class_name Character
extends RefCounted
## One playable character belonging to an account.
##
## Characters outlive a session and a server restart, so this is a persistence
## record first and a gameplay object second: everything here has to survive a
## round trip through JSON without losing meaning.
##
## Death does not delete a character. It clears [member active], which retires
## it from the roster while keeping the record for archival and for working out
## what happened after the fact.

const MAX_NAME := 20

var id: String = ""
var display_name: String = "adventurer"
## Placeholder identity until there is a cosmetic system. Random per character
## so party members are told apart at a glance.
var colour := Color.WHITE
var level: int = Progression.START_LEVEL
var total_xp: int = 0
## False once the character has died. Never deleted -- see the class note.
var active: bool = true
var created_unix: int = 0
var died_unix: int = 0
## Carried items, one id per slot, [constant Items.NONE] where empty. Stored on
## the character rather than on the session so that swapping in the hub swaps
## bags, and so a server restart does not quietly confiscate everyone's potions.
var inventory: Array[StringName] = []

## Upgrades taken, in the order they were taken. Duplicates are meaningful --
## two Split Shots really is two splits -- so this is a list, not a set.
##
## The derived numbers (damage, fire rate, health multiplier) are NOT stored:
## [PlayerStats] rebuilds them from this list, so a saved stat can never
## disagree with the upgrades that produced it.
var upgrades: Array[StringName] = []
## Level-ups not yet spent at the hub NPC. They queue: reaching two levels in
## one run owes you two choices, because losing one for doing well is a
## punishment nobody would guess at.
var pending_choices: int = 0
## The choices currently on the table, held so that walking away and coming back
## shows the same three. Without this, closing and reopening the screen would be
## a free reroll until a legendary turned up.
var offer: Array[StringName] = []


## Suggested names, offered when creating a character so the field is never
## blank. Deliberately a pair of short word lists rather than a big table: the
## point is a usable default the player can overwrite, not a naming system.
const NAME_FIRST: PackedStringArray = [
	"Ash", "Bram", "Cass", "Dorn", "Elm", "Fen", "Gale", "Hale", "Iva", "Jory",
	"Kit", "Lark", "Mox", "Nell", "Orin", "Pike", "Quill", "Ren", "Sable", "Thorn",
	"Vesper", "Wren", "Yarrow", "Zel",
]
const NAME_LAST: PackedStringArray = [
	"blade", "briar", "creek", "dusk", "ember", "fell", "grim", "hollow",
	"iron", "kettle", "moor", "night", "quarry", "rook", "shade", "thistle",
	"vale", "wick",
]


static func random_name(rng: RandomNumberGenerator) -> String:
	return "%s%s" % [
		NAME_FIRST[rng.randi() % NAME_FIRST.size()],
		NAME_LAST[rng.randi() % NAME_LAST.size()],
	]


func _init() -> void:
	inventory.resize(SimConfig.INVENTORY_SLOTS)
	inventory.fill(Items.NONE)


static func create(character_name: String, rng: RandomNumberGenerator) -> Character:
	var c := Character.new()
	# Random-but-readable: full saturation and high value, so two characters are
	# never both muddy browns, and none of them vanish against the floor.
	c.colour = Color.from_hsv(rng.randf(), 0.55, 1.0)
	c.id = "%d-%d" % [Time.get_unix_time_from_system(), rng.randi() & 0xFFFFFF]
	c.display_name = sanitize_name(character_name)
	c.created_unix = int(Time.get_unix_time_from_system())
	return c


## Names come from clients and are shown to other players, so they are clamped
## here rather than trusted anywhere downstream.
static func sanitize_name(raw: String) -> String:
	var clean := raw.strip_edges().substr(0, MAX_NAME)
	# Control characters would let a name break the HUD's layout.
	var out := ""
	for ch in clean:
		if ch.unicode_at(0) >= 32:
			out += ch
	out = out.strip_edges()
	return out if not out.is_empty() else "adventurer"


