extends Control

# Main menu: one handler per game mode. Match's opponent is a curated
# Easy/Medium/Hard difficulty picker (DIFFICULTIES) rather than a raw
# checkpoint list — see TRAINING.md for promoting new tiers into
# res://bots/promoted/. Raw-checkpoint testing and Spectate (bot vs bot) are
# dev-only tools, grouped under DevSection and hidden outside debug builds so
# they disappear automatically from release exports. Selections are pushed
# into the GameSettings autoload for the target mode to read, and restored
# when returning to the menu within a session.

const BOTS_DIR := "res://bots"

# Every tier runs its promoted checkpoint at full trained capability —
# difficulty is a genuinely different policy, never the same policy
# handicapped with reaction delay or action noise. All three tiers are now
# distinct models: medium.json beats easy.json 65-22-13, and hard.json (the
# generation-5 Stage-5 policy) beats medium.json 47-32-21. Keep the tiers
# monotonic: never leave a lower tier pointing at a stronger model than the
# one above it.
const DIFFICULTIES := [
	{"name": "Easy", "model": "res://bots/promoted/easy.json", "reaction_ticks": 8, "action_noise": 0.0},
	{"name": "Medium", "model": "res://bots/promoted/medium.json", "reaction_ticks": 8, "action_noise": 0.0},
	{"name": "Hard", "model": "res://bots/promoted/hard.json", "reaction_ticks": 8, "action_noise": 0.0},
]

@onready var difficulty_dropdown: OptionButton = %DifficultyDropdown
@onready var arena_dropdown: OptionButton = %ArenaDropdown
@onready var dev_section: Control = %DevSection
@onready var dev_bot_dropdown: OptionButton = %DevBotDropdown
@onready var bot_a_dropdown: OptionButton = %BotADropdown
@onready var bot_b_dropdown: OptionButton = %BotBDropdown
@onready var join_address_edit: LineEdit = %JoinAddressEdit
@onready var multiplayer_error_label: Label = %MultiplayerErrorLabel
@onready var connecting_overlay: Control = %ConnectingOverlay
@onready var connecting_status_label: Label = %ConnectingStatusLabel


func _ready() -> void:
	AudioManager.bind_tree_buttons(self)
	# An idle menu has no reason to render past the display's own refresh
	# rate; gameplay scenes are uncapped again by _leave_to_gameplay below.
	var refresh_rate := DisplayServer.screen_get_refresh_rate()
	Engine.max_fps = int(refresh_rate) if refresh_rate > 0 else 0
	_populate_difficulty_dropdown()
	_populate_arena_dropdown()
	dev_section.visible = OS.is_debug_build()
	if dev_section.visible:
		var bots := _list_bots()
		_populate_dropdown(dev_bot_dropdown, bots, GameSettings.dev_bot_override_path, true)
		_populate_dropdown(bot_a_dropdown, bots, GameSettings.spectate_bot_a_path)
		_populate_dropdown(bot_b_dropdown, bots, GameSettings.spectate_bot_b_path)
	NetworkManager.connected_to_server.connect(_on_connected_to_server)
	NetworkManager.connection_failed.connect(_on_connection_failed)
	%FreePlayButton.grab_focus()


# main_menu.gd's first async flow (task 1.7): Host is synchronous
# (NetworkManager.host() either succeeds immediately or fails immediately),
# but Join is not — it can take anywhere from a clean local-network round
# trip to ENet's own ~5s connect timeout to resolve, so unlike every other
# handler in this file (GameSettings.x = y; change_scene_to_file(...)) it
# needs a loading state (ConnectingOverlay), a cancel path, and a failure
# path that returns the player to a sane, retryable menu state rather than
# just hanging with no feedback.
func _process(_delta: float) -> void:
	NetworkManager.poll()


func _physics_process(_delta: float) -> void:
	NetworkManager.poll()


func _populate_difficulty_dropdown() -> void:
	difficulty_dropdown.clear()
	for tier in DIFFICULTIES:
		difficulty_dropdown.add_item(tier["name"])
	var selected := 0
	for i in DIFFICULTIES.size():
		if DIFFICULTIES[i]["name"] == GameSettings.selected_difficulty_name:
			selected = i
			break
	difficulty_dropdown.select(selected)


