import pytest

from thoughtsync.app import create_app
from thoughtsync.sync import DEFAULT_LIMIT, MAX_LIMIT, _clamp_limit, _page_cursor, _parse_since


@pytest.fixture
def app():
    return create_app()


async def test_changes_requires_auth(app):
    client = app.test_client()
    resp = await client.get("/api/sync/changes")
    assert resp.status_code == 401


def test_parse_since():
    assert _parse_since(None) == 0
    assert _parse_since("42") == 42
    assert _parse_since("-5") == 0  # negative clamps to 0
    assert _parse_since("garbage") == 0


def test_clamp_limit():
    assert _clamp_limit(None) == DEFAULT_LIMIT
    assert _clamp_limit("10") == 10
    assert _clamp_limit("0") == 1  # floor of 1
    assert _clamp_limit("999999") == MAX_LIMIT
    assert _clamp_limit("nope") == DEFAULT_LIMIT


def test_page_cursor_all_drained():
    # Neither stream is full → cursor is the max revision seen; nothing more to page.
    cursor, more = _page_cursor([1, 3, 5], [2, 4], since=0, limit=500)
    assert cursor == 5
    assert more is False


def test_page_cursor_empty():
    # No changes since the cursor → cursor stays put, no more pages.
    cursor, more = _page_cursor([], [], since=7, limit=500)
    assert cursor == 7
    assert more is False


def test_page_cursor_one_stream_full_advances_to_its_boundary():
    # Notes came back full (limit=3) → truncate at its boundary; later labels defer.
    cursor, more = _page_cursor([1, 2, 3], [4, 5], since=0, limit=3)
    assert cursor == 3
    assert more is True


def test_page_cursor_both_full_uses_min_boundary():
    # Both full → advance only to the SMALLER boundary so neither stream skips a gap.
    cursor, more = _page_cursor([1, 2, 10], [3, 4, 5], since=0, limit=3)
    assert cursor == 5
    assert more is True