extends Node
# This script is added as an Autoload named 'GameState'

# ==========================================
# SIGNALS
# ==========================================
signal gold_changed(new_amount: BigNumber)
signal gems_changed(new_amount: BigNumber)
signal generator_state_changed(generator_id: StringName, state: Dictionary)

enum CurrencyType { gold, gems }

# ==========================================
# STATE VARIABLES
# ==========================================
var gold: BigNumber = BigNumber.from_float(0.0)
var gems: BigNumber = BigNumber.from_float(0.0)
var generator_states: Dictionary = {}

var last_save_time: int = 0 # Unix timestamp

static var file_name: String = "user://idle_save.json"

const GENERATOR_OWNED_KEY: String = "owned"
const GENERATOR_PURCHASED_COUNT_KEY: String = "purchased_count"
const GENERATOR_UNLOCKED_KEY: String = "unlocked"
const GENERATOR_AVAILABLE_KEY: String = "available"

func _ready() -> void:
	load_game()

# ==========================================
# STATE MODIFIERS
# ==========================================
func add_gold(amount: BigNumber) -> void:
	gold.add_in_place(amount)
	gold_changed.emit(gold)

func spend_gold(cost: BigNumber) -> bool:
	if gold.is_greater_than(cost) or gold.is_equal_to(cost):
		var negative_cost = BigNumber.new(-cost.mantissa, cost.exponent)
		gold.add_in_place(negative_cost)
		gold_changed.emit(gold)
		return true
	return false

func add_gems(amount: BigNumber) -> void:
	gems.add_in_place(amount)
	gems_changed.emit(gems)

func spend_gems(cost: BigNumber) -> bool:
	if gems.is_greater_than(cost) or gems.is_equal_to(cost):
		var negative_cost = BigNumber.new(-cost.mantissa, cost.exponent)
		gems.add_in_place(negative_cost)
		gems_changed.emit(gems)
		return true
	return false

func register_generator(generator_id: StringName, unlocked: bool = false, available: bool = false) -> void:
	var key: String = String(generator_id)
	if key.is_empty():
		return

	if generator_states.has(key):
		var existing_raw: Variant = generator_states.get(key)
		if existing_raw is Dictionary:
			generator_states[key] = _sanitize_generator_state(existing_raw, unlocked, available)
			return

	var new_state: Dictionary = _default_generator_state(unlocked, available)
	generator_states[key] = new_state
	generator_state_changed.emit(StringName(key), new_state.duplicate(true))

func get_generator_state(generator_id: StringName) -> Dictionary:
	return _get_generator_state(generator_id).duplicate(true)

func get_generator_owned(generator_id: StringName) -> int:
	var state: Dictionary = _get_generator_state(generator_id)
	return int(state.get(GENERATOR_OWNED_KEY, 0))

func set_generator_owned(generator_id: StringName, value: int) -> void:
	var state: Dictionary = _get_generator_state(generator_id)
	var next_owned: int = maxi(value, 0)
	if int(state.get(GENERATOR_OWNED_KEY, 0)) == next_owned:
		return

	state[GENERATOR_OWNED_KEY] = next_owned
	state[GENERATOR_PURCHASED_COUNT_KEY] = maxi(int(state.get(GENERATOR_PURCHASED_COUNT_KEY, 0)), next_owned)
	_set_generator_state(generator_id, state)

func get_generator_purchased_count(generator_id: StringName) -> int:
	var state: Dictionary = _get_generator_state(generator_id)
	return int(state.get(GENERATOR_PURCHASED_COUNT_KEY, 0))

func set_generator_purchased_count(generator_id: StringName, value: int) -> void:
	var state: Dictionary = _get_generator_state(generator_id)
	var min_purchased: int = int(state.get(GENERATOR_OWNED_KEY, 0))
	var next_purchased: int = maxi(value, min_purchased)
	if int(state.get(GENERATOR_PURCHASED_COUNT_KEY, 0)) == next_purchased:
		return

