extends CanvasLayer
## In-game HUD: crosshair, interaction prompt, hotbar, toasts, and the
## inventory screen. Rendering only: it reads player state and forwards
## clicks to Actions.

const UITheme = preload("res://scripts/ui/theme.gd")
const SlotScript = preload("res://scripts/ui/slot.gd")
const InventoryScreen = preload("res://scripts/ui/inventory_screen.gd")
const PauseMenu = preload("res://scripts/ui/pause_menu.gd")

var player: CharacterBody3D
var _prompt: Label
var _held_name: Label
var _hotbar: Array = []
var _toasts: VBoxContainer
var _screen: Control
var _menu: Control
var _bars: Dictionary = {}
var _diet_bars: Dictionary = {}
var _status: Label
var _clock: Label
var _hurt: ColorRect

## A red flash at the screen edge when something hits you.
func _on_hurt(amount: float, _from: Vector3) -> void:
	_hurt.color.a = clampf(0.15 + amount / 60.0, 0.15, 0.45)
	var tw := _hurt.create_tween()
	tw.tween_property(_hurt, "color:a", 0.0, 0.6)

func bind(p: CharacterBody3D) -> void:
	player = p
	layer = 5
	var root := Control.new()
	root.set_anchors_preset(Control.PRESET_FULL_RECT)
	root.mouse_filter = Control.MOUSE_FILTER_IGNORE
	add_child(root)

	# Crosshair.
	var dot := ColorRect.new()
	dot.color = Color(1, 1, 1, 0.8)
	dot.size = Vector2(4, 4)
	dot.set_anchors_preset(Control.PRESET_CENTER)
	dot.position -= Vector2(2, 2)
	dot.mouse_filter = Control.MOUSE_FILTER_IGNORE
	root.add_child(dot)

	_prompt = UITheme.label("", 18)
	_prompt.set_anchors_and_offsets_preset(Control.PRESET_CENTER)
	_prompt.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	_prompt.grow_horizontal = Control.GROW_DIRECTION_BOTH
	_prompt.offset_top = 28
	_prompt.offset_bottom = 56
	root.add_child(_prompt)

	# Hotbar.
	var bar := HBoxContainer.new()
	bar.add_theme_constant_override("separation", 6)
	bar.set_anchors_and_offsets_preset(Control.PRESET_CENTER_BOTTOM)
	bar.grow_horizontal = Control.GROW_DIRECTION_BOTH
	bar.grow_vertical = Control.GROW_DIRECTION_BEGIN
	bar.offset_bottom = -18
	bar.mouse_filter = Control.MOUSE_FILTER_IGNORE
	for i in range(8):
		var s: Panel = SlotScript.new(i, 64, str(i + 1))
		s.mouse_filter = Control.MOUSE_FILTER_IGNORE
		bar.add_child(s)
		_hotbar.append(s)
	root.add_child(bar)

	_held_name = UITheme.label("", 15, UITheme.TEXT_DIM)
	_held_name.set_anchors_and_offsets_preset(Control.PRESET_CENTER_BOTTOM)
	_held_name.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	_held_name.grow_horizontal = Control.GROW_DIRECTION_BOTH
	_held_name.offset_top = -112
	_held_name.offset_bottom = -90
	root.add_child(_held_name)

	_toasts = VBoxContainer.new()
	_toasts.set_anchors_and_offsets_preset(Control.PRESET_BOTTOM_RIGHT)
	_toasts.grow_horizontal = Control.GROW_DIRECTION_BEGIN
	_toasts.grow_vertical = Control.GROW_DIRECTION_BEGIN
	_toasts.offset_right = -24
	_toasts.offset_bottom = -110
	_toasts.alignment = BoxContainer.ALIGNMENT_END
	_toasts.mouse_filter = Control.MOUSE_FILTER_IGNORE
	root.add_child(_toasts)

	_build_stats(root)

	_screen = InventoryScreen.new()
	root.add_child(_screen)
	_screen.bind(player)

