import importlib
import io
import unittest
from contextlib import redirect_stdout
from unittest import mock


class FakeResponse:
    def __init__(self, body, raw_body):
        self.body = body
        self.raw_body = raw_body


class FakePage:
    def __init__(self, url: str):
        self.url = url


class FakePacketResponse:
    def __init__(self, body):
        self.body = body
        self.raw_body = ""


class FakePacket:
    def __init__(self, body):
        self.response = FakePacketResponse(body)


class FakeListener:
    def __init__(self, packet):
        self.packet = packet
        self.started_targets = []
        self.call_count = 0

    def start(self, target):
        self.started_targets.append(target)

    def wait(self, timeout):
        self.call_count += 1
        if self.call_count == 1:
            return self.packet
        return None


class FakeRuntimePage:
    def __init__(self, url: str, packet):
        self.url = url
        self.listen = FakeListener(packet)
        self.visited_urls = []

    def get(self, url):
        self.visited_urls.append(url)
        self.url = url

    def run_js(self, script):
        # Allow both old scroll_to_next_page and new human_like_scroll
        if "window.scrollTo" in script or "window.scrollBy" in script:
            return
        raise AssertionError(f"unexpected scroll script: {script}")


class FakeScrollPage:
    def __init__(self):
        self.scripts = []

    def run_js(self, script):
        self.scripts.append(script)


class DouyinModuleTests(unittest.TestCase):
    def test_module_can_import_without_optional_runtime_dependencies(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertIsNotNone(module)

    def test_sanitize_filename_removes_invalid_characters(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertEqual(
            module.sanitize_filename('a/b:c*?d"e<f>g|h\n'),
            "a_b_c__d_e_f_g_h",
        )

    def test_choose_video_url_prefers_douyinvod_link(self) -> None:
        module = importlib.import_module("Douyin")
        urls = [
            "https://www.douyin.com/aweme/v1/play/?video_id=123",
            "https://v11-weba.douyinvod.com/example/video.mp4",
            "https://v26-web.douyinvod.com/example/video.mp4",
        ]
        self.assertEqual(
            module.choose_video_url(urls),
            "https://v11-weba.douyinvod.com/example/video.mp4",
        )

    def test_build_output_path_uses_video_directory(self) -> None:
        module = importlib.import_module("Douyin")
        output_path = module.build_output_path("测试标题", "123456")
        self.assertEqual(output_path.as_posix(), "video/测试标题-123456.mp4")

    def test_build_output_path_with_author_uses_bracket_format(self) -> None:
        module = importlib.import_module("Douyin")
        output_path = module.build_output_path(
            title="测试标题", 
            video_id="123456",
            author_name="测试博主"
        )
        self.assertEqual(output_path.as_posix(), "video/[测试博主]测试标题-123456.mp4")

    def test_build_output_path_limits_long_filename(self) -> None:
        module = importlib.import_module("Douyin")
        output_path = module.build_output_path(
            title="超长标题" * 100,
            video_id="7619989983668240802",
            author_name="超长博主名" * 20,
        )
        self.assertLessEqual(len(output_path.name.encode("utf-8")), 240)
        self.assertTrue(output_path.name.endswith("-7619989983668240802.mp4"))

    def test_extract_aweme_payload_uses_dict_body(self) -> None:
        module = importlib.import_module("Douyin")
        response = FakeResponse({"aweme_list": []}, "")
        self.assertEqual(module.extract_aweme_payload(response), {"aweme_list": []})

    def test_extract_aweme_payload_falls_back_to_raw_json(self) -> None:
        module = importlib.import_module("Douyin")
        response = FakeResponse("", '{"aweme_list": [{"aweme_id": "1"}]}')
        self.assertEqual(
            module.extract_aweme_payload(response),
            {"aweme_list": [{"aweme_id": "1"}]},
        )

    def test_wait_for_aweme_packet_treats_false_listener_result_as_missing(self) -> None:
        module = importlib.import_module("Douyin")
        page = mock.MagicMock()
        page.listen.wait.return_value = False
        self.assertIsNone(module.wait_for_aweme_packet(page, timeout=10))

    def test_build_browser_address_from_port(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertEqual(module.build_browser_address(9223), "127.0.0.1:9223")
        self.assertIsNone(module.build_browser_address(None))

    def test_default_scroll_settings_uses_human_mode(self) -> None:
        module = importlib.import_module("Douyin")
        settings = module.ScrollSettings()
        self.assertEqual(settings.mode, "human")
        self.assertEqual(settings.min_wait, 2.0)
        self.assertEqual(settings.max_wait, 8.0)
        self.assertEqual(settings.reverse_scroll_probability, 0.2)

