//go:build linux

package openfolder

import (
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"strings"

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

func OpenLocation(path string) error {
	if isKDESession() {
		if err := openFolderKDEDBus(path); err == nil {
			return nil
		}
		// Fallback: launching dolphin directly typically forwards to an existing
		// instance (opening a tab) and avoids portal/session-restore oddities.
		if err := exec.Command("dolphin", path).Start(); err == nil {
			return nil
		}
	}

	return exec.Command("xdg-open", path).Start()
}

func isKDESession() bool {
	// Plasma sets XDG_CURRENT_DESKTOP=KDE. Some setups provide multiple entries.
	cd := strings.ToLower(strings.TrimSpace(os.Getenv("XDG_CURRENT_DESKTOP")))
	return strings.Contains(cd, "kde")
}

// openFolderKDEDBus asks the running file manager (Dolphin on Plasma) to show
// the folder via D-Bus. This tends to reuse an existing Dolphin window and open
// a new tab instead of spawning a new window and restoring unrelated session
// tabs.
//
// Note: On Plasma Wayland, reliably forcing the window to the foreground is
// gated by XDG activation mechanisms; we do a best-effort activation call but it may
// be ignored by the compositor.
func openFolderKDEDBus(path string) error {
	conn, err := dbus.SessionBus()
	if err != nil {
		return err
	}
	defer conn.Close()

	uri := (&url.URL{Scheme: "file", Path: filepath.ToSlash(path)}).String()
	obj := conn.Object("org.freedesktop.FileManager1", dbus.ObjectPath("/org/freedesktop/FileManager1"))
	call := obj.Call("org.freedesktop.FileManager1.ShowFolders", 0, []string{uri}, "")
	if call.Err != nil {
		return call.Err
	}

	// Best-effort activation of an existing Dolphin window.
	if dolphinSvc, _ := findFirstDBusName(conn, "org.kde.dolphin-"); dolphinSvc != "" {
		app := conn.Object(dolphinSvc, dbus.ObjectPath("/org/kde/dolphin"))
		_ = app.Call("org.freedesktop.Application.Activate", 0, map[string]dbus.Variant{}).Err
	}

	return nil
}

func findFirstDBusName(conn *dbus.Conn, prefix string) (string, error) {
	var names []string
	if err := conn.BusObject().Call("org.freedesktop.DBus.ListNames", 0).Store(&names); err != nil {
		return "", err
	}
	for _, n := range names {
		if strings.HasPrefix(n, prefix) {
			return n, nil
		}
	}
	return "", nil
}