import os
from celery import Celery
from celery.schedules import crontab
from datetime import datetime, timedelta
import logging
from services.database_service import DatabaseService
from services.notification_service import NotificationService
from utils.image_processor import ImageProcessor

# Initialize Celery
redis_url = os.getenv("REDIS_URL", "redis://localhost:6379")
celery_app = Celery("glowai", broker=redis_url, backend=redis_url)

# Configure Celery
celery_app.conf.update(
    task_serializer="json",
    accept_content=["json"],
    result_serializer="json",
    timezone="UTC",
    enable_utc=True,
    task_track_started=True,
    task_time_limit=30 * 60,  # 30 minutes
    task_soft_time_limit=25 * 60,  # 25 minutes
    worker_max_tasks_per_child=200,
    worker_prefetch_multiplier=4,
)

# Schedule periodic tasks
celery_app.conf.beat_schedule = {
    "delete-expired-images": {
        "task": "worker.delete_expired_images",
        "schedule": crontab(hour="*/6"),  # Every 6 hours
    },
    "send-streak-reminders": {
        "task": "worker.send_streak_reminders",
        "schedule": crontab(hour="20", minute="0"),  # 8 PM daily
    },
    "update-leaderboard": {
        "task": "worker.update_leaderboard",
        "schedule": crontab(hour="0", minute="0"),  # Midnight daily
    },
    "cleanup-privacy-logs": {
        "task": "worker.cleanup_privacy_logs",
        "schedule": crontab(day_of_month="1"),  # First day of month
    },
    "backup-database": {
        "task": "worker.backup_database",
        "schedule": crontab(hour="2", minute="0"),  # 2 AM daily
    },
    "sync-product-catalog": {
        "task": "worker.sync_product_catalog",
        "schedule": crontab(hour="3", minute="0"),  # 3 AM daily
    },
}

logger = logging.getLogger(__name__)
db_service = DatabaseService()
notification_service = NotificationService()
image_processor = ImageProcessor()

@celery_app.task
def delete_expired_images():
    """
    Delete images older than retention period (GDPR compliance)
    """
    try:
        logger.info("Starting expired image deletion task")
        cutoff_time = datetime.utcnow() - timedelta(hours=24)
        
        # Get expired images from database
        expired_images = db_service.get_expired_images(cutoff_time)
        
        deleted_count = 0
        for image in expired_images:
            try:
                # Delete from storage
                image_processor.delete_image(image["url"])
                # Update database
                db_service.mark_image_deleted(image["id"])
                deleted_count += 1
            except Exception as e:
                logger.error(f"Failed to delete image {image['id']}: {e}")
        
        logger.info(f"Deleted {deleted_count} expired images")
        return {"deleted_count": deleted_count}
        
    except Exception as e:
        logger.error(f"Image deletion task failed: {e}")
        raise

@celery_app.task
def send_streak_reminders():
    """
    Send push notifications to users who haven't checked in
    """
    try:
        logger.info("Starting streak reminder task")
        
        # Get users who haven't checked in today
        users_to_remind = db_service.get_users_for_reminder()
        
        sent_count = 0
        for user in users_to_remind:
            try:
                streak = db_service.get_streak(user["id"])
                notification_service.send_push_notification(
                    user_id=user["id"],
                    title="Don't Break Your Streak! 🔥",
                    body=f"You're on a {streak['current_streak']} day streak. Check in now!",
                    data={"type": "streak_reminder"}
                )
                sent_count += 1
            except Exception as e:
                logger.error(f"Failed to send reminder to user {user['id']}: {e}")
        
        logger.info(f"Sent {sent_count} streak reminders")
        return {"sent_count": sent_count}
        
    except Exception as e:
        logger.error(f"Streak reminder task failed: {e}")
        raise

@celery_app.task
def update_leaderboard():
    """
    Update leaderboard rankings
    """
    try:
        logger.info("Starting leaderboard update task")
        
        # Calculate weekly leaderboard
        weekly = db_service.calculate_leaderboard("weekly")
        # Calculate monthly leaderboard
        monthly = db_service.calculate_leaderboard("monthly")
        # Calculate all-time leaderboard
        all_time = db_service.calculate_leaderboard("all_time")
        
        # Store in cache
        db_service.update_leaderboard_cache({
            "weekly": weekly,
            "monthly": monthly,
            "all_time": all_time
        })
        
        logger.info("Leaderboard updated successfully")
        return {
            "weekly_count": len(weekly),
            "monthly_count": len(monthly),
            "all_time_count": len(all_time)
        }
        
    except Exception as e:
        logger.error(f"Leaderboard update failed: {e}")
        raise

