"""Unit tests for the cleanup bookkeeping added to SqlWriter / AccessReader.

These mock pyodbc so no database is required. They pin the contract that
``mark_cleaned`` / ``purge_cleaned`` issue the right statements, and that
``delete_log_ids`` returns the actual number of rows deleted (not ``None``).
"""
from unittest.mock import MagicMock, patch

from sync.sql_writer import SqlWriter
from sync.access_reader import AccessReader


def _writer():
    """Build a SqlWriter whose pyodbc connection is a MagicMock."""
    with patch("sync.sql_writer.pyodbc.connect") as mconnect:
        conn = MagicMock()
        mconnect.return_value = conn
        w = SqlWriter("conn_str", "dbo.SyncQueue")
    return w, conn


def test_mark_cleaned_updates_only_applied_rows_for_file():
    w, conn = _writer()
    cur = conn.cursor.return_value
    w.mark_cleaned("a.accdb", [1, 2, 3])
    assert cur.execute.call_count == 1
    sql = cur.execute.call_args.args[0]
    assert "UPDATE dbo.SyncQueue SET Status='cleaned'" in sql
    assert "CleanedAt=sysdatetime()" in sql
    assert "SourceFile=?" in sql
    assert "Status='applied'" in sql
    # first param is the file, the rest are the SourceLogIDs
    assert cur.execute.call_args.args[1] == "a.accdb"
    assert list(cur.execute.call_args.args[2:]) == [1, 2, 3]


def test_mark_cleaned_no_ids_is_noop():
    w, conn = _writer()
    cur = conn.cursor.return_value
    w.mark_cleaned("a.accdb", [])
    cur.execute.assert_not_called()


def test_purge_cleaned_deletes_old_cleaned_rows():
    w, conn = _writer()
    cur = conn.cursor.return_value
    cur.rowcount = 42
    n = w.purge_cleaned(24)
    assert n == 42
    sql = cur.execute.call_args.args[0]
    assert "DELETE FROM dbo.SyncQueue" in sql
    assert "Status='cleaned'" in sql
    assert "CleanedAt < DATEADD(hour, -?, GETDATE())" in sql
    assert cur.execute.call_args.args[1] == 24


def test_delete_log_ids_returns_rowcount_and_chunks():
    r = AccessReader("x.accdb", "drv")
    fake_conn = MagicMock()
    fake_cur = MagicMock()
    fake_cur.rowcount = 7  # per-chunk affected rows
    fake_conn.cursor.return_value = fake_cur
    with patch.object(r, "_connect", return_value=fake_conn):
        # 5 ids, batch size 2 -> 3 chunks, 3 DELETEs, total 21 rows
        n = r.delete_log_ids([1, 2, 3, 4, 5], 2, 3)
    assert n == 21
    assert fake_cur.execute.call_count == 3