class_name PlayerStateRecord
extends RefCounted

const SCHEMA_VERSION := 1
const HUNGER_DEATH_THRESHOLD := 100.0
const STACK_THRESHOLD := 90.0
const DEATH_STANDING_PENALTY := 0.5
const RESET_HUNGER := 20.0
const RESET_ENERGY := 70.0
const DEFAULT_CARRY_CAPACITY := 4.0

var data: Dictionary


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


static func create() -> PlayerStateRecord:
	return (
		PlayerStateRecord
		. new(
			{
				"schema_version": SCHEMA_VERSION,
				"hunger": 20.0,
				"energy": 90.0,
				"is_starving": false,
				"starvation_ticks": 0,
				"starvation_death_threshold": 600,
				"is_dead": false,
				"deaths": 0,
				"inventory": {},
				"carry_capacity": DEFAULT_CARRY_CAPACITY,
			}
		)
	)


static func from_dictionary(record_data: Dictionary) -> PlayerStateRecord:
	if int(record_data.get("schema_version", -1)) != SCHEMA_VERSION:
		return null
	if not (
		record_data
		. has_all(
			[
				"hunger",
				"energy",
				"is_starving",
				"starvation_ticks",
				"starvation_death_threshold",
				"is_dead",
				"deaths",
			]
		)
	):
		return null
	var hunger := float(record_data["hunger"])
	var energy := float(record_data["energy"])
	var starvation_ticks := int(record_data["starvation_ticks"])
	var death_threshold := int(record_data["starvation_death_threshold"])
	var deaths := int(record_data["deaths"])
	if (
		not is_finite(hunger)
		or hunger < 0.0
		or hunger > HUNGER_DEATH_THRESHOLD
		or not is_finite(energy)
		or energy < 0.0
		or energy > 100.0
		or starvation_ticks < 0
		or death_threshold < 1
		or deaths < 0
	):
		return null
	var inventory := {}
	var carry_capacity := DEFAULT_CARRY_CAPACITY
	if record_data.has("inventory"):
		if not record_data["inventory"] is Dictionary:
			return null
		var normalized := {}
		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.has(item_id)
				or not is_finite(amount)
				or amount < 0.0
			):
				return null
			normalized[item_id] = amount
		inventory = normalized
	if record_data.has("carry_capacity"):
		carry_capacity = float(record_data["carry_capacity"])
		if not is_finite(carry_capacity) or carry_capacity < 0.0:
			return null
	return (
		PlayerStateRecord
		. new(
			{
				"schema_version": SCHEMA_VERSION,
				"hunger": hunger,
				"energy": energy,
				"is_starving": bool(record_data["is_starving"]),
				"starvation_ticks": starvation_ticks,
				"starvation_death_threshold": death_threshold,
				"is_dead": bool(record_data["is_dead"]),
				"deaths": deaths,
				"inventory": inventory,
				"carry_capacity": carry_capacity,
			}
		)
	)


func get_hunger() -> float:
	return float(data["hunger"])


func get_energy() -> float:
	return float(data["energy"])


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


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


func get_starvation_ticks() -> int:
	return int(data["starvation_ticks"])


func get_deaths() -> int:
	return int(data["deaths"])


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


func get_carry_capacity() -> float:
	return float(data["carry_capacity"])


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


func get_available_carry() -> float:
	return maxf(get_carry_capacity() - get_carried_total(), 0.0)


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


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
	if is_equal_approx(get_inventory_amount(item_id), 0.0):
		data["inventory"].erase(String(item_id))
	return removed


func eat(amount: float) -> float:
	if amount <= 0.0 or is_dead():
		return 0.0
	var previous := get_hunger()
	data["hunger"] = clampf(previous - amount, 0.0, HUNGER_DEATH_THRESHOLD)
	var consumed := previous - get_hunger()
	if consumed > 0.0:
		data["energy"] = minf(get_energy() + consumed * 0.5, 100.0)
	return consumed


func advance(hunger_rate: float, energy_rate: float) -> bool:
	if is_dead():
		return false
	data["hunger"] = minf(get_hunger() + maxf(hunger_rate, 0.0), HUNGER_DEATH_THRESHOLD)
	data["energy"] = clampf(get_energy() - maxf(energy_rate, 0.0), 0.0, 100.0)
	data["is_starving"] = get_hunger() >= STACK_THRESHOLD
	if is_starving():
		data["starvation_ticks"] = int(data["starvation_ticks"]) + 1
		if get_starvation_ticks() >= int(data["starvation_death_threshold"]):
			return true
	else:
		data["starvation_ticks"] = 0
	return false


func die() -> void:
	data["is_dead"] = true
	data["deaths"] = int(data["deaths"]) + 1


func respawn() -> void:
	data["hunger"] = RESET_HUNGER
	data["energy"] = RESET_ENERGY
	data["is_starving"] = false
	data["starvation_ticks"] = 0
	data["is_dead"] = false


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