from dataclasses import dataclass

import asyncpg

_LOAD = """
SELECT catchup_pts, catchup_qts, catchup_date FROM accounts WHERE account_id = $1
"""

_SAVE = """
UPDATE accounts SET catchup_pts = $2, catchup_qts = $3, catchup_date = $4
WHERE account_id = $1
"""

_CLEAR = """
UPDATE accounts SET catchup_pts = NULL, catchup_qts = NULL, catchup_date = NULL
WHERE account_id = $1
"""


@dataclass(frozen=True)
class UpdateCursor:
    pts: int
    qts: int
    date: int


async def load_cursor(pool: asyncpg.Pool, account_id: int) -> UpdateCursor | None:
    row = await pool.fetchrow(_LOAD, account_id)
    if row is None or row["catchup_pts"] is None:
        return None
    return UpdateCursor(row["catchup_pts"], row["catchup_qts"], row["catchup_date"])


async def save_cursor(
    pool: asyncpg.Pool, account_id: int, cursor: UpdateCursor
) -> None:
    await pool.execute(_SAVE, account_id, cursor.pts, cursor.qts, cursor.date)


async def clear_cursor(pool: asyncpg.Pool, account_id: int) -> None:
    await pool.execute(_CLEAR, account_id)