from asyncio.log import logger
from typing import Any
from uuid import UUID

from celery import Task
from sqlalchemy.orm import Session

import app.shared.db.models as models
from app.shared.celery import get_celery_binding
from app.shared.db.base import SessionLocal
from app.shared.settings import settings
from app.worker.strategies.base import TaskProtocol
from app.worker.strategies.local import LocalStrategy

celery = get_celery_binding()


class TranscribeTask(Task):
    abstract = True

    def __init__(self) -> None:
        super().__init__()
        # currently only `LocalStrategy` is implemented.
        self.strategy: LocalStrategy | None = None

    def __call__(self, *args: Any, **kwargs: Any) -> Any:
        # load model into memory once when the first task is processed.
        if not self.strategy:
            self.strategy = LocalStrategy()
        return self.run(*args, **kwargs)


def select_task_processor(task: Task, job: models.Job) -> TaskProtocol:
    if job.type == models.JobType.transcript:
        return task.strategy.transcribe
    elif job.type == models.JobType.translation:
        return task.strategy.translate
    else:
        return task.strategy.detect_language


@celery.task(
    base=TranscribeTask,
    bind=True,
    soft_time_limit=settings.TASK_SOFT_TIME_LIMIT,
    time_limit=settings.TASK_HARD_TIME_LIMIT,
)
def transcribe(self: Task, job_id: UUID) -> None:
    try:
        # runs in a separate thread => requires sqlite's WAL mode to be enabled.
        db: Session = SessionLocal()

        # check if passed job should be processed.

        job = db.query(models.Job).filter(models.Job.id == job_id).one_or_none()

        if job is None:
            logger.warn("[{job.id}]: Received unknown job, abort.")
            return

        if job.status in [models.JobStatus.error, models.JobStatus.success]:
            logger.warn("[{job.id}]: job has already been processed, abort.")
            return

        logger.debug(f"[{job.id}]: start processing {job.type} job.")

        # unit of work: set task status to processing.

        job.meta = {"task_id": self.request.id}
        job.status = models.JobStatus.processing
        db.commit()

        logger.debug(f"[{job.id}]: finished setting task to {job.status}.")

        # unit of work: process job with whisper.

        processor = select_task_processor(self, job)

        result_type, result = processor(job)

        logger.debug(f"[{job.id}]: successfully processed audio.")

        artifact = models.Artifact(job_id=str(job.id), data=result, type=result_type)

        db.add(artifact)

        job.status = models.JobStatus.success

        db.commit()
        logger.debug(f"[{job.id}]: successfully stored artifact.")

    except Exception as e:
        if job and db:
            db.rollback()
            job.meta = {**job.meta, "error": str(e)}  # type: ignore
            job.status = models.JobStatus.error
            db.commit()
        raise
    finally:
        self.strategy.cleanup(job_id=job_id)
        db.close()