import os
import json
import tempfile
import time
from typing import Dict, List, Optional, Any
from google.oauth2 import service_account
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
import streamlit as st
import ssl

def retry_on_ssl_error(max_retries=3, delay=1):
    """Decorator to retry functions on SSL errors"""
    def decorator(func):
        def wrapper(*args, **kwargs):
            for attempt in range(max_retries):
                try:
                    return func(*args, **kwargs)
                except (ssl.SSLError, ConnectionError, OSError) as e:
                    if attempt == max_retries - 1:
                        print(f"SSL/Connection error after {max_retries} attempts: {e}")
                        raise
                    print(f"SSL/Connection error (attempt {attempt + 1}/{max_retries}): {e}")
                    time.sleep(delay * (attempt + 1))  # Exponential backoff
                except Exception as e:
                    # Don't retry on other types of errors
                    raise
            return None
        return wrapper
    return decorator

class GoogleDriveManager:
    def __init__(self):
        self.service = None
        self.folder_id = None
        self.is_huggingface = os.getenv('SPACE_ID') is not None
        self.temp_dir = "/tmp/wedding_data" if self.is_huggingface else "temp_data"
        
        # Ensure temp directory exists
        os.makedirs(self.temp_dir, exist_ok=True)
        
    def initialize(self, folder_id: str = None):
        """Initialize Google Drive service and set folder ID"""
        try:
            if self.is_huggingface:
                self._setup_huggingface_auth()
            else:
                self._setup_local_auth()
            
            if folder_id:
                self.folder_id = folder_id
            else:
                # Try to get folder ID from environment
                self.folder_id = os.getenv('GOOGLE_DRIVE_FOLDER_ID')
            
            if not self.folder_id:
                st.error("Google Drive folder ID not found. Please set GOOGLE_DRIVE_FOLDER_ID environment variable.")
                return False
            
            return True
        except Exception as e:
            st.error(f"Failed to initialize Google Drive: {str(e)}")
            return False
    
    def _setup_huggingface_auth(self):
        """Set up authentication for Hugging Face Spaces"""
        # For Hugging Face, we'll use service account credentials
        # stored as environment variables
        service_account_info = {
            "type": "service_account",
            "project_id": os.getenv('GOOGLE_PROJECT_ID'),
            "private_key_id": os.getenv('GOOGLE_PRIVATE_KEY_ID'),
            "private_key": os.getenv('GOOGLE_PRIVATE_KEY', '').replace('\\n', '\n'),
            "client_email": os.getenv('GOOGLE_CLIENT_EMAIL'),
            "client_id": os.getenv('GOOGLE_CLIENT_ID'),
            "auth_uri": "https://accounts.google.com/o/oauth2/auth",
            "token_uri": "https://oauth2.googleapis.com/token",
            "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
            "client_x509_cert_url": f"https://www.googleapis.com/robot/v1/metadata/x509/{os.getenv('GOOGLE_CLIENT_EMAIL')}"
        }
        
        # Validate that all required fields are present
        required_fields = ['project_id', 'private_key_id', 'private_key', 'client_email', 'client_id']
        missing_fields = [field for field in required_fields if not service_account_info.get(field)]
        
        if missing_fields:
            raise ValueError(f"Missing Google service account credentials: {missing_fields}")
        
        credentials = service_account.Credentials.from_service_account_info(
            service_account_info,
            scopes=['https://www.googleapis.com/auth/drive']
        )
        
        self.service = build('drive', 'v3', credentials=credentials)
    
    def _setup_local_auth(self):
        """Set up authentication for local development"""
        # For local development, you can use OAuth or service account
        # This is a simplified version - you might want to implement OAuth flow
        service_account_path = os.getenv('GOOGLE_SERVICE_ACCOUNT_PATH')
        
        if service_account_path and os.path.exists(service_account_path):
            credentials = service_account.Credentials.from_service_account_file(
                service_account_path,
                scopes=['https://www.googleapis.com/auth/drive']
            )
            self.service = build('drive', 'v3', credentials=credentials)
        else:
            st.warning("Google service account file not found. Using local data only.")
            self.service = None
    
    @retry_on_ssl_error(max_retries=3, delay=1)
    def list_files(self) -> List[Dict[str, Any]]:
        """List all files in the Google Drive folder"""
        if not self.service or not self.folder_id:
            return []
        
        try:
            query = f"'{self.folder_id}' in parents and trashed=false"
            results = self.service.files().list(
                q=query,
                fields="files(id, name, modifiedTime, size)"
            ).execute()
            
            return results.get('files', [])
        except HttpError as e:
            st.error(f"Error listing files: {str(e)}")
            return []
    
    @retry_on_ssl_error(max_retries=3, delay=1)
    def download_file(self, file_name: str) -> Optional[Dict[str, Any]]:
        """Download a file from Google Drive and return its content"""
        if not self.service or not self.folder_id:
            return None
        
        try:
            # Handle subfolder paths like 'laraandumang/wedding_config.json'
            if '/' in file_name:
                folder_name, actual_file_name = file_name.split('/', 1)
                
                # First, find the subfolder
                folder_query = f"name='{folder_name}' and '{self.folder_id}' in parents and trashed=false and mimeType='application/vnd.google-apps.folder'"
                folder_results = self.service.files().list(q=folder_query).execute()
                folders = folder_results.get('files', [])
                
                if not folders:
                    st.warning(f"File '{file_name}' not found in Google Drive")
                    return None
                
                folder_id = folders[0]['id']
                
