class_name BrowserApp
extends ImplantApp
## Data browser implant app (T-1133, D-254 §4). A SEPARATE app from the Atlas
## (implant/map) — the six registry entities do not share the Atlas's
## geographic drill-down (D-254 SS4, Jeroen's IA ruling). Registered as
## "implant/browser" in FULLSCREEN mode, key B.
##
## Nav: kind menu (root) -> index (per kind, scrollable + searchable) ->
## detail (per entity). Same push/pop convention the Atlas app uses.
##
## Composed entirely from D-169 implant components via the three screen
## classes below (BrowserKindMenuScreen/BrowserIndexScreen/BrowserDetailScreen)
## — no new UI primitives.

var _kind_menu_screen = null  # BrowserKindMenuScreen
var _index_screen = null  # BrowserIndexScreen
var _detail_screen = null  # BrowserDetailScreen


func _ready() -> void:
	manifest = load("res://ui/implant/apps/browser/app.tres")
	super._ready()


func on_install() -> void:
	var implant_theme = load("res://ui/implant/default_implant.tres")

	_kind_menu_screen = BrowserKindMenuScreen.new()
	_kind_menu_screen.setup(implant_theme)
	_kind_menu_screen.kind_selected.connect(_on_kind_selected)
	register_screen("kind_menu", _kind_menu_screen)

	_index_screen = BrowserIndexScreen.new()
	_index_screen.setup(implant_theme)
	_index_screen.row_selected.connect(_on_row_selected)
	register_screen("index", _index_screen)

	_detail_screen = BrowserDetailScreen.new()
	_detail_screen.setup(implant_theme)
	register_screen("detail", _detail_screen)

	SimBridge.browse_response_received.connect(_on_browse_response_received)

	nav.set_default("kind_menu")


func _unhandled_key_input(event: InputEvent) -> void:
	if not event is InputEventKey:
		return
	if manifest == null or not HudGroups.is_app_active(manifest.app_path):
		return
	if not event.is_pressed() or event.is_echo():
		return
	_handle_key(event as InputEventKey)
	get_viewport().set_input_as_handled()


func _handle_key(event: InputEventKey) -> void:
	# Search-mode: on the index screen, printable keys type into the live
	# filter instead of being interpreted as navigation. Split into its own
	# function (not inlined here) — it is a genuinely separate input mode
	# from the top-level app navigation below, and keeping it here would
	# push this function's branch/return count well past what one function
	# should hold.
	if current_screen_id() == "index" and _index_screen:
		_handle_index_search_key(event)
		return

	match event.physical_keycode:
		KEY_B:
			HudGroups.close_app()
		KEY_ESCAPE:
			_close_or_pop()
		KEY_ENTER, KEY_KP_ENTER:
			_handle_enter()
		KEY_UP:
			if current_screen_id() == "kind_menu" and _kind_menu_screen:
				_kind_menu_screen.navigate(-1)
		KEY_DOWN:
			if current_screen_id() == "kind_menu" and _kind_menu_screen:
				_kind_menu_screen.navigate(1)


## Key handling while the index screen is current. Arrows/enter/escape/
## backspace are the always-active control keys; everything else in the
## printable range (D-254 §4: "filterable/searchable by name") appends to
## the live search buffer. This mirrors the implant's existing
## keyboard-as-input-surface convention (no OS textbox anywhere in this
## component library) — there is no separate "focus the search box" step.
func _handle_index_search_key(event: InputEventKey) -> void:
	match event.physical_keycode:
		KEY_UP:
			_index_screen.navigate(-1)
			return
		KEY_DOWN:
			_index_screen.navigate(1)
			return
		KEY_ENTER, KEY_KP_ENTER:
			_index_screen.trigger_enter()
			return
		KEY_ESCAPE:
			if _index_screen.has_search_text():
				_index_screen.clear_search()
			else:
				_close_or_pop()
			return
		KEY_BACKSPACE:
			_index_screen.backspace_search()
			return

	# event.unicode carries the actual typed character (shift/caps already
	# resolved by the platform), NOT the physical keycode — String.chr() is
	# GDScript's codepoint-to-one-char-String conversion. Printable range
	# only (32 = space .. 126 = ~): control characters (arrows, tab, etc.
	# already handled above by physical_keycode) report unicode == 0 or a
	# non-printable codepoint and must not leak into the search buffer.
	if event.unicode >= 32 and event.unicode < 127:
		_index_screen.append_search_char(String.chr(event.unicode))


func _close_or_pop() -> void:
	if current_screen_id() == "kind_menu":
		HudGroups.close_app()
	else:
		nav.pop()


func _handle_enter() -> void:
	match current_screen_id():
		"kind_menu":
			if _kind_menu_screen:
				_kind_menu_screen.trigger_enter()


# =============================================================================
# Signal handlers
# =============================================================================


func _on_kind_selected(kind: String) -> void:
	nav.push("index", {"kind": kind, "filter_system_id": ""})


func _on_row_selected(entity_id: String) -> void:
	var kind: String = _index_screen.current_kind() if _index_screen else ""
	nav.push("detail", {"kind": kind, "entity_id": entity_id})


func _on_browse_response_received(response: Dictionary) -> void:
	if response == null:
		return
	# Fan out to whichever screen is currently waiting on a response for this
	# kind — both screens no-op via their own kind-match guard if the
	# response isn't theirs (a stale one from a prior navigation, or one
	# meant for the other screen type).
	if _index_screen:
		_index_screen.receive_response(response)
	if _detail_screen:
		_detail_screen.receive_response(response)