class_name AssetSelector
extends PopupPanel

signal item_selected(entry: Dictionary)
signal cancelled()
signal browse_requested()
signal refresh_requested()

const COLUMNS := 4
const ROWS := 3
const PAGE_SIZE := COLUMNS * ROWS

const CELL_MIN_SIZE := Vector2(140.0, 168.0)
const THUMB_SIZE := Vector2(120.0, 120.0)

var kind: String = ""

var _entries: Array[Dictionary] = []
var _page: int = 0
var _thumbnails: Dictionary = {}
var _cell_texrects: Dictionary = {}
var _placeholder_tex: ImageTexture = null
var _ui_font: Font = null
var _emoji_font: Font = null

@onready var _title_label: Label = %TitleLabel
@onready var _grid: GridContainer = %GridContainer
@onready var _empty_label: Label = %EmptyLabel
@onready var _page_label: Label = %PageLabel
@onready var _prev_button: Button = %PrevButton
@onready var _next_button: Button = %NextButton
@onready var _browse_button: Button = %BrowseButton
@onready var _refresh_button: Button = %RefreshButton
@onready var _close_button: Button = %CloseButton


func _ready() -> void:
	exclusive = true
	_prev_button.pressed.connect(_on_prev)
	_next_button.pressed.connect(_on_next)
	_browse_button.pressed.connect(func() -> void: browse_requested.emit())
	_refresh_button.pressed.connect(func() -> void: refresh_requested.emit())
	_close_button.pressed.connect(func() -> void: cancelled.emit())
	get_tree().root.size_changed.connect(_on_root_size_changed)


func _on_root_size_changed() -> void:
	if visible:
		popup_centered()


func open(p_kind: String, entries: Array[Dictionary]) -> void:
	kind = p_kind
	_title_label.text = "Choose Your Stickman" if kind == "stickman" else "Choose a Prop"
	_browse_button.visible = kind == "stickman"
	_refresh_button.visible = kind == "stickman"
	set_entries(entries)
	popup_centered()


func set_entries(entries: Array[Dictionary]) -> void:
	_entries = entries
	_thumbnails.clear()
	_cell_texrects.clear()
	_page = 0
	_rebuild()


func set_thumbnail(entry: Dictionary, tex: Texture2D) -> void:
	var key := _entry_key(entry)
	_thumbnails[key] = tex
	if _cell_texrects.has(key):
		(_cell_texrects[key] as TextureRect).texture = tex


func close() -> void:
	hide()


func apply_font(ui_font: Font, emoji_font: Font) -> void:
	_ui_font = ui_font
	_emoji_font = emoji_font
	var controls: Array = [
		_title_label, _empty_label, _page_label,
		_prev_button, _next_button, _browse_button, _refresh_button, _close_button,
	]
	for c: Control in controls:
		_apply_font_to(c)


func _unhandled_input(event: InputEvent) -> void:
	if visible and event is InputEventKey:
		var key := event as InputEventKey
		if key.pressed and not key.echo and key.keycode == KEY_ESCAPE:
			get_viewport().set_input_as_handled()
			cancelled.emit()


static func page_bounds(total: int, page: int, page_size: int = PAGE_SIZE) -> Dictionary:
	var page_count := maxi(1, int(ceil(float(total) / float(page_size))))
	var start := page * page_size
	if start >= total:
		start = 0
	var end := mini(start + page_size, total)
	return { "start": start, "end": end, "total": total, "page_count": page_count }


func _entry_key(entry: Dictionary) -> String:
	if kind == "stickman":
		return String(entry.get("path", ""))
	return String(entry.get("id", ""))


func _on_prev() -> void:
	if _page > 0:
		_page -= 1
		_rebuild()


func _on_next() -> void:
	if (_page + 1) * PAGE_SIZE < _entries.size():
		_page += 1
		_rebuild()


func _page_count() -> int:
	if _entries.is_empty():
		return 1
	return int(ceil(float(_entries.size()) / float(PAGE_SIZE)))


func _rebuild() -> void:
	for c: Node in _grid.get_children():
		c.queue_free()
	_cell_texrects.clear()
	_empty_label.visible = _entries.is_empty()
	_grid.visible = not _entries.is_empty()
	var total := _page_count()
	var single := total <= 1
	_prev_button.visible = not single
	_next_button.visible = not single
	_page_label.visible = not single
	_prev_button.disabled = _page <= 0
	_next_button.disabled = (_page + 1) * PAGE_SIZE >= _entries.size()
	_page_label.text = "Page %d/%d" % [_page + 1, total]
	if _entries.is_empty():
		return
	var bounds := page_bounds(_entries.size(), _page)
	for i: int in range(int(bounds["start"]), int(bounds["end"])):
		_grid.add_child(_build_cell(_entries[i]))


func _build_cell(entry: Dictionary) -> Control:
	var key := _entry_key(entry)
	var cell := Button.new()
	cell.custom_minimum_size = CELL_MIN_SIZE
	cell.toggle_mode = false
	cell.focus_mode = Control.FOCUS_NONE
	cell.pressed.connect(_on_cell_pressed.bind(entry))

	var vbox := VBoxContainer.new()
	vbox.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	vbox.mouse_filter = Control.MOUSE_FILTER_IGNORE
	vbox.add_theme_constant_override("separation", 2)
	cell.add_child(vbox)

	var tex_rect := TextureRect.new()
	tex_rect.custom_minimum_size = THUMB_SIZE
	tex_rect.size_flags_horizontal = Control.SIZE_SHRINK_CENTER
	tex_rect.expand_mode = TextureRect.EXPAND_IGNORE_SIZE
	tex_rect.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
	tex_rect.mouse_filter = Control.MOUSE_FILTER_IGNORE
	var tex: Texture2D = _thumbnails.get(key, null)
	tex_rect.texture = tex if tex != null else _get_placeholder()
	vbox.add_child(tex_rect)
	_cell_texrects[key] = tex_rect

	var name_label := Label.new()
	name_label.text = String(entry.get("name", ""))
	name_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	name_label.mouse_filter = Control.MOUSE_FILTER_IGNORE
	name_label.add_theme_font_size_override("font_size", 14)
	_apply_font_to(name_label)
	vbox.add_child(name_label)

	if kind == "prop":
		var badge := Label.new()
		badge.text = String(entry.get("material_label", ""))
		badge.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
		badge.mouse_filter = Control.MOUSE_FILTER_IGNORE
		badge.add_theme_font_size_override("font_size", 12)
		badge.add_theme_color_override("font_color", Color(0.7, 0.7, 0.7, 1.0))
		_apply_font_to(badge)
		vbox.add_child(badge)

	return cell


func _on_cell_pressed(entry: Dictionary) -> void:
	item_selected.emit(entry)


func _apply_font_to(c: Control) -> void:
	if c == null:
		return
	if _ui_font != null:
		c.add_theme_font_override("font", _ui_font)
	elif _emoji_font != null:
		c.add_theme_font_override("font", _emoji_font)


func _get_placeholder() -> ImageTexture:
	if _placeholder_tex == null:
		var img := Image.create(THUMB_SIZE.x, THUMB_SIZE.y, false, Image.FORMAT_RGBA8)
		img.fill(Color(0.16, 0.16, 0.16, 1.0))
		_placeholder_tex = ImageTexture.create_from_image(img)
	return _placeholder_tex