class_name LeaderboardScreen
extends CanvasLayer

## LeaderboardScreen - Displays top players ranked by ELO

signal back_pressed

# Window dimensions
const WINDOW_SIZE := Vector2i(600, 700)

# Pagination
const PLAYERS_PER_PAGE = 20

# UI Components
var main_container: VBoxContainer
var back_button: Button
var title_label: Label
var info_label: Label
var leaderboard_section: PanelContainer
var leaderboard_list: VBoxContainer
var header_row: HBoxContainer
var pagination_container: HBoxContainer
var prev_button: Button
var page_label: Label
var next_button: Button
var loading_label: Label
var error_label: Label

# State
var current_page: int = 0
var is_loading: bool = false
var players_cache: Array = []

# Styling
var custom_font: Font = preload("res://JimNightshade-Regular.ttf")
const BG_COLOR := Color(0.12, 0.11, 0.15, 1.0)
const PANEL_COLOR := Color(0.18, 0.16, 0.22, 1.0)
const ACCENT_COLOR := Color(0.4, 0.35, 0.55, 1.0)
const GOLD_COLOR := Color(1.0, 0.84, 0.0, 1.0)
const SILVER_COLOR := Color(0.75, 0.75, 0.75, 1.0)
const BRONZE_COLOR := Color(0.8, 0.5, 0.2, 1.0)
const TEXT_COLOR := Color(0.9, 0.88, 0.82, 1.0)
const MUTED_COLOR := Color(0.6, 0.58, 0.52, 1.0)
const HIGHLIGHT_COLOR := Color(0.3, 0.35, 0.5, 1.0)


func _ready() -> void:
	_create_ui()
	_load_leaderboard()


func _create_ui() -> void:
	# Background
	var bg = ColorRect.new()
	bg.color = BG_COLOR
	bg.set_anchors_preset(Control.PRESET_FULL_RECT)
	add_child(bg)

	# Main container
	main_container = VBoxContainer.new()
	main_container.set_anchors_preset(Control.PRESET_FULL_RECT)
	main_container.add_theme_constant_override("separation", 16)
	add_child(main_container)

	var margin = MarginContainer.new()
	margin.add_theme_constant_override("margin_left", 24)
	margin.add_theme_constant_override("margin_right", 24)
	margin.add_theme_constant_override("margin_top", 16)
	margin.add_theme_constant_override("margin_bottom", 16)
	margin.set_anchors_preset(Control.PRESET_FULL_RECT)
	main_container.add_child(margin)

	var content = VBoxContainer.new()
	content.add_theme_constant_override("separation", 16)
	margin.add_child(content)

	# Back button
	back_button = _create_button("< Back", false)
	back_button.custom_minimum_size = Vector2(80, 32)
	back_button.pressed.connect(_on_back_pressed)
	content.add_child(back_button)

	# Title
	title_label = Label.new()
	title_label.add_theme_font_override("font", custom_font)
	title_label.add_theme_font_size_override("font_size", 28)
	title_label.add_theme_color_override("font_color", TEXT_COLOR)
	title_label.text = "LEADERBOARD"
	title_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	content.add_child(title_label)

	# Info label
	info_label = Label.new()
	info_label.add_theme_font_override("font", custom_font)
	info_label.add_theme_font_size_override("font_size", 12)
	info_label.add_theme_color_override("font_color", MUTED_COLOR)
	info_label.text = "Minimum 10 games required to appear on leaderboard"
	info_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	content.add_child(info_label)

	# Leaderboard section
	_create_leaderboard_section(content)

	# Error label
	error_label = Label.new()
	error_label.add_theme_font_override("font", custom_font)
	error_label.add_theme_font_size_override("font_size", 14)
	error_label.add_theme_color_override("font_color", Color(0.9, 0.3, 0.3))
	error_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	error_label.autowrap_mode = TextServer.AUTOWRAP_WORD
	error_label.visible = false
	content.add_child(error_label)


func _create_leaderboard_section(parent: VBoxContainer) -> void:
	leaderboard_section = _create_panel_section("TOP PLAYERS")
	leaderboard_section.size_flags_vertical = Control.SIZE_EXPAND_FILL
	parent.add_child(leaderboard_section)

	var content = leaderboard_section.get_child(0) as VBoxContainer

	# Header row
	header_row = _create_header_row()
	content.add_child(header_row)

	# Separator
	var separator = HSeparator.new()
	var sep_style = StyleBoxFlat.new()
	sep_style.bg_color = MUTED_COLOR
	sep_style.content_margin_top = 1
	separator.add_theme_stylebox_override("separator", sep_style)
	content.add_child(separator)

	# Loading indicator
	loading_label = Label.new()
	loading_label.add_theme_font_override("font", custom_font)
	loading_label.add_theme_font_size_override("font_size", 14)
	loading_label.add_theme_color_override("font_color", MUTED_COLOR)
	loading_label.text = "Loading..."
	loading_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	content.add_child(loading_label)

