# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2026)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""streamlit.LocalSourcesWatcher unit test."""

from __future__ import annotations

import contextlib
import os
import sys
import unittest
from unittest.mock import MagicMock, call, patch

import tests.streamlit.watcher.test_data.dummy_module1 as DUMMY_MODULE_1
import tests.streamlit.watcher.test_data.dummy_module2 as DUMMY_MODULE_2
import tests.streamlit.watcher.test_data.misbehaved_module as MISBEHAVED_MODULE
import tests.streamlit.watcher.test_data.nested_module_child as NESTED_MODULE_CHILD
import tests.streamlit.watcher.test_data.nested_module_parent as NESTED_MODULE_PARENT
from streamlit import config
from streamlit.runtime.pages_manager import PagesManager
from streamlit.watcher import local_sources_watcher
from streamlit.watcher.path_watcher import NoOpPathWatcher, _is_watchdog_available

SCRIPT_PATH = os.path.join(
    os.path.dirname(__file__), "test_data", "not_a_real_script.py"
)

DUMMY_MODULE_1_FILE = os.path.abspath(DUMMY_MODULE_1.__file__)
DUMMY_MODULE_2_FILE = os.path.abspath(DUMMY_MODULE_2.__file__)

NESTED_MODULE_CHILD_FILE = os.path.abspath(NESTED_MODULE_CHILD.__file__)


def NOOP_CALLBACK(_filepath):
    pass


@patch("streamlit.file_util.file_in_pythonpath", MagicMock(return_value=False))
class LocalSourcesWatcherTest(unittest.TestCase):
    def setUp(self):
        modules = [
            "DUMMY_MODULE_1",
            "DUMMY_MODULE_2",
            "MISBEHAVED_MODULE",
            "NESTED_MODULE_PARENT",
            "NESTED_MODULE_CHILD",
        ]

        the_globals = globals()

        for name in modules:
            with contextlib.suppress(Exception):
                del sys.modules[the_globals[name].__name__]

            with contextlib.suppress(Exception):
                del sys.modules[name]

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_just_script(self, fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()
        args, _ = fob.call_args
        assert os.path.realpath(args[0]) == os.path.realpath(SCRIPT_PATH)
        method_type = type(self.setUp)
        assert type(args[1]) is method_type

        fob.reset_mock()
        lsw.update_watched_modules()
        lsw.update_watched_modules()
        lsw.update_watched_modules()
        lsw.update_watched_modules()

        assert fob.call_count == 1  # __init__.py

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_permission_error(self, fob):
        fob.side_effect = PermissionError("This error should be caught!")
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_script_and_2_modules_at_once(self, fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()

        sys.modules["DUMMY_MODULE_1"] = DUMMY_MODULE_1
        sys.modules["DUMMY_MODULE_2"] = DUMMY_MODULE_2

        fob.reset_mock()
        lsw.update_watched_modules()

        assert fob.call_count == 3  # dummy modules and __init__.py

        method_type = type(self.setUp)

        call_args_list = sort_args_list(fob.call_args_list)

        args, _ = call_args_list[0]
        assert "__init__.py" in args[0]
        args, _ = call_args_list[1]
        assert args[0] == DUMMY_MODULE_1_FILE
        assert type(args[1]) is method_type
        args, _ = call_args_list[2]
        assert args[0] == DUMMY_MODULE_2_FILE
        assert type(args[1]) is method_type

        fob.reset_mock()
        lsw.update_watched_modules()

        assert fob.call_count == 0

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_script_and_2_modules_in_series(self, fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()

        sys.modules["DUMMY_MODULE_1"] = DUMMY_MODULE_1
        fob.reset_mock()

        lsw.update_watched_modules()

        assert fob.call_count == 2  # dummy module and __init__.py

        method_type = type(self.setUp)

        call_args_list = sort_args_list(fob.call_args_list)

        args, _ = call_args_list[0]
        assert "__init__.py" in args[0]

        args, _ = call_args_list[1]
        assert args[0] == DUMMY_MODULE_1_FILE
        assert type(args[1]) is method_type

        sys.modules["DUMMY_MODULE_2"] = DUMMY_MODULE_2
        fob.reset_mock()
        lsw.update_watched_modules()

        args, _ = fob.call_args
        assert args[0] == DUMMY_MODULE_2_FILE
        assert type(args[1]) is method_type

        fob.assert_called_once()

    @patch("streamlit.watcher.local_sources_watcher._LOGGER")
    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_misbehaved_module(self, fob, patched_logger):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()

        sys.modules["MISBEHAVED_MODULE"] = MISBEHAVED_MODULE.MisbehavedModule
        fob.reset_mock()
        lsw.update_watched_modules()

        fob.assert_called_once()  # Just __init__.py

        # Check that the warning was called with the expected message
        patched_logger.warning.assert_called_once_with(
            "Examining the path of %s raised:",
            "MisbehavedModule",
            exc_info=True,
        )

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_nested_module_parent_unloaded(self, fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()

        with patch(
            "sys.modules",
            {
                "DUMMY_MODULE_1": DUMMY_MODULE_1,
                "NESTED_MODULE_PARENT": NESTED_MODULE_PARENT,
                "NESTED_MODULE_CHILD": NESTED_MODULE_CHILD,
            },
        ):
            lsw.update_watched_modules()

