extends Node

## CardDatabase - Singleton for managing card data
## Loads card definitions from JSON and provides lookup methods

const CARDS_PATH = "res://data/cards.json"
const STARTER_DECKS_PATH = "res://data/starter_decks.json"

# Loaded card data
var _cards: Dictionary = {}  # id -> CardData
var _cards_by_element: Dictionary = {}  # Element -> Array[CardData]
var _cards_by_type: Dictionary = {}  # CardType -> Array[CardData]
var _card_textures: Dictionary = {}  # id -> Texture2D
var _starter_decks: Array = []  # Array of StarterDeckData

# Signals
signal database_loaded
signal load_error(message: String)

func _ready() -> void:
	_load_database()
	_load_starter_decks()

func _load_database() -> void:
	var file = FileAccess.open(CARDS_PATH, FileAccess.READ)
	if not file:
		push_error("Failed to open cards database: " + CARDS_PATH)
		load_error.emit("Failed to open cards database")
		return

	var json_text = file.get_as_text()
	file.close()

	var json = JSON.new()
	var error = json.parse(json_text)
	if error != OK:
		push_error("Failed to parse cards JSON: " + json.get_error_message())
		load_error.emit("Failed to parse cards JSON")
		return

	var data = json.get_data()
	if not data.has("cards"):
		push_error("Cards database missing 'cards' array")
		load_error.emit("Invalid database format")
		return

	# Initialize element and type dictionaries
	for element in Enums.Element.values():
		_cards_by_element[element] = []
	for card_type in Enums.CardType.values():
		_cards_by_type[card_type] = []

	# Parse cards
	for card_data in data["cards"]:
		var card = _parse_card(card_data)
		if card:
			_cards[card.id] = card

			# Index by element(s)
			for element in card.elements:
				_cards_by_element[element].append(card)

			# Index by type
			_cards_by_type[card.type].append(card)

	print("CardDatabase: Loaded ", _cards.size(), " cards")
	database_loaded.emit()

func _parse_card(data: Dictionary) -> CardData:
	var card = CardData.new()

	# Required fields
	if not data.has("id") or not data.has("name") or not data.has("type") or not data.has("element") or not data.has("cost"):
		push_error("Card missing required fields: " + str(data))
		return null

	card.id = data["id"]
	card.name = data["name"]
	card.type = Enums.card_type_from_string(data["type"])
	card.cost = data["cost"]

	# Parse element (can be string or array)
	if data["element"] is Array:
		for elem_str in data["element"]:
			card.elements.append(Enums.element_from_string(elem_str))
	else:
		card.elements.append(Enums.element_from_string(data["element"]))

	# Optional fields
	card.power = data.get("power", 0) if data.get("power") != null else 0
	card.job = data.get("job", "") if data.get("job") != null else ""
	card.category = data.get("category", "") if data.get("category") != null else ""
	card.is_generic = data.get("is_generic", false) if data.get("is_generic") != null else false
	card.has_ex_burst = data.get("has_ex_burst", false) if data.get("has_ex_burst") != null else false
	card.has_haste = data.get("has_haste", false) if data.get("has_haste") != null else false
	card.image_path = data.get("image", "") if data.get("image") != null else ""

	# Parse abilities
	if data.has("abilities"):
		for ability_data in data["abilities"]:
			var ability = _parse_ability(ability_data)
			if ability:
				card.abilities.append(ability)

	return card

func _parse_ability(data: Dictionary) -> AbilityData:
	var ability = AbilityData.new()

	if not data.has("type") or not data.has("effect"):
		push_error("Ability missing required fields")
		return null

	match data["type"].to_lower():
		"field": ability.type = Enums.AbilityType.FIELD
		"auto": ability.type = Enums.AbilityType.AUTO
		"action": ability.type = Enums.AbilityType.ACTION
		"special": ability.type = Enums.AbilityType.SPECIAL

	ability.effect = data["effect"]
	ability.name = data.get("name", "")
	ability.trigger = data.get("trigger", "")
	ability.is_ex_burst = data.get("is_ex_burst", false)

	# Parse cost if present
	if data.has("cost"):
		ability.cost = _parse_cost(data["cost"])

	return ability

func _parse_cost(data: Dictionary) -> CostData:
	var cost = CostData.new()

	cost.generic = data.get("generic", 0)
	cost.fire = data.get("fire", 0)
	cost.ice = data.get("ice", 0)
	cost.wind = data.get("wind", 0)
	cost.lightning = data.get("lightning", 0)
	cost.water = data.get("water", 0)
	cost.earth = data.get("earth", 0)
	cost.light = data.get("light", 0)
	cost.dark = data.get("dark", 0)
	cost.requires_dull = data.get("dull", false)
	cost.discard_count = data.get("discard", 0)
	cost.specific_discard = data.get("specific_discard", "")

	return cost

## Get a card by ID
func get_card(id: String) -> CardData:
	return _cards.get(id)

## Get all cards
func get_all_cards() -> Array:
	return _cards.values()

## Get cards by element
func get_cards_by_element(element: Enums.Element) -> Array:
	return _cards_by_element.get(element, [])

