import io
import hashlib

from django.db import transaction

from celery import shared_task
from celery.exceptions import Retry
from PIL import Image as PillowImage
import blurhash

from .models import PostFileModel


@shared_task(autoretry_for=(Exception,), retry_backoff=True, max_retries=5)
def generate_blur_hash_PostFile(file_id):
    try:
        with transaction.atomic():
            img = PostFileModel.objects.select_for_update().get(id=file_id)
            image_data = io.BytesIO(img.file.read())
            pil_img = PillowImage.open(image_data)

            blurhash_string = blurhash.encode(pil_img, 4, 3)

            img.refresh_from_db()
            img.blur_hash = blurhash_string
            img.save()
        return f"Successfully generated blur hash for file {file_id}"  # Success message
    except Exception as e:
        error_message = f"Error generating blur hash for file {file_id}: {e}"
        print(error_message)
        raise Retry(exc=e)  # Retry on exception
        return error_message  # This ensures the error message is stored in the results


@shared_task(autoretry_for=(Exception,), retry_backoff=True, max_retries=5)
def generate_md5_hash_PostFile(file_id):
    try:
        with transaction.atomic():
            pstfile = PostFileModel.objects.select_for_update().get(id=file_id)
            hash_md5 = hashlib.md5()
            with open(pstfile.file.path, "rb") as f:
                for chunk in iter(lambda: f.read(4096), b""):
                    hash_md5.update(chunk)
            md5_hash = hash_md5.hexdigest()

            pstfile.refresh_from_db()
            pstfile.hash_md5 = md5_hash
            pstfile.save()
        return f"Successfully generated MD5 hash for file {file_id}"  # Success message
    except Exception as e:
        error_message = f"Error generating MD5 hash for file {file_id}: {e}"
        print(error_message)
        raise Retry(exc=e)  # Retry on exception
        return error_message  # This ensures the error message is stored in the results