	state[GENERATOR_PURCHASED_COUNT_KEY] = next_purchased
	_set_generator_state(generator_id, state)

func is_generator_unlocked(generator_id: StringName) -> bool:
	var state: Dictionary = _get_generator_state(generator_id)
	return bool(state.get(GENERATOR_UNLOCKED_KEY, false))

func set_generator_unlocked(generator_id: StringName, value: bool) -> void:
	var state: Dictionary = _get_generator_state(generator_id)
	if bool(state.get(GENERATOR_UNLOCKED_KEY, false)) == value:
		return

	state[GENERATOR_UNLOCKED_KEY] = value
	_set_generator_state(generator_id, state)

func is_generator_available(generator_id: StringName) -> bool:
	var state: Dictionary = _get_generator_state(generator_id)
	return bool(state.get(GENERATOR_AVAILABLE_KEY, false))

func set_generator_available(generator_id: StringName, value: bool) -> void:
	var state: Dictionary = _get_generator_state(generator_id)
	if bool(state.get(GENERATOR_AVAILABLE_KEY, false)) == value:
		return

	state[GENERATOR_AVAILABLE_KEY] = value
	_set_generator_state(generator_id, state)

# ==========================================
# PERSISTENCE (Save/Load)
# ==========================================
func save_game() -> void:
	var save_data = {
		"gold": gold.serialize(),
		"gems": gems.serialize(),
		"generator_states": _serialize_generator_states(),
		"last_save_time": Time.get_unix_time_from_system()
	}
	
	var file = FileAccess.open(file_name, FileAccess.WRITE)
	if file:
		file.store_string(JSON.stringify(save_data))

func load_game() -> void:
	if not FileAccess.file_exists(file_name):
		return
		
	var file = FileAccess.open(file_name, FileAccess.READ)
	if file:
		var parsed = JSON.parse_string(file.get_as_text())
		if parsed is Dictionary:
			gold = BigNumber.deserialize(parsed.get("gold", {}))
			gems = BigNumber.deserialize(parsed.get("gems", {}))
			generator_states = _deserialize_generator_states(parsed.get("generator_states", {}))
			last_save_time = parsed.get("last_save_time", Time.get_unix_time_from_system())

func _default_generator_state(unlocked: bool, available: bool) -> Dictionary:
	return {
		GENERATOR_OWNED_KEY: 0,
		GENERATOR_PURCHASED_COUNT_KEY: 0,
		GENERATOR_UNLOCKED_KEY: unlocked,
		GENERATOR_AVAILABLE_KEY: available,
	}

func _get_generator_state(generator_id: StringName) -> Dictionary:
	var key: String = String(generator_id)
	if key.is_empty():
		return _default_generator_state(false, false)

	if not generator_states.has(key):
		register_generator(generator_id)

	var existing_raw: Variant = generator_states.get(key, _default_generator_state(false, false))
	if existing_raw is Dictionary:
		var state: Dictionary = existing_raw
		var sanitized: Dictionary = _sanitize_generator_state(state, false, false)
		generator_states[key] = sanitized
		return sanitized

	var fallback: Dictionary = _default_generator_state(false, false)
	generator_states[key] = fallback
	return fallback

func _set_generator_state(generator_id: StringName, state: Dictionary) -> void:
	var key: String = String(generator_id)
	if key.is_empty():
		return

	var sanitized: Dictionary = _sanitize_generator_state(state, false, false)
	generator_states[key] = sanitized
	generator_state_changed.emit(StringName(key), sanitized.duplicate(true))

func _serialize_generator_states() -> Dictionary:
	var result: Dictionary = {}
	for key_variant in generator_states.keys():
		var key: String = String(key_variant)
		if key.is_empty():
			continue

		var value: Variant = generator_states.get(key_variant)
		if value is Dictionary:
			result[key] = _serialize_generator_state_entry(value)
	return result

