extends Node

# 全地图统一交互：收集角色附近的动作，通过方向键选择、E 执行。
const SCAN_INTERVAL: float = 0.10
const MAX_ACTIONS_VISIBLE: int = 5
const ACCENT: Color = Color("58c7db")
const PANEL_COLOR: Color = Color(0.035, 0.071, 0.106, 0.94)
const INTERACTION_POINT_MARKERS_SCRIPT: Script = preload("res://_Core/ui/InteractionPointMarkers.gd")

var _actions: Array[InteractionAction] = []
var _selected_index: int = 0
var _last_selected_id: String = ""
var _scan_elapsed: float = SCAN_INTERVAL
var _canvas: CanvasLayer
var _panel: PanelContainer
var _list: VBoxContainer
var _hint: Label
var _executing: bool = false
var _pointMarkers: Node2D

func _ready() -> void:
	_build_hud()

func _process(delta: float) -> void:
	_scan_elapsed += delta
	if _scan_elapsed < SCAN_INTERVAL:
		return
	_scan_elapsed = 0.0
	_refresh_actions()

func _unhandled_input(event: InputEvent) -> void:
	if _actions.is_empty() or _is_text_input_focused():
		return
	if not (event is InputEventKey):
		return
	var key_event := event as InputEventKey
	if not key_event.pressed or key_event.echo:
		return
	if key_event.keycode == KEY_UP:
		_select_offset(-1)
		get_viewport().set_input_as_handled()
	elif key_event.keycode == KEY_DOWN:
		_select_offset(1)
		get_viewport().set_input_as_handled()
	elif key_event.keycode == KEY_E:
		_execute_selected()
		get_viewport().set_input_as_handled()

func is_selection_active() -> bool:
	return not _actions.is_empty() and not _is_text_input_focused()

func _refresh_actions() -> void:
	if _is_text_input_focused() or SceneManager.is_changing_scene:
		_set_actions([])
		return
	var player := _local_player()
	if player == null:
		_set_actions([])
		return
	var collected: Array[InteractionAction] = []
	for node: Node in get_tree().get_nodes_in_group(InteractableComponent.GROUP):
		var interactable: InteractableComponent = node as InteractableComponent
		if interactable == null:
			continue
		for action: InteractionAction in interactable.get_actions(player):
			collected.append(action)
	collected.sort_custom(func(a: InteractionAction, b: InteractionAction) -> bool:
		if a.priority != b.priority:
			return a.priority < b.priority
		if not is_equal_approx(a.distance, b.distance):
			return a.distance < b.distance
		return a.title < b.title
	)
	_set_actions(collected)

func _set_actions(next_actions: Array[InteractionAction]) -> void:
	_actions = next_actions
	if _actions.is_empty():
		_selected_index = 0
		_last_selected_id = ""
		_render()
		return
	var matched_index := -1
	for index in _actions.size():
		if _actions[index].id == _last_selected_id:
			matched_index = index
			break
	_selected_index = matched_index if matched_index >= 0 else clampi(_selected_index, 0, _actions.size() - 1)
	_last_selected_id = _actions[_selected_index].id
	_render()

func _select_offset(offset: int) -> void:
	if _actions.is_empty():
		return
	_selected_index = posmod(_selected_index + offset, _actions.size())
	_last_selected_id = _actions[_selected_index].id
	_render()

func _execute_selected() -> void:
	if _executing or _actions.is_empty():
		return
	var action: InteractionAction = _actions[_selected_index]
	if not action.activate.is_valid():
		return
	_executing = true
	_render()
	action.activate.call()
	await get_tree().create_timer(0.18).timeout
	_executing = false
	_refresh_actions()

func _local_player() -> Node2D:
	var players := get_tree().get_nodes_in_group("whaletown_local_player")
	return players.front() as Node2D if not players.is_empty() else null

func _build_hud() -> void:
	_canvas = CanvasLayer.new()
	_canvas.layer = 90
	add_child(_canvas)
	_panel = PanelContainer.new()
	_panel.set_anchors_preset(Control.PRESET_CENTER_BOTTOM)
	_panel.position = Vector2(-250, -282)
	_panel.size = Vector2(500, 214)
	_panel.mouse_filter = Control.MOUSE_FILTER_IGNORE
	_panel.add_theme_stylebox_override("panel", _panel_style())
	_canvas.add_child(_panel)
	var margin := MarginContainer.new()
	margin.add_theme_constant_override("margin_left", 14)
	margin.add_theme_constant_override("margin_top", 10)
	margin.add_theme_constant_override("margin_right", 14)
	margin.add_theme_constant_override("margin_bottom", 10)
	_panel.add_child(margin)
	var content := VBoxContainer.new()
	content.add_theme_constant_override("separation", 4)
	margin.add_child(content)
	_list = VBoxContainer.new()
	_list.add_theme_constant_override("separation", 2)
	content.add_child(_list)
	_hint = Label.new()
	_hint.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	_hint.add_theme_color_override("font_color", Color(0.67, 0.79, 0.85, 1.0))
	_hint.add_theme_font_size_override("font_size", 14)
	_hint.text = "[↑/↓] 选择   [E] 交互"
	content.add_child(_hint)
	_render()

