#!/usr/bin/env python3
"""
Signal Bridge for Alertmanager
Receives webhooks from Alertmanager and forwards to Signal API
"""

import os
import json
import requests
from flask import Flask, request, jsonify

app = Flask(__name__)

# Configuration from environment variables
SIGNAL_API_URL = os.environ.get('SIGNAL_API_URL', 'http://signal-api:8080')
SIGNAL_SENDER = os.environ.get('SIGNAL_SENDER', '')  # Your Signal number
SIGNAL_RECIPIENTS = os.environ.get('SIGNAL_RECIPIENTS', '').split(',')  # Comma-separated

def format_alert_message(alert_data):
    """Format Alertmanager webhook payload into a readable message"""
    messages = []

    status = alert_data.get('status', 'unknown')

    for alert in alert_data.get('alerts', []):
        alert_status = alert.get('status', status)
        labels = alert.get('labels', {})
        annotations = alert.get('annotations', {})

        severity = labels.get('severity', 'unknown')
        alertname = labels.get('alertname', 'Unknown Alert')
        instance = labels.get('instance', 'unknown')

        summary = annotations.get('summary', alertname)
        description = annotations.get('description', '')

        # Status emoji
        if alert_status == 'resolved':
            status_emoji = '✅'
            status_text = 'RESOLVED'
        elif severity == 'critical':
            status_emoji = '🚨'
            status_text = 'CRITICAL'
        else:
            status_emoji = '⚠️'
            status_text = 'WARNING'

        msg = f"{status_emoji} [{status_text}] {summary}"
        if description:
            msg += f"\n{description}"

        messages.append(msg)

    return "\n\n".join(messages)

def send_signal_message(message):
    """Send message via Signal API"""
    if not SIGNAL_SENDER or not SIGNAL_RECIPIENTS:
        app.logger.error("Signal sender or recipients not configured")
        return False

    success = True
    for recipient in SIGNAL_RECIPIENTS:
        recipient = recipient.strip()
        if not recipient:
            continue

        try:
            payload = {
                "message": message,
                "number": SIGNAL_SENDER,
                "recipients": [recipient]
            }

            response = requests.post(
                f"{SIGNAL_API_URL}/v2/send",
                json=payload,
                timeout=30
            )

            if response.status_code in [200, 201]:
                app.logger.info(f"Message sent to {recipient}")
            else:
                app.logger.error(f"Failed to send to {recipient}: {response.status_code} - {response.text}")
                success = False

        except Exception as e:
            app.logger.error(f"Error sending to {recipient}: {e}")
            success = False

    return success

@app.route('/health', methods=['GET'])
def health():
    return jsonify({"status": "healthy"}), 200

@app.route('/alert', methods=['POST'])
def receive_alert():
    """Receive alert from Alertmanager and forward to Signal"""
    try:
        alert_data = request.get_json()

        if not alert_data:
            return jsonify({"error": "No data received"}), 400

        app.logger.info(f"Received alert: {json.dumps(alert_data, indent=2)}")

        message = format_alert_message(alert_data)

        if send_signal_message(message):
            return jsonify({"status": "sent"}), 200
        else:
            return jsonify({"status": "partial_failure"}), 207

    except Exception as e:
        app.logger.error(f"Error processing alert: {e}")
        return jsonify({"error": str(e)}), 500

@app.route('/test', methods=['POST'])
def test_message():
    """Send a test message"""
    message = request.json.get('message', '🧪 Test alert from Signal Bridge')

    if send_signal_message(message):
        return jsonify({"status": "sent"}), 200
    else:
        return jsonify({"status": "failed"}), 500

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)