            # Simulate a change to the child module
            lsw.on_path_changed(NESTED_MODULE_CHILD_FILE)

            # Assert that both the parent and child are unloaded, ready for reload
            assert "NESTED_MODULE_CHILD" not in sys.modules
            assert "NESTED_MODULE_PARENT" not in sys.modules

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_config_blacklist(self, fob):
        """Test server.folderWatchBlacklist"""
        prev_blacklist = config.get_option("server.folderWatchBlacklist")

        config.set_option(
            "server.folderWatchBlacklist", [os.path.dirname(DUMMY_MODULE_1.__file__)]
        )

        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()

        sys.modules["DUMMY_MODULE_1"] = DUMMY_MODULE_1
        fob.reset_mock()

        lsw.update_watched_modules()

        fob.assert_not_called()

        # Reset the config object.
        config.set_option("server.folderWatchBlacklist", prev_blacklist)

    def test_config_watcherType(self):
        """Test server.fileWatcherType"""

        config.set_option("server.fileWatcherType", "none")
        assert (
            local_sources_watcher.get_default_path_watcher_class().__name__
            == "NoOpPathWatcher"
        )

        config.set_option("server.fileWatcherType", "poll")
        assert (
            local_sources_watcher.get_default_path_watcher_class().__name__
            == "PollingPathWatcher"
        )

        config.set_option("server.fileWatcherType", "watchdog")
        assert local_sources_watcher.get_default_path_watcher_class().__name__ == (
            "EventBasedPathWatcher" if _is_watchdog_available() else "NoOpPathWatcher"
        )

        config.set_option("server.fileWatcherType", "auto")
        assert local_sources_watcher.get_default_path_watcher_class() is not None

        if sys.modules["streamlit.watcher.event_based_path_watcher"] is not None:
            assert (
                local_sources_watcher.get_default_path_watcher_class().__name__
                == "EventBasedPathWatcher"
            )
        else:
            assert (
                local_sources_watcher.get_default_path_watcher_class().__name__
                == "PollingPathWatcher"
            )

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher", new=NoOpPathWatcher)
    def test_does_nothing_if_NoOpPathWatcher(self):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)
        lsw.update_watched_modules()
        assert len(lsw._watched_modules) == 0

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_namespace_package_unloaded(self, fob):
        import tests.streamlit.watcher.test_data.namespace_package as pkg

        pkg_path = os.path.abspath(pkg.__path__._path[0])

        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        fob.assert_called_once()

        with patch("sys.modules", {"pkg": pkg}):
            lsw.update_watched_modules()

            # Simulate a change to the child module
            lsw.on_path_changed(pkg_path)

            # Assert that both the parent and child are unloaded, ready for reload
            assert "pkg" not in sys.modules

        del sys.modules["tests.streamlit.watcher.test_data.namespace_package"]

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_module_caching(self, _fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        register = MagicMock()
        lsw._register_necessary_watchers = register

        # Updates modules on first run
        lsw.update_watched_modules()
        register.assert_called_once()

        # Skips update when module list hasn't changed
        register.reset_mock()
        lsw.update_watched_modules()
        register.assert_not_called()

        # Invalidates cache when a new module is imported
        register.reset_mock()
        sys.modules["DUMMY_MODULE_2"] = DUMMY_MODULE_2
        lsw.update_watched_modules()
        register.assert_called_once()

        # Skips update when new module is part of cache
        register.reset_mock()
        lsw.update_watched_modules()
        register.assert_not_called()

    @patch(
        "streamlit.runtime.pages_manager.PagesManager.get_pages",
        MagicMock(
            return_value={
                "someHash1": {
                    "page_name": "streamlit_app",
                    "script_path": "streamlit_app.py",
                },
                "someHash2": {
                    "page_name": "streamlit_app2",
                    "script_path": "streamlit_app2.py",
                },
            }
        ),
    )
    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_watches_all_page_scripts(self, fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        args1, _ = fob.call_args_list[0]
        args2, _ = fob.call_args_list[1]
        assert os.path.basename(args1[0]) == "streamlit_app.py"
        assert os.path.basename(args2[0]) == "streamlit_app2.py"

    @patch(
        "streamlit.runtime.pages_manager.PagesManager.get_pages",
        MagicMock(
            side_effect=[
                {
                    "someHash1": {
                        "page_name": "streamlit_app",
                        "script_path": "streamlit_app.py",
                    },
                    "someHash2": {
                        "page_name": "streamlit_app2",
                        "script_path": "streamlit_app2.py",
                    },
                },
                {
                    "someHash1": {
                        "page_name": "streamlit_app",
                        "script_path": "streamlit_app.py",
                    },
                    "someHash3": {
                        "page_name": "streamlit_app3",
                        "script_path": "streamlit_app3.py",
                    },
                },
            ]
        ),
    )
    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_watches_new_page_scripts(self, fob):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        args1, _ = fob.call_args_list[0]
        args2, _ = fob.call_args_list[1]

        assert os.path.basename(args1[0]) == "streamlit_app.py"
        assert os.path.basename(args2[0]) == "streamlit_app2.py"

        lsw.update_watched_pages()
        args3, _ = fob.call_args_list[2]
        assert os.path.basename(args3[0]) == "streamlit_app3.py"

