.Fatal("a second video window must not change presence")
	}
	if removeVideoWindow(windows, second) {
		t.Fatal("removing one of two video windows must not change presence")
	}
	if !removeVideoWindow(windows, video) {
		t.Fatal("removing the last video window must change presence")
	}
	if removeVideoWindow(windows, video) {
		t.Fatal("removing an untracked window must not change presence")
	}
	if len(windows) != 0 {
		t.Fatalf("set %v must be empty after all video ended", windows)
	}
}

func TestEWMHNonVideoWindowTypesExcludeDesktopHelpers(t *testing.T) {
	for _, name := range []string{"DOCK", "DESKTOP", "TOOLBAR", "MENU", "UTILITY", "SPLASH", "DIALOG", "NOTIFICATION", "TOOLTIP"} {
		if !ewmhNonVideoTypes[name] {
			t.Fatalf("window type %q must not count as video", name)
		}
	}
	for _, name := range []string{"NORMAL", "", "VIDEO_PLAY"} {
		if ewmhNonVideoTypes[name] {
			t.Fatalf("window type %q must count as video", name)
		}
	}
}

func TestUTF16Char2bEncodesPolishFallbackText(t *testing.T) {
	chars := utf16Char2b(wantFallbackText, maxImageText16Units)
	want := []xproto.Char2b{
		{Byte1: 0, Byte2: 'B'}, {Byte1: 0, Byte2: 'r'}, {Byte1: 0, Byte2: 'a'}, {Byte1: 0, Byte2: 'k'}, {Byte1: 0, Byte2: ' '},
		{Byte1: 0, Byte2: 'p'}, {Byte1: 0, Byte2: 'o'},
		{Byte1: 0x01, Byte2: 0x42}, // ł
		{Byte1: 0x01, Byte2: 0x05}, // ą
		{Byte1: 0, Byte2: 'c'}, {Byte1: 0, Byte2: 'z'}, {Byte1: 0, Byte2: 'e'}, {Byte1: 0, Byte2: 'n'}, {Byte1: 0, Byte2: 'i'}, {Byte1: 0, Byte2: 'a'}, {Byte1: 0, Byte2: ' '},
		{Byte1: 0, Byte2: 'W'}, {Byte1: 0, Byte2: 'F'}, {Byte1: 0, Byte2: 'B'},
	}
	if len(chars) != len(want) {
		t.Fatalf("units=%v want %v", chars, want)
	}
	for i := range want {
		if chars[i] != want[i] {
			t.Fatalf("unit %d=%v want %v", i, chars[i], want[i])
		}
	}
}

func TestUTF16Char2bTruncatesToOneRequestLength(t *testing.T) {
	if chars := utf16Char2b(wantFallbackText, 10); len(chars) != 10 {
		t.Fatalf("units=%d want 10", len(chars))
	}
}

func TestUTF16Char2bNeverSplitsSurrogatePairs(t *testing.T) {
	// U+1F3A5 encodes as a surrogate pair (0xD83C, 0xDFA5): a cut that would
	// land between the two units must back off instead of splitting it.
	if chars := utf16Char2b("a🎥", 2); len(chars) != 1 || chars[0].Byte2 != 'a' {
		t.Fatalf("units=%v want only the leading ASCII unit", chars)
	}
	if chars := utf16Char2b("🎥", 1); len(chars) != 0 {
		t.Fatalf("units=%v want none, the pair does not fit", chars)
	}
	if chars := utf16Char2b("🎥", 2); len(chars) != 2 {
		t.Fatalf("units=%v want the intact pair", chars)
	}
	if chars := utf16Char2b(wantFallbackText, 0); len(chars) != 0 {
		t.Fatalf("units=%v want none for a zero limit", chars)
	}
}

func TestFoldToASCIIStripsPolishDiacritics(t *testing.T) {
	if got := foldToASCII(wantFallbackText); got != "Brak polaczenia WFB" {
		t.Fatalf("foldToASCII=%q want %q", got, "Brak polaczenia WFB")
	}
}

func TestFoldToASCIIKeepsPlainASCIIUntouched(t *testing.T) {
	if got := foldToASCII("plain text"); got != "plain text" {
		t.Fatalf("foldToASCII=%q want %q", got, "plain text")
	}
}

func TestX11FontPatternRequestsUnicodeFixedFont(t *testing.T) {
	if !strings.Contains(iso10646FontPattern, "fixed") {
		t.Fatalf("font pattern %q must select a fixed font", iso10646FontPattern)
	}
	if !strings.Contains(iso10646FontPattern, "iso10646") {
		t.Fatalf("font pattern %q must select a Unicode encoding for the exact fallback text", iso10646FontPattern)
	}
}

