"""ARQ background jobs for large import operations.

When an import file exceeds BACKGROUND_JOB_THRESHOLD rows, the import is
enqueued as an ARQ job instead of running synchronously.  Job status is
tracked in Redis with the key pattern 'leocrm:import_job:{job_id}'.
"""

from __future__ import annotations

import json
import logging
import uuid
from typing import Any

from app.core.job_registry import register_job
from app.services import import_export_service

logger = logging.getLogger(__name__)

_JOB_KEY_PREFIX = "leocrm:import_job"
_JOB_TTL = 3600  # 1 hour


def _job_key(job_id: str) -> str:
    return f"{_JOB_KEY_PREFIX}:{job_id}"


async def _set_job_status(
    redis_client: Any,
    job_id: str,
    status: str,
    **extra: Any,
) -> None:
    """Store job status in Redis with TTL."""
    data = {"status": status, **extra}
    await redis_client.set(_job_key(job_id), json.dumps(data, default=str), ex=_JOB_TTL)


async def _get_job_status(redis_client: Any, job_id: str) -> dict[str, Any] | None:
    """Retrieve job status from Redis."""
    raw = await redis_client.get(_job_key(job_id))
    if raw is None:
        return None
    if isinstance(raw, bytes):
        raw = raw.decode("utf-8")
    return json.loads(raw)


async def import_background_job(ctx: dict[str, Any], job_id: str, params: dict[str, Any]) -> dict[str, Any]:
    """ARQ job function: run import in background with status tracking.

    Args:
        ctx: ARQ worker context.
        job_id: Unique job identifier.
        params: Dict with keys:
            - entity_type: 'contacts' or 'companies'
            - csv_content: File content as string
            - tenant_id: Tenant UUID string
            - user_id: User UUID string
            - field_mapping: Optional dict[str, str]
    """
    from app.core.auth import get_redis
    from app.core.db import get_worker_session_factory, set_tenant_context

    redis_client = get_redis()
    entity_type = params["entity_type"]
    csv_content = params["csv_content"]
    tenant_id = uuid.UUID(params["tenant_id"])
    user_id = uuid.UUID(params["user_id"])
    field_mapping = params.get("field_mapping")

    # Set initial status
    await _set_job_status(redis_client, job_id, "processing", progress=0, total=0)

    factory = get_worker_session_factory()
    try:
        async with factory() as db:
            # Set tenant context for RLS
            await set_tenant_context(db, tenant_id)

            result = await import_export_service.import_csv(
                db,
                tenant_id,
                user_id,
                csv_content,
                entity_type=entity_type,
                dry_run=False,
                field_mapping=field_mapping,
            )

        # Determine final status
        status = result.get("status", "completed")
        if status == "success":
            final_status = "completed"
        elif status == "partial_success":
            final_status = "partial_success"
        else:
            final_status = "failed"

        await _set_job_status(
            redis_client,
            job_id,
            final_status,
            progress=100,
            total=result.get("total", 0),
            succeeded=result.get("succeeded", 0),
            failed=result.get("failed", 0),
            error_report=result.get("error_report", {}),
            created_count=len(result.get("created", [])),
        )
        return result

    except Exception as exc:
        logger.error("Import background job %s failed: %s", job_id, exc, exc_info=True)
        await _set_job_status(
            redis_client,
            job_id,
            "failed",
            progress=0,
            total=0,
            error=str(exc),
        )
        raise


# Register the job so it appears in WorkerSettings.functions
register_job("import_background", import_background_job)


async def get_import_job_status(job_id: str) -> dict[str, Any] | None:
    """Public helper to get job status from Redis."""
    from app.core.auth import get_redis

    redis_client = get_redis()
    return await _get_job_status(redis_client, job_id)


async def create_import_job(
    entity_type: str,
    csv_content: str,
    tenant_id: uuid.UUID,
    user_id: uuid.UUID,
    field_mapping: dict[str, str] | None = None,
) -> str:
    """Enqueue an import as ARQ background job and return job_id."""
    from app.core.jobs import enqueue_job

    job_id = str(uuid.uuid4())
    params = {
        "entity_type": entity_type,
        "csv_content": csv_content,
        "tenant_id": str(tenant_id),
        "user_id": str(user_id),
        "field_mapping": field_mapping,
    }

    # Pre-set status as pending
    from app.core.auth import get_redis

    redis_client = get_redis()
    await _set_job_status(redis_client, job_id, "pending", progress=0, total=0)

    await enqueue_job("import_background", job_id, params)
    return job_id