extends CanvasLayer
##
## StudioUI - dark material theme + floating, collapsible panels (Step 4).
##
## Layout (all built in code, resolution independent, scaled by a UI_SCALE
## constant so it fits phones in portrait/landscape and tablets):
##
##   TopBar        : project name, memory HUD, undo/redo
##   LeftDock      : tool rail (mesh / sculpt / rig / sim / anim)
##   RightPanels   : collapsible panels -> Tools, Layers, Timeline
##   BottomBar     : play/pause + timeline scrubber
##
## Touch targets are >= 48px. The theme is Material-ish dark to match the
## viewport and reduce OLED power draw on phones.
##

const UI_SCALE := 1.0
const TOUCH_MIN := 48.0

var _touch_camera: Camera3D = null
var _ui_root: Control
var _panels: Dictionary = {}     # panel_id -> PanelContainer
var _tool_buttons: Dictionary = {}
var _memory_label: Label
var _fps_label: Label
var _timeline: HSlider
var _play_button: Button
var _status: Label

var _active_brush := "sculpt.draw"


func _ready() -> void:
	layer = 10
	_touch_camera = get_parent().get_node_or_null("Camera3D") as Camera3D
	_build_theme()
	_build_root()
	_build_top_bar()
	_build_tool_rail()
	_build_panels()
	_build_bottom_bar()
	_connect_bus()


## --- Theme ------------------------------------------------------------------

func _build_theme() -> void:
	var theme := Theme.new()
	theme.default_font_size = int(16 * UI_SCALE)

	var panel := StyleBoxFlat.new()
	panel.bg_color = Color(0.11, 0.12, 0.15, 0.94)
	panel.corner_radius_top_left = 10
	panel.corner_radius_top_right = 10
	panel.corner_radius_bottom_left = 10
	panel.corner_radius_bottom_right = 10
	panel.content_margin_left = 10
	panel.content_margin_right = 10
	panel.content_margin_top = 8
	panel.content_margin_bottom = 8
	theme.set_stylebox("panel", "PanelContainer", panel)

	var btn := StyleBoxFlat.new()
	btn.bg_color = Color(0.18, 0.2, 0.25)
	btn.corner_radius_top_left = 8
	btn.corner_radius_top_right = 8
	btn.corner_radius_bottom_left = 8
	btn.corner_radius_bottom_right = 8
	btn.content_margin_left = 12
	btn.content_margin_right = 12
	btn.content_margin_top = 8
	btn.content_margin_bottom = 8
	theme.set_stylebox("normal", "Button", btn)

	var btn_hover := btn.duplicate() as StyleBoxFlat
	btn_hover.bg_color = Color(0.24, 0.27, 0.33)
	theme.set_stylebox("hover", "Button", btn_hover)

	var btn_pressed := btn.duplicate() as StyleBoxFlat
	btn_pressed.bg_color = Color(0.31, 0.55, 0.86)
	theme.set_stylebox("pressed", "Button", btn_pressed)

	theme.set_color("font_color", "Label", Color(0.88, 0.9, 0.94))
	theme.set_color("font_color", "Button", Color(0.88, 0.9, 0.94))

	_ui_root_theme = theme


var _ui_root_theme: Theme


## --- Layout -----------------------------------------------------------------

func _build_root() -> void:
	var root := Control.new()
	root.name = "Root"
	root.theme = _ui_root_theme
	root.set_anchors_preset(Control.PRESET_FULL_RECT)
	root.mouse_filter = Control.MOUSE_FILTER_IGNORE
	add_child(root)
	_ui_root = root


func _build_top_bar() -> void:
	var bar := PanelContainer.new()
	bar.name = "TopBar"
	bar.set_anchors_preset(Control.PRESET_TOP_WIDE)
	bar.custom_minimum_size = Vector2(0, 52 * UI_SCALE)
	bar.mouse_filter = Control.MOUSE_FILTER_STOP
	_ui_root.add_child(bar)

	var hbox := HBoxContainer.new()
	hbox.add_theme_constant_override("separation", 10)
	bar.add_child(hbox)

	var title := Label.new()
	title.text = "  MonkeyStudio"
	title.add_theme_font_size_override("font_size", int(20 * UI_SCALE))
	hbox.add_child(title)

	var spacer := Control.new()
	spacer.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	hbox.add_child(spacer)

	_fps_label = Label.new()
	_fps_label.text = "FPS --"
	hbox.add_child(_fps_label)