func TestLayerMarkerIdentifiesOwnLayerWindows(t *testing.T) {
	if layerMarkerValue(RoleBelow) == layerMarkerValue(RoleAbove) {
		t.Fatal("roles must carry distinct marker payloads")
	}
	for _, role := range []LayerRole{RoleBelow, RoleAbove} {
		if !markerIsGroundstation(layerMarkerValue(role)) {
			t.Fatalf("marker %q must identify our own window", layerMarkerValue(role))
		}
	}
	for _, foreign := range []string{"", "video", "desktop", "groundstation-fake"} {
		if markerIsGroundstation(foreign) {
			t.Fatalf("foreign marker payload %q must not identify our windows", foreign)
		}
	}
}

func TestMarkerWalkBoundsStayBoundedAndCoverFrameDepth(t *testing.T) {
	depth, nodes := markerWalkBounds()
	if depth <= 0 || nodes <= 0 {
		t.Fatalf("marker walk bounds depth=%d nodes=%d must be positive", depth, nodes)
	}
	if nodes < depth {
		t.Fatalf("node budget %d must cover at least a depth-%d ancestor chain", nodes, depth)
	}
	// A reparenting window manager puts each of our two layer windows inside
	// its own frame, so the walk must reach our window below one frame.
	if depth < 2 {
		t.Fatalf("marker walk depth %d must cover our window below a window-manager frame", depth)
	}
}

func TestEWMHWindowTypeAnnouncesOverlayRoleOnly(t *testing.T) {
	if name := ewmhWindowTypeName(RoleAbove); !strings.Contains(name, "DOCK") {
		t.Fatalf("OSD overlay window type %q must be the always-above helper role", name)
	}
	if name := ewmhWindowTypeName(RoleBelow); name != "" {
		t.Fatalf("fallback canvas must keep announcing no window type, got %q", name)
	}
}

func TestPresentedVideoDecisionExcludesOwnLayersAndHelpers(t *testing.T) {
	video := windowFacts{inputOutput: true, viewable: true}
	if !isPresentedVideoWindow(video) {
		t.Fatal("a presented output window must count as video")
	}
	for name, facts := range map[string]windowFacts{
		"input-only":           {viewable: true},
		"override-redirect":    {inputOutput: true, viewable: true, overrideRedirect: true},
		"unmapped":             {inputOutput: true},
		"auxiliary":            {inputOutput: true, viewable: true, auxiliary: true},
		"groundstation-canvas": {inputOutput: true, viewable: true, groundstation: true},
		"groundstation-osd":    {inputOutput: true, viewable: true, groundstation: true},
	} {
		if isPresentedVideoWindow(facts) {
			t.Fatalf("%s window must never count as video", name)
		}
	}
	// Window-manager frames around our layer windows carry no marker of
	// their own; groundstationLayerWindow finds the marker below the frame,
	// so framed Ground Station layers land in these same excluded facts.
}

func TestStackOrderByRoleKeepsLayersOnTheirSideOfVideo(t *testing.T) {
	if mode := stackModeForVideoAppear(RoleBelow); mode != xproto.StackModeBelow {
		t.Fatalf("canvas must park below appearing video, got %v", mode)
	}
	if mode := stackModeForVideoAppear(RoleAbove); mode != xproto.StackModeAbove {
		t.Fatalf("OSD overlay must rise above appearing video, got %v", mode)
	}
	if !raisesOnVideoEnd(RoleBelow) {
		t.Fatal("canvas must raise itself when video ends so the fallback returns")
	}
	if raisesOnVideoEnd(RoleAbove) {
		t.Fatal("OSD overlay is already above video and must not restack on video end")
	}
}

func TestOSDEventMaskNeverSelectsDeviceInput(t *testing.T) {
	if osdEventMask&deviceInputEventMask != 0 {
		t.Fatalf("OSD event mask must not select pointer or key input: %b", osdEventMask)
	}
	if osdEventMask&xproto.EventMaskExposure == 0 {
		t.Fatal("OSD event mask must still select exposure for redraws")
	}
}

func TestTransparentShapesEmptyInputAndOutput(t *testing.T) {
	var input, output bool
	for _, kind := range transparentShapeKinds() {
		switch kind {
		case shape.SkInput:
			input = true
		case shape.SkBounding:
			output = true
		}
	}
	if !input || !output {
		t.Fatalf("shape kinds %v must empty both the input and the bounding region", transparentShapeKinds())
	}
}