class_name SettingsPanel
extends CanvasLayer
## Settings: mouse look sensitivity and HUD font scale, persisted through the
## `Save` autoload into `user://settings.json`.
##
## Emits `applied(settings)` so the game manager can push values into the guard
## and HUD as soon as the player confirms.

const InputBindings := preload("res://src/core/input_bindings.gd")
const UiArt := preload("res://src/game/ui/art.gd")

signal applied(settings: Dictionary)
signal closed()

var _root: Control = null
var _sensitivity: HSlider = null
var _font_scale: HSlider = null
var _sensitivity_value: Label = null
var _font_scale_value: Label = null
var _invert_y: CheckButton = null
var _head_bob: CheckButton = null
var _bind_buttons := {}
var _listening_action := ""
var settings: Dictionary = {}

func _ready() -> void:
	layer = 22
	_build()
	hide()

func _init() -> void:
	layer = 22
	_build()
	hide()

func _build() -> void:
	_root = Control.new()
	_root.name = "SettingsRoot"
	_root.set_anchors_preset(Control.PRESET_FULL_RECT)
	_root.mouse_filter = Control.MOUSE_FILTER_STOP
	add_child(_root)

	var art := UiArt.new()
	if not art.add_screen_backdrop(_root, "settings_panel",
			Rect2(0.117, 0.049, 0.703, 0.895)):
		var bg := ColorRect.new()
		bg.color = Color(0.02, 0.03, 0.05, 0.9)
		bg.set_anchors_preset(Control.PRESET_FULL_RECT)
		bg.mouse_filter = Control.MOUSE_FILTER_IGNORE
		_root.add_child(bg)

	var center := CenterContainer.new()
	center.set_anchors_preset(Control.PRESET_FULL_RECT)
	_root.add_child(center)

	var column := VBoxContainer.new()
	column.custom_minimum_size = Vector2(640, 0)
	column.add_theme_constant_override("separation", 12)
	center.add_child(column)

	var title := Label.new()
	title.text = "Settings"
	title.add_theme_font_size_override("font_size", 32)
	title.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	column.add_child(title)

	var sens_row := VBoxContainer.new()
	column.add_child(sens_row)
	_sensitivity_value = _add_label_row(sens_row, "Mouse look sensitivity")
	_sensitivity = _add_slider(sens_row, 0.0005, 0.0060, 0.0001)
	_sensitivity.value_changed.connect(_on_sensitivity_changed)

	var font_row := VBoxContainer.new()
	column.add_child(font_row)
	_font_scale_value = _add_label_row(font_row, "HUD font scale")
	_font_scale = _add_slider(font_row, 0.75, 1.75, 0.05)
	_font_scale.value_changed.connect(_on_font_scale_changed)

	_invert_y = CheckButton.new()
	_invert_y.text = "Invert vertical look"
	_invert_y.toggled.connect(_on_invert_y_toggled)
	column.add_child(_invert_y)

	_head_bob = CheckButton.new()
	_head_bob.text = "Head bob and camera motion"
	_head_bob.toggled.connect(_on_head_bob_toggled)
	column.add_child(_head_bob)

	var controls_title := Label.new()
	controls_title.text = "Controls (click a binding, then press a key or pad button)"
	controls_title.add_theme_font_size_override("font_size", 13)
	controls_title.modulate = Color(0.75, 0.8, 0.9)
	column.add_child(controls_title)
	var grid := GridContainer.new()
	grid.columns = 4
	grid.add_theme_constant_override("h_separation", 10)
	grid.add_theme_constant_override("v_separation", 6)
	column.add_child(grid)
	for action in InputBindings.REMAPPABLE:
		var label := Label.new()
		label.text = str(action).replace("_", " ").capitalize()
		label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
		grid.add_child(label)
		var button := Button.new()
		button.custom_minimum_size = Vector2(130, 0)
		button.pressed.connect(_on_rebind.bind(action))
		grid.add_child(button)
		_bind_buttons[action] = button

	var row := HBoxContainer.new()
	row.alignment = BoxContainer.ALIGNMENT_CENTER
	row.add_theme_constant_override("separation", 12)
	column.add_child(row)

	var save_button := Button.new()
	save_button.name = "ApplyButton"
	save_button.text = "Apply"
	save_button.pressed.connect(_on_apply)
	row.add_child(save_button)