@celery_app.task
def cleanup_privacy_logs():
    """
    Clean up old privacy logs (GDPR compliance)
    """
    try:
        logger.info("Starting privacy logs cleanup")
        
        # Keep logs for 90 days
        cutoff_date = datetime.utcnow() - timedelta(days=90)
        deleted_count = db_service.delete_old_privacy_logs(cutoff_date)
        
        logger.info(f"Deleted {deleted_count} old privacy logs")
        return {"deleted_count": deleted_count}
        
    except Exception as e:
        logger.error(f"Privacy logs cleanup failed: {e}")
        raise

@celery_app.task
def backup_database():
    """
    Create database backup
    """
    try:
        logger.info("Starting database backup")
        
        backup_file = f"backup_{datetime.utcnow().strftime('%Y%m%d_%H%M%S')}.sql"
        db_service.create_backup(backup_file)
        
        # Upload to cloud storage
        cloudinary_service.upload_backup(backup_file)
        
        logger.info(f"Database backup created: {backup_file}")
        return {"backup_file": backup_file}
        
    except Exception as e:
        logger.error(f"Database backup failed: {e}")
        raise

@celery_app.task
def sync_product_catalog():
    """
    Sync product catalog with suppliers
    """
    try:
        logger.info("Starting product catalog sync")
        
        # Fetch latest product data from suppliers
        updated_products = db_service.sync_products_with_suppliers()
        
        # Update prices and availability
        db_service.update_product_prices(updated_products)
        
        logger.info(f"Synced {len(updated_products)} products")
        return {"synced_count": len(updated_products)}
        
    except Exception as e:
        logger.error(f"Product catalog sync failed: {e}")
        raise

@celery_app.task
def process_analysis_batch(image_batch):
    """
    Process batch of images for analysis (for bulk operations)
    """
    try:
        logger.info(f"Processing batch of {len(image_batch)} images")
        
        from models.skin_analysis_model import SkinAnalysisModel
        model = SkinAnalysisModel()
        
        results = []
        for image_data in image_batch:
            try:
                result = model.analyze_skin(image_data["bytes"])
                results.append({
                    "user_id": image_data["user_id"],
                    "result": result
                })
            except Exception as e:
                logger.error(f"Failed to process image: {e}")
                results.append({
                    "user_id": image_data["user_id"],
                    "error": str(e)
                })
        
        return {"processed": len(results), "results": results}
        
    except Exception as e:
        logger.error(f"Batch processing failed: {e}")
        raise

@celery_app.task
def generate_recommendations_for_user(user_id):
    """
    Generate product recommendations for user
    """
    try:
        logger.info(f"Generating recommendations for user {user_id}")
        
        # Get user's latest analysis
        analysis = db_service.get_latest_analysis(user_id)
        
        if not analysis:
            return {"error": "No analysis found"}
        
        # Generate recommendations
        from models.cosmetics_matcher import CosmeticMatcher
        matcher = CosmeticMatcher()
        
        recommendations = matcher.find_matches(
            skin_tone=analysis["skin_tone"],
            conditions=analysis["conditions"]
        )
        
        # Store recommendations
        db_service.save_recommendations(user_id, recommendations)
        
        return {"user_id": user_id, "recommendations_count": len(recommendations)}
        
    except Exception as e:
        logger.error(f"Recommendation generation failed: {e}")
        raise

@celery_app.task
def send_onboarding_emails():
    """
    Send onboarding emails to new users
    """
    try:
        logger.info("Sending onboarding emails")
        
        # Get users who registered in last 24h and haven't received onboarding
        new_users = db_service.get_new_users_for_onboarding()
        
        sent_count = 0
        for user in new_users:
            try:
                notification_service.send_email(
                    to=user["email"],
                    subject="Welcome to Glow AI! ✨",
                    template="onboarding",
                    context={
                        "name": user["name"],
                        "get_started_link": "https://glowai.app/get-started"
                    }
                )
                db_service.mark_onboarding_email_sent(user["id"])
                sent_count += 1
            except Exception as e:
                logger.error(f"Failed to send onboarding email to {user['email']}: {e}")
        
        logger.info(f"Sent {sent_count} onboarding emails")
        return {"sent_count": sent_count}
        
    except Exception as e:
        logger.error(f"Onboarding email task failed: {e}")
        raise