## Get cards by type
func get_cards_by_type(card_type: Enums.CardType) -> Array:
	return _cards_by_type.get(card_type, [])


## Filter cards by multiple criteria
## filters: Dictionary with optional keys:
##   - name: String (substring search, case-insensitive)
##   - elements: Array[Enums.Element] (OR logic - card has any of these)
##   - type: Enums.CardType (-1 or omit for any)
##   - cost_min: int
##   - cost_max: int
##   - job: String (exact match, case-insensitive)
##   - category: String (exact match)
##   - power_min: int
##   - power_max: int
##   - ex_burst_only: bool
##   - set: String (card ID prefix, e.g. "1-", "2-")
func filter_cards(filters: Dictionary) -> Array[CardData]:
	var results: Array[CardData] = []

	for card in _cards.values():
		if _matches_filters(card, filters):
			results.append(card)

	return results


func _matches_filters(card: CardData, filters: Dictionary) -> bool:
	# Name search (case-insensitive substring)
	if filters.has("name") and not filters.name.is_empty():
		if not card.name.to_lower().contains(filters.name.to_lower()):
			return false

	# Element filter (OR logic for multi-select)
	if filters.has("elements") and filters.elements.size() > 0:
		var has_element = false
		for elem in card.elements:
			if elem in filters.elements:
				has_element = true
				break
		if not has_element:
			return false

	# Type filter
	if filters.has("type") and filters.type != -1:
		if card.type != filters.type:
			return false

	# Cost filter (range)
	if filters.has("cost_min") and card.cost < filters.cost_min:
		return false
	if filters.has("cost_max") and card.cost > filters.cost_max:
		return false

	# Job filter (case-insensitive)
	if filters.has("job") and not filters.job.is_empty():
		if card.job.to_lower() != filters.job.to_lower():
			return false

	# Category filter
	if filters.has("category") and not filters.category.is_empty():
		if card.category != filters.category:
			return false

	# Power range
	if filters.has("power_min") and card.power < filters.power_min:
		return false
	if filters.has("power_max") and card.power > filters.power_max:
		return false

	# EX Burst filter
	if filters.has("ex_burst_only") and filters.ex_burst_only:
		if not card.has_ex_burst:
			return false

	# Set/Opus filter (card ID prefix)
	if filters.has("set") and not filters.set.is_empty():
		if not card.id.begins_with(filters.set):
			return false

	return true


## Get all unique job values from loaded cards
func get_unique_jobs() -> Array[String]:
	var jobs: Dictionary = {}
	for card in _cards.values():
		if not card.job.is_empty():
			jobs[card.job] = true
	var result: Array[String] = []
	for job in jobs.keys():
		result.append(job)
	result.sort()
	return result


## Get all unique category values from loaded cards
func get_unique_categories() -> Array[String]:
	var categories: Dictionary = {}
	for card in _cards.values():
		if not card.category.is_empty():
			categories[card.category] = true
	var result: Array[String] = []
	for category in categories.keys():
		result.append(category)
	result.sort()
	return result


## Get all unique set/opus prefixes from card IDs
func get_card_sets() -> Array[String]:
	var sets: Dictionary = {}
	for card in _cards.values():
		# Extract prefix before first dash (e.g., "1" from "1-001H")
		var dash_pos = card.id.find("-")
		if dash_pos > 0:
			var prefix = card.id.substr(0, dash_pos)
			sets[prefix] = true
	var result: Array[String] = []
	for set_id in sets.keys():
		result.append(set_id)
	# Sort numerically if possible
	result.sort_custom(func(a, b):
		var a_num = a.to_int() if a.is_valid_int() else 9999
		var b_num = b.to_int() if b.is_valid_int() else 9999
		return a_num < b_num
	)
	return result


## Get card count
func get_card_count() -> int:
	return _cards.size()

## Get or load a card texture
func get_card_texture(card: CardData) -> Texture2D:
	if card.id in _card_textures:
		return _card_textures[card.id]

	if card.image_path.is_empty():
		return null

	# Try source-cards directory first (primary location for card images)
	var texture_path = "res://source-cards/" + card.image_path
	if ResourceLoader.exists(texture_path):
		var texture = load(texture_path)
		_card_textures[card.id] = texture
		return texture

	# Fallback to assets/cards directory
	texture_path = "res://assets/cards/" + card.image_path
	if ResourceLoader.exists(texture_path):
		var texture = load(texture_path)
		_card_textures[card.id] = texture
		return texture

	return null

## Create a list of card IDs for a deck (for testing)
## Player 0 gets Fire/Ice deck, Player 1 gets Wind/Lightning deck
func create_test_deck(player_index: int) -> Array[String]:
	var deck: Array[String] = []

	# Define element pairs for each player
	var primary_element: Enums.Element
	var secondary_element: Enums.Element

	if player_index == 0:
		primary_element = Enums.Element.FIRE
		secondary_element = Enums.Element.ICE
	else:
		primary_element = Enums.Element.WIND
		secondary_element = Enums.Element.LIGHTNING

	# Get cards by element
	var primary_cards = get_cards_by_element(primary_element)
	var secondary_cards = get_cards_by_element(secondary_element)

