"""Paging cursor correctness.

The subtle invariant: `page.oldest` must be computed over the RAW batch, before the
acted-on filter — otherwise a page that is mostly hidden would report a too-recent cursor
(or none) and the client would stop early, silently truncating the folder with no error.
"""

from conftest import login_static


def _records(n, start_hour=9):
    return [
        {"date": f"2026-07-14 {start_hour - i:02d}:00:00", "from": "s@x",
         "rcpts": ["r@y"], "subject": f"m{i}", "guid": f"g{i}", "localguid": f"6:6:{i}",
         "size": "10"}
        for i in range(n)
    ]


def test_oldest_from_raw_batch_not_filtered(app_client):
    login_static(app_client)
    pps = app_client._pps
    pps._records = _records(3)   # 09,08,07
    # Hide the two newest by enqueuing an action on them.
    q = app_client._queue
    q.enqueue("delete", "Quarantine",
              [{"localguid": "6:6:0"}, {"localguid": "6:6:1"}], {}, user="dev@example.invalid")

    data = app_client.get("/api/messages?folder=Quarantine&limit=1000").get_json()
    # Only the un-acted message is shown...
    assert len(data["messages"]) == 1
    # ...but the cursor still reflects the oldest RAW record (07:00), not the shown one.
    assert data["page"]["oldest"] == "2026-07-14 07:00:00"
    assert data["page"]["raw_count"] == 3


def test_has_more_boundary(app_client):
    login_static(app_client)
    pps = app_client._pps
    pps._records = _records(5)
    data = app_client.get("/api/messages?folder=Quarantine&limit=5").get_json()
    assert data["page"]["has_more"] is True     # raw_count == page_size
    data = app_client.get("/api/messages?folder=Quarantine&limit=6").get_json()
    assert data["page"]["has_more"] is False    # raw_count < page_size


def test_clamp_limit_edges(app_client):
    from app import _clamp_limit
    cfg = {"default_limit": 200}
    assert _clamp_limit(None, cfg) == 200
    assert _clamp_limit("abc", cfg) == 200
    assert _clamp_limit("0", cfg) == 1
    assert _clamp_limit("-5", cfg) == 1
    assert _clamp_limit("99999", cfg) == 1000
    assert _clamp_limit("500", cfg) == 500