import os
import zipfile
from werkzeug.utils import secure_filename
from PIL import Image, UnidentifiedImageError
from app import db
from plugins.media.models import ZipJob

# Re‐import your create_app and utility plugin to get Celery
from plugins.utility.celery import celery_app

# Constants
IMAGE_EXTS    = {'.jpg','.jpeg','.png','.gif'}
DOC_EXTS      = {'.pdf','.txt','.csv'}
MAX_ZIP_FILES = 1000
MAX_PIXELS    = 8000 * 8000

def validate_image(path):
    try:
        with Image.open(path) as img:
            img.verify()
        w, h = Image.open(path).size
        return (w*h) <= MAX_PIXELS
    except (UnidentifiedImageError, IOError):
        return False

@celery_app.task(bind=True)
def process_zip(self, job_id, zip_path):
    job = ZipJob.query.get(job_id)
    job.status = 'processing'
    db.session.commit()

    extract_dir = zip_path + '_contents'
    try:
        with zipfile.ZipFile(zip_path) as zf:
            names = zf.namelist()
            if len(names) > MAX_ZIP_FILES:
                raise ValueError('ZIP contains too many files.')

            os.makedirs(extract_dir, exist_ok=True)
            for member in names:
                safe = secure_filename(member)
                if safe != member:
                    raise ValueError(f'Illegal filename {member}')

                _, ext = os.path.splitext(safe.lower())
                if ext not in IMAGE_EXTS | DOC_EXTS:
                    raise ValueError(f'Unsupported type {ext}')

                target = os.path.join(extract_dir, safe)
                with zf.open(member) as src, open(target, 'wb') as dst:
                    dst.write(src.read())

                if ext in IMAGE_EXTS and not validate_image(target):
                    raise ValueError(f'Bad image: {member}')
                elif ext == '.pdf':
                    if open(target,'rb').read(5)!=b'%PDF-':
                        raise ValueError(f'Bad PDF: {member}')
                else:
                    # txt/csv → simple UTF-8 check
                    open(target,'rb').read(1024).decode('utf-8')

        job.status = 'done'

    except Exception as e:
        job.status = 'failed'
        job.error = str(e)

    finally:
        db.session.commit()