## What this character actually walks around with: the level's health, scaled by
## whatever the upgrades do to it. Shown on the roster screen, so it has to be
## the real number and not the pre-upgrade one.
func max_hp() -> int:
	return maxi(1, roundi(float(Progression.max_hp_for_level(level))
		* PlayerStats.build(upgrades).max_hp_mult))


func xp_progress() -> float:
	return Progression.level_progress(total_xp)


## Award experience and return how many levels it produced, so the caller can
## announce them. Level is derived from lifetime xp rather than tracked
## separately: one source of truth means a level can never disagree with the
## experience that earned it.
func grant_xp(amount: int) -> int:
	if amount <= 0 or not active:
		return 0
	var before := level
	total_xp += amount
	level = Progression.level_for_xp(total_xp)
	return level - before


func retire(when_unix: int = 0) -> void:
	active = false
	died_unix = when_unix if when_unix > 0 else int(Time.get_unix_time_from_system())


func to_dict() -> Dictionary:
	return {
		"id": id,
		"name": display_name,
		"colour": colour.to_html(false),
		"level": level,
		"xp": total_xp,
		"active": active,
		"created": created_unix,
		"died": died_unix,
		# Written as ids rather than indices: a save file has to survive
		# Items.ORDER being appended to, and a human editing it should be able
		# to tell what a character is carrying.
		"inventory": _inventory_ids(),
		"upgrades": _name_list(upgrades),
		"pending_choices": pending_choices,
		"offer": _name_list(offer),
	}


static func _name_list(ids: Array[StringName]) -> Array:
	var out := []
	for id in ids:
		out.append(String(id))
	return out


func _inventory_ids() -> Array:
	var out := []
	for item in inventory:
		out.append(String(item))
	return out


## Tolerant of missing keys so an older save file still loads: a character that
## has lost a field is far better than an account that will not open.
static func from_dict(d: Dictionary) -> Character:
	var c := Character.new()
	c.id = String(d.get("id", ""))
	c.display_name = sanitize_name(String(d.get("name", "")))
	c.colour = Color.from_string(String(d.get("colour", "ffffff")), Color.WHITE)
	c.total_xp = maxi(int(d.get("xp", 0)), 0)
	# Derived, not read: a hand-edited or corrupted level cannot desync from xp.
	c.level = Progression.level_for_xp(c.total_xp)
	c.active = bool(d.get("active", true))
	c.created_unix = int(d.get("created", 0))
	c.died_unix = int(d.get("died", 0))
	# Unknown ids decay to empty rather than to a wrong item -- a save written
	# by a build with an item this one has never heard of must still load.
	var carried: Array[StringName] = []
	for raw in d.get("inventory", []):
		var carried_id := StringName(String(raw))
		carried.append(carried_id if Items.get_def(carried_id) != null else Items.NONE)
	c.set_inventory(carried)
	# Unknown upgrade ids are dropped rather than kept as dead entries, so a
	# save from a build with an upgrade this one lacks still produces coherent
	# stats instead of a phantom that counts toward the +5% and does nothing.
	c.upgrades = _known_upgrades(d.get("upgrades", []))
	c.pending_choices = maxi(int(d.get("pending_choices", 0)), 0)
	c.offer = _known_upgrades(d.get("offer", []))
	return c


static func _known_upgrades(raw: Array) -> Array[StringName]:
	var out: Array[StringName] = []
	for entry in raw:
		var id := StringName(String(entry))
		if Upgrades.get_def(id) != null:
			out.append(id)
	return out


## Replace the whole inventory, padded or trimmed to the current slot count.
func set_inventory(items: Array[StringName]) -> void:
	inventory.resize(SimConfig.INVENTORY_SLOTS)
	for i in SimConfig.INVENTORY_SLOTS:
		inventory[i] = items[i] if i < items.size() else Items.NONE