// 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 TestNativeMateWindowSwitcherOutsideForeground(t *testing.T) {
	if os.Getenv("CTHULHU_NATIVE_WINDOW_SWITCHER") != "1" {
		t.Skip("requires private Xorg/AT-SPI session")
	}
	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(name string) (io.WriteCloser, string) {
		command := exec.CommandContext(ctx, "/usr/bin/python3", "../../tests/gtk_window_switcher.py", name)
		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) != 2 || fields[0] != "ready" {
			t.Fatalf("fixture readiness: %q, %v", line, err)
		}
		return input, fields[1]
	}
	switcher, _ := start("marco")
	foreground, xid := start("editor")
	if _, err := adapter.CaptureDesktop(ctx); err != nil {
		t.Fatal(err)
	}
	if output, err := exec.CommandContext(ctx, "xdotool", "windowfocus", "--sync", xid).CombinedOutput(); err != nil {
		t.Fatalf("focus: %s, %v", output, err)
	}
	wait := func(eventType, title string, switcher bool) Event {
		t.Helper()
		var last Event
		count := 0
		for {
			select {
			case event := <-adapter.Events():
				last = event
				count++
				if event.Type == eventType && (event.Source.Name == title || event.Payload == title) {
					if IsWindowSwitcherSelection(event) != switcher {
						t.Fatalf("switcher classification: %+v", event)
					}
					return event
				}
			case <-ctx.Done():
				t.Fatalf("missing %s %q; background-filtered=%d received=%d last=%+v", eventType, title, adapter.backgroundEventsFiltered.Load(), count, last)
			}
		}
	}
	fmt.Fprintln(foreground, "select Foreground ready")
	owned := wait(TextInsertedEvent, "Foreground ready", false)
	if owned.ForegroundMismatch || !owned.Foreground.Client.Known {
		t.Fatalf("fixture has no correlated foreground: %+v", owned)
	}
	for _, title := range []string{"Editor", "Terminal", "Editor"} {
		fmt.Fprintln(switcher, "select "+title)
		event := wait(TextInsertedEvent, title, true)
		if !event.ForegroundMismatch || event.Foreground != owned.Foreground || event.Source.Focused {
			t.Fatalf("switcher acquired foreground/native focus: %+v", event)
		}
	}
	fmt.Fprintln(switcher, "showing")
	wait(ShowingStateEvent, "Editor", true)
	// The provider stays separate from the old foreground after the popup
	// disappears. Ordinary application events still use native correlation.
	fmt.Fprintln(switcher, "hide")
	fmt.Fprintln(foreground, "select Foreground retained")
	retained := wait(TextInsertedEvent, "Foreground retained", false)
	if retained.ForegroundMismatch || retained.Window != owned.Window {
		t.Fatalf("switcher changed foreground ownership: %+v", retained)
	}
}