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

package sessionbus

import (
	"bufio"
	"bytes"
	"context"
	"log/slog"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"

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

func TestSessionBusHelper(t *testing.T) {
	expectedID := os.Getenv("CTHULHU_SESSIONBUS_EXPECTED_ID")
	if expectedID == "" {
		t.Skip("subprocess helper")
	}
	before, present := os.LookupEnv("DBUS_SESSION_BUS_ADDRESS")
	var output bytes.Buffer
	logger := slog.New(slog.NewJSONHandler(&output, &slog.HandlerOptions{Level: slog.LevelDebug}))
	connection, err := Connect(logger, "test")
	if err != nil {
		t.Fatal(err)
	}
	defer connection.Close()
	var busID string
	if err := connection.BusObject().Call("org.freedesktop.DBus.GetId", 0).Store(&busID); err != nil {
		t.Fatal(err)
	}
	if busID != expectedID {
		t.Fatalf("selected bus %q, want %q", busID, expectedID)
	}
	if after, exists := os.LookupEnv("DBUS_SESSION_BUS_ADDRESS"); after != before || exists != present {
		t.Fatal("session discovery changed process environment")
	}
	if !strings.Contains(output.String(), `"bus_id":"`+expectedID+`"`) {
		t.Fatal("missing bus identity diagnostic")
	}
	if strings.Contains(output.String(), os.Getenv("XDG_RUNTIME_DIR")) {
		t.Fatal("diagnostic exposes runtime directory")
	}
}

func TestNativeDesktopSessionBusDiscovery(t *testing.T) {
	if os.Getenv("CTHULHU_NATIVE_DBUS_TEST") != "1" {
		t.Skip("requires private session bus sockets")
	}
	startBus := func() (string, string, string) {
		runtimeDirectory := t.TempDir()
		process := exec.Command("dbus-daemon", "--session", "--nofork", "--address=unix:path="+filepath.Join(runtimeDirectory, "bus"), "--print-address=1")
		stdout, err := process.StdoutPipe()
		if err != nil {
			t.Fatal(err)
		}
		if err := process.Start(); err != nil {
			t.Fatal(err)
		}
		t.Cleanup(func() { process.Process.Kill(); process.Wait() })
		address, err := bufio.NewReader(stdout).ReadString('\n')
		if err != nil {
			t.Fatal(err)
		}
		connection, err := dbus.Connect(strings.TrimSpace(address))
		if err != nil {
			t.Fatal(err)
		}
		defer connection.Close()
		var busID string
		if err := connection.BusObject().CallWithContext(context.Background(), "org.freedesktop.DBus.GetId", 0).Store(&busID); err != nil {
			t.Fatal(err)
		}
		return runtimeDirectory, strings.TrimSpace(address), busID
	}
	runtimeDirectory, _, runtimeID := startBus()
	_, explicitAddress, explicitID := startBus()
	executable, err := os.Executable()
	if err != nil {
		t.Fatal(err)
	}
	for _, explicit := range []bool{false, true} {
		expectedID := runtimeID
		environment := make([]string, 0)
		for _, value := range os.Environ() {
			if !strings.HasPrefix(value, "DBUS_SESSION_BUS_ADDRESS=") && !strings.HasPrefix(value, "XDG_RUNTIME_DIR=") {
				environment = append(environment, value)
			}
		}
		if explicit {
			environment = append(environment, "DBUS_SESSION_BUS_ADDRESS="+explicitAddress)
			expectedID = explicitID
		}
		environment = append(environment, "XDG_RUNTIME_DIR="+runtimeDirectory, "CTHULHU_SESSIONBUS_EXPECTED_ID="+expectedID)
		process := exec.Command(executable, "-test.run=^TestSessionBusHelper$", "-test.v")
		process.Env = environment
		if output, err := process.CombinedOutput(); err != nil {
			t.Fatalf("explicit=%v: %v\n%s", explicit, err, output)
		}
	}
}