	_menu = PauseMenu.new()
	root.add_child(_menu)
	_menu.bind(player)
	process_mode = Node.PROCESS_MODE_ALWAYS   # so ESC works while paused
	_screen.process_mode = Node.PROCESS_MODE_PAUSABLE

	player.inventory.changed.connect(_refresh)
	player.selected_changed.connect(_refresh)
	player.inventory_requested.connect(_on_inventory_requested)
	player.hands.prompt_changed.connect(func(t): _prompt.text = t)
	_hurt = ColorRect.new()
	_hurt.color = Color(0.7, 0.0, 0.0, 0.0)
	_hurt.set_anchors_preset(Control.PRESET_FULL_RECT)
	_hurt.mouse_filter = Control.MOUSE_FILTER_IGNORE
	root.add_child(_hurt)
	root.move_child(_hurt, 0)
	player.survival.hurt.connect(_on_hurt)
	Actions.notify.connect(toast)
	ItemDB.icons_ready.connect(_refresh)
	_refresh()

## Bars bottom-left (health, stamina, food, warmth), status tags above them,
## clock top-right.
func _build_stats(root: Control) -> void:
	var box := VBoxContainer.new()
	box.set_anchors_and_offsets_preset(Control.PRESET_BOTTOM_LEFT)
	box.grow_vertical = Control.GROW_DIRECTION_BEGIN
	box.offset_left = 22
	box.offset_bottom = -22
	box.add_theme_constant_override("separation", 5)
	box.mouse_filter = Control.MOUSE_FILTER_IGNORE
	root.add_child(box)
	_status = UITheme.label("", 15, UITheme.TEXT)
	box.add_child(_status)
	for spec in [["health", "Health", Color(0.85, 0.22, 0.2)], ["stamina", "Stamina", Color(0.9, 0.78, 0.25)],
			["hunger", "Food", Color(0.85, 0.5, 0.2)], ["warmth", "Warmth", Color(0.95, 0.55, 0.3)]]:
		var row := HBoxContainer.new()
		row.add_theme_constant_override("separation", 8)
		row.mouse_filter = Control.MOUSE_FILTER_IGNORE
		var name_l := UITheme.label(spec[1], 14, UITheme.TEXT_DIM)
		name_l.custom_minimum_size = Vector2(62, 0)
		row.add_child(name_l)
		var bar := ProgressBar.new()
		bar.custom_minimum_size = Vector2(190, 14)
		bar.show_percentage = false
		bar.max_value = 100.0
		bar.mouse_filter = Control.MOUSE_FILTER_IGNORE
		bar.add_theme_stylebox_override("background", UITheme.box(Color(0, 0, 0, 0.55), UITheme.SLOT_BORDER, 1, 4, 0))
		bar.add_theme_stylebox_override("fill", UITheme.box(spec[2], spec[2].lightened(0.2), 1, 4, 0))
		row.add_child(bar)
		box.add_child(row)
		_bars[spec[0]] = bar
	# Diet: three short bars (meat, fish, greens), so a gap shows early.
	var drow := HBoxContainer.new()
	drow.add_theme_constant_override("separation", 6)
	drow.mouse_filter = Control.MOUSE_FILTER_IGNORE
	var dl := UITheme.label("Diet", 14, UITheme.TEXT_DIM)
	dl.custom_minimum_size = Vector2(64, 0)
	drow.add_child(dl)
	for spec in [["meat", "Meat", Color(0.75, 0.3, 0.25)], ["fish", "Fish", Color(0.35, 0.6, 0.85)], ["plants", "Greens", Color(0.45, 0.75, 0.3)]]:
		var cell := VBoxContainer.new()
		cell.add_theme_constant_override("separation", 0)
		cell.mouse_filter = Control.MOUSE_FILTER_IGNORE
		var bar := ProgressBar.new()
		bar.custom_minimum_size = Vector2(58, 8)
		bar.show_percentage = false
		bar.max_value = 100.0
		bar.mouse_filter = Control.MOUSE_FILTER_IGNORE
		bar.add_theme_stylebox_override("background", UITheme.box(Color(0, 0, 0, 0.55), UITheme.SLOT_BORDER, 1, 3, 0))
		bar.add_theme_stylebox_override("fill", UITheme.box(spec[2], spec[2].lightened(0.2), 1, 3, 0))
		cell.add_child(bar)
		cell.add_child(UITheme.label(spec[1], 11, UITheme.TEXT_DIM))
		drow.add_child(cell)
		_diet_bars[spec[0]] = bar
	box.add_child(drow)
	_clock = UITheme.label("", 18)
	_clock.set_anchors_and_offsets_preset(Control.PRESET_TOP_RIGHT)
	_clock.grow_horizontal = Control.GROW_DIRECTION_BEGIN
	_clock.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	_clock.offset_right = -22
	_clock.offset_top = 14
	root.add_child(_clock)