    def test_create_human_scroll_plan_uses_configured_ranges(self) -> None:
        module = importlib.import_module("Douyin")
        settings = module.ScrollSettings(
            min_wait=2.0,
            max_wait=4.0,
            min_scroll=300,
            max_scroll=900,
            reverse_scroll_probability=0.0,
        )
        plan = module.create_human_scroll_plan(settings, random_module=module.random.Random(7))
        self.assertGreaterEqual(plan.down_distance, 300)
        self.assertLessEqual(plan.down_distance, 900)
        self.assertGreaterEqual(plan.down_wait, 2.0)
        self.assertLessEqual(plan.down_wait, 4.0)
        self.assertEqual(plan.reverse_distance, 0)

    def test_create_human_scroll_plan_can_include_reverse_scroll(self) -> None:
        module = importlib.import_module("Douyin")
        settings = module.ScrollSettings(reverse_scroll_probability=1.0)
        plan = module.create_human_scroll_plan(settings, random_module=module.random.Random(3))
        self.assertGreaterEqual(plan.reverse_distance, 80)
        self.assertLessEqual(plan.reverse_distance, 250)
        self.assertGreater(plan.reverse_wait, 0)

    def test_run_human_scroll_sequence_scrolls_down_and_optionally_back_up(self) -> None:
        module = importlib.import_module("Douyin")
        page = FakeScrollPage()
        plan = module.HumanScrollPlan(
            down_distance=500,
            down_wait=2.5,
            reverse_distance=120,
            reverse_wait=1.0,
            settle_wait=3.0,
        )
        with mock.patch.object(module.time, "sleep") as mocked_sleep:
            module.run_human_scroll_sequence(page, plan)
        self.assertEqual(
            page.scripts,
            [
                "window.scrollBy(0, 500);",
                "window.scrollBy(0, -120);",
                "window.scrollBy(0, 240);",
            ],
        )
        mocked_sleep.assert_has_calls([mock.call(2.5), mock.call(1.0), mock.call(3.0)])

    def test_ensure_browser_debug_port_ready_accepts_open_port(self) -> None:
        module = importlib.import_module("Douyin")
        connection = mock.MagicMock()
        connection.__enter__.return_value = connection
        connection.__exit__.return_value = False
        with mock.patch.object(module.socket, "create_connection", return_value=connection) as mocked_connect:
            module.ensure_browser_debug_port_ready(9223)
        mocked_connect.assert_called_once()

    def test_ensure_browser_debug_port_ready_rejects_closed_port(self) -> None:
        module = importlib.import_module("Douyin")
        with mock.patch.object(module.socket, "create_connection", side_effect=OSError("boom")):
            with self.assertRaisesRegex(RuntimeError, "login_douyin.py"):
                module.ensure_browser_debug_port_ready(9223)

    def test_is_recommendation_url_accepts_douyin_homepage(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertTrue(module.is_recommendation_url("https://www.douyin.com/"))
        self.assertTrue(module.is_recommendation_url("https://www.douyin.com"))
        self.assertTrue(module.is_recommendation_url("https://www.douyin.com/?from=web"))
        self.assertFalse(module.is_recommendation_url("https://www.douyin.com/user/xxx"))
        self.assertFalse(module.is_recommendation_url("https://www.douyin.com/video/123"))

    def test_is_creator_url_accepts_supported_douyin_creator_url(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertTrue(
            module.is_creator_url(
                "https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main"
            )
        )
        self.assertFalse(module.is_creator_url("https://www.douyin.com/video/7619989983668240802"))

    def test_is_video_url_accepts_supported_douyin_video_url(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertTrue(module.is_video_url("https://www.douyin.com/video/7619989983668240802"))
        self.assertFalse(
            module.is_video_url("https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main")
        )

    def test_is_aweme_id_accepts_numeric_identifier(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertTrue(module.is_aweme_id("7619989983668240802"))
        self.assertFalse(module.is_aweme_id("not-an-aweme-id"))

    def test_parse_target_input_classifies_recommendation_url(self) -> None:
        module = importlib.import_module("Douyin")
        target = module.parse_target_input("https://www.douyin.com/", source="manual")
        self.assertEqual(target.kind, "recommendation")
        self.assertEqual(target.value, "https://www.douyin.com/")
        self.assertEqual(target.source, "manual")

    def test_parse_target_input_classifies_creator_url(self) -> None:
        module = importlib.import_module("Douyin")
        target = module.parse_target_input(
            "https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
            source="manual",
        )
        self.assertEqual(target.kind, "creator")
        self.assertEqual(
            target.value,
            "https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
        )
        self.assertEqual(target.source, "manual")

