zoom_plugin/webhook_handler.py

"""
Deepfake Hunter - Zoom Webhook Handler

Handles Zoom meeting webhooks and processes video streams for deepfake detection.

Author: Deepfake Hunter Team
License: MIT
"""

import os
import json
import hmac
import hashlib
from typing import Dict, Any, Optional
from datetime import datetime

from fastapi import FastAPI, Request, HTTPException, Header
from pydantic import BaseModel
import uvicorn
from loguru import logger

# Initialize FastAPI
app = FastAPI(title="Deepfake Hunter - Zoom Webhook Handler")

# Configuration
ZOOM_WEBHOOK_SECRET = os.getenv("ZOOM_WEBHOOK_SECRET", "your-zoom-webhook-secret")
ZOOM_VERIFICATION_TOKEN = os.getenv("ZOOM_VERIFICATION_TOKEN", "your-zoom-verification-token")
API_BASE_URL = os.getenv("DEEPFAKE_API_URL", "http://localhost:8001")
API_KEY = os.getenv("DEEPFAKE_API_KEY", "your-secret-api-key")

# Store active meeting sessions
active_meetings = {}


class ZoomWebhookEvent(BaseModel):
    """Zoom webhook event model"""
    event: str
    payload: Dict[str, Any]


def verify_zoom_webhook(
    request_body: bytes,
    signature: str,
    timestamp: str
) -> bool:
    """
    Verify Zoom webhook signature

    Args:
        request_body: Raw request body
        signature: X-Zm-Signature header
        timestamp: X-Zm-Request-Timestamp header

    Returns:
        True if signature is valid
    """
    # Create message to hash
    message = f"v0:{timestamp}:".encode('utf-8') + request_body

    # Calculate expected signature
    expected_signature = hmac.new(
        ZOOM_WEBHOOK_SECRET.encode('utf-8'),
        message,
        hashlib.sha256
    ).hexdigest()

    expected_signature = f"v0={expected_signature}"

    return hmac.compare_digest(expected_signature, signature)


@app.get("/health")
async def health_check():
    """Health check endpoint"""
    return {
        "status": "healthy",
        "service": "Deepfake Hunter Zoom Webhook Handler",
        "active_meetings": len(active_meetings)
    }


@app.post("/zoom/webhook")
async def handle_zoom_webhook(
    request: Request,
    x_zm_signature: Optional[str] = Header(None),
    x_zm_request_timestamp: Optional[str] = Header(None)
):
    """
    Handle Zoom webhook events

    Processes meeting events and triggers deepfake analysis for video streams.
    """
    try:
        # Get raw body for signature verification
        body = await request.body()

        # Verify webhook signature (in production)
        if x_zm_signature and x_zm_request_timestamp:
            if not verify_zoom_webhook(body, x_zm_signature, x_zm_request_timestamp):
                logger.warning("Invalid webhook signature")
                raise HTTPException(status_code=401, detail="Invalid signature")

        # Parse event
        event_data = json.loads(body)

        event_type = event_data.get("event")
        payload = event_data.get("payload", {})

        logger.info(f"Received Zoom event: {event_type}")

        # Handle different event types
        if event_type == "endpoint.url_validation":
            # Respond to URL validation
            return handle_url_validation(payload)

        elif event_type == "meeting.started":
            return await handle_meeting_started(payload)

        elif event_type == "meeting.participant_joined":
            return await handle_participant_joined(payload)

        elif event_type == "meeting.ended":
            return await handle_meeting_ended(payload)

        else:
            logger.info(f"Unhandled event type: {event_type}")
            return {"status": "ok"}

    except Exception as e:
        logger.error(f"Webhook handler error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


def handle_url_validation(payload: Dict[str, Any]) -> Dict[str, str]:
    """
    Handle Zoom URL validation challenge

    Args:
        payload: Event payload with challenge

    Returns:
        Response with encrypted token
    """
    plain_token = payload.get("plainToken")

    if not plain_token:
        raise HTTPException(status_code=400, detail="Missing plainToken")

    # Encrypt token with webhook secret
    encrypted_token = hmac.new(
        ZOOM_WEBHOOK_SECRET.encode('utf-8'),
        plain_token.encode('utf-8'),
        hashlib.sha256
    ).hexdigest()

    return {
        "plainToken": plain_token,
        "encryptedToken": encrypted_token
    }


async def handle_meeting_started(payload: Dict[str, Any]) -> Dict[str, str]:
    """
    Handle meeting started event

