#!/usr/bin/env python3

import sys
sys.path.insert(0, '/usr/local/bin')

import json
import logging
from http.server import HTTPServer, BaseHTTPRequestHandler
from typing import Dict

from alerts.matrix import send_matrix
from alerts.grafana import process_grafana
from alerts.pbs import detect_backup_source, process_backup
from alerts.config import PORT

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger(__name__)


class WebhookHandler(BaseHTTPRequestHandler):
    def log_message(self, format, *args):
        logger.info("%s - %s", self.address_string(), format % args)

    def do_POST(self):
        try:
            content_length = int(self.headers.get('Content-Length', 0))
            body = self.rfile.read(content_length).decode('utf-8')

            try:
                obj = json.loads(body)
            except json.JSONDecodeError as e:
                logger.error("JSON parse error: %s", e)
                self.send_error(400, "Invalid JSON")
                return

            self.process_webhook(obj)
            self.send_response(200)
            self.send_header('Content-Type', 'text/plain')
            self.end_headers()
            self.wfile.write(b"OK")

        except Exception as e:
            logger.exception("Error processing request")
            self.send_error(500, "Internal Server Error")

    def process_webhook(self, obj: Dict) -> None:
        source = detect_backup_source(obj)
        if source:
            logger.info("Processing backup notification (source=%s)", source.value)
            process_backup(obj, send_matrix, source)
            return

        if "alerts" in obj:
            alerts = obj["alerts"]
            logger.info("Processing Grafana alerts: %d items", len(alerts))
            process_grafana({"alerts": alerts}, send_matrix)
            return

        logger.warning("Unknown webhook type")
        send_matrix(
            "<b>Webhook received</b><br><br><pre>" +
            json.dumps(obj, ensure_ascii=False, indent=2) +
            "</pre>"
        )


def main():
    server = HTTPServer(("0.0.0.0", PORT), WebhookHandler)
    logger.info("Matrix Relay started on port %s", PORT)

    try:
        server.serve_forever()
    except KeyboardInterrupt:
        logger.info("Shutting down...")
        server.shutdown()


if __name__ == "__main__":
    main()