# Free Play only — Match/Spectate pick a random arena in code instead.
func _populate_arena_dropdown() -> void:
	arena_dropdown.clear()
	for tier in ArenaRegistry.ARENAS:
		arena_dropdown.add_item(tier["name"])
	var selected := 0
	for i in ArenaRegistry.ARENAS.size():
		if ArenaRegistry.ARENAS[i]["path"] == GameSettings.selected_arena_path:
			selected = i
			break
	arena_dropdown.select(selected)


# Lists bot checkpoints as paths relative to BOTS_DIR, including the
# top-level curriculum checkpoints and anything under promoted/.
func _list_bots() -> Array[String]:
	var files: Array[String] = []
	var dir := DirAccess.open(BOTS_DIR)
	if dir:
		for f in dir.get_files():
			if f.get_extension() == "json":
				files.append(f)
	var promoted_dir := DirAccess.open(BOTS_DIR + "/promoted")
	if promoted_dir:
		for f in promoted_dir.get_files():
			if f.get_extension() == "json":
				files.append("promoted/" + f)
	files.sort()
	return files


# Fills a dropdown with bot names (metadata = full model path). When
# include_none is true, prepends a "(Use difficulty)" sentinel (metadata "")
# and defaults selection to it. Reselects `preferred_path` if it's still on
# disk, else the newest (last) bot.
func _populate_dropdown(dropdown: OptionButton, bots: Array[String], preferred_path: String, include_none: bool = false) -> void:
	dropdown.clear()
	# These are filled from whatever checkpoints happen to be in res://bots, so
	# a long filename would otherwise widen the OptionButton (size_flags_h =
	# EXPAND_FILL) and drag the whole menu past its 420px minimum width.
	dropdown.clip_text = true
	dropdown.fit_to_longest_item = false
	if include_none:
		dropdown.add_item("(Use difficulty)")
		dropdown.set_item_metadata(0, "")
	for f in bots:
		dropdown.add_item(f.get_basename())
		dropdown.set_item_metadata(dropdown.item_count - 1, BOTS_DIR + "/" + f)
	if dropdown.item_count == 0:
		return
	dropdown.select(0 if include_none else dropdown.item_count - 1)
	for i in dropdown.item_count:
		if dropdown.get_item_metadata(i) == preferred_path:
			dropdown.select(i)
			break


func _selected_path(dropdown: OptionButton) -> String:
	if dropdown.item_count > 0 and dropdown.selected >= 0:
		return dropdown.get_item_metadata(dropdown.selected)
	return ""


# The menu's own refresh-rate fps cap (see _ready) is a menu-only concern;
# gameplay scenes respect the player's own VideoSettings fps cap instead
# (task 0.17), which only actually caps anything when vsync is Disabled and a
# divisor is chosen — otherwise this uncaps exactly like the old hardcoded 0.
func _leave_to_gameplay(scene_path: String) -> void:
	VideoSettings.apply_fps_cap()
	get_tree().change_scene_to_file(scene_path)


func _on_free_play_pressed() -> void:
	var chosen: Dictionary = ArenaRegistry.ARENAS[0] if arena_dropdown.selected < 0 else ArenaRegistry.ARENAS[arena_dropdown.selected]
	GameSettings.selected_arena_path = chosen["path"]
	_leave_to_gameplay("res://scenes/free_play.tscn")


