Add read-only Caldav todo platform (#103415)

* Add Caldav todo enttiy for VTODO components

* Use new shared apis for todos

* Update homeassistant/components/caldav/todo.py

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

* Update todo item conversion checks

* Iterate over results once

* Add 15 minute poll interval for caldav todo

---------

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

tests/components/caldav/test_todo.py

@@ -0,0 +1,146 @@
+"""The tests for the webdav todo component."""
+from collections.abc import Awaitable, Callable
+from unittest.mock import MagicMock, Mock
+
+from caldav.objects import Todo
+import pytest
+
+from homeassistant.const import Platform
+from homeassistant.core import HomeAssistant
+
+CALENDAR_NAME = "My Tasks"
+ENTITY_NAME = "My tasks"
+TEST_ENTITY = "todo.my_tasks"
+
+TODO_NO_STATUS = """BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//E-Corp.//CalDAV Client//EN
+BEGIN:VTODO
+UID:1
+DTSTAMP:20231125T000000Z
+SUMMARY:Milk
+END:VTODO
+END:VCALENDAR"""
+
+TODO_NEEDS_ACTION = """BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//E-Corp.//CalDAV Client//EN
+BEGIN:VTODO
+UID:2
+DTSTAMP:20171125T000000Z
+SUMMARY:Cheese
+STATUS:NEEDS-ACTION
+END:VTODO
+END:VCALENDAR"""
+
+TODO_COMPLETED = """BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//E-Corp.//CalDAV Client//EN
+BEGIN:VTODO
+UID:3
+DTSTAMP:20231125T000000Z
+SUMMARY:Wine
+STATUS:COMPLETED
+END:VTODO
+END:VCALENDAR"""
+
+
+TODO_NO_SUMMARY = """BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//E-Corp.//CalDAV Client//EN
+BEGIN:VTODO
+UID:4
+DTSTAMP:20171126T000000Z
+STATUS:NEEDS-ACTION
+END:VTODO
+END:VCALENDAR"""
+
+
+@pytest.fixture
+def platforms() -> list[Platform]:
+    """Fixture to set up config entry platforms."""
+    return [Platform.TODO]
+
+
+@pytest.fixture(name="todos")
+def mock_todos() -> list[str]:
+    """Fixture to return VTODO objects for the calendar."""
+    return []
+
+
+@pytest.fixture(name="supported_components")
+def mock_supported_components() -> list[str]:
+    """Fixture to set supported components of the calendar."""
+    return ["VTODO"]
+
+
+@pytest.fixture(name="calendars")
+def mock_calendars(todos: list[str], supported_components: list[str]) -> list[Mock]:
+    """Fixture to create calendars for the test."""
+    calendar = Mock()
+    items = [
+        Todo(None, f"{idx}.ics", item, calendar, str(idx))
+        for idx, item in enumerate(todos)
+    ]
+    calendar.search = MagicMock(return_value=items)
+    calendar.name = CALENDAR_NAME
+    calendar.get_supported_components = MagicMock(return_value=supported_components)
+    return [calendar]
+
+
+@pytest.mark.parametrize(
+    ("todos", "expected_state"),
+    [
+        ([], "0"),
+        (
+            [TODO_NEEDS_ACTION],
+            "1",
+        ),
+        (
+            [TODO_NO_STATUS],
+            "1",
+        ),
+        ([TODO_COMPLETED], "0"),
+        ([TODO_NO_STATUS, TODO_NEEDS_ACTION, TODO_COMPLETED], "2"),
+        ([TODO_NO_SUMMARY], "0"),
+    ],
+    ids=(
+        "empty",
+        "needs_action",
+        "no_status",
+        "completed",
+        "all",
+        "no_summary",
+    ),
+)
+async def test_todo_list_state(
+    hass: HomeAssistant,
+    setup_integration: Callable[[], Awaitable[bool]],
+    expected_state: str,
+) -> None:
+    """Test a calendar entity from a config entry."""
+    assert await setup_integration()
+
+    state = hass.states.get(TEST_ENTITY)
+    assert state
+    assert state.name == ENTITY_NAME
+    assert state.state == expected_state
+    assert dict(state.attributes) == {
+        "friendly_name": ENTITY_NAME,
+    }
+
+
+@pytest.mark.parametrize(
+    ("supported_components", "has_entity"),
+    [([], False), (["VTODO"], True), (["VEVENT"], False), (["VEVENT", "VTODO"], True)],
+)
+async def test_supported_components(
+    hass: HomeAssistant,
+    setup_integration: Callable[[], Awaitable[bool]],
+    has_entity: bool,
+) -> None:
+    """Test a calendar supported components matches VTODO."""
+    assert await setup_integration()
+
+    state = hass.states.get(TEST_ENTITY)
+    assert (state is not None) == has_entity