## Single-goal tile showing the current (first uncompleted) goal from GoalCatalogue.
## Mirrors a single row from goals_debug_ui: goal name, requirements text, and a resolve button.
extends PanelContainer

@onready var _game_state: LevelGameState = find_parent("LevelGameState")
@onready var _goal_label: Label = $VBoxContainer/GoalLabel
@onready var _requirements_label: Label = $VBoxContainer/RequirementsLabel
@onready var _resolve_button: Button = $VBoxContainer/ResolveButton

var _current_goal: GoalData


func _ready() -> void:
	_resolve_button.pressed.connect(_on_resolve_pressed)
	if _game_state:
		_game_state.currency_changed.connect(_on_currency_changed)
		_game_state.generator_state_changed.connect(_on_generator_state_changed)
		_game_state.goal_completed.connect(_on_goal_completed)
		if not _game_state.goal_catalogue or _game_state.goal_catalogue.goals.is_empty():
			_game_state.ready.connect(_on_level_state_ready)

	_refresh_current_goal()
	_refresh_ui()
	_refresh_ui.call_deferred()


func _get_current_goal() -> GoalData:
	if _game_state == null:
		return null
	var catalogue: GoalCatalogue = _game_state.goal_catalogue
	if catalogue == null:
		return null

	for goal in catalogue.goals:
		if goal == null:
			continue
		if not goal.has_id():
			continue
		if _game_state.is_goal_completed(goal.id):
			continue
		return goal

	return null


func _refresh_current_goal() -> void:
	_current_goal = _get_current_goal()


func _refresh_ui() -> void:
	if _current_goal == null:
		_goal_label.text = "All goals complete!"
		_requirements_label.text = ""
		_resolve_button.disabled = true
		_resolve_button.text = "Done"
		return

	_goal_label.text = String(_current_goal.id)

	if _game_state == null:
		return

	var already_completed: bool = _game_state.is_goal_completed(_current_goal.id)

	_requirements_label.text = _get_requirements_text(_current_goal)

	var met: bool = _game_state.is_goal_met(_current_goal)
	var can_click: bool = met and not already_completed

	_resolve_button.disabled = not can_click
	_resolve_button.text = "Done" if already_completed else "Resolve"


func _get_requirements_text(goal: GoalData) -> String:
	if goal == null or _game_state == null:
		return ""

	var parts: Array[String] = []
	for req in goal.get_requirements():
		if req == null:
			continue

		var currency: Currency = req.get_currency()
		if currency == null:
			continue

		var currency_id: StringName = _game_state.get_currency_id(currency)
		var total_amount: BigNumber = _game_state.get_total_currency_acquired_by_id(currency_id)
		var required_amount: BigNumber = req.get_amount()
		var currency_name: String = _game_state.get_currency_name(currency_id)

		parts.append(
			"%s %s / %s" % [
				currency_name,
				total_amount.to_string_suffix(2),
				required_amount.to_string_suffix(2),
			]
		)

	if parts.is_empty():
		return "No requirements"
	return " | ".join(parts)


func _on_resolve_pressed() -> void:
	if _current_goal == null:
		return
	if _game_state == null:
		return
	if _game_state.is_goal_completed(_current_goal.id):
		return
	if not _game_state.is_goal_met(_current_goal):
		return

	if _current_goal.unlock_behavior == GoalData.UnlockBehavior.MANUAL:
		_game_state._complete_goal_manually(_current_goal.id)

	_refresh_current_goal()
	_refresh_ui()


func _on_currency_changed(_currency_id: StringName, _new_amount: BigNumber) -> void:
	_refresh_current_goal()
	_refresh_ui()


func _on_generator_state_changed(_generator_id: StringName, _state: Dictionary) -> void:
	_refresh_current_goal()
	_refresh_ui()


func _on_goal_completed(_goal_id: StringName) -> void:
	_refresh_current_goal()
	_refresh_ui()


func _on_level_state_ready() -> void:
	if _game_state:
		_game_state.ready.disconnect(_on_level_state_ready)
	_refresh_current_goal()
	_refresh_ui()


func _exit_tree() -> void:
	if _game_state:
		if _game_state.currency_changed.is_connected(_on_currency_changed):
			_game_state.currency_changed.disconnect(_on_currency_changed)
		if _game_state.generator_state_changed.is_connected(_on_generator_state_changed):
			_game_state.generator_state_changed.disconnect(_on_generator_state_changed)
		if _game_state.goal_completed.is_connected(_on_goal_completed):
			_game_state.goal_completed.disconnect(_on_goal_completed)
		if _game_state.ready.is_connected(_on_level_state_ready):
			_game_state.ready.disconnect(_on_level_state_ready)