    def test_parse_target_input_classifies_video_url(self) -> None:
        module = importlib.import_module("Douyin")
        target = module.parse_target_input(
            "https://www.douyin.com/video/7619989983668240802",
            source="manual",
        )
        self.assertEqual(target.kind, "single-video")
        self.assertEqual(target.aweme_id, "7619989983668240802")
        self.assertEqual(target.source, "manual")

    def test_parse_target_input_classifies_aweme_id(self) -> None:
        module = importlib.import_module("Douyin")
        target = module.parse_target_input("7619989983668240802", source="manual")
        self.assertEqual(target.kind, "single-video")
        self.assertEqual(target.value, "7619989983668240802")
        self.assertEqual(target.aweme_id, "7619989983668240802")

    def test_resolve_target_uses_current_page_when_cli_target_is_absent(self) -> None:
        module = importlib.import_module("Douyin")
        target = module.resolve_target(
            page=FakePage("https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main"),
            cli_target=None,
        )
        self.assertEqual(target.kind, "creator")
        self.assertEqual(target.source, "current-page")

    def test_resolve_target_raises_readable_error_when_current_page_is_unsupported(self) -> None:
        module = importlib.import_module("Douyin")
        with self.assertRaisesRegex(RuntimeError, "手动传入链接或 `aweme_id`"):
            module.resolve_target(page=FakePage("https://www.example.com/"), cli_target=None)

    def test_resolve_target_raises_readable_error_when_manual_input_is_unsupported(self) -> None:
        module = importlib.import_module("Douyin")
        with self.assertRaisesRegex(RuntimeError, "不支持的目标"):
            module.resolve_target(page=FakePage("https://www.douyin.com/video/7619989983668240802"), cli_target="abc")

    def test_collect_videos_does_not_auto_scroll_when_processing_current_page_only(self) -> None:
        module = importlib.import_module("Douyin")
        packet = FakePacket(
            {
                "aweme_list": [
                    {
                        "aweme_id": "7619989983668240802",
                        "desc": "当前页视频",
                        "video": {
                            "play_addr": {
                                "url_list": ["https://v26-web.douyinvod.com/example/video.mp4"]
                            }
                        },
                    }
                ]
            }
        )
        page = FakeRuntimePage(
            "https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
            packet,
        )
        with mock.patch.object(module, "import_runtime_dependencies", return_value=(object(), object(), object())):
            with mock.patch.object(module, "create_page", return_value=page):
                with mock.patch.object(module, "download_video"):
                    with mock.patch.object(module, "scroll_to_next_page") as mocked_scroll:
                        downloaded = module.collect_videos(
                            user_url="https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
                            max_pages=1,
                            timeout=10,
                            output_dir=module.Path("video"),
                            browser_port=None,
                        )
        self.assertEqual(downloaded, 1)
        mocked_scroll.assert_not_called()

    def test_collect_videos_raises_readable_error_when_no_aweme_items_are_available(self) -> None:
        module = importlib.import_module("Douyin")
        packet = FakePacket({"aweme_list": []})
        page = FakeRuntimePage(
            "https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
            packet,
        )
        with mock.patch.object(module, "import_runtime_dependencies", return_value=(object(), object(), object())):
            with mock.patch.object(module, "create_page", return_value=page):
                with mock.patch.object(module, "download_video"):
                    with self.assertRaisesRegex(RuntimeError, "当前页面未加载出可用作品数据"):
                        module.collect_videos(
                            user_url="https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
                            max_pages=1,
                            timeout=10,
                            output_dir=module.Path("video"),
                            browser_port=None,
                        )

    def test_parse_aweme_items_extracts_author_info(self) -> None:
        module = importlib.import_module("Douyin")
        payload = {
            "aweme_list": [
                {
                    "aweme_id": "7619989983668240802",
                    "desc": "测试视频",
                    "author": {
                        "nickname": "测试博主",
                        "uid": "123456789"
                    },
                    "video": {
                        "play_addr": {
                            "url_list": ["https://v26-web.douyinvod.com/example/video.mp4"]
                        }
                    },
                }
            ]
        }
        items = module.parse_aweme_items(payload)
        self.assertEqual(len(items), 1)
        self.assertEqual(items[0]["author_name"], "测试博主")
        self.assertEqual(items[0]["author_id"], "123456789")

