extends TestCase


func test_the_player_key_is_created_once_and_kept() -> void:
	var directory := TestFiles.temporary_dir("key")
	var first := SaveStore.new(directory).player_key()
	var second := SaveStore.new(directory).player_key()
	check_eq(first.size(), SaveStore.KEY_BYTES, "sixteen bytes")
	check_eq(second, first, "the same key on the next start")
	TestFiles.remove_dir(directory)


func test_a_save_is_written_and_read_back() -> void:
	var directory := TestFiles.temporary_dir("save")
	var store := SaveStore.new(directory)
	check(not store.has_save(), "no save at first")
	check(store.write_save(PackedByteArray([1, 2, 3])), "written")
	check(store.write_save(PackedByteArray([4, 5])), "overwritten")
	check(store.has_save(), "a save exists")
	check_eq(store.read_save(), PackedByteArray([4, 5]), "the newest save is read")
	check(not FileAccess.file_exists(directory.path_join(SaveStore.SAVE_FILE + ".tmp")), "no temporary file is left")
	check(not FileAccess.file_exists(directory.path_join(SaveStore.BACKUP_FILE)), "no backup is left")
	TestFiles.remove_dir(directory)


func test_an_empty_save_is_not_written() -> void:
	var directory := TestFiles.temporary_dir("empty")
	var store := SaveStore.new(directory)
	check(not store.write_save(PackedByteArray()), "refused")
	check(not store.has_save(), "no file")
	TestFiles.remove_dir(directory)


func test_a_save_that_cannot_be_written_keeps_the_previous_one() -> void:
	var directory := TestFiles.temporary_dir("blocked")
	var store := SaveStore.new(directory)
	store.write_save(PackedByteArray([1, 2, 3]))
	# A folder in place of the temporary file makes the write fail.
	DirAccess.make_dir_absolute(directory.path_join(SaveStore.SAVE_FILE + ".tmp"))
	check(not store.write_save(PackedByteArray([4, 5])), "the failed save is reported")
	check_eq(store.read_save(), PackedByteArray([1, 2, 3]), "the previous save is untouched")
	check(not store.write_save(PackedByteArray()), "an empty save is refused")
	check_eq(store.read_save(), PackedByteArray([1, 2, 3]), "still untouched")
	TestFiles.remove_dir(directory)


func test_a_save_that_cannot_be_moved_into_place_keeps_the_previous_one() -> void:
	var directory := TestFiles.temporary_dir("held")
	var store := SaveStore.new(directory)
	store.write_save(PackedByteArray([1, 2, 3]))
	# The open handle stands for an outside program, for example a virus
	# scanner. The new save can be written, but Windows refuses to move a file
	# that is held open.
	var holder := FileAccess.open(directory.path_join(SaveStore.SAVE_FILE + ".tmp"), FileAccess.WRITE)
	check(not store.write_save(PackedByteArray([4, 5])), "the failed save is reported")
	check_eq(store.read_save(), PackedByteArray([1, 2, 3]), "the previous save is untouched")
	check(not FileAccess.file_exists(directory.path_join(SaveStore.BACKUP_FILE)), "no backup is left")
	holder.close()
	TestFiles.remove_dir(directory)


func test_a_save_that_cannot_move_the_previous_one_aside_keeps_it() -> void:
	var directory := TestFiles.temporary_dir("aside-blocked")
	var store := SaveStore.new(directory)
	store.write_save(PackedByteArray([1, 2, 3]))
	# A folder under the backup name keeps the previous save from moving.
	DirAccess.make_dir_absolute(directory.path_join(SaveStore.BACKUP_FILE))
	check(not store.write_save(PackedByteArray([4, 5])), "the failed save is reported")
	check_eq(store.read_save(), PackedByteArray([1, 2, 3]), "the previous save is untouched")
	check(not FileAccess.file_exists(directory.path_join(SaveStore.SAVE_FILE + ".tmp")), "no temporary file is left")
	TestFiles.remove_dir(directory)


func test_an_interrupted_save_is_recovered_from_the_backup() -> void:
	var directory := TestFiles.temporary_dir("recover")
	# A crash between the two moves of write_save leaves only the backup.
	var backup := directory.path_join(SaveStore.BACKUP_FILE)
	var file := FileAccess.open(backup, FileAccess.WRITE)
	file.store_buffer(PackedByteArray([7, 8, 9]))
	file.close()
	var store := SaveStore.new(directory)
	check(store.has_save(), "the previous save is back")
	check_eq(store.read_save(), PackedByteArray([7, 8, 9]), "with its content")
	check(not FileAccess.file_exists(backup), "the backup is moved, not copied")
	TestFiles.remove_dir(directory)


func test_a_backup_never_replaces_an_existing_save() -> void:
	var directory := TestFiles.temporary_dir("keep")
	SaveStore.new(directory).write_save(PackedByteArray([1, 2, 3]))
	var file := FileAccess.open(directory.path_join(SaveStore.BACKUP_FILE), FileAccess.WRITE)
	file.store_buffer(PackedByteArray([9, 9]))
	file.close()
	var store := SaveStore.new(directory)
	check_eq(store.read_save(), PackedByteArray([1, 2, 3]), "the save is not replaced by the older backup")
	TestFiles.remove_dir(directory)


func test_setting_aside_without_a_save_reports_nothing_moved() -> void:
	var directory := TestFiles.temporary_dir("nothing")
	check_eq(SaveStore.new(directory).set_aside_save(), "", "no save, nothing moved")
	TestFiles.remove_dir(directory)


func test_an_unusable_save_can_be_set_aside() -> void:
	var directory := TestFiles.temporary_dir("aside")
	var store := SaveStore.new(directory)
	store.write_save(PackedByteArray([9, 9]))
	var aside := store.set_aside_save()
	check(not store.has_save(), "the save is out of the way")
	check_eq(FileAccess.get_file_as_bytes(aside), PackedByteArray([9, 9]), "its content is kept")
	TestFiles.remove_dir(directory)


func test_only_the_newest_recordings_are_kept() -> void:
	var directory := TestFiles.temporary_dir("recordings")
	var store := SaveStore.new(directory)
	var paths: PackedStringArray = []
	for number in SaveStore.KEEP_RECORDINGS + 2:
		paths.append(store.write_recording(PackedByteArray([number])))
		OS.delay_usec(10)
	var names := store.recordings()
	check_eq(names.size(), SaveStore.KEEP_RECORDINGS, "only the newest are kept")
	check(not FileAccess.file_exists(paths[0]), "the oldest is gone")
	check(not FileAccess.file_exists(paths[1]), "the second oldest is gone")
	check(FileAccess.file_exists(paths[paths.size() - 1]), "the newest is there")
	check_eq(store.write_recording(PackedByteArray()), "", "an empty recording is not written")
	TestFiles.remove_dir(directory)