	_memory_label = Label.new()
	_memory_label.text = "MEM --"
	hbox.add_child(_memory_label)


func _build_tool_rail() -> void:
	var rail := PanelContainer.new()
	rail.name = "LeftDock"
	rail.set_anchors_preset(Control.PRESET_CENTER_LEFT)
	rail.position = Vector2(8, 0)
	rail.mouse_filter = Control.MOUSE_FILTER_STOP
	_ui_root.add_child(rail)

	var vbox := VBoxContainer.new()
	vbox.add_theme_constant_override("separation", 8)
	rail.add_child(vbox)

	var tools := [
		["mesh", "Mesh", "mesh.cube"],
		["sculpt", "Sculpt", "sculpt.draw"],
		["rig", "Rig", "rig.skeleton"],
		["sim", "Sim", "sim.cloth"],
		["anim", "Anim", "anim.timeline"],
	]
	for t in tools:
		var b := Button.new()
		b.text = t[1]
		b.custom_minimum_size = Vector2(96 * UI_SCALE, TOUCH_MIN * UI_SCALE)
		b.pressed.connect(_on_tool_pressed.bind(t[2]))
		vbox.add_child(b)
		_tool_buttons[t[0]] = b


func _build_panels() -> void:
	var stack := VBoxContainer.new()
	stack.name = "RightPanels"
	stack.set_anchors_preset(Control.PRESET_TOP_RIGHT)
	stack.position = Vector2(-8, 60)
	stack.add_theme_constant_override("separation", 8)
	_ui_root.add_child(stack)

	_add_panel(stack, "tools", "Tools", _build_tools_panel())
	_add_panel(stack, "layers", "Layers", _build_layers_panel())
	_add_panel(stack, "timeline", "Timeline", _build_timeline_panel())


func _add_panel(parent: Control, id: String, title: String, content: Control) -> void:
	var panel := PanelContainer.new()
	panel.name = "Panel_" + id
	panel.custom_minimum_size = Vector2(220 * UI_SCALE, 0)
	parent.add_child(panel)

	var vbox := VBoxContainer.new()
	panel.add_child(vbox)

	var header := Button.new()
	header.text = "v  " + title
	header.alignment = HORIZONTAL_ALIGNMENT_LEFT
	header.custom_minimum_size = Vector2(0, TOUCH_MIN * UI_SCALE * 0.8)
	header.pressed.connect(_toggle_panel.bind(id))
	vbox.add_child(header)

	var body := MarginContainer.new()
	body.name = "Body"
	body.add_child(content)
	vbox.add_child(body)
	_panels[id] = panel


func _build_tools_panel() -> Control:
	var box := VBoxContainer.new()
	box.add_theme_constant_override("separation", 6)
	var label := Label.new()
	label.text = "Brush"
	box.add_child(label)
	for b in ["draw", "grab", "pinch", "smooth", "flatten"]:
		var btn := Button.new()
		btn.text = b.capitalize()
		btn.custom_minimum_size = Vector2(0, TOUCH_MIN * UI_SCALE)
		btn.pressed.connect(_on_brush_selected.bind("sculpt." + b))
		box.add_child(btn)
	box.add_child(_make_slider("Radius", 0.05, 2.0, 0.5, func(v): StudioBus.brush_radius_changed.emit(v)))
	box.add_child(_make_slider("Strength", 0.05, 1.0, 0.5, func(v): StudioBus.brush_strength_changed.emit(v)))
	return box


func _build_layers_panel() -> Control:
	var box := VBoxContainer.new()
	var label := Label.new()
	label.text = "Scene objects appear here."
	box.add_child(label)
	return box


func _build_timeline_panel() -> Control:
	var box := VBoxContainer.new()
	var label := Label.new()
	label.text = "Keyframe the selected object at the playhead."
	box.add_child(label)
	var key_btn := Button.new()
	key_btn.text = "Add Keyframe"
	key_btn.custom_minimum_size = Vector2(0, TOUCH_MIN * UI_SCALE)
	key_btn.pressed.connect(_on_add_keyframe)
	box.add_child(key_btn)
	return box


func _make_slider(label_text: String, mn: float, mx: float, val: float, on_change: Callable) -> Control:
	var wrap := VBoxContainer.new()
	var l := Label.new()
	l.text = label_text
	wrap.add_child(l)
	var s := HSlider.new()
	s.min_value = mn
	s.max_value = mx
	s.step = 0.01
	s.value = val
	s.custom_minimum_size = Vector2(180 * UI_SCALE, TOUCH_MIN * UI_SCALE)
	s.value_changed.connect(on_change)
	wrap.add_child(s)
	return wrap


func _build_bottom_bar() -> void:
	var bar := PanelContainer.new()
	bar.name = "BottomBar"
	bar.set_anchors_preset(Control.PRESET_BOTTOM_WIDE)
	bar.custom_minimum_size = Vector2(0, 56 * UI_SCALE)
	bar.mouse_filter = Control.MOUSE_FILTER_STOP
	_ui_root.add_child(bar)

	var hbox := HBoxContainer.new()
	hbox.add_theme_constant_override("separation", 10)
	bar.add_child(hbox)

	_play_button = Button.new()
	_play_button.text = "Play"
	_play_button.custom_minimum_size = Vector2(84 * UI_SCALE, TOUCH_MIN * UI_SCALE)
	_play_button.pressed.connect(_on_play_pressed)
	hbox.add_child(_play_button)

