import os
import msal
import requests
import base64

# Graph API Konfiguration (aus .env laden)
CLIENT_ID = os.getenv("AZURE_CLIENT_ID")
CLIENT_SECRET = os.getenv("AZURE_CLIENT_SECRET")
TENANT_ID = os.getenv("AZURE_TENANT_ID")
AUTHORITY = f"https://login.microsoftonline.com/{TENANT_ID}"
SCOPE = ["https://graph.microsoft.com/.default"]

SENDER_EMAIL = "info@robo-planet.de"

def get_access_token():
    """Holt ein Token für die Graph API."""
    app = msal.ConfidentialClientApplication(
        CLIENT_ID, authority=AUTHORITY, client_credential=CLIENT_SECRET
    )
    result = app.acquire_token_for_client(scopes=SCOPE)
    if "access_token" in result:
        return result["access_token"]
    else:
        raise Exception(f"Fehler beim Abrufen des Tokens: {result.get('error_description')}")

def send_email_via_graph(to_email, subject, body_html, banner_path=None):
    """
    Sendet eine E-Mail über die Microsoft Graph API.
    """
    token = get_access_token()
    headers = {
        "Authorization": f"Bearer {token}",
        "Content-Type": "application/json"
    }
    
    # E-Mail Struktur für Graph API
    email_msg = {
        "message": {
            "subject": subject,
            "body": {
                "contentType": "HTML",
                "content": body_html
            },
            "toRecipients": [
                {
                    "emailAddress": {
                        "address": to_email
                    }
                }
            ],
            "from": {
                "emailAddress": {
                    "address": SENDER_EMAIL
                }
            }
        },
        "saveToSentItems": "true"
    }

    # Optional: Banner-Bild als Inline-Attachment einfügen
    if banner_path and os.path.exists(banner_path):
        with open(banner_path, "rb") as f:
            content_bytes = f.read()
            content_b64 = base64.b64encode(content_bytes).decode("utf-8")
            
        email_msg["message"]["attachments"] = [
            {
                "@odata.type": "#microsoft.graph.fileAttachment",
                "name": "banner.png",
                "contentBytes": content_b64,
                "isInline": True,
                "contentId": "banner_image"
            }
        ]

    endpoint = f"https://graph.microsoft.com/v1.0/users/{SENDER_EMAIL}/sendMail"
    
    response = requests.post(endpoint, headers=headers, json=email_msg)
    
    if response.status_code == 202:
        print(f"E-Mail erfolgreich an {to_email} gesendet.")
        return True
    else:
        print(f"Fehler beim Senden: {response.status_code} - {response.text}")
        return False