extends Node
class_name TestUtils

# ═══════════════════════════════════════════════════════════════════════════
#  TestUtils — Minimal assertion framework for headless Godot unit tests
#
#  Usage:
#    var tu = TestUtils.new()
#    add_child(tu)
#    tu.describe("Movement validation")
#    tu.assert_eq(result.x, 5, "x should be 5")
#    tu.assert_true(valid, "should be valid")
#    tu.finish()  # prints summary
# ═══════════════════════════════════════════════════════════════════════════

var _passed: int = 0
var _failed: int = 0
var _current_suite: String = ""
var _assertions_in_suite: int = 0

func describe(name: String) -> void:
	"""Start a named test suite/section."""
	_current_suite = name
	_assertions_in_suite = 0
	print("\n  === " + name + " ===")

func assert_eq(got, expected, msg: String = "") -> void:
	_assertions_in_suite += 1
	if got == expected:
		_passed += 1
	else:
		_failed += 1
		var detail = "got '%s', expected '%s'" % [str(got), str(expected)]
		print("    [FAIL] " + msg + " — " + detail)

func assert_ne(got, unexpected, msg: String = "") -> void:
	_assertions_in_suite += 1
	if got != unexpected:
		_passed += 1
	else:
		_failed += 1
		print("    [FAIL] " + msg + " — got '%s' which matches unexpected value" % str(got))

func assert_true(cond: bool, msg: String = "") -> void:
	_assertions_in_suite += 1
	if cond:
		_passed += 1
	else:
		_failed += 1
		print("    [FAIL] " + msg + " — expected true, got false")

func assert_false(cond: bool, msg: String = "") -> void:
	_assertions_in_suite += 1
	if not cond:
		_passed += 1
	else:
		_failed += 1
		print("    [FAIL] " + msg + " — expected false, got true")

func assert_almost_eq(got: float, expected: float, tolerance: float = 0.001, msg: String = "") -> void:
	_assertions_in_suite += 1
	if abs(got - expected) <= tolerance:
		_passed += 1
	else:
		_failed += 1
		var detail = "got %.4f, expected %.4f ± %.4f" % [got, expected, tolerance]
		print("    [FAIL] " + msg + " — " + detail)

func assert_violation(result: Dictionary, category: int, msg: String = "") -> void:
	"""Assert the validation result contains at least one violation of the given category."""
	_assertions_in_suite += 1
	for v in result.get("violations", []):
		if v.get("category", -1) == category:
			_passed += 1
			return
	_failed += 1
	print("    [FAIL] " + msg + " — expected violation category " + str(category) + ", none found")

func assert_no_violation(result: Dictionary, msg: String = "") -> void:
	"""Assert the validation result has zero violations."""
	_assertions_in_suite += 1
	var count = result.get("violations", []).size()
	if count == 0:
		_passed += 1
	else:
		_failed += 1
		print("    [FAIL] " + msg + " — expected 0 violations, got " + str(count) + ": " + str(result["violations"]))

func assert_corrected(result: Dictionary, field: String, msg: String = "") -> void:
	"""Assert the result's corrected dict has a different value for `field` than the original."""
	_assertions_in_suite += 1
	if result.get("corrected", {}).has(field):
		_passed += 1
	else:
		_failed += 1
		print("    [FAIL] " + msg + " — expected correction in field '%s', none found" % field)

func finish() -> void:
	"""Print test summary and return exit code via OS."""
	var total = _passed + _failed
	print("\n  ──────────────────────────────────────")
	print("  Suite: " + _current_suite)
	print("  Passed: %d / %d" % [_passed, total])
	if _failed > 0:
		print("  FAILED: %d test(s)" % _failed)
	else:
		print("  All passed.")
	print("")

func exit_code() -> int:
	return 0 if _failed == 0 else 1