    def test_parse_aweme_items_uses_play_addr_h264_when_play_addr_is_missing(self) -> None:
        module = importlib.import_module("Douyin")
        payload = {
            "aweme_list": [
                {
                    "aweme_id": "7619989983668240802",
                    "desc": "推荐视频",
                    "video": {
                        "play_addr_h264": {
                            "url_list": ["https://v26-web.douyinvod.com/example/h264.mp4"]
                        }
                    },
                }
            ]
        }
        items = module.parse_aweme_items(payload)
        self.assertEqual(len(items), 1)
        self.assertEqual(items[0]["video_url"], "https://v26-web.douyinvod.com/example/h264.mp4")

    def test_parse_aweme_items_uses_bit_rate_play_addr_when_top_level_addresses_are_missing(self) -> None:
        module = importlib.import_module("Douyin")
        payload = {
            "aweme_list": [
                {
                    "aweme_id": "7619989983668240802",
                    "desc": "推荐视频",
                    "video": {
                        "bit_rate": [
                            {
                                "format": "mp4",
                                "play_addr": {
                                    "url_list": ["https://v11-weba.douyinvod.com/example/bitrate.mp4"]
                                },
                            }
                        ]
                    },
                }
            ]
        }
        items = module.parse_aweme_items(payload)
        self.assertEqual(len(items), 1)
        self.assertEqual(items[0]["video_url"], "https://v11-weba.douyinvod.com/example/bitrate.mp4")

    def test_build_video_page_url_uses_aweme_id(self) -> None:
        module = importlib.import_module("Douyin")
        self.assertEqual(
            module.build_video_page_url("7619989983668240802"),
            "https://www.douyin.com/video/7619989983668240802",
        )

    def test_collect_recommendations_downloads_videos_with_author_prefix(self) -> None:
        module = importlib.import_module("Douyin")
        packet = FakePacket(
            {
                "aweme_list": [
                    {
                        "aweme_id": "7619989983668240802",
                        "desc": "推荐视频1",
                        "author": {"nickname": "博主A", "uid": "111"},
                        "video": {
                            "play_addr": {
                                "url_list": ["https://v26-web.douyinvod.com/example/video1.mp4"]
                            }
                        },
                    }
                ]
            }
        )
        page = FakeRuntimePage("https://www.douyin.com/", packet)
        
        with mock.patch.object(module, "import_runtime_dependencies", return_value=(object(), object(), object())):
            with mock.patch.object(module, "create_page", return_value=page):
                with mock.patch.object(module, "download_video") as mocked_download:
                    with mock.patch.object(module, "human_like_scroll"):
                        downloaded = module.collect_recommendations(
                            max_videos=50,
                            timeout=10,
                            output_dir=module.Path("video"),
                            browser_port=None,
                        )
        
        self.assertEqual(downloaded, 1)
        # 验证文件名包含博主前缀
        call_kwargs = mocked_download.call_args[1]
        self.assertIn("[博主A]", str(call_kwargs["output_path"]))

    def test_collect_single_video_downloads_exactly_one_file_for_video_url_target(self) -> None:
        module = importlib.import_module("Douyin")
        packet = FakePacket(
            {
                "aweme_detail": {
                    "aweme_id": "7619989983668240802",
                    "desc": "单视频页面",
                    "video": {
                        "play_addr": {
                            "url_list": ["https://v26-web.douyinvod.com/example/single.mp4"]
                        }
                    },
                }
            }
        )
        page = FakeRuntimePage("https://www.douyin.com/video/7619989983668240802", packet)
        target = module.ResolvedTarget(
            kind="single-video",
            value="https://www.douyin.com/video/7619989983668240802",
            source="manual",
            aweme_id="7619989983668240802",
        )
        with mock.patch.object(module, "import_runtime_dependencies", return_value=(object(), object(), object())):
            with mock.patch.object(module, "create_page", return_value=page):
                with mock.patch.object(module, "download_video") as mocked_download:
                    downloaded = module.collect_single_video(
                        target=target,
                        timeout=10,
                        output_dir=module.Path("video"),
                        browser_port=None,
                    )
        self.assertEqual(downloaded, 1)
        self.assertEqual(page.visited_urls, ["https://www.douyin.com/video/7619989983668240802"])
        mocked_download.assert_called_once()

