Use worker for research

core/research/research_panel.gd

@@ -5,6 +5,7 @@ const RESEARCH_ROW_SCENE: PackedScene = preload("res://core/research/research_ro
 
 @onready var _title_label: Label = $ScrollContainer/VBoxContainer/TitleLabel
 @onready var _research_rows_container: VBoxContainer = $ScrollContainer/VBoxContainer/ResearchRows
+@onready var _buy_worker_button: Button = $ScrollContainer/VBoxContainer/HBoxContainer/BuyWorkerButton
 
 var _game_state: LevelGameState
 var _research_rows: Dictionary = {}
@@ -18,9 +19,12 @@ func _ready() -> void:
 	
 	_game_state.research_xp_changed.connect(_on_research_xp_changed)
 	_game_state.research_level_up.connect(_on_research_level_up)
+	_game_state.currency_changed.connect(_on_currency_changed)
+	_game_state.research_workers_changed.connect(_on_research_workers_changed)
 	
 	_build_research_rows()
 	_refresh_all()
+	_refresh_worker_button()
 
 func _build_research_rows() -> void:
 	for child in _research_rows_container.get_children():
@@ -109,3 +113,43 @@ func activate_research(research_id: StringName) -> void:
 	if _research_rows.has(research_id):
 		var row: ResearchRow = _research_rows[research_id]
 		row.set_active(true)
+
+func _on_currency_changed(currency_id: StringName, _new_amount: BigNumber) -> void:
+	if currency_id == &"worker":
+		_refresh_worker_button()
+
+func _on_research_workers_changed(_new_count: int) -> void:
+	_refresh_worker_button()
+
+func _can_buy_worker() -> bool:
+	if _game_state == null:
+		return false
+	
+	var worker_currency: BigNumber = _game_state.get_currency_amount_by_id(&"worker")
+	
+	return worker_currency.mantissa >= 1.0
+
+func _buy_worker() -> void:
+	if _game_state == null:
+		return
+	
+	_game_state.assign_worker_to_research()
+
+func _on_buy_worker_pressed() -> void:
+	_buy_worker()
+	_refresh_worker_button()
+
+func _refresh_worker_button() -> void:
+	if _buy_worker_button == null:
+		return
+	
+	if _game_state == null:
+		_buy_worker_button.disabled = true
+		return
+	
+	var can_buy: bool = _can_buy_worker()
+	_buy_worker_button.disabled = not can_buy
+	
+	var worker_currency: BigNumber = _game_state.get_currency_amount_by_id(&"worker")
+	var research_workers: int = _game_state.get_research_workers()
+	_buy_worker_button.text = "Assign Worker to Research (%d available, %d assigned)" % [int(worker_currency.mantissa), research_workers]