	var cancel_button := Button.new()
	cancel_button.name = "CancelButton"
	cancel_button.text = "Cancel"
	cancel_button.pressed.connect(_on_cancel)
	row.add_child(cancel_button)

func _add_label_row(parent: Control, text: String) -> Label:
	var row := HBoxContainer.new()
	parent.add_child(row)
	var label := Label.new()
	label.text = text
	label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	row.add_child(label)
	var value := Label.new()
	value.add_theme_color_override("font_color", Color(0.75, 0.8, 0.9))
	row.add_child(value)
	return value

func _add_slider(parent: Control, min_v: float, max_v: float, step: float) -> HSlider:
	var slider := HSlider.new()
	slider.min_value = min_v
	slider.max_value = max_v
	slider.step = step
	slider.custom_minimum_size = Vector2(420, 24)
	parent.add_child(slider)
	return slider

func open(current: Dictionary) -> void:
	settings = current.duplicate(true)
	var sens: float = float(settings.get("look_sensitivity", 0.0022))
	var scale: float = float(settings.get("hud_font_scale", 1.0))
	if _sensitivity:
		_sensitivity.set_value_no_signal(clampf(sens, _sensitivity.min_value, _sensitivity.max_value))
	if _font_scale:
		_font_scale.set_value_no_signal(clampf(scale, _font_scale.min_value, _font_scale.max_value))
	if _invert_y:
		_invert_y.set_pressed_no_signal(bool(settings.get("invert_y", false)))
	if _head_bob:
		_head_bob.set_pressed_no_signal(bool(settings.get("head_bob", true)))
	_listening_action = ""
	_refresh_bind_buttons()
	_sync_labels()
	visible = true
	_root.visible = true
	Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)

func close() -> void:
	visible = false
	_root.visible = false

func _sync_labels() -> void:
	if _sensitivity_value and _sensitivity:
		_sensitivity_value.text = "%.4f" % _sensitivity.value
	if _font_scale_value and _font_scale:
		_font_scale_value.text = "%.2fx" % _font_scale.value

func _on_sensitivity_changed(value: float) -> void:
	settings["look_sensitivity"] = value
	_sync_labels()

func _on_font_scale_changed(value: float) -> void:
	settings["hud_font_scale"] = value
	_sync_labels()

func _on_invert_y_toggled(pressed: bool) -> void:
	settings["invert_y"] = pressed

func _on_head_bob_toggled(pressed: bool) -> void:
	settings["head_bob"] = pressed

func _refresh_bind_buttons() -> void:
	var remaps: Dictionary = settings.get("input_bindings", {})
	for action in _bind_buttons.keys():
		var button: Button = _bind_buttons[action]
		var descriptor: Dictionary = remaps.get(action, {})
		if descriptor.is_empty():
			descriptor = InputBindings.current_descriptor(action)
		button.text = InputBindings.label_for(descriptor)

func _on_rebind(action: String) -> void:
	_listening_action = action
	var button: Button = _bind_buttons.get(action)
	if button:
		button.text = "Press…"
		if button.is_inside_tree():
			button.grab_focus()

func _apply_remap(event: InputEvent) -> bool:
	if _listening_action == "":
		return false
	var descriptor := InputBindings.descriptor_from_event(event)
	if descriptor.is_empty():
		return false
	var remaps: Dictionary = settings.get("input_bindings", {})
	remaps[_listening_action] = descriptor
	settings["input_bindings"] = remaps
	_listening_action = ""
	_refresh_bind_buttons()
	return true

func _on_apply() -> void:
	if Save:
		Save.save_settings(settings)
	applied.emit(settings)
	close()
	closed.emit()

func _on_cancel() -> void:
	close()
	closed.emit()

func _unhandled_input(event: InputEvent) -> void:
	if not visible:
		return
	if _listening_action != "":
		var pressed: bool = (event is InputEventKey and event.pressed and not event.echo) \
			or (event is InputEventJoypadButton and event.pressed)
		if pressed and _apply_remap(event):
			get_viewport().set_input_as_handled()
			return
	if event is InputEventKey and event.pressed and not event.echo and event.keycode == KEY_ESCAPE:
		_on_cancel()
		get_viewport().set_input_as_handled()