extends GdUnitTestSuite
## Character pictures cached on disk: downloaded once, then only again when they changed
## on the server, or when they are old and the server can't tell.

var _server: FakeHttpTransport
var _config_dir_before: String
var _png: PackedByteArray


func before_test() -> void:
	_server = FakeHttpTransport.new().install()
	_config_dir_before = OS.get_environment(Settings.CONFIG_DIR_ENV)
	OS.set_environment(Settings.CONFIG_DIR_ENV, create_temp_dir("character_cache"))
	if DirAccess.dir_exists_absolute(CharacterCache.folder()):
		for file_name: String in DirAccess.get_files_at(CharacterCache.folder()):
			DirAccess.remove_absolute(CharacterCache.folder().path_join(file_name))
	var image: Image = Image.create(4, 4, false, Image.FORMAT_RGB8)
	image.fill(Color.ORANGE)
	_png = image.save_png_to_buffer()


func after_test() -> void:
	OS.set_environment(Settings.CONFIG_DIR_ENV, _config_dir_before)
	_server.uninstall()


func _serve(characters: Dictionary) -> void:
	var details: Array = []
	for character_name: String in characters:
		details.append({"name": character_name, "modified": characters[character_name]})
		_server.respond_bytes(_image_path(character_name), _png)
	_server.respond_json("/character/details", details)


# Serves the names only, like a server older than /character/details
func _serve_names_only(names: Array[String]) -> void:
	_server.respond_json("/character/list", names)
	for character_name: String in names:
		_server.respond_bytes(_image_path(character_name), _png)


func _image_path(character_name: String) -> String:
	return "/character?name=" + character_name.uri_encode()


# Loads the list and every picture with a new cache, like starting the game
func _load_all() -> Array[Image]:
	var cache: CharacterCache = CharacterCache.new()
	var images: Array[Image] = []
	cache.load_list(func(names: Array[String]) -> void:
		for character_name: String in names:
			cache.fetch_image(character_name, func(image: Image) -> void: images.append(image)))
	return images


func _index() -> Dictionary:
	return JSON.parse_string(FileAccess.get_file_as_string(
			CharacterCache.folder().path_join(CharacterCache.INDEX_FILE_NAME)))


func _set_index(index: Dictionary) -> void:
	FileAccess.open(CharacterCache.folder().path_join(CharacterCache.INDEX_FILE_NAME),
			FileAccess.WRITE).store_string(JSON.stringify(index))


func test_first_load_downloads_and_keeps_every_picture() -> void:
	_serve({"Crono.png": 100, "Marle.png": 200})

	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(2)
	assert_int(_server.count(_image_path("Crono.png"))).is_equal(1)
	assert_bool(FileAccess.file_exists(CharacterCache.folder().path_join("Crono.png"))).is_true()
	assert_int(int(_index()["Marle.png"]["modified"])).is_equal(200)


func test_unchanged_pictures_come_from_disk() -> void:
	_serve({"Crono.png": 100, "Marle.png": 200})
	_load_all()

	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(2)
	assert_int(_server.count(_image_path("Crono.png"))).is_equal(1)
	assert_int(_server.count(_image_path("Marle.png"))).is_equal(1)


func test_only_changed_pictures_are_downloaded_again() -> void:
	_serve({"Crono.png": 100, "Marle.png": 200})
	_load_all()

	_serve({"Crono.png": 100, "Marle.png": 300})
	_load_all()

	assert_int(_server.count(_image_path("Crono.png"))).is_equal(1)
	assert_int(_server.count(_image_path("Marle.png"))).is_equal(2)
	assert_int(int(_index()["Marle.png"]["modified"])).is_equal(300)


func test_new_character_is_downloaded() -> void:
	_serve({"Crono.png": 100})
	_load_all()

	_serve({"Crono.png": 100, "Lucca.png": 100})
	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(2)
	assert_int(_server.count(_image_path("Lucca.png"))).is_equal(1)


func test_characters_removed_on_the_server_are_deleted() -> void:
	_serve({"Crono.png": 100, "Magus.png": 100})
	_load_all()

	_serve({"Crono.png": 100})
	_load_all()

	assert_bool(FileAccess.file_exists(CharacterCache.folder().path_join("Magus.png"))) \
			.is_false()
	assert_bool(_index().has("Magus.png")).is_false()


func test_broken_cached_picture_is_downloaded_again() -> void:
	_serve({"Crono.png": 100})
	_load_all()
	FileAccess.open(CharacterCache.folder().path_join("Crono.png"), FileAccess.WRITE) \
			.store_string("not a picture")

	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(1)
	assert_int(_server.count(_image_path("Crono.png"))).is_equal(2)


func test_older_server_lists_names_and_young_pictures_come_from_disk() -> void:
	_serve_names_only(["Crono.png"])
	_load_all()

	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(1)
	assert_int(_server.count("/character/details")).is_equal(2)
	assert_int(_server.count(_image_path("Crono.png"))).is_equal(1)
	assert_int(int(_index()["Crono.png"]["modified"])).is_equal(CharacterCache.UNKNOWN_TIME)


func test_older_server_pictures_are_downloaded_again_when_old() -> void:
	_serve_names_only(["Crono.png", "Marle.png"])
	_load_all()
	var index: Dictionary = _index()
	var too_old: int = int(Time.get_unix_time_from_system()) - CharacterCache.MAX_AGE_SECONDS - 1
	index["Marle.png"]["downloaded"] = too_old
	_set_index(index)

	_load_all()

	assert_int(_server.count(_image_path("Crono.png"))).is_equal(1)
	assert_int(_server.count(_image_path("Marle.png"))).is_equal(2)


func test_picture_cached_without_a_time_is_downloaded_once_the_server_has_times() -> void:
	_serve_names_only(["Crono.png"])
	_load_all()

	_serve({"Crono.png": 100})
	_load_all()
	_load_all()

	assert_int(_server.count(_image_path("Crono.png"))).is_equal(2)


func test_picture_that_cannot_be_read_is_not_cached() -> void:
	_server.respond_json("/character/details", [{"name": "Crono.png", "modified": 100}])
	_server.respond_bytes(_image_path("Crono.png"), "not a picture".to_utf8_buffer())

	var images: Array[Image] = _load_all()

	assert_array(images).is_empty()
	assert_bool(FileAccess.file_exists(CharacterCache.folder().path_join("Crono.png"))).is_false()


func test_broken_index_starts_over() -> void:
	_serve({"Crono.png": 100})
	_load_all()
	FileAccess.open(CharacterCache.folder().path_join(CharacterCache.INDEX_FILE_NAME),
			FileAccess.WRITE).store_string("{broken")

	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(1)
	assert_int(_server.count(_image_path("Crono.png"))).is_equal(2)


func test_cached_pictures_are_shown_when_the_server_cannot_be_reached() -> void:
	_serve({"Crono.png": 100, "Marle.png": 200})
	_load_all()
	_server.respond_json("/character/details", {}, 503)
	_server.respond_json("/character/list", {}, 503)

	var images: Array[Image] = _load_all()

	assert_int(images.size()).is_equal(2)
	assert_int(_server.count(_image_path("Crono.png"))).is_equal(1)
	assert_bool(FileAccess.file_exists(CharacterCache.folder().path_join("Marle.png"))).is_true()


func test_nothing_is_shown_without_a_server_or_cached_pictures() -> void:
	var cache: CharacterCache = CharacterCache.new()
	var listed: Array = []

	cache.load_list(func(names: Array[String]) -> void: listed.append(names))

	assert_array(listed).has_size(1)
	assert_array(listed[0]).is_empty()