"""
Cloudflare R2 Storage Service
Handles all interactions with R2 bucket for templates and converted resumes
"""
import boto3
from botocore.client import Config
from typing import List, Dict, Optional
from datetime import datetime
import io
import socket
from app.core.config import settings

# Force IPv4 to avoid Docker IPv6 issues
original_getaddrinfo = socket.getaddrinfo

def getaddrinfo_ipv4_only(host, port, family=0, type=0, proto=0, flags=0):
    """Force IPv4 resolution only"""
    return original_getaddrinfo(host, port, socket.AF_INET, type, proto, flags)

socket.getaddrinfo = getaddrinfo_ipv4_only


class R2Service:
    """Service for interacting with Cloudflare R2 storage"""
    
    def __init__(self):
        """Initialize R2 client with credentials from settings"""
        self.s3_client = boto3.client(
            's3',
            endpoint_url=settings.R2_ENDPOINT,
            aws_access_key_id=settings.R2_ACCESS_KEY_ID,
            aws_secret_access_key=settings.R2_SECRET_ACCESS_KEY,
            config=Config(
                signature_version='s3v4',
                s3={'addressing_style': 'path'}
            ),
            region_name='auto'
        )
        self.bucket_name = settings.R2_BUCKET_NAME
        self.templates_prefix = "templates/"
        self.converted_prefix = "converted_resumes/"
    
    def list_templates(self) -> List[str]:
        """
        List all available template names from R2
        Returns: List of template names (without .html extension)
        """
        try:
            print(f"Attempting to list templates from bucket: {self.bucket_name}, prefix: {self.templates_prefix}")
            print(f"Using endpoint: {settings.R2_ENDPOINT}")
            
            response = self.s3_client.list_objects_v2(
                Bucket=self.bucket_name,
                Prefix=self.templates_prefix
            )
            
            print(f"R2 Response: {response}")
            
            if 'Contents' not in response:
                print(f"No contents found in bucket with prefix {self.templates_prefix}")
                return []
            
            templates = []
            for obj in response['Contents']:
                key = obj['Key']
                # Extract template name (remove prefix and .html extension)
                if key.endswith('.html'):
                    template_name = key.replace(self.templates_prefix, '').replace('.html', '')
                    if template_name:  # Skip if empty (i.e., if key was just the prefix)
                        templates.append(template_name)
            
            print(f"Found templates: {templates}")
            return templates
        except Exception as e:
            print(f"Error listing templates: {e}")
            import traceback
            traceback.print_exc()
            return []
    
    def get_template_content(self, template_name: str) -> Optional[str]:
        """
        Get the HTML content of a specific template
        Args:
            template_name: Name of the template (without .html extension)
        Returns: HTML content as string, or None if not found
        """
        try:
            key = f"{self.templates_prefix}{template_name}.html"
            response = self.s3_client.get_object(
                Bucket=self.bucket_name,
                Key=key
            )
            content = response['Body'].read().decode('utf-8')
            return content
        except Exception as e:
            print(f"Error getting template content for {template_name}: {e}")
            return None
    
    def upload_converted_file(
        self, 
        file_content: bytes, 
        filename: str, 
        content_type: str,
        metadata: Optional[Dict[str, str]] = None
    ) -> Optional[str]:
        """
        Upload a converted resume file to R2
        Args:
            file_content: File content as bytes
            filename: Name of the file
            content_type: MIME type (text/html or application/pdf)
            metadata: Optional metadata dict
        Returns: Public URL of uploaded file, or None if failed
        """
        try:
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            key = f"{self.converted_prefix}{timestamp}_{filename}"
            
            upload_args = {
                'Bucket': self.bucket_name,
                'Key': key,
                'Body': file_content,
                'ContentType': content_type
            }
            
            if metadata:
                upload_args['Metadata'] = metadata
            
            self.s3_client.put_object(**upload_args)
            
            # Generate public URL
            url = f"{settings.R2_ENDPOINT}/{self.bucket_name}/{key}"
            return url
        except Exception as e:
            print(f"Error uploading file {filename}: {e}")
            return None
    
    def list_converted_resumes(self, limit: int = 50) -> List[Dict]:
        """
        List converted resumes from R2
        Args:
            limit: Maximum number of files to return
        Returns: List of dicts with file metadata
        """
        try:
            response = self.s3_client.list_objects_v2(
                Bucket=self.bucket_name,
                Prefix=self.converted_prefix,
                MaxKeys=limit
            )
            
            if 'Contents' not in response:
                return []
            
            files = []
            for obj in response['Contents']:
                key = obj['Key']
                # Skip directory markers
                if key.endswith('/'):
                    continue
                
                filename = key.replace(self.converted_prefix, '')
                file_url = f"{settings.R2_ENDPOINT}/{self.bucket_name}/{key}"
                
                files.append({
                    'id': key,
                    'name': filename,
                    'url': file_url,
                    'size': obj['Size'],
                    'lastModified': obj['LastModified'].isoformat(),
                    'timestamp': obj['LastModified']
                })
            
            # Sort by timestamp, newest first
            files.sort(key=lambda x: x['timestamp'], reverse=True)
            
            return files
        except Exception as e:
            print(f"Error listing converted resumes: {e}")
            return []
    
    def get_file_url(self, key: str, expires_in: int = 3600) -> Optional[str]:
        """
        Generate a presigned URL for a file
        Args:
            key: Object key in R2
            expires_in: URL expiration time in seconds (default 1 hour)
        Returns: Presigned URL or None if failed
        """
        try:
            url = self.s3_client.generate_presigned_url(
                'get_object',
                Params={'Bucket': self.bucket_name, 'Key': key},
                ExpiresIn=expires_in
            )
            return url
        except Exception as e:
            print(f"Error generating presigned URL for {key}: {e}")
            return None


# Singleton instance
r2_service = R2Service()