"""Cloudflare R2 storage service for saving generated images."""

import os
import sys
from typing import Optional
from datetime import datetime
import uuid

# Add parent directory to path for imports
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

try:
    import boto3
    from botocore.exceptions import ClientError, BotoCoreError
    BOTO3_AVAILABLE = True
except ImportError:
    BOTO3_AVAILABLE = False
    print("Warning: boto3 not installed. R2 storage will not be available.")

from config import settings


class R2StorageService:
    """Service for uploading images to Cloudflare R2."""
    
    def __init__(self):
        """Initialize R2 client."""
        if not BOTO3_AVAILABLE:
            raise ImportError("boto3 is required for R2 storage. Install it with: pip install boto3")
        
        if not all([
            settings.r2_endpoint,
            settings.r2_bucket_name,
            settings.r2_access_key,
            settings.r2_secret_key,
        ]):
            raise ValueError("R2 credentials not configured. Please set R2_ENDPOINT, R2_BUCKET_NAME, R2_ACCESS_KEY, and R2_SECRET_KEY in .env")
        
        # Initialize S3-compatible client for R2
        self.s3_client = boto3.client(
            's3',
            endpoint_url=settings.r2_endpoint,
            aws_access_key_id=settings.r2_access_key,
            aws_secret_access_key=settings.r2_secret_key,
            region_name='auto',  # R2 doesn't use regions
        )
        self.bucket_name = settings.r2_bucket_name
        self.folder = "psyadgenesis"
    
    def upload_image(
        self,
        image_bytes: bytes,
        filename: Optional[str] = None,
        niche: Optional[str] = None,
    ) -> str:
        """
        Upload image to R2.
        
        Args:
            image_bytes: Image file bytes
            filename: Optional filename (if not provided, generates one)
            niche: Optional niche name for filename generation
            
        Returns:
            Public URL of the uploaded image
        """
        # Generate filename if not provided
        if not filename:
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            unique_id = str(uuid.uuid4())[:8]
            niche_prefix = niche or "ad"
            filename = f"{niche_prefix}_{timestamp}_{unique_id}.png"
        
        # Construct R2 key (path in bucket)
        r2_key = f"{self.folder}/{filename}"
        
        try:
            # Upload to R2
            # Note: R2 doesn't support ACL parameter, use custom domain or presigned URLs for public access
            self.s3_client.put_object(
                Bucket=self.bucket_name,
                Key=r2_key,
                Body=image_bytes,
                ContentType='image/png',
            )
            
            # Construct public URL
            # R2 public URLs work best with a custom domain
            # If custom domain is set via R2_PUBLIC_DOMAIN, use it
            # Otherwise, generate a presigned URL (valid for 1 year)
            # Note: R2 presigned URLs from boto3 include bucket name in path, which is correct for R2
            if hasattr(settings, 'r2_public_domain') and settings.r2_public_domain:
                public_url = f"https://{settings.r2_public_domain}/{r2_key}"
            else:
                # Generate presigned URL (valid for 1 week - R2 maximum)
                # R2 presigned URLs include bucket name in path - this is correct for R2
                # R2 limits presigned URLs to max 1 week (604800 seconds)
                public_url = self.s3_client.generate_presigned_url(
                    'get_object',
                    Params={'Bucket': self.bucket_name, 'Key': r2_key},
                    ExpiresIn=604800  # 1 week (R2 maximum)
                )
            
            print(f"Successfully uploaded image to R2: {r2_key}")
            print(f"R2 URL: {public_url}")
            return public_url
            
        except (ClientError, BotoCoreError) as e:
            print(f"Error uploading to R2: {e}")
            raise Exception(f"Failed to upload image to R2: {str(e)}")
    
    def get_public_url(self, filename: str) -> str:
        """
        Get public URL for an image in R2.
        
        Args:
            filename: Filename in R2
            
        Returns:
            Public URL
        """
        r2_key = f"{self.folder}/{filename}"
        
        if hasattr(settings, 'r2_public_domain') and settings.r2_public_domain:
            return f"https://{settings.r2_public_domain}/{r2_key}"
        else:
            # Generate presigned URL (valid for 1 week - R2 maximum)
            # R2 presigned URLs include bucket name in path - this is correct for R2
            # R2 limits presigned URLs to max 1 week (604800 seconds)
            return self.s3_client.generate_presigned_url(
                'get_object',
                Params={'Bucket': self.bucket_name, 'Key': r2_key},
                ExpiresIn=604800  # 1 week (R2 maximum)
            )


# Global instance (will be None if R2 not configured)
r2_storage: Optional[R2StorageService] = None

def get_r2_storage() -> Optional[R2StorageService]:
    """Get R2 storage service instance, creating it if needed."""
    global r2_storage
    
    if r2_storage is None:
        try:
            r2_storage = R2StorageService()
        except (ImportError, ValueError) as e:
            print(f"R2 storage not available: {e}")
            return None
    
    return r2_storage