"""
Object Storage Service for FTC Team Website
Handles persistent file uploads using Google Cloud Storage (Replit Object Storage)
"""

from google.cloud import storage
from google.auth import identity_pool
import os
import json
from uuid import uuid4
from werkzeug.utils import secure_filename

REPLIT_SIDECAR_ENDPOINT = "http://127.0.0.1:1106"


def get_replit_credentials():
    """Create proper credentials for Replit Object Storage"""
    credentials_config = {
        "audience": "replit",
        "subject_token_type": "access_token",
        "token_url": f"{REPLIT_SIDECAR_ENDPOINT}/token",
        "type": "external_account",
        "credential_source": {
            "url": f"{REPLIT_SIDECAR_ENDPOINT}/credential",
            "format": {
                "type": "json",
                "subject_token_field_name": "access_token",
            },
        },
        "universe_domain": "googleapis.com",
    }
    
    credentials = identity_pool.Credentials.from_info(credentials_config)
    return credentials


class ObjectStorageService:
    def __init__(self):
        """Initialize the object storage client with Replit credentials"""
        credentials = get_replit_credentials()
        self.client = storage.Client(
            credentials=credentials,
            project="",
        )
        
        self.bucket_name = os.environ.get('OBJECT_STORAGE_BUCKET')
        if not self.bucket_name:
            raise ValueError(
                "OBJECT_STORAGE_BUCKET environment variable not set. "
                "Please create a bucket in the Object Storage pane and set this variable."
            )
        
        self.bucket = self.client.bucket(self.bucket_name)
    
    def upload_file(self, file, folder='uploads'):
        """
        Upload a file to object storage
        
        Args:
            file: Werkzeug FileStorage object
            folder: Folder name in the bucket (default: 'uploads')
        
        Returns:
            str: Public URL of the uploaded file
        """
        if not file or not file.filename:
            return None
        
        original_filename = secure_filename(file.filename)
        file_extension = os.path.splitext(original_filename)[1]
        unique_filename = f"{uuid4()}{file_extension}"
        object_name = f"{folder}/{unique_filename}"
        
        blob = self.bucket.blob(object_name)
        blob.upload_from_file(
            file.stream,
            content_type=file.content_type or 'application/octet-stream'
        )
        
        blob.make_public()
        
        return blob.public_url
    
    def get_blob(self, url):
        """Get a blob object from a URL"""
        if not url or not url.startswith('https://storage.googleapis.com/'):
            return None
        
        parts = url.replace(f'https://storage.googleapis.com/{self.bucket_name}/', '')
        return self.bucket.blob(parts)
    
    def delete_file(self, url):
        """Delete a file from object storage"""
        blob = self.get_blob(url)
        if blob and blob.exists():
            blob.delete()
            return True
        return False