func _on_match_pressed() -> void:
	var tier: Dictionary = DIFFICULTIES[difficulty_dropdown.selected] if difficulty_dropdown.selected >= 0 else DIFFICULTIES[0]
	var override_path := _selected_path(dev_bot_dropdown) if dev_section.visible else ""
	GameSettings.dev_bot_override_path = override_path
	GameSettings.selected_difficulty_name = tier["name"]
	if override_path.is_empty():
		GameSettings.selected_bot_path = tier["model"]
		GameSettings.selected_bot_reaction_ticks = tier["reaction_ticks"]
		GameSettings.selected_bot_action_noise = tier["action_noise"]
	else:
		GameSettings.selected_bot_path = override_path
		GameSettings.selected_bot_reaction_ticks = -1
		GameSettings.selected_bot_action_noise = -1.0
	_leave_to_gameplay("res://scenes/match.tscn")


func _on_settings_pressed() -> void:
	get_tree().change_scene_to_file(ScenePaths.SETTINGS)


func _on_spectate_pressed() -> void:
	GameSettings.spectate_bot_a_path = _selected_path(bot_a_dropdown)
	GameSettings.spectate_bot_b_path = _selected_path(bot_b_dropdown)
	_leave_to_gameplay("res://scenes/spectate.tscn")


func _on_host_pressed() -> void:
	_clear_multiplayer_error()
	var err := NetworkManager.host()
	if err != OK:
		_show_multiplayer_error("Could not host: %s" % error_string(err))
		return
	_leave_to_lobby()


func _on_find_match_pressed() -> void:
	get_tree().change_scene_to_file("res://scenes/matchmaking.tscn")


func _on_join_pressed() -> void:
	_start_join()


func _on_join_address_submitted(_new_text: String) -> void:
	_start_join()


# ENet's own give-up-and-fire-connection_failed schedule is not bounded to
# anything a menu should make a player wait for — verified empirically
# (tests/main_menu_test_hooks.gd's join_refused case) against a genuinely
# refused loopback connection: connection_failed never fired within 14s.
# This timer is what actually guarantees "connection-refused reaches a sane
# UI state" rather than leaving the overlay up indefinitely.
const CONNECT_TIMEOUT_SECONDS := 6.0

var _connect_timeout_token := 0   # bumped on every new attempt/cancel/resolution so a stale timer callback is a no-op


func _start_join() -> void:
	_clear_multiplayer_error()
	var address := join_address_edit.text.strip_edges()
	if address.is_empty():
		_show_multiplayer_error("Enter an IP address to join")
		return
	var err := NetworkManager.join(address)
	if err != OK:
		_show_multiplayer_error("Could not join: %s" % error_string(err))
		return
	connecting_status_label.text = "Connecting to %s..." % address
	connecting_overlay.visible = true
	_connect_timeout_token += 1
	var my_token := _connect_timeout_token
	get_tree().create_timer(CONNECT_TIMEOUT_SECONDS).timeout.connect(func(): _on_connect_timeout(my_token))


func _on_connect_timeout(token: int) -> void:
	if token != _connect_timeout_token or not connecting_overlay.visible:
		return   # a newer attempt (or Cancel, or a real success/failure) already resolved this
	NetworkManager.shutdown()
	connecting_overlay.visible = false
	_show_multiplayer_error("Connection timed out — check the address and that a server is hosting on that port")


func _on_connecting_cancel_pressed() -> void:
	_connect_timeout_token += 1
	NetworkManager.shutdown()
	connecting_overlay.visible = false


func _on_connected_to_server() -> void:
	if not connecting_overlay.visible:
		return   # e.g. a stray/late signal after Cancel already shut the peer down
	_connect_timeout_token += 1
	connecting_overlay.visible = false
	_leave_to_lobby()


func _on_connection_failed() -> void:
	if not connecting_overlay.visible:
		return
	_connect_timeout_token += 1
	connecting_overlay.visible = false
	_show_multiplayer_error("Connection failed — check the address and that a server is hosting on that port")


func _leave_to_lobby() -> void:
	get_tree().change_scene_to_file("res://scenes/lobby.tscn")


func _show_multiplayer_error(message: String) -> void:
	multiplayer_error_label.text = message
	multiplayer_error_label.visible = true


func _clear_multiplayer_error() -> void:
	multiplayer_error_label.visible = false