extends Node

const QUESTION_FILE := "res://data/questions/sample_questions.json"
const DEFAULT_QUESTIONS_API_URL := "http://localhost:5008/api/questions/search"

signal questions_changed

var questions: Array = []
var request: HTTPRequest
var questions_api_url := DEFAULT_QUESTIONS_API_URL

func _ready() -> void:
	questions_api_url = str(ProjectSettings.get_setting("step3/questions_api_url", DEFAULT_QUESTIONS_API_URL))
	request = HTTPRequest.new()
	request.request_completed.connect(_on_api_questions_loaded)
	add_child(request)
	load_questions()


func load_questions() -> void:
	questions.clear()
	var file := FileAccess.open(QUESTION_FILE, FileAccess.READ)
	if file == null:
		push_error("Unable to open question file: %s" % QUESTION_FILE)
		return

	var parsed = JSON.parse_string(file.get_as_text())
	if typeof(parsed) != TYPE_ARRAY:
		push_error("Question file must contain an array.")
		return

	for item in parsed:
		if _is_valid_question(item):
			questions.append(item)
		else:
			push_warning("Skipping invalid question: %s" % str(item.get("id", "unknown")))

	questions_changed.emit()


func load_questions_from_api() -> void:
	if AuthState.access_token.is_empty():
		return

	var headers := PackedStringArray([
		"Content-Type: application/json",
		"Authorization: Bearer %s" % AuthState.access_token
	])
	var payload := {
		"limit": 80
	}
	var err := request.request(questions_api_url, headers, HTTPClient.METHOD_POST, JSON.stringify(payload))
	if err != OK:
		push_warning("Failed to request questions API. Using local question bank.")


func _on_api_questions_loaded(result: int, response_code: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
	if result != HTTPRequest.RESULT_SUCCESS or response_code < 200 or response_code >= 300:
		push_warning("Questions API request failed. Using local question bank.")
		return

	var parsed: Variant = JSON.parse_string(body.get_string_from_utf8())
	if typeof(parsed) != TYPE_ARRAY:
		push_warning("Questions API response was not an array. Using local question bank.")
		return

	var api_questions: Array = []
	for item in parsed:
		var normalized := _normalize_api_question(item)
		if _is_valid_question(normalized):
			api_questions.append(normalized)

	if api_questions.is_empty():
		push_warning("Questions API returned no usable questions. Using local question bank.")
		return

	questions = api_questions
	questions_changed.emit()


func get_all_questions() -> Array:
	return questions.duplicate(true)


func get_systems() -> Array[String]:
	var system_names: Array[String] = []
	for question in questions:
		var system_name := str(question.get("system", "General"))
		if not system_names.has(system_name):
			system_names.append(system_name)
	system_names.sort()
	return system_names


func get_questions_for_system(system_name: String) -> Array:
	if system_name == "All Systems":
		return get_all_questions()

	var filtered: Array = []
	for question in questions:
		if str(question.get("system", "")) == system_name:
			filtered.append(question.duplicate(true))
	return filtered


func build_block(system_name: String, block_size: int) -> Array:
	var pool := get_questions_for_system(system_name)
	pool.shuffle()
	return pool.slice(0, min(block_size, pool.size()))


func _is_valid_question(item: Variant) -> bool:
	if typeof(item) != TYPE_DICTIONARY:
		return false
	var required := ["id", "stem", "lead_in", "choices", "correct_choice_id", "explanation", "system", "discipline"]
	for key in required:
		if not item.has(key):
			return false
	return typeof(item["choices"]) == TYPE_ARRAY and item["choices"].size() >= 2


func _normalize_api_question(item: Variant) -> Dictionary:
	if typeof(item) != TYPE_DICTIONARY:
		return {}

	var normalized := {
		"id": str(item.get("externalId", item.get("id", ""))),
		"api_id": str(item.get("id", "")),
		"stem": str(item.get("stem", "")),
		"lead_in": str(item.get("leadIn", item.get("lead_in", ""))),
		"choices": item.get("choices", []),
		"correct_choice_id": str(item.get("correctChoiceId", item.get("correct_choice_id", ""))),
		"explanation": str(item.get("explanation", "")),
		"choice_explanations": item.get("choiceExplanations", item.get("choice_explanations", {})),
		"discipline": str(item.get("discipline", "")),
		"system": str(item.get("system", "")),
		"difficulty": int(item.get("difficulty", 1)),
		"labs": item.get("labs", []),
		"media": item.get("media", []),
		"tags": item.get("tags", [])
	}
	return normalized