                # Now search for the file within that folder
                file_query = f"name='{actual_file_name}' and '{folder_id}' in parents and trashed=false"
                results = self.service.files().list(q=file_query).execute()
                files = results.get('files', [])
                
                if not files:
                    st.warning(f"File '{file_name}' not found in Google Drive")
                    return None
            else:
                # Direct file search in root folder
                query = f"name='{file_name}' and '{self.folder_id}' in parents and trashed=false"
                results = self.service.files().list(q=query).execute()
                files = results.get('files', [])
                
                if not files:
                    st.warning(f"File '{file_name}' not found in Google Drive")
                    return None
            
            file_id = files[0]['id']
            
            # Download file content
            request = self.service.files().get_media(fileId=file_id)
            content = request.execute()
            
            # Try to parse as JSON
            try:
                return json.loads(content.decode('utf-8'))
            except json.JSONDecodeError:
                # If not JSON, return as string
                return content.decode('utf-8')
                
        except HttpError as e:
            st.error(f"Error downloading file '{file_name}': {str(e)}")
            return None
    
    @retry_on_ssl_error(max_retries=3, delay=1)
    def upload_file(self, file_name: str, content: Any) -> bool:
        """Upload a file to Google Drive"""
        if not self.service or not self.folder_id:
            return False
        
        try:
            # Convert content to appropriate string format
            if isinstance(content, (dict, list)):
                if file_name.endswith('.yaml') or file_name.endswith('.yml'):
                    # For YAML files, convert to YAML string
                    import yaml
                    content_str = yaml.dump(content, default_flow_style=False, sort_keys=False)
                else:
                    # For JSON files, convert to JSON string
                    content_str = json.dumps(content, indent=2)
            else:
                content_str = str(content)
            
            # Convert string to bytes
            content_bytes = content_str.encode('utf-8')
            
            # Create a temporary file-like object
            from io import BytesIO
            media_body = BytesIO(content_bytes)
            
            # Determine MIME type based on file extension
            if file_name.endswith('.yaml') or file_name.endswith('.yml'):
                mimetype = 'text/yaml'
            else:
                mimetype = 'application/json'
            
            # Handle subfolder paths like 'laraandumang/wedding_config.json'
            target_folder_id = self.folder_id
            actual_file_name = file_name
            
            if '/' in file_name:
                folder_name, actual_file_name = file_name.split('/', 1)
                
                # First, find the subfolder
                folder_query = f"name='{folder_name}' and '{self.folder_id}' in parents and trashed=false and mimeType='application/vnd.google-apps.folder'"
                folder_results = self.service.files().list(q=folder_query).execute()
                folders = folder_results.get('files', [])
                
                if not folders:
                    # Create the subfolder if it doesn't exist
                    folder_metadata = {
                        'name': folder_name,
                        'mimeType': 'application/vnd.google-apps.folder',
                        'parents': [self.folder_id]
                    }
                    created_folder = self.service.files().create(
                        body=folder_metadata,
                        fields='id'
                    ).execute()
                    target_folder_id = created_folder.get('id')
                else:
                    target_folder_id = folders[0]['id']
            
            # Check if file already exists in the target folder
            query = f"name='{actual_file_name}' and '{target_folder_id}' in parents and trashed=false"
            results = self.service.files().list(q=query).execute()
            existing_files = results.get('files', [])
            
            if existing_files:
                # Update existing file
                file_id = existing_files[0]['id']
                from googleapiclient.http import MediaIoBaseUpload
                media = MediaIoBaseUpload(media_body, mimetype=mimetype, resumable=True)
                self.service.files().update(
                    fileId=file_id,
                    media_body=media
                ).execute()
            else:
                # Create new file
                file_metadata = {
                    'name': actual_file_name,
                    'parents': [target_folder_id]
                }
                from googleapiclient.http import MediaIoBaseUpload
                media = MediaIoBaseUpload(media_body, mimetype=mimetype, resumable=True)
                self.service.files().create(
                    body=file_metadata,
                    media_body=media
                ).execute()
            
            return True
            
        except HttpError as e:
            st.error(f"Error uploading file '{file_name}': {str(e)}")
            return False
        except Exception as e:
            st.error(f"Unexpected error uploading file '{file_name}': {str(e)}")
            return False
    
    def sync_from_drive(self, file_names: List[str]) -> Dict[str, Any]:
        """Download multiple files from Google Drive"""
        synced_files = {}
        
        for file_name in file_names:
            content = self.download_file(file_name)
            if content is not None:
                synced_files[file_name] = content
                # Save to local temp directory
                local_path = os.path.join(self.temp_dir, file_name)
                with open(local_path, 'w') as f:
                    if isinstance(content, (dict, list)):
                        json.dump(content, f, indent=2)
                    else:
                        f.write(str(content))
        
        return synced_files
    
    def sync_to_drive(self, file_names: List[str], local_data: Dict[str, Any]) -> bool:
        """Upload multiple files to Google Drive"""
        success = True
        
        for file_name in file_names:
            if file_name in local_data:
                if not self.upload_file(file_name, local_data[file_name]):
                    success = False
        
        return success
    
    def get_file_info(self, file_name: str) -> Optional[Dict[str, Any]]:
        """Get metadata for a specific file"""
        if not self.service or not self.folder_id:
            return None
        
        try:
            query = f"name='{file_name}' and '{self.folder_id}' in parents and trashed=false"
            results = self.service.files().list(q=query).execute()
            files = results.get('files', [])
            
            if files:
                return files[0]
            return None
            
        except HttpError as e:
            st.error(f"Error getting file info for '{file_name}': {str(e)}")
            return None
    
    def is_online(self) -> bool:
        """Check if Google Drive service is available"""
        return self.service is not None and self.folder_id is not None