Use worker for research

core/level_game_state.gd

@@ -23,6 +23,10 @@ signal goal_progress_changed(goal_id: StringName, progress: float)
 signal research_xp_changed(research_id: StringName, new_xp: BigNumber)
 ## Emitted when a research track levels up.
 signal research_level_up(research_id: StringName, old_level: int, new_level: int)
+## Emitted when worker count changes (derived from currency balance).
+signal worker_count_changed(currency_id: StringName, new_count: int)
+## Emitted when research workers change.
+signal research_workers_changed(new_count: int)
 
 # ==============================================================================
 # EXPORTED REFERENCES
@@ -72,6 +76,8 @@ var _goal_completed: Dictionary = {}
 var research_xp: Dictionary = {}
 ## Research levels by research ID.
 var research_levels: Dictionary = {}
+## Workers assigned to research (total across all tracks).
+var research_workers: int = 0
 
 ## Unix timestamp of last save.
 var last_save_time: int = 0
@@ -81,8 +87,8 @@ var last_save_time: int = 0
 # ==============================================================================
 ## JSON key for save format version.
 const SAVE_FORMAT_VERSION_KEY: String = "save_format_version"
-## Current save format version (5 includes research XP BigNumber serialization).
-const CURRENT_SAVE_FORMAT_VERSION: int = 5
+## Current save format version (7 includes research workers tracking).
+const CURRENT_SAVE_FORMAT_VERSION: int = 7
 ## JSON key for generator owned count.
 const GENERATOR_OWNED_KEY: String = "owned"
 ## JSON key for generator purchased count.
@@ -120,6 +126,8 @@ const LAST_SAVE_TIME_KEY: String = "last_save_time"
 const RESEARCH_XP_KEY: String = "research_xp"
 ## JSON key for research levels section.
 const RESEARCH_LEVELS_KEY: String = "research_levels"
+## JSON key for research workers section.
+const RESEARCH_WORKERS_KEY: String = "research_workers"
 
 ## Reference to the PrestigeManager autoload node (set in _ready).
 var prestige_manager: PrestigeManager
@@ -484,6 +492,31 @@ func get_research_multiplier(research_id: StringName) -> float:
 		return 1.0
 	return research.get_multiplier_for_level(level)
 
+## Returns the total number of workers assigned to research.
+func get_research_workers() -> int:
+	return research_workers
+
+## Assigns a worker to research (called when spending worker currency on research).
+func assign_worker_to_research() -> bool:
+	var worker_currency: BigNumber = get_currency_amount_by_id("worker")
+	if worker_currency.mantissa < 1.0:
+		return false
+	
+	spend_currency_by_id("worker", BigNumber.from_float(1.0))
+	research_workers += 1
+	research_workers_changed.emit(research_workers)
+	return true
+
+## Removes a worker from research (returns to worker currency).
+func remove_worker_from_research() -> bool:
+	if research_workers <= 0:
+		return false
+	
+	research_workers -= 1
+	add_currency_by_id("worker", BigNumber.from_float(1.0))
+	research_workers_changed.emit(research_workers)
+	return true
+
 ## Adds XP to a research track, applying buff modifiers and emitting signals on level up.
 func add_research_xp(research_id: StringName, xp: BigNumber) -> void:
 	var actual_xp: BigNumber = ResearchBuffCalculator.apply_buffs(self, research_id, xp)
@@ -508,6 +541,11 @@ func _get_research_data(research_id: StringName) -> ResearchData:
 		return null
 	return research_catalogue.get_research_by_id(research_id)
 
+## Returns the current worker count (derived from "worker" currency balance).
+func get_worker_count() -> int:
+	var worker_amount: BigNumber = get_currency_amount_by_id("worker")
+	return int(worker_amount.mantissa) if worker_amount.mantissa >= 0 else 0
+
 #endregion
 
 # ==============================================================================
@@ -588,6 +626,7 @@ func save_game() -> void:
 		GOALS_KEY: _serialize_goals(),
 		RESEARCH_XP_KEY: _serialize_research_xp(),
 		RESEARCH_LEVELS_KEY: research_levels.duplicate(),
+		RESEARCH_WORKERS_KEY: research_workers,
 		LAST_SAVE_TIME_KEY: Time.get_unix_time_from_system()
 	}
 
@@ -639,13 +678,15 @@ func load_game() -> void:
 				research_xp = _deserialize_research_xp(parsed_data.get(RESEARCH_XP_KEY, {}))
 			if parsed_data.has(RESEARCH_LEVELS_KEY):
 				research_levels = parsed_data.get(RESEARCH_LEVELS_KEY, {})
+			if parsed_data.has(RESEARCH_WORKERS_KEY):
+				research_workers = int(parsed_data.get(RESEARCH_WORKERS_KEY, 0))
 			
 			last_save_time = parsed_data.get(LAST_SAVE_TIME_KEY, Time.get_unix_time_from_system())
 			for save_key_variant in parsed_data.keys():
 				var save_key: String = String(save_key_variant)
 				if save_key.is_empty():
 					continue
-				if save_key in [SAVE_FORMAT_VERSION_KEY, CURRENCIES_KEY, GENERATOR_STATES_KEY, BUFF_LEVELS_KEY, BUFF_UNLOCKED_KEY, BUFF_ACTIVE_KEY, GOALS_KEY, RESEARCH_XP_KEY, RESEARCH_LEVELS_KEY, LAST_SAVE_TIME_KEY]:
+				if save_key in [SAVE_FORMAT_VERSION_KEY, CURRENCIES_KEY, GENERATOR_STATES_KEY, BUFF_LEVELS_KEY, BUFF_UNLOCKED_KEY, BUFF_ACTIVE_KEY, GOALS_KEY, RESEARCH_XP_KEY, RESEARCH_LEVELS_KEY, RESEARCH_WORKERS_KEY, LAST_SAVE_TIME_KEY]:
 					continue
 
 				var section_payload: Variant = parsed_data.get(save_key_variant)