func _render() -> void:
	if not is_instance_valid(_panel):
		return
	var show_hints: bool = _should_show_interaction_hints()
	_panel.visible = show_hints and not _actions.is_empty()
	_render_interaction_points()
	for child in _list.get_children():
		child.queue_free()
	if _actions.is_empty():
		return
	var start: int = clampi(_selected_index - 2, 0, maxi(0, _actions.size() - MAX_ACTIONS_VISIBLE))
	var finish: int = mini(_actions.size(), start + MAX_ACTIONS_VISIBLE)
	for index in range(start, finish):
		var action: InteractionAction = _actions[index]
		var row := Label.new()
		row.custom_minimum_size = Vector2(0, 29)
		row.vertical_alignment = VERTICAL_ALIGNMENT_CENTER
		row.add_theme_font_size_override("font_size", 16)
		var selected := index == _selected_index
		row.text = ("› " if selected else "  ") + action.title + ("  …" if selected and _executing else "")
		row.add_theme_color_override("font_color", ACCENT if selected else Color(0.92, 0.96, 0.98, 1.0))
		if selected:
			row.add_theme_stylebox_override("normal", _selected_style())
		_list.add_child(row)
	_hint.text = "[↑/↓] 选择   [E] 交互   [Esc] 关闭" + ("   %d 项" % _actions.size() if _actions.size() > 1 else "")

func _render_interaction_points() -> void:
	if not _should_show_interaction_points():
		if is_instance_valid(_pointMarkers):
			var empty_points: Array[Vector2] = []
			_pointMarkers.call("set_points", empty_points)
		return
	var markers: Node2D = _ensure_point_markers()
	if markers == null:
		return
	var positions: Array[Vector2] = []
	for node: Node in get_tree().get_nodes_in_group(InteractableComponent.GROUP):
		var interactable: InteractableComponent = node as InteractableComponent
		if interactable == null:
			continue
		for position: Vector2 in interactable.get_marker_positions():
			positions.append(position)
	markers.call("set_points", positions)

func _ensure_point_markers() -> Node2D:
	var current_scene: Node = get_tree().current_scene
	var world_root: Node2D = current_scene as Node2D
	if world_root == null:
		return null
	if is_instance_valid(_pointMarkers) and _pointMarkers.get_parent() == world_root:
		return _pointMarkers
	var markers: Node2D = INTERACTION_POINT_MARKERS_SCRIPT.new() as Node2D
	if markers == null:
		return null
	markers.name = "InteractionPointMarkers"
	markers.z_index = 4096
	markers.z_as_relative = false
	world_root.add_child(markers)
	_pointMarkers = markers
	return _pointMarkers

func _should_show_interaction_hints() -> bool:
	return _get_setting_enabled("show_interaction_hints", true)

func _should_show_interaction_points() -> bool:
	return _get_setting_enabled("show_interaction_points", false)

func _get_setting_enabled(setting_key: String, fallback: bool) -> bool:
	var settings_manager: Node = get_node_or_null("/root/SettingsManager")
	if settings_manager != null and settings_manager.has_method("get_bool"):
		return bool(settings_manager.call("get_bool", setting_key))
	return fallback

func _panel_style() -> StyleBoxFlat:
	var style := StyleBoxFlat.new()
	style.bg_color = PANEL_COLOR
	style.border_color = Color(0.20, 0.45, 0.54, 0.86)
	style.set_border_width_all(1)
	style.corner_radius_top_left = 10
	style.corner_radius_top_right = 10
	style.corner_radius_bottom_left = 10
	style.corner_radius_bottom_right = 10
	style.shadow_color = Color(0, 0, 0, 0.35)
	style.shadow_size = 10
	return style

func _selected_style() -> StyleBoxFlat:
	var style := StyleBoxFlat.new()
	style.bg_color = Color(0.12, 0.32, 0.38, 0.74)
	style.corner_radius_top_left = 6
	style.corner_radius_top_right = 6
	style.corner_radius_bottom_left = 6
	style.corner_radius_bottom_right = 6
	style.content_margin_left = 6
	return style

func _is_text_input_focused() -> bool:
	var focus_owner := get_viewport().gui_get_focus_owner()
	return focus_owner is LineEdit or focus_owner is TextEdit