class_name PlayerStateRecord
extends RefCounted

const SCHEMA_VERSION := 2
const LEGACY_SCHEMA_VERSION := 1
const MAX_HEALTH := 100.0

var data: Dictionary


func _init(record_data: Dictionary = {}) -> void:
	data = record_data.duplicate(true)


static func create_default() -> PlayerStateRecord:
	return (
		PlayerStateRecord
		. new(
			{
				"schema_version": SCHEMA_VERSION,
				"hunger": 40.0,
				"energy": 100.0,
				"health": MAX_HEALTH,
				"max_health": MAX_HEALTH,
				"downed": false,
				"downed_ticks": 0,
				"inventory": {},
			}
		)
	)


static func from_dictionary(record_data: Dictionary) -> PlayerStateRecord:
	var version := int(record_data.get("schema_version", -1))
	if version == LEGACY_SCHEMA_VERSION:
		record_data = _migrate_v1(record_data)
	elif version != SCHEMA_VERSION:
		return null
	if not record_data.has_all(
		["hunger", "energy", "health", "max_health", "downed", "downed_ticks", "inventory"]
	):
		return null
	if not record_data["inventory"] is Dictionary:
		return null
	var hunger := float(record_data["hunger"])
	var energy := float(record_data["energy"])
	var health := float(record_data["health"])
	var max_health := float(record_data["max_health"])
	if (
		not is_finite(hunger)
		or not is_finite(energy)
		or not is_finite(health)
		or not is_finite(max_health)
	):
		return null
	var normalized_inventory := {}
	for raw_item_id in record_data["inventory"]:
		var item_id := String(raw_item_id)
		var amount := float(record_data["inventory"][raw_item_id])
		if (
			item_id.is_empty()
			or normalized_inventory.has(item_id)
			or not is_finite(amount)
			or amount < 0.0
		):
			return null
		normalized_inventory[item_id] = amount
	return (
		PlayerStateRecord
		. new(
			{
				"schema_version": SCHEMA_VERSION,
				"hunger": clampf(hunger, 0.0, 100.0),
				"energy": clampf(energy, 0.0, 100.0),
				"health": clampf(health, 0.0, max_health),
				"max_health": max_health,
				"downed": bool(record_data["downed"]),
				"downed_ticks": int(record_data["downed_ticks"]),
				"inventory": normalized_inventory,
			}
		)
	)


static func _migrate_v1(legacy_data: Dictionary) -> Dictionary:
	var migrated := legacy_data.duplicate(true)
	migrated["schema_version"] = SCHEMA_VERSION
	migrated["health"] = MAX_HEALTH
	migrated["max_health"] = MAX_HEALTH
	migrated["downed"] = false
	migrated["downed_ticks"] = 0
	return migrated


func get_hunger() -> float:
	return clampf(float(data["hunger"]), 0.0, 100.0)


func get_energy() -> float:
	return clampf(float(data["energy"]), 0.0, 100.0)


func get_health() -> float:
	return clampf(float(data["health"]), 0.0, get_max_health())


func get_max_health() -> float:
	return maxf(float(data["max_health"]), 1.0)


func is_downed() -> bool:
	return bool(data["downed"])


func get_downed_ticks() -> int:
	return int(data["downed_ticks"])


func set_hunger(amount: float) -> void:
	data["hunger"] = clampf(amount, 0.0, 100.0)


func set_energy(amount: float) -> void:
	data["energy"] = clampf(amount, 0.0, 100.0)


func take_damage(amount: float) -> float:
	if not is_finite(amount) or amount <= 0.0 or is_downed():
		return 0.0
	var previous := get_health()
	data["health"] = clampf(previous - amount, 0.0, get_max_health())
	if get_health() <= 0.0:
		data["downed"] = true
		data["downed_ticks"] = 20
	return previous - get_health()


func advance_health() -> void:
	if is_downed():
		data["downed_ticks"] = maxi(get_downed_ticks() - 1, 0)
		if get_downed_ticks() <= 0:
			data["downed"] = false
			data["health"] = get_max_health() * 0.5
		return
	if get_health() < get_max_health():
		data["health"] = clampf(get_health() + 0.25, 0.0, get_max_health())


func get_inventory_amount(item_id: StringName) -> float:
	return float(data["inventory"].get(String(item_id), 0.0))


func get_carried_total() -> float:
	var total := 0.0
	for amount in data["inventory"].values():
		total += float(amount)
	return total


func add_inventory(item_id: StringName, amount: float) -> void:
	if item_id.is_empty() or not is_finite(amount) or amount <= 0.0:
		return
	data["inventory"][String(item_id)] = get_inventory_amount(item_id) + amount


func remove_inventory(item_id: StringName, requested_amount: float) -> float:
	if item_id.is_empty() or not is_finite(requested_amount) or requested_amount <= 0.0:
		return 0.0
	var removed := minf(requested_amount, get_inventory_amount(item_id))
	if removed <= 0.0:
		return 0.0
	data["inventory"][String(item_id)] = get_inventory_amount(item_id) - removed
	return removed


func to_dictionary() -> Dictionary:
	return data.duplicate(true)