"""Import run repository for blocklist import idempotency tracking.

Persists and queries import run records in the ``import_runs`` table.
Enables detection of duplicate import attempts and prevents re-running bans
on scheduler retry after a crash.

All methods are plain async functions that accept an :class:`aiosqlite.Connection`.
"""

from __future__ import annotations

from typing import TYPE_CHECKING

if TYPE_CHECKING:
    import aiosqlite

from app.models.blocklist import ImportRunEntry


async def get_by_source_and_hash(
    db: aiosqlite.Connection,
    source_id: int,
    content_hash: str,
) -> ImportRunEntry | None:
    """Check if a specific import (by source and content hash) already exists.

    Args:
        db: Active aiosqlite connection.
        source_id: FK to ``blocklist_sources.id``.
        content_hash: SHA256 hash of the downloaded blocklist content.

    Returns:
        ImportRunEntry if found, None otherwise.
    """
    async with db.execute(
        """
        SELECT
            id, source_id, content_hash, status,
            imported_count, skipped_count, error_message,
            created_at, updated_at
        FROM import_runs
        WHERE source_id = ? AND content_hash = ?
        """,
        (source_id, content_hash),
    ) as cursor:
        row = await cursor.fetchone()

    if not row:
        return None

    return ImportRunEntry(
        id=row[0],
        source_id=row[1],
        content_hash=row[2],
        status=row[3],
        imported_count=row[4],
        skipped_count=row[5],
        error_message=row[6],
        created_at=row[7],
        updated_at=row[8],
    )


async def upsert_pending(
    db: aiosqlite.Connection,
    source_id: int,
    content_hash: str,
) -> int:
    """Atomically insert or reset a pending import run entry.

    Uses ``INSERT ... ON CONFLICT`` to make the operation fully atomic —
    no window between check and insert where a concurrent request can create
    a duplicate row.  If a row for ``(source_id, content_hash)`` already exists,
    its status is reset to ``pending`` and its ID is returned.

    Args:
        db: Active aiosqlite connection.
        source_id: FK to ``blocklist_sources.id``.
        content_hash: SHA256 hash of the downloaded blocklist content.

    Returns:
        Primary key of the inserted or updated row.
    """
    cursor = await db.execute(
        """
        INSERT INTO import_runs (source_id, content_hash, status)
        VALUES (?, ?, 'pending')
        ON CONFLICT(source_id, content_hash) DO UPDATE SET
            status = 'pending',
            updated_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now')
        RETURNING id;
        """,
        (source_id, content_hash),
    )
    row = await cursor.fetchone()
    return int(row[0])  # type: ignore[arg-type]


async def mark_completed(
    db: aiosqlite.Connection,
    run_id: int,
    imported_count: int,
    skipped_count: int,
) -> None:
    """Mark an import run as completed with final counts.

    Wraps the update in an explicit transaction to ensure atomicity.

    Args:
        db: Active aiosqlite connection.
        run_id: Primary key of the import run.
        imported_count: Number of IPs successfully banned.
        skipped_count: Number of entries skipped (invalid or CIDR).
    """
    try:
        await db.execute("BEGIN IMMEDIATE")
        await db.execute(
            """
            UPDATE import_runs
            SET status = 'completed',
                imported_count = ?,
                skipped_count = ?,
                updated_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now')
            WHERE id = ?
            """,
            (imported_count, skipped_count, run_id),
        )
        await db.commit()
    except Exception:
        await db.rollback()
        raise


async def mark_failed(
    db: aiosqlite.Connection,
    run_id: int,
    error_message: str,
) -> None:
    """Mark an import run as failed with error details.

    Wraps the update in an explicit transaction to ensure atomicity.

    Args:
        db: Active aiosqlite connection.
        run_id: Primary key of the import run.
        error_message: Error description.
    """
    try:
        await db.execute("BEGIN IMMEDIATE")
        await db.execute(
            """
            UPDATE import_runs
            SET status = 'failed',
                error_message = ?,
                updated_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now')
            WHERE id = ?
            """,
            (error_message, run_id),
        )
        await db.commit()
    except Exception:
        await db.rollback()
        raise