"""Redis LIST queue for report generation jobs."""

from __future__ import annotations

import asyncio
import logging
from collections.abc import Awaitable, Callable

from app.config import settings
from app.jobs.models import GenerationJob, JobType
from app.redis_client import get_redis, job_queue_enabled
from app.services.generation import mark_report_generation_failed, run_agentic_full_report_job, run_generation

logger = logging.getLogger(__name__)


def job_queue_active() -> bool:
    return job_queue_enabled()


async def enqueue_generation_job(job: GenerationJob) -> None:
    """Push a job onto the Redis list (left = newest; worker BRPOP from right)."""
    redis = await get_redis()
    await redis.lpush(settings.job_queue_key, job.model_dump_json())
    logger.info(
        "Enqueued %s job report=%s tenant=%s",
        job.job_type.value,
        job.report_id,
        job.tenant_id,
    )


async def _brpop_job() -> GenerationJob | None:
    redis = await get_redis()
    result = await redis.brpop(
        settings.job_queue_key,
        timeout=int(settings.job_queue_block_seconds),
    )
    if not result:
        return None
    _, raw = result
    return GenerationJob.model_validate_json(raw)


async def _execute_job(job: GenerationJob) -> None:
    if job.job_type == JobType.generate:
        p = job.payload
        await run_generation(
            report_id=job.report_id,
            tenant_id=job.tenant_id,
            template_id=str(p.get("template_id") or ""),
            bullets=list(p.get("bullets") or []),
            mode=str(p.get("mode") or "generate"),
            ai_level=int(p.get("ai_level") or 3),
            ai_percent=p.get("ai_percent"),
            retrieval_level=str(p.get("retrieval_level") or "paragraph"),
            force_regenerate=bool(p.get("force_regenerate", False)),
            strict_uploaded_only=bool(p.get("strict_uploaded_only", False)),
            reference_document_ids=p.get("reference_document_ids"),
            draft_paragraph=p.get("draft_paragraph"),
            interference_level=p.get("interference_level"),
            template_ids=p.get("template_ids"),
            bullets_by_section=p.get("bullets_by_section"),
        )
        return

    if job.job_type == JobType.agentic_full:
        p = job.payload
        await run_agentic_full_report_job(
            job.report_id,
            job.tenant_id,
            bullets_by_section=dict(p.get("bullets_by_section") or {}),
            ai_percent=int(p.get("ai_percent") or 50),
            retrieval_level=str(p.get("retrieval_level") or "paragraph"),
            reference_document_ids=p.get("reference_document_ids"),
            similarity_scan=bool(p.get("similarity_scan", False)),
            peer_sections=dict(p.get("peer_sections") or {}),
            similarity_exclude_document_ids=p.get("similarity_exclude_document_ids"),
            interference_level=p.get("interference_level"),
        )
        return

    raise ValueError(f"Unknown job type: {job.job_type}")


async def _run_job_safe(job: GenerationJob) -> None:
    try:
        await _execute_job(job)
    except Exception as exc:  # noqa: BLE001
        logger.exception(
            "Job failed type=%s report=%s",
            job.job_type.value,
            job.report_id,
        )
        await mark_report_generation_failed(job.report_id, job.tenant_id, str(exc))


async def process_jobs_forever() -> None:
    """Blocking worker loop — run from ``jobs_worker.py``."""
    sem = asyncio.Semaphore(int(settings.job_queue_max_concurrent))
    _tasks: set[asyncio.Task] = set()  # type: ignore[type-arg]
    logger.info(
        "Jobs worker listening key=%s concurrency=%s",
        settings.job_queue_key,
        settings.job_queue_max_concurrent,
    )

    async def _worker(job: GenerationJob) -> None:
        async with sem:
            await _run_job_safe(job)

    while True:
        job = await _brpop_job()
        if job is None:
            continue
        from app.api.background_tasks import _log_task_outcome

        t = asyncio.create_task(_worker(job))
        _tasks.add(t)
        t.add_done_callback(_tasks.discard)
        t.add_done_callback(_log_task_outcome)


async def dispatch_or_enqueue(
    *,
    job: GenerationJob,
    inline_factory: Callable[[], Awaitable[None]],
) -> str:
    """Enqueue to Redis or run inline; returns ``redis`` | ``inline``.

    Falls back to in-process execution when Redis is configured but unreachable.
    """
    from app.api.background_tasks import spawn_background_task

    if job_queue_active():
        try:
            await enqueue_generation_job(job)
            return "redis"
        except Exception as exc:  # noqa: BLE001
            logger.warning(
                "Redis enqueue failed for report=%s (%s); falling back to in-process task",
                job.report_id,
                exc,
            )
    spawn_background_task(inline_factory())
    return "inline"