import os
import logging
import google_auth_oauthlib.flow
import googleapiclient.discovery
import googleapiclient.http

logger = logging.getLogger(__name__)

# Load Google OAuth config from environment variables
GOOGLE_OAUTH_CONFIG = {
    "web": {
        "client_id": os.environ.get("GOOGLE_CLIENT_ID"),
        "project_id": os.environ.get("GOOGLE_PROJECT_ID"),
        "auth_uri": os.environ.get("GOOGLE_AUTH_URI", "https://accounts.google.com/o/oauth2/auth"),
        "token_uri": os.environ.get("GOOGLE_TOKEN_URI", "https://oauth2.googleapis.com/token"),
        "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
        "client_secret": os.environ.get("GOOGLE_CLIENT_SECRET"),
        "redirect_uris": [os.environ.get("GOOGLE_REDIRECT_URI")]
    }
}

def get_google_auth_url():
    """Generate URL for Google Auth"""
    client_config = GOOGLE_OAUTH_CONFIG["web"]
    flow = google_auth_oauthlib.flow.Flow.from_client_config(
        {"web": client_config},
        scopes=["https://www.googleapis.com/auth/drive.file"]
    )
    flow.redirect_uri = client_config["redirect_uris"][0]
    authorization_url, _ = flow.authorization_url(
        access_type="offline",
        include_granted_scopes="true",
        prompt="consent"
    )
    return authorization_url

def exchange_code_for_credentials(auth_code):
    """Exchange authorization code for credentials"""
    if not auth_code.strip():
        return None, "No code provided."
    try:
        client_config = GOOGLE_OAUTH_CONFIG["web"]
        flow = google_auth_oauthlib.flow.Flow.from_client_config(
            {"web": client_config},
            scopes=["https://www.googleapis.com/auth/drive.file"]
        )
        flow.redirect_uri = client_config["redirect_uris"][0]
        flow.fetch_token(code=auth_code.strip())
        creds = flow.credentials
        if not creds or not creds.valid:
            return None, "Could not validate credentials. Check code and try again."
        return creds, "Google Sign-In successful!"
    except Exception as e:
        return None, f"Error during token exchange: {e}"

def google_drive_upload(file_path, credentials, folder_id=None):
    """Upload a file to Google Drive"""
    try:
        drive_service = googleapiclient.discovery.build("drive", "v3", credentials=credentials)
        file_metadata = {'name': os.path.basename(file_path)}
        if folder_id:
            file_metadata['parents'] = [folder_id]
        media = googleapiclient.http.MediaFileUpload(file_path, resumable=True)
        created = drive_service.files().create(body=file_metadata, media_body=media, fields='id').execute()
        return created.get("id", "")
    except Exception as e:
        return f"Error uploading to Drive: {str(e)}"

def create_drive_folder(drive_service, name):
    """Create a folder in Google Drive"""
    folder_metadata = {'name': name, 'mimeType': 'application/vnd.google-apps.folder'}
    folder = drive_service.files().create(body=folder_metadata, fields='id').execute()
    return folder.get('id')