	# Player list
	leaderboard_list = VBoxContainer.new()
	leaderboard_list.add_theme_constant_override("separation", 4)
	leaderboard_list.size_flags_vertical = Control.SIZE_EXPAND_FILL
	content.add_child(leaderboard_list)

	# Pagination
	pagination_container = HBoxContainer.new()
	pagination_container.add_theme_constant_override("separation", 16)
	pagination_container.alignment = BoxContainer.ALIGNMENT_CENTER
	content.add_child(pagination_container)

	prev_button = _create_button("< Prev", false)
	prev_button.custom_minimum_size = Vector2(80, 32)
	prev_button.pressed.connect(_on_prev_page)
	pagination_container.add_child(prev_button)

	page_label = Label.new()
	page_label.add_theme_font_override("font", custom_font)
	page_label.add_theme_font_size_override("font_size", 14)
	page_label.add_theme_color_override("font_color", TEXT_COLOR)
	page_label.text = "Page 1"
	pagination_container.add_child(page_label)

	next_button = _create_button("Next >", false)
	next_button.custom_minimum_size = Vector2(80, 32)
	next_button.pressed.connect(_on_next_page)
	pagination_container.add_child(next_button)


func _create_header_row() -> HBoxContainer:
	var row = HBoxContainer.new()
	row.add_theme_constant_override("separation", 12)

	# Rank
	var rank_header = _create_header_label("RANK", 50)
	row.add_child(rank_header)

	# Player
	var player_header = _create_header_label("PLAYER", 0)
	player_header.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	row.add_child(player_header)

	# ELO
	var elo_header = _create_header_label("ELO", 60)
	elo_header.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	row.add_child(elo_header)

	# Win Rate
	var wr_header = _create_header_label("WIN%", 60)
	wr_header.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	row.add_child(wr_header)

	# Games
	var games_header = _create_header_label("GAMES", 60)
	games_header.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	row.add_child(games_header)

	return row


func _create_header_label(text: String, min_width: int) -> Label:
	var label = Label.new()
	label.add_theme_font_override("font", custom_font)
	label.add_theme_font_size_override("font_size", 12)
	label.add_theme_color_override("font_color", MUTED_COLOR)
	label.text = text
	if min_width > 0:
		label.custom_minimum_size.x = min_width
	return label


func _create_panel_section(title: String) -> PanelContainer:
	var panel = PanelContainer.new()
	var style = StyleBoxFlat.new()
	style.bg_color = PANEL_COLOR
	style.set_corner_radius_all(8)
	style.set_content_margin_all(16)
	panel.add_theme_stylebox_override("panel", style)

	var vbox = VBoxContainer.new()
	vbox.add_theme_constant_override("separation", 12)
	panel.add_child(vbox)

	var title_label = Label.new()
	title_label.add_theme_font_override("font", custom_font)
	title_label.add_theme_font_size_override("font_size", 18)
	title_label.add_theme_color_override("font_color", TEXT_COLOR)
	title_label.text = title
	title_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	vbox.add_child(title_label)

	return panel


func _create_button(text: String, primary: bool) -> Button:
	var button = Button.new()
	button.text = text
	button.add_theme_font_override("font", custom_font)
	button.add_theme_font_size_override("font_size", 16)
	button.custom_minimum_size = Vector2(0, 40)

	var normal = StyleBoxFlat.new()
	var hover = StyleBoxFlat.new()
	var pressed = StyleBoxFlat.new()
	var disabled = StyleBoxFlat.new()

	if primary:
		normal.bg_color = ACCENT_COLOR
		hover.bg_color = ACCENT_COLOR.lightened(0.15)
		pressed.bg_color = ACCENT_COLOR.darkened(0.15)
		button.add_theme_color_override("font_color", Color.WHITE)
		button.add_theme_color_override("font_hover_color", Color.WHITE)
	else:
		normal.bg_color = Color(0.25, 0.23, 0.3)
		hover.bg_color = Color(0.3, 0.28, 0.35)
		pressed.bg_color = Color(0.2, 0.18, 0.25)
		button.add_theme_color_override("font_color", TEXT_COLOR)
		button.add_theme_color_override("font_hover_color", TEXT_COLOR)

	disabled.bg_color = Color(0.2, 0.18, 0.22)
	button.add_theme_color_override("font_disabled_color", MUTED_COLOR)

	for style in [normal, hover, pressed, disabled]:
		style.set_corner_radius_all(6)
		style.set_content_margin_all(8)

	button.add_theme_stylebox_override("normal", normal)
	button.add_theme_stylebox_override("hover", hover)
	button.add_theme_stylebox_override("pressed", pressed)
	button.add_theme_stylebox_override("disabled", disabled)

	return button


func _load_leaderboard() -> void:
	is_loading = true
	loading_label.visible = true
	_clear_leaderboard_list()

	var offset = current_page * PLAYERS_PER_PAGE
	var result = await NetworkManager.get_leaderboard(PLAYERS_PER_PAGE, offset)