func _deserialize_generator_states(raw_value: Variant) -> Dictionary:
	var result: Dictionary = {}
	if not (raw_value is Dictionary):
		return result

	for key_variant in raw_value.keys():
		var key: String = String(key_variant)
		if key.is_empty():
			continue

		var entry: Variant = raw_value.get(key_variant)
		if entry is Dictionary:
			result[key] = _deserialize_generator_state_entry(entry)
	return result

func _serialize_generator_state_entry(raw_state: Dictionary) -> Dictionary:
	var owned_value: int = _to_non_negative_int(raw_state.get(GENERATOR_OWNED_KEY, 0), 0)
	var purchased_value: int = _to_non_negative_int(raw_state.get(GENERATOR_PURCHASED_COUNT_KEY, owned_value), owned_value)

	var serialized_state: Dictionary = {
		GENERATOR_OWNED_KEY: owned_value,
		GENERATOR_PURCHASED_COUNT_KEY: maxi(purchased_value, owned_value),
	}

	if raw_state.has(GENERATOR_UNLOCKED_KEY) and raw_state.get(GENERATOR_UNLOCKED_KEY) is bool:
		serialized_state[GENERATOR_UNLOCKED_KEY] = raw_state.get(GENERATOR_UNLOCKED_KEY)
	if raw_state.has(GENERATOR_AVAILABLE_KEY) and raw_state.get(GENERATOR_AVAILABLE_KEY) is bool:
		serialized_state[GENERATOR_AVAILABLE_KEY] = raw_state.get(GENERATOR_AVAILABLE_KEY)

	return serialized_state

func _deserialize_generator_state_entry(raw_state: Dictionary) -> Dictionary:
	var owned_value: int = _to_non_negative_int(raw_state.get(GENERATOR_OWNED_KEY, 0), 0)
	var purchased_value: int = _to_non_negative_int(raw_state.get(GENERATOR_PURCHASED_COUNT_KEY, owned_value), owned_value)

	var parsed_state: Dictionary = {
		GENERATOR_OWNED_KEY: owned_value,
		GENERATOR_PURCHASED_COUNT_KEY: maxi(purchased_value, owned_value),
	}

	if raw_state.has(GENERATOR_UNLOCKED_KEY) and raw_state.get(GENERATOR_UNLOCKED_KEY) is bool:
		parsed_state[GENERATOR_UNLOCKED_KEY] = raw_state.get(GENERATOR_UNLOCKED_KEY)
	if raw_state.has(GENERATOR_AVAILABLE_KEY) and raw_state.get(GENERATOR_AVAILABLE_KEY) is bool:
		parsed_state[GENERATOR_AVAILABLE_KEY] = raw_state.get(GENERATOR_AVAILABLE_KEY)

	return parsed_state

func _sanitize_generator_state(raw_state: Dictionary, default_unlocked: bool, default_available: bool) -> Dictionary:
	var owned_value: int = _to_non_negative_int(raw_state.get(GENERATOR_OWNED_KEY, 0), 0)
	var purchased_value: int = _to_non_negative_int(raw_state.get(GENERATOR_PURCHASED_COUNT_KEY, owned_value), owned_value)

	return {
		GENERATOR_OWNED_KEY: owned_value,
		GENERATOR_PURCHASED_COUNT_KEY: maxi(purchased_value, owned_value),
		GENERATOR_UNLOCKED_KEY: _to_bool(raw_state.get(GENERATOR_UNLOCKED_KEY, default_unlocked), default_unlocked),
		GENERATOR_AVAILABLE_KEY: _to_bool(raw_state.get(GENERATOR_AVAILABLE_KEY, default_available), default_available),
	}

func _to_non_negative_int(value: Variant, fallback: int = 0) -> int:
	if value is int:
		return maxi(value, 0)
	if value is float:
		return maxi(int(value), 0)
	return maxi(fallback, 0)

func _to_bool(value: Variant, fallback: bool) -> bool:
	if value is bool:
		return value
	return fallback