extends Node

# Headless test runner (task 1.0). Discovers every *.gd under tests/cases/,
# instances it, and calls every test_*() method by name — a test case is
# picked up by dropping a file in that folder, not by registering it here.
# Run with: godot --headless --path Game res://tests/test_runner.tscn

const CASES_DIR := "res://tests/cases"
const TestCase = preload("res://tests/test_case.gd")

func _ready() -> void:
	var case_paths := _discover_case_paths()
	var total := 0
	var failed := 0
	var failure_messages: Array[String] = []

	for path in case_paths:
		# Adversarial-review regression: a case file with a parse/compile
		# error used to hang the whole runner forever. load() on a broken
		# script does NOT return null here — it returns a non-null but
		# uninstantiable GDScript resource, so a plain null check doesn't
		# catch it; calling .new() on it throws "Invalid call: Nonexistent
		# function 'new'", severe enough to abort _ready() entirely without
		# ever reaching quit(). can_instantiate() is the real guard.
		var script: GDScript = load(path)
		if script == null or not script.can_instantiate():
			failed += 1
			failure_messages.append("%s: failed to load (parse/compile error — see SCRIPT ERROR above)" % path.get_file())
			continue
		var instance = script.new()
		if instance == null:
			failed += 1
			failure_messages.append("%s: script.new() returned null" % path.get_file())
			continue

		for method in instance.get_method_list():
			var method_name: String = method["name"]
			if not method_name.begins_with("test_"):
				continue
			total += 1
			instance.failures.clear()
			instance.assertions_made = 0
			instance.call(method_name)
			# Adversarial-review regression: GDScript has no exceptions, so
			# a runtime error partway through a test (before it reaches its
			# first assert_*) just logs a SCRIPT ERROR and returns —
			# `failures` stays empty exactly as if every assertion passed,
			# and this used to count as a PASS. A test that completes
			# having made zero assertions is itself a failure: it proved
			# nothing, whether because it crashed early or was just never
			# written to assert anything.
			if instance.assertions_made == 0:
				failed += 1
				failure_messages.append("%s.%s: made no assertions (crashed before the first assert_*, or the test itself is incomplete)" % [path.get_file(), method_name])
			elif not instance.failures.is_empty():
				failed += 1
				for f in instance.failures:
					failure_messages.append("%s.%s: %s" % [path.get_file(), method_name, f])

	print("Ran %d tests from %d case file(s), %d failed" % [total, case_paths.size(), failed])
	for message in failure_messages:
		print("  FAIL: " + message)

	get_tree().quit(1 if failed > 0 else 0)


func _discover_case_paths() -> Array[String]:
	var paths: Array[String] = []
	var dir := DirAccess.open(CASES_DIR)
	if dir == null:
		push_error("Cannot open " + CASES_DIR)
		return paths
	dir.list_dir_begin()
	var file_name := dir.get_next()
	while file_name != "":
		if file_name.ends_with(".gd") and not dir.current_is_dir():
			paths.append(CASES_DIR + "/" + file_name)
		file_name = dir.get_next()
	dir.list_dir_end()
	paths.sort()
	return paths