"""Background file push — API returns immediately; progress via WebSocket."""

from __future__ import annotations

import logging
from typing import List, Optional

logger = logging.getLogger("nexus.sync_push_runner")


async def run_sync_files_background(
    *,
    server_ids: List[int],
    source_path: str,
    target_path: Optional[str],
    sync_mode: str,
    operator: str,
    batch_size: int,
    concurrency: int,
    batch_id: str,
) -> None:
    """Execute sync_files in an isolated DB session (not request-scoped)."""
    from server.application.services.sync_engine_v2 import SyncEngineV2
    from server.infrastructure.database.audit_log_repo import AuditLogRepositoryImpl
    from server.infrastructure.database.push_schedule_repo import PushRetryJobRepositoryImpl
    from server.infrastructure.database.server_repo import ServerRepositoryImpl
    from server.infrastructure.database.session import AsyncSessionLocal
    from server.infrastructure.database.sync_log_repo import SyncLogRepositoryImpl

    try:
        async with AsyncSessionLocal() as session:
            engine = SyncEngineV2(
                server_repo=ServerRepositoryImpl(session),
                sync_log_repo=SyncLogRepositoryImpl(session),
                audit_repo=AuditLogRepositoryImpl(session),
                retry_repo=PushRetryJobRepositoryImpl(session),
            )
            await engine.sync_files(
                server_ids=server_ids,
                source_path=source_path,
                target_path=target_path,
                sync_mode=sync_mode,
                operator=operator,
                batch_size=batch_size,
                concurrency=concurrency,
                batch_id=batch_id,
            )
    except Exception:
        logger.exception("Background sync_files failed: batch_id=%s", batch_id)


def schedule_sync_files(**kwargs) -> None:
    """Fire-and-forget push task on the running event loop."""
    import asyncio

    asyncio.create_task(
        run_sync_files_background(**kwargs),
        name=f"sync_push:{kwargs.get('batch_id', '')}",
    )