    def test_collect_single_video_downloads_exactly_one_file_for_aweme_id_target(self) -> None:
        module = importlib.import_module("Douyin")
        packet = FakePacket(
            {
                "aweme_detail": {
                    "aweme_id": "7619989983668240802",
                    "desc": "单视频页面",
                    "video": {
                        "play_addr": {
                            "url_list": ["https://v26-web.douyinvod.com/example/single.mp4"]
                        }
                    },
                }
            }
        )
        page = FakeRuntimePage("about:blank", packet)
        target = module.ResolvedTarget(
            kind="single-video",
            value="7619989983668240802",
            source="manual",
            aweme_id="7619989983668240802",
        )
        with mock.patch.object(module, "import_runtime_dependencies", return_value=(object(), object(), object())):
            with mock.patch.object(module, "create_page", return_value=page):
                with mock.patch.object(module, "download_video") as mocked_download:
                    downloaded = module.collect_single_video(
                        target=target,
                        timeout=10,
                        output_dir=module.Path("video"),
                        browser_port=None,
                    )
        self.assertEqual(downloaded, 1)
        self.assertEqual(page.visited_urls, ["https://www.douyin.com/video/7619989983668240802"])
        mocked_download.assert_called_once()

    def test_build_parser_has_max_videos_argument(self) -> None:
        module = importlib.import_module("Douyin")
        args = module.build_parser().parse_args(["--max-videos", "30"])
        self.assertEqual(args.max_videos, 30)

    def test_build_parser_has_human_scroll_arguments(self) -> None:
        module = importlib.import_module("Douyin")
        args = module.build_parser().parse_args(
            [
                "--scroll-mode",
                "human",
                "--min-wait",
                "3",
                "--max-wait",
                "9",
                "--reverse-scroll-probability",
                "0.4",
                "--max-runtime",
                "600",
            ]
        )
        self.assertEqual(args.scroll_mode, "human")
        self.assertEqual(args.min_wait, 3)
        self.assertEqual(args.max_wait, 9)
        self.assertEqual(args.reverse_scroll_probability, 0.4)
        self.assertEqual(args.max_runtime, 600)

    def test_build_parser_defaults_to_zero_argument_current_page_flow(self) -> None:
        module = importlib.import_module("Douyin")
        args = module.build_parser().parse_args([])
        self.assertIsNone(args.target)
        self.assertEqual(args.browser_port, 9223)
        self.assertEqual(args.pages, 1)

    def test_resolve_cli_target_prefers_manual_target_without_attaching_browser(self) -> None:
        module = importlib.import_module("Douyin")
        with mock.patch.object(module, "import_runtime_dependencies") as mocked_imports:
            target = module.resolve_cli_target("7619989983668240802", browser_port=9223)
        self.assertEqual(target.kind, "single-video")
        self.assertEqual(target.aweme_id, "7619989983668240802")
        mocked_imports.assert_not_called()

    def test_main_dispatches_recommendation_flow_for_recommendation_url(self) -> None:
        module = importlib.import_module("Douyin")
        stdout = io.StringIO()
        recommendation_target = module.ResolvedTarget(
            kind="recommendation",
            value="https://www.douyin.com/",
            source="current-page",
        )
        with redirect_stdout(stdout):
            with mock.patch.object(module, "resolve_cli_target", return_value=recommendation_target):
                with mock.patch.object(module, "collect_recommendations", return_value=5) as mocked_collect:
                    exit_code = module.main([])
        self.assertEqual(exit_code, 0)
        mocked_collect.assert_called_once_with(
            max_videos=50,
            timeout=10,
            output_dir=module.Path("video"),
            browser_port=9223,
            scroll_settings=module.ScrollSettings(),
        )

    def test_main_without_target_dispatches_current_page_creator_flow(self) -> None:
        module = importlib.import_module("Douyin")
        stdout = io.StringIO()
        creator_target = module.ResolvedTarget(
            kind="creator",
            value="https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
            source="current-page",
        )
        with redirect_stdout(stdout):
            with mock.patch.object(module, "resolve_cli_target", return_value=creator_target):
                with mock.patch.object(module, "collect_videos", return_value=2) as mocked_collect:
                    exit_code = module.main([])
        self.assertEqual(exit_code, 0)
        mocked_collect.assert_called_once_with(
            user_url="https://www.douyin.com/user/MS4wLjABAAAAexample?from_tab_name=main",
            max_pages=1,
            timeout=10,
            output_dir=module.Path("video"),
            browser_port=9223,
            auto_scroll=False,
        )
        self.assertIn("处理结束，共下载 2 个视频", stdout.getvalue())

    def test_main_returns_fallback_hint_when_current_page_is_unsupported(self) -> None:
        module = importlib.import_module("Douyin")
        stdout = io.StringIO()
        with redirect_stdout(stdout):
            with mock.patch.object(
                module,
                "resolve_cli_target",
                side_effect=RuntimeError("请切到目标页面后重试，或手动传入链接或 `aweme_id`。"),
            ):
                exit_code = module.main([])
        self.assertEqual(exit_code, 1)
        self.assertIn("手动传入链接或 `aweme_id`", stdout.getvalue())


if __name__ == "__main__":
    unittest.main()