    @patch(
        "streamlit.runtime.pages_manager.PagesManager.get_pages",
        MagicMock(
            side_effect=[
                {
                    "someHash1": {
                        "page_name": "page1",
                        "script_path": "page1.py",
                    },
                    "someHash2": {
                        "page_name": "page2",
                        "script_path": "page2.py",
                    },
                },
                {
                    "someHash1": {
                        "page_name": "page1",
                        "script_path": "page1.py",
                    },
                    "someHash3": {
                        "page_name": "page3",
                        "script_path": "page3.py",
                    },
                },
            ]
        ),
    )
    @patch("streamlit.watcher.local_sources_watcher.PathWatcher", MagicMock())
    def test_watches_union_of_page_scripts(self):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        assert len(lsw._watched_pages) == 2
        assert "page1.py" in ",".join(lsw._watched_pages)
        assert "page2.py" in ",".join(lsw._watched_pages)

        def isfile_mock(x):
            return True

        with patch("os.path.isfile", wraps=isfile_mock):
            lsw.update_watched_pages()
            assert len(lsw._watched_pages) == 3
            assert "page1.py" in ",".join(lsw._watched_pages)
            assert "page2.py" in ",".join(lsw._watched_pages)
            assert "page3.py" in ",".join(lsw._watched_pages)

    @patch(
        "streamlit.runtime.pages_manager.PagesManager.get_pages",
        MagicMock(
            side_effect=[
                {
                    "someHash1": {
                        "page_name": "page1",
                        "script_path": "page1.py",
                    },
                    "someHash2": {
                        "page_name": "page2",
                        "script_path": "page2.py",
                    },
                },
                {
                    "someHash1": {
                        "page_name": "page1",
                        "script_path": "page1.py",
                    },
                    "someHash3": {
                        "page_name": "page3",
                        "script_path": "page3.py",
                    },
                },
            ]
        ),
    )
    @patch("streamlit.watcher.local_sources_watcher.PathWatcher", MagicMock())
    def test_unwatches_invalid_page_script_paths(self):
        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        assert len(lsw._watched_pages) == 2
        assert "page1.py" in ",".join(lsw._watched_pages)
        assert "page2.py" in ",".join(lsw._watched_pages)

        def isfile_mock(x):
            return "page2.py" not in x

        with patch("os.path.isfile", wraps=isfile_mock):
            lsw.update_watched_pages()
            assert len(lsw._watched_pages) == 2
            assert "page1.py" in ",".join(lsw._watched_pages)
            assert "page3.py" in ",".join(lsw._watched_pages)

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    def test_passes_filepath_to_callback(self, fob):
        saved_filepath = None

        def callback(filepath):
            nonlocal saved_filepath

            saved_filepath = filepath

        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(callback)

        # Simulate a change to the report script
        lsw.on_path_changed(SCRIPT_PATH)

        assert saved_filepath == SCRIPT_PATH

    @patch("streamlit.watcher.local_sources_watcher.PathWatcher")
    @patch("os.path.isdir")
    def test_folder_watch_list(self, mock_isdir, mock_path_watcher):
        watch_folders = ["/watch/path1", "/watch/path2"]
        config.set_option("server.folderWatchList", watch_folders)

        mock_isdir.return_value = True

        lsw = local_sources_watcher.LocalSourcesWatcher(PagesManager(SCRIPT_PATH))
        lsw.register_file_change_callback(NOOP_CALLBACK)

        # Check that PathWatcher was called for the main script and each directory
        # with the glob_pattern
        expected_calls = [
            # Watcher for the main script file (always created)
            call(
                lsw._main_script_path,
                lsw.on_path_changed,
                glob_pattern=None,
                allow_nonexistent=False,
            ),
            # Watchers for the specified folders
            call(
                "/watch/path1",
                lsw.on_path_changed,
                glob_pattern="**/*",
                allow_nonexistent=False,
            ),
            call(
                "/watch/path2",
                lsw.on_path_changed,
                glob_pattern="**/*",
                allow_nonexistent=False,
            ),
        ]

        # Check if all expected calls were made, regardless of order or extra calls
        actual_calls = mock_path_watcher.call_args_list
        assert expected_calls[1] in actual_calls
        assert expected_calls[2] in actual_calls

        # Simulate file changes in watched directories
        test_file = "/watch/path1/test.txt"
        lsw.on_path_changed(test_file)

        # Clean up
        config.set_option("server.folderWatchList", [])


def test_get_module_paths_outputs_abs_paths():
    mock_module = MagicMock()
    mock_module.__file__ = os.path.relpath(DUMMY_MODULE_1_FILE)

    module_paths = local_sources_watcher.get_module_paths(mock_module)
    assert module_paths == {DUMMY_MODULE_1_FILE}


def sort_args_list(args_list):
    return sorted(args_list, key=lambda args: args[0])