	_timeline = HSlider.new()
	_timeline.min_value = 0.0
	_timeline.max_value = 5.0
	_timeline.step = 0.01
	_timeline.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	_timeline.custom_minimum_size = Vector2(0, TOUCH_MIN * UI_SCALE)
	_timeline.value_changed.connect(_on_timeline_scrub)
	hbox.add_child(_timeline)

	_status = Label.new()
	_status.text = "0.00s"
	hbox.add_child(_status)


## --- Behaviour --------------------------------------------------------------

func _connect_bus() -> void:
	StudioBus.timeline_playhead.connect(_on_playhead)
	StudioBus.playback_state_changed.connect(_on_playback_state)
	StudioBus.brush_changed.connect(_on_brush_changed)
	MemoryManager.memory_warning.connect(func(_u, _b): _refresh_hud())


func _process(_delta: float) -> void:
	_fps_label.text = "FPS %d" % Engine.get_frames_per_second()
	_refresh_hud()


func _refresh_hud() -> void:
	var used: float = MemoryManager.get_loaded_mb()
	_memory_label.text = "MEM %.0f/%.0f MB" % [used, MemoryManager.asset_budget_mb]


func _toggle_panel(id: String) -> void:
	var panel: PanelContainer = _panels.get(id)
	if panel == null:
		return
	var body := panel.get_node_or_null("VBoxContainer/Body")
	# PanelContainer -> VBox -> [Button, MarginContainer]
	var vbox := panel.get_child(0)
	var body_node := vbox.get_node_or_null("Body") as Control
	if body_node != null:
		body_node.visible = not body_node.visible
	StudioBus.panel_toggled.emit(id, body_node != null and body_node.visible)


func _on_tool_pressed(feature_id: String) -> void:
	# Turning on a sculpt brush means the finger paints; navigation uses 2 fingers.
	var is_sculpt := feature_id.begins_with("sculpt.")
	if _touch_camera != null:
		_touch_camera.set("one_finger_orbit", not is_sculpt)
	if is_sculpt:
		var ok := FeatureRegistry.activate("sculpt.draw")
		if ok:
			# Ensure the sculpt module is wired to the selected object.
			var sculpt: Node = find_sculpt_module()
			if sculpt != null and StudioBus.has_signal("brush_changed"):
				StudioBus.brush_changed.emit(feature_id)
	_activate_feature_family(feature_id)
	_set_status("Tool: " + feature_id)


func find_sculpt_module() -> Node:
	var host := get_parent().get_node_or_null("Features")
	if host == null:
		return null
	return host.get_node_or_null("Feature_sculpt.draw")


func _activate_feature_family(feature_id: String) -> void:
	match feature_id:
		"mesh.cube": FeatureRegistry.activate("mesh.cube")
		"rig.skeleton": FeatureRegistry.activate("rig.skeleton")
		"sim.cloth":
			FeatureRegistry.activate("sim.cloth")
			StudioBus.sim_toggled.emit("sim.cloth", true)
		"anim.timeline": FeatureRegistry.activate("anim.timeline")
		_: pass


func _on_brush_selected(id: String) -> void:
	_active_brush = id
	StudioBus.brush_changed.emit(id)
	_set_status("Brush: " + id)


func _on_brush_changed(id: String) -> void:
	_set_status("Brush: " + id)


func _on_play_pressed() -> void:
	var tl := _get_timeline_module()
	if tl == null:
		return
	if tl.call("is_playing"):
		tl.call("pause")
	else:
		tl.call("play")


func _on_timeline_scrub(value: float) -> void:
	var tl := _get_timeline_module()
	if tl != null:
		tl.call("scrub", value)
	_status.text = "%.2fs" % value


func _on_playhead(t: float) -> void:
	_timeline.set_value_no_signal(t)
	_status.text = "%.2fs" % t


func _on_playback_state(playing: bool) -> void:
	_play_button.text = "Pause" if playing else "Play"


func _on_add_keyframe() -> void:
	var tl := _get_timeline_module()
	if tl == null:
		FeatureRegistry.activate("anim.timeline")
		tl = _get_timeline_module()
	if tl == null:
		return
	var selected := _selected_object()
	if selected != null:
		tl.call("add_keyframe", selected, "position", _timeline.value, selected.position)
		_set_status("Keyframe added")


func _get_timeline_module() -> Node:
	var host := get_parent().get_node_or_null("Features")
	if host == null:
		return null
	return host.get_node_or_null("Feature_anim.timeline")


func _selected_object() -> Node3D:
	var geom := get_parent().get_node_or_null("Geometry")
	if geom == null:
		return null
	for child in geom.get_children():
		if child is MeshInstance3D:
			return child
	return null


func _set_status(text: String) -> void:
	if _status != null:
		_status.text = text