// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package atspi

import (
	"bufio"
	"context"
	"fmt"
	"io"
	"os"
	"os/exec"
	"strings"
	"testing"
	"time"
)

func TestNativeEmbeddedPanelApplet(t *testing.T) {
	if os.Getenv("CTHULHU_NATIVE_PANEL_APPLET") != "1" {
		t.Skip("requires private Xorg/AT-SPI session")
	}
	// Embedding belongs to the window ancestry contract, not a process-name
	// exception. Both MATE and an ordinary GTK host must retain ownership.
	for _, hostName := range []string{"panel", "other-host"} {
		t.Run(hostName, func(t *testing.T) { check_native_embedded_applet(t, hostName) })
	}
}

func check_native_embedded_applet(t *testing.T, hostName string) {
	t.Helper()
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
	defer cancel()
	adapter := New()
	if err := adapter.Start(ctx); err != nil {
		t.Fatal(err)
	}
	defer adapter.Stop(context.Background())
	start := func(args ...string) (io.WriteCloser, string, string) {
		t.Helper()
		command := exec.CommandContext(ctx, "/usr/bin/python3", append([]string{"../../tests/gtk_panel_applet.py"}, args...)...)
		input, err := command.StdinPipe()
		if err != nil {
			t.Fatal(err)
		}
		output, err := command.StdoutPipe()
		if err != nil {
			t.Fatal(err)
		}
		command.Stderr = os.Stderr
		if err := command.Start(); err != nil {
			t.Fatal(err)
		}
		t.Cleanup(func() { input.Close(); command.Process.Kill(); command.Wait() })
		line, err := bufio.NewReader(output).ReadString('\n')
		fields := strings.Fields(line)
		if err != nil || len(fields) != 3 || fields[0] != "ready" {
			t.Fatalf("fixture readiness: %q, %v", line, err)
		}
		return input, fields[1], fields[2]
	}
	host, xid, socketID := start(hostName)
	applet, _, _ := start("applet", socketID)
	editor, editorXID, _ := start("editor")
	wait := func(predicate func(Event) bool) Event {
		t.Helper()
		var last Event
		for {
			select {
			case event := <-adapter.Events():
				last = event
				if predicate(event) {
					return event
				}
			case <-ctx.Done():
				t.Fatalf("native event missing; filtered=%d last=%s %q window=%+v mismatch=%v", adapter.backgroundEventsFiltered.Load(), last.Type, last.Source.Name, last.Window, last.ForegroundMismatch)
			}
		}
	}
	key := func(args ...string) {
		t.Helper()
		if output, err := exec.CommandContext(ctx, "xdotool", args...).CombinedOutput(); err != nil {
			t.Fatalf("xdotool %v: %s, %v", args, output, err)
		}
	}
	key("windowfocus", "--sync", xid)
	fmt.Fprintln(host, "first")
	owned := wait(func(event Event) bool {
		return event.Source.Name == "Before applet" && event.Source.Focused && !event.ForegroundMismatch
	})
	key("key", "Tab")
	icon := wait(func(event Event) bool { return event.Source.Role == "icon" && event.Source.Focused })
	if icon.ForegroundMismatch || icon.Window != owned.Window || icon.Source.BusName == owned.Source.BusName || icon.Foreground != owned.Foreground {
		t.Fatalf("embedded icon lost host ownership: host=%+v icon=%+v source=%+v mismatch=%v foreground=%+v want=%+v", owned.Window, icon.Window, icon.Source.ID(), icon.ForegroundMismatch, icon.Foreground, owned.Foreground)
	}
	if icon.Source.Name != "Network applet" || icon.Source.ApplicationProcess != "applet" {
		t.Fatalf("embedded icon lost its label or provider identity: %+v", icon)
	}
	key("key", "Tab")
	wait(func(event Event) bool {
		return event.Source.Name == "Applet settings" && event.Source.Focused && event.Window == owned.Window && !event.ForegroundMismatch
	})
	key("key", "shift+Tab")
	wait(func(event Event) bool {
		return event.Source.Role == "icon" && event.Source.Focused && !event.ForegroundMismatch
	})
	key("key", "Tab")
	wait(func(event Event) bool {
		return event.Source.Name == "Applet settings" && event.Source.Focused && !event.ForegroundMismatch
	})
	key("key", "Tab")
	wait(func(event Event) bool {
		return event.Source.Name == "After applet" && event.Source.Focused && !event.ForegroundMismatch
	})
	for _, name := range []string{"Applet settings", "Network applet", "Before applet"} {
		key("key", "shift+Tab")
		wait(func(event Event) bool {
			return event.Source.Name == name && event.Source.Focused && !event.ForegroundMismatch
		})
	}
	key("windowfocus", "--sync", editorXID)
	fmt.Fprintln(editor, "edit Foreground restored")
	wait(func(event Event) bool { return event.Payload == "Foreground restored" && !event.ForegroundMismatch })
	fmt.Fprintln(applet, "stale")
	wait(func(event Event) bool {
		if event.Source.Role == "icon" && !event.ForegroundMismatch {
			t.Fatalf("background applet stole foreground: %+v", event)
		}
		return event.Payload == "Applet barrier"
	})
	// A separately published applet window cannot borrow the host's identity.
	standalone, standaloneXID, _ := start("standalone")
	key("windowfocus", "--sync", standaloneXID)
	fmt.Fprintln(standalone, "first")
	wait(func(event Event) bool {
		return event.Source.Role == "icon" && event.Source.Focused && !event.ForegroundMismatch
	})
	key("windowfocus", "--sync", xid)
	fmt.Fprintln(host, "first")
	wait(func(event Event) bool {
		return event.Source.Name == "Before applet" && event.Source.Focused && !event.ForegroundMismatch
	})
	fmt.Fprintln(standalone, "stale")
	wait(func(event Event) bool {
		if event.Source.Role == "icon" && !event.ForegroundMismatch {
			t.Fatalf("unembedded applet borrowed host ownership: %+v", event)
		}
		return event.Payload == "Applet barrier"
	})
	fmt.Fprintln(host, "detach")
	wait(func(event Event) bool { return event.Payload == "Detached host barrier" })
	fmt.Fprintln(applet, "stale")
	wait(func(event Event) bool {
		if event.Source.Role == "icon" && !event.ForegroundMismatch {
			t.Fatalf("detached applet retained host ownership: %+v", event)
		}
		return event.Payload == "Applet barrier"
	})
}