	# Add 3 copies of each primary element card
	for card in primary_cards:
		for i in range(3):
			if deck.size() < 50:
				deck.append(card.id)

	# Add 3 copies of each secondary element card
	for card in secondary_cards:
		for i in range(3):
			if deck.size() < 50:
				deck.append(card.id)

	# If we still need cards, add from Earth/Water
	if deck.size() < 50:
		var filler_element = Enums.Element.EARTH if player_index == 0 else Enums.Element.WATER
		var filler_cards = get_cards_by_element(filler_element)
		for card in filler_cards:
			for i in range(3):
				if deck.size() < 50:
					deck.append(card.id)

	# Final fallback: add any cards
	if deck.size() < 50:
		var all_cards = get_all_cards()
		for card in all_cards:
			for i in range(3):
				if deck.size() < 50:
					deck.append(card.id)

	return deck


## Starter Deck Methods

func _load_starter_decks() -> void:
	var file = FileAccess.open(STARTER_DECKS_PATH, FileAccess.READ)
	if not file:
		push_warning("Failed to open starter decks: " + STARTER_DECKS_PATH)
		return

	var json_text = file.get_as_text()
	file.close()

	var json = JSON.new()
	var error = json.parse(json_text)
	if error != OK:
		push_error("Failed to parse starter decks JSON: " + json.get_error_message())
		return

	var data = json.get_data()
	if not data.has("starter_decks"):
		push_error("Starter decks file missing 'starter_decks' array")
		return

	for deck_data in data["starter_decks"]:
		var deck = StarterDeckData.new()
		deck.id = deck_data.get("id", "")
		deck.name = deck_data.get("name", "")
		deck.opus = deck_data.get("opus", "")
		deck.description = deck_data.get("description", "")
		deck.elements = deck_data.get("elements", [])
		deck.cards = deck_data.get("cards", [])
		deck.image = deck_data.get("image", "")
		_starter_decks.append(deck)

	print("CardDatabase: Loaded ", _starter_decks.size(), " starter decks")


## Get all starter decks
func get_starter_decks() -> Array:
	return _starter_decks


## Get a starter deck by ID
func get_starter_deck(deck_id: String) -> StarterDeckData:
	for deck in _starter_decks:
		if deck.id == deck_id:
			return deck
	return null


## Get a random starter deck
func get_random_starter_deck() -> StarterDeckData:
	if _starter_decks.is_empty():
		return null
	return _starter_decks[randi() % _starter_decks.size()]


## Data Classes

class StarterDeckData:
	var id: String = ""
	var name: String = ""
	var opus: String = ""
	var description: String = ""
	var elements: Array = []  # Array of element name strings
	var cards: Array = []  # Array of card IDs
	var image: String = ""  # Path to box art image

	func get_texture() -> Texture2D:
		if image.is_empty():
			return null
		var texture_path = "res://assets/ui/" + image
		if ResourceLoader.exists(texture_path):
			return load(texture_path)
		return null


class CardData:
	var id: String = ""
	var name: String = ""
	var type: Enums.CardType = Enums.CardType.FORWARD
	var elements: Array[Enums.Element] = []
	var cost: int = 0
	var power: int = 0
	var job: String = ""
	var category: String = ""
	var is_generic: bool = false
	var has_ex_burst: bool = false
	var has_haste: bool = false
	var image_path: String = ""
	var abilities: Array[AbilityData] = []

	func get_primary_element() -> Enums.Element:
		if elements.size() > 0:
			return elements[0]
		return Enums.Element.FIRE

	func is_multi_element() -> bool:
		return elements.size() > 1

	## Check if card has a specific ability by name (e.g., "Brave", "Haste", "First Strike")
	func has_ability(ability_name: String) -> bool:
		for ability in abilities:
			if ability.name.to_lower() == ability_name.to_lower():
				return true
		return false


class AbilityData:
	var type: Enums.AbilityType = Enums.AbilityType.FIELD
	var name: String = ""
	var effect: String = ""
	var trigger: String = ""
	var is_ex_burst: bool = false
	var cost: CostData = null

class CostData:
	var generic: int = 0
	var fire: int = 0
	var ice: int = 0
	var wind: int = 0
	var lightning: int = 0
	var water: int = 0
	var earth: int = 0
	var light: int = 0
	var dark: int = 0
	var requires_dull: bool = false
	var discard_count: int = 0
	var specific_discard: String = ""

	func get_total_cp() -> int:
		return generic + fire + ice + wind + lightning + water + earth + light + dark

	func get_element_requirements() -> Dictionary:
		var reqs = {}
		if fire > 0: reqs[Enums.Element.FIRE] = fire
		if ice > 0: reqs[Enums.Element.ICE] = ice
		if wind > 0: reqs[Enums.Element.WIND] = wind
		if lightning > 0: reqs[Enums.Element.LIGHTNING] = lightning
		if water > 0: reqs[Enums.Element.WATER] = water
		if earth > 0: reqs[Enums.Element.EARTH] = earth
		if light > 0: reqs[Enums.Element.LIGHT] = light
		if dark > 0: reqs[Enums.Element.DARK] = dark
		return reqs