    Initializes deepfake detection for the meeting.
    """
    meeting_id = payload.get("object", {}).get("id")
    meeting_topic = payload.get("object", {}).get("topic", "Unknown")

    logger.info(f"Meeting started: {meeting_id} - {meeting_topic}")

    # Initialize meeting session
    active_meetings[meeting_id] = {
        "topic": meeting_topic,
        "started_at": datetime.now().isoformat(),
        "participants": {},
        "alerts": []
    }

    return {"status": "meeting_monitoring_started"}


async def handle_participant_joined(payload: Dict[str, Any]) -> Dict[str, str]:
    """
    Handle participant joined event

    Starts deepfake analysis for the participant's video stream.
    """
    meeting_id = payload.get("object", {}).get("id")
    participant = payload.get("object", {}).get("participant", {})
    participant_id = participant.get("id")
    participant_name = participant.get("user_name", "Unknown")

    logger.info(f"Participant joined: {participant_name} in meeting {meeting_id}")

    if meeting_id not in active_meetings:
        active_meetings[meeting_id] = {
            "participants": {},
            "alerts": []
        }

    # Initialize participant tracking
    active_meetings[meeting_id]["participants"][participant_id] = {
        "name": participant_name,
        "joined_at": datetime.now().isoformat(),
        "deepfake_scores": [],
        "is_suspicious": False,
        "analysis_count": 0
    }

    # Note: Actual video stream analysis would be triggered here
    # For now, this is a placeholder
    # In production, you would:
    # 1. Subscribe to participant's video stream
    # 2. Periodically capture frames
    # 3. Send frames to deepfake detection API
    # 4. Update participant's deepfake_scores
    # 5. Alert host if scores consistently high

    logger.info(f"Started monitoring participant: {participant_name}")

    return {"status": "participant_monitoring_started"}


async def handle_meeting_ended(payload: Dict[str, Any]) -> Dict[str, str]:
    """
    Handle meeting ended event

    Cleanup and generate final report.
    """
    meeting_id = payload.get("object", {}).get("id")

    logger.info(f"Meeting ended: {meeting_id}")

    if meeting_id in active_meetings:
        meeting_data = active_meetings[meeting_id]

        # Generate summary
        total_participants = len(meeting_data["participants"])
        suspicious_count = sum(
            1 for p in meeting_data["participants"].values()
            if p.get("is_suspicious", False)
        )

        logger.info(
            f"Meeting summary - Total participants: {total_participants}, "
            f"Suspicious: {suspicious_count}"
        )

        # Cleanup
        del active_meetings[meeting_id]

    return {"status": "meeting_monitoring_ended"}


@app.post("/zoom/analyze_participant")
async def analyze_participant(
    meeting_id: str,
    participant_id: str,
    frame_data: str
):
    """
    Analyze participant video frame

    Args:
        meeting_id: Zoom meeting ID
        participant_id: Participant ID
        frame_data: Base64-encoded frame data

    Returns:
        Analysis results
    """
    # This endpoint would be called periodically to analyze participant frames
    # Implementation would:
    # 1. Decode frame data
    # 2. Send to deepfake detection API
    # 3. Update participant scores
    # 4. Generate alerts if needed

    logger.info(f"Analyzing participant {participant_id} in meeting {meeting_id}")

    # Placeholder response
    return {
        "meeting_id": meeting_id,
        "participant_id": participant_id,
        "is_deepfake": False,
        "confidence": 0.0,
        "timestamp": datetime.now().isoformat()
    }


@app.get("/zoom/meetings")
async def get_active_meetings():
    """Get list of active meetings being monitored"""
    return {
        "active_meetings": len(active_meetings),
        "meetings": {
            meeting_id: {
                "topic": data.get("topic", "Unknown"),
                "participants": len(data.get("participants", {})),
                "alerts": len(data.get("alerts", []))
            }
            for meeting_id, data in active_meetings.items()
        }
    }


@app.get("/zoom/meeting/{meeting_id}")
async def get_meeting_details(meeting_id: str):
    """Get details for specific meeting"""
    if meeting_id not in active_meetings:
        raise HTTPException(status_code=404, detail="Meeting not found")

    return active_meetings[meeting_id]


if __name__ == "__main__":
    logger.info("Starting Deepfake Hunter Zoom Webhook Handler...")

    uvicorn.run(
        app,
        host="0.0.0.0",
        port=8002,
        log_level="info"
    )