	loading_label.visible = false
	is_loading = false

	if result.success:
		var players = result.get("players", [])
		players_cache = players
		_display_players(players)
		_update_pagination()
	else:
		_show_error(result.get("message", "Failed to load leaderboard"))


func _display_players(players: Array) -> void:
	_clear_leaderboard_list()

	if players.is_empty():
		var empty_label = Label.new()
		empty_label.add_theme_font_override("font", custom_font)
		empty_label.add_theme_font_size_override("font_size", 14)
		empty_label.add_theme_color_override("font_color", MUTED_COLOR)
		empty_label.text = "No players found"
		empty_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
		leaderboard_list.add_child(empty_label)
		return

	for player_data in players:
		var player_row = _create_player_row(player_data)
		leaderboard_list.add_child(player_row)


func _create_player_row(player_data: Dictionary) -> PanelContainer:
	var panel = PanelContainer.new()
	var style = StyleBoxFlat.new()
	style.set_corner_radius_all(4)
	style.set_content_margin_all(8)

	# Check if this is the current user
	var current_username = ""
	if NetworkManager and NetworkManager.is_authenticated:
		current_username = NetworkManager.current_user.get("username", "")

	var is_current_user = player_data.get("username", "") == current_username
	if is_current_user:
		style.bg_color = HIGHLIGHT_COLOR
	else:
		style.bg_color = Color(0.15, 0.14, 0.18, 0.5)

	panel.add_theme_stylebox_override("panel", style)

	var row = HBoxContainer.new()
	row.add_theme_constant_override("separation", 12)
	panel.add_child(row)

	var rank = player_data.get("rank", 0)

	# Rank with medal colors for top 3
	var rank_label = Label.new()
	rank_label.add_theme_font_override("font", custom_font)
	rank_label.add_theme_font_size_override("font_size", 16)
	rank_label.custom_minimum_size.x = 50
	rank_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER

	match rank:
		1:
			rank_label.text = "#1"
			rank_label.add_theme_color_override("font_color", GOLD_COLOR)
		2:
			rank_label.text = "#2"
			rank_label.add_theme_color_override("font_color", SILVER_COLOR)
		3:
			rank_label.text = "#3"
			rank_label.add_theme_color_override("font_color", BRONZE_COLOR)
		_:
			rank_label.text = "#%d" % rank
			rank_label.add_theme_color_override("font_color", TEXT_COLOR)
	row.add_child(rank_label)

	# Player name
	var name_label = Label.new()
	name_label.add_theme_font_override("font", custom_font)
	name_label.add_theme_font_size_override("font_size", 16)
	name_label.add_theme_color_override("font_color", ACCENT_COLOR if is_current_user else TEXT_COLOR)
	name_label.text = player_data.get("username", "Unknown")
	name_label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	row.add_child(name_label)

	# ELO
	var elo_label = Label.new()
	elo_label.add_theme_font_override("font", custom_font)
	elo_label.add_theme_font_size_override("font_size", 16)
	elo_label.add_theme_color_override("font_color", TEXT_COLOR)
	elo_label.text = str(player_data.get("eloRating", 1000))
	elo_label.custom_minimum_size.x = 60
	elo_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	row.add_child(elo_label)

	# Win rate
	var wr_label = Label.new()
	wr_label.add_theme_font_override("font", custom_font)
	wr_label.add_theme_font_size_override("font_size", 14)
	wr_label.add_theme_color_override("font_color", MUTED_COLOR)
	wr_label.text = "%d%%" % player_data.get("winRate", 0)
	wr_label.custom_minimum_size.x = 60
	wr_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	row.add_child(wr_label)

	# Games played
	var games_label = Label.new()
	games_label.add_theme_font_override("font", custom_font)
	games_label.add_theme_font_size_override("font_size", 14)
	games_label.add_theme_color_override("font_color", MUTED_COLOR)
	games_label.text = str(player_data.get("gamesPlayed", 0))
	games_label.custom_minimum_size.x = 60
	games_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_RIGHT
	row.add_child(games_label)

	return panel


func _clear_leaderboard_list() -> void:
	for child in leaderboard_list.get_children():
		child.queue_free()


func _update_pagination() -> void:
	page_label.text = "Page %d" % (current_page + 1)
	prev_button.disabled = current_page == 0
	# Disable next if we got fewer results than requested
	next_button.disabled = players_cache.size() < PLAYERS_PER_PAGE


func _show_error(message: String) -> void:
	error_label.text = message
	error_label.visible = true
	await get_tree().create_timer(5.0).timeout
	if is_instance_valid(error_label):
		error_label.visible = false


func _on_back_pressed() -> void:
	back_pressed.emit()


func _on_prev_page() -> void:
	if current_page > 0:
		current_page -= 1
		_load_leaderboard()


func _on_next_page() -> void:
	current_page += 1
	_load_leaderboard()


func refresh() -> void:
	current_page = 0
	_load_leaderboard()