package main

import "strings"

// Shell surfaces often have an empty title and are omitted by upstream's
// ordinary application-window enumeration. They still require exact HWND/PID.
func shellKind(class string) string {
	switch class {
	case "Shell_TrayWnd", "Shell_SecondaryTrayWnd":
		return "taskbar"
	case "NotifyIconOverflowWindow", "TopLevelWindowForOverflowXamlIsland":
		return "tray"
	case "#32768":
		return "menu"
	case "Progman", "WorkerW":
		return "desktop"
	}
	return ""
}

func shellMatches(window, query obj) bool {
	if query["pid"] != nil && num(query["pid"]) != num(window["pid"]) {
		return false
	}
	app := strings.TrimSuffix(strings.ToLower(str(query["app"])), ".exe")
	name := strings.TrimSuffix(strings.ToLower(str(window["app_name"])), ".exe")
	return (app == "" || strings.Contains(name, app)) && (query["on_screen_only"] != true || window["is_on_screen"] == true)
}

func supplementShellWindows(result, query obj, native []obj) obj {
	if result["isError"] == true {
		return result
	}
	data := object(result["structuredContent"])
	windows, ok := data["windows"].([]any)
	if !ok { // Do not turn an upstream observation failure into a valid list.
		return result
	}
	known := map[int64]obj{}
	for _, value := range windows {
		w := object(value)
		known[num(w["window_id"])] = w
	}
	for _, w := range native {
		if shellKind(str(w["class_name"])) == "" || !shellMatches(w, query) {
			continue
		}
		if old, exists := known[num(w["window_id"])]; exists {
			old["class_name"] = w["class_name"]
			old["window_kind"] = shellKind(str(w["class_name"]))
		} else {
			w["window_kind"] = shellKind(str(w["class_name"]))
			windows = append(windows, w)
			known[num(w["window_id"])] = w
		}
	}
	data["windows"] = windows
	result["structuredContent"] = data
	return result
}

// Follow only native keyboard focus or a uniquely associated active menu.
// A different foreground application never silently becomes screenshot scope.
func postActionTarget(args, requested, focus obj, candidates []obj) (obj, string) {
	selected := object(focus["focus_root"])
	if focus["probe_ok"] != true {
		return observationArgs(args), "keyboard_focus_unavailable"
	}
	if focus["menu_active"] == true {
		owner := object(focus["menu_owner"])
		var menus []obj
		for _, w := range candidates {
			if shellKind(str(w["class_name"])) == "menu" && w["is_on_screen"] == true &&
				num(w["pid"]) == num(args["pid"]) && num(owner["pid"]) == num(args["pid"]) &&
				(num(w["owner_id"]) == num(owner["window_id"]) ||
					(num(w["thread_id"]) != 0 && num(w["thread_id"]) == num(owner["thread_id"]))) {
				menus = append(menus, w)
			}
		}
		if len(menus) == 1 {
			selected = menus[0]
		} else if len(menus) > 1 {
			return observationArgs(args), "ambiguous_active_menu_observe_candidates_explicitly"
		}
	}
	if num(selected["window_id"]) == num(args["window_id"]) {
		return observationArgs(args), "keyboard_focus_remains_in_requested_window"
	}
	if num(selected["pid"]) != num(args["pid"]) || selected["is_on_screen"] != true {
		return observationArgs(args), "unrelated_or_unverified_focus_not_followed"
	}
	kind := shellKind(str(selected["class_name"]))
	relatedShell := shellKind(str(requested["class_name"])) != "" && kind != "" && kind != "desktop"
	menuOwner := object(focus["menu_owner"])
	// Native #32768 menus can report GW_OWNER=0. GetGUIThreadInfo still
	// identifies their owning window; the candidate was also matched by PID
	// and UI thread above. Do not broaden this to arbitrary same-PID windows.
	relatedPopup := kind == "menu" && (num(selected["owner_id"]) == num(args["window_id"]) ||
		(focus["menu_active"] == true && num(menuOwner["window_id"]) == num(args["window_id"])))
	if !relatedShell && !relatedPopup {
		return observationArgs(args), "unrelated_focus_not_followed"
	}
	next := observationArgs(args)
	next["pid"], next["window_id"] = selected["pid"], selected["window_id"]
	return next, "associated_native_keyboard_focus"
}