import aiosqlite


SCHEMA = """
PRAGMA journal_mode=WAL;
PRAGMA synchronous=FULL;
CREATE TABLE IF NOT EXISTS deliveries (
  idempotency_key TEXT NOT NULL,
  channel TEXT NOT NULL,
  delivered INTEGER NOT NULL DEFAULT 0,
  attempts INTEGER NOT NULL DEFAULT 0,
  last_error TEXT,
  updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (idempotency_key, channel)
);
"""


class DeliveryStore:
    def __init__(self, path: str) -> None:
        self.path = path

    async def init(self) -> None:
        async with aiosqlite.connect(self.path) as db:
            await db.executescript(SCHEMA)
            await db.commit()

    async def delivered(self, key: str, channel: str) -> bool:
        async with aiosqlite.connect(self.path) as db:
            row = await (await db.execute(
                "SELECT delivered FROM deliveries WHERE idempotency_key=? AND channel=?",
                (key, channel),
            )).fetchone()
            return bool(row and row[0])

    async def record(self, key: str, channel: str, ok: bool, error: str = "") -> None:
        async with aiosqlite.connect(self.path) as db:
            await db.execute(
                """INSERT INTO deliveries(idempotency_key,channel,delivered,attempts,last_error)
                   VALUES(?,?,?,?,?)
                   ON CONFLICT(idempotency_key,channel) DO UPDATE SET
                     delivered=MAX(deliveries.delivered, excluded.delivered),
                     attempts=deliveries.attempts+1,
                     last_error=CASE WHEN excluded.delivered=1 THEN NULL ELSE excluded.last_error END,
                     updated_at=CURRENT_TIMESTAMP""",
                (key, channel, int(ok), 1, error[:500] or None),
            )
            await db.commit()