func _process(_d: float) -> void:
	var s = player.survival
	for k in _bars:
		_bars[k].value = s.get(k)
	for g in _diet_bars:
		_diet_bars[g].value = s.diet[g]
		# A group running low blinks, so you notice before it hurts.
		_diet_bars[g].modulate.a = 0.45 + 0.55 * absf(sin(Time.get_ticks_msec() / 300.0)) if s.diet[g] < s.DIET_LOW else 1.0
	# Warmth bar shifts from icy blue (cold) to orange (warm).
	var w: float = s.warmth / 100.0
	var wc := Color(0.35, 0.6, 0.95).lerp(Color(0.95, 0.55, 0.3), w)
	(_bars["warmth"].get_theme_stylebox("fill") as StyleBoxFlat).bg_color = wc
	_status.text = "  ".join(s.statuses)
	var dn = player.get_parent().day_night
	if dn != null:
		var wx = player.get_parent().weather
		_clock.text = dn.clock_text() + ("   " + wx.label() if wx != null else "")

## Fades to black, runs `mid` (e.g. skipping the night), and fades back in.
func fade(mid: Callable) -> void:
	var black := ColorRect.new()
	black.color = Color(0, 0, 0, 0)
	black.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	black.mouse_filter = Control.MOUSE_FILTER_STOP
	add_child(black)
	player.ui_open = true
	var tw := black.create_tween()
	tw.tween_property(black, "color:a", 1.0, 0.8)
	tw.tween_callback(mid)
	tw.tween_interval(0.7)
	tw.tween_property(black, "color:a", 0.0, 1.0)
	tw.tween_callback(func():
		player.ui_open = false
		black.queue_free())

## Closes the inventory / menu (e.g. on death).
func close_screens() -> void:
	if _screen.is_open():
		_screen.close()

func _on_inventory_requested(container: Node) -> void:
	if not _screen.is_open():
		_screen.open(container)

## ESC: close the inventory if it's open, otherwise toggle the pause menu.
func _input(event: InputEvent) -> void:
	if event is InputEventKey and event.pressed and not event.echo and event.keycode == KEY_ESCAPE:
		if _screen.is_open():
			_screen.close()
		elif _menu.is_open():
			_menu.back()
		else:
			_menu.open()
		get_viewport().set_input_as_handled()

func _unhandled_input(event: InputEvent) -> void:
	if _menu.is_open():
		return
	if event.is_action_pressed("inventory") and not _screen.is_open():
		_screen.open(null)
		get_viewport().set_input_as_handled()

func _refresh() -> void:
	for i in range(_hotbar.size()):
		_hotbar[i].set_stack(player.inventory.get_slot(i))
		_hotbar[i].set_selected(i == player.selected)
	var id: String = player.held_item_id()
	_held_name.text = ItemDB.item_name(id) if not id.is_empty() else ""

func toast(text: String) -> void:
	# Merge repeated "+N Item" toasts so chopping doesn't spam the corner.
	for c in _toasts.get_children():
		if c.get_meta("base", "") == text:
			c.modulate.a = 1.0
			return
	var l := UITheme.label(text, 17)
	l.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	l.set_meta("base", text)
	_toasts.add_child(l)
	while _toasts.get_child_count() > 6:
		_toasts.get_child(0).free()
	var tw := l.create_tween()
	tw.tween_interval(2.2)
	tw.tween_property(l, "modulate:a", 0.0, 0.8)
	tw.tween_callback(l.queue_free)