#!/usr/bin/env python3
"""GitHub Webhook Listener for Auto-Pull on Push."""

import hmac
import hashlib
import json
import os
import subprocess
from http.server import BaseHTTPRequestHandler, HTTPServer

PORT = int(os.environ.get("WEBHOOK_PORT", 9000))
SECRET = os.environ.get("WEBHOOK_SECRET", "").encode("utf-8")
REPO_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

class WebhookHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        if self.path != "/webhook":
            self.send_response(404)
            self.end_headers()
            return

        content_length = int(self.headers.get("Content-Length", 0))
        body = self.rfile.read(content_length)

        if SECRET:
            signature = self.headers.get("X-Hub-Signature-256", "")
            expected = "sha256=" + hmac.new(SECRET, body, hashlib.sha256).hexdigest()
            if not hmac.compare_digest(signature, expected):
                self.send_response(403)
                self.end_headers()
                self.wfile.write(b"Invalid signature\n")
                return

        event = self.headers.get("X-GitHub-Event", "push")
        if event == "push":
            print("[Webhook] Received push event. Pulling latest code...")
            try:
                result = subprocess.run(
                    ["git", "pull", "origin", "main"],
                    cwd=REPO_DIR,
                    capture_output=True,
                    text=True,
                    check=True,
                )
                output = result.stdout
                print(f"[Webhook] Git pull success:\n{output}")
                self.send_response(200)
                self.end_headers()
                self.wfile.write(f"Updated successfully:\n{output}".encode("utf-8"))
            except subprocess.CalledProcessError as err:
                error_msg = f"Git pull failed:\n{err.stderr}"
                print(f"[Webhook] {error_msg}")
                self.send_response(500)
                self.end_headers()
                self.wfile.write(error_msg.encode("utf-8"))
        else:
            self.send_response(200)
            self.end_headers()
            self.wfile.write(f"Ignored event: {event}\n".encode("utf-8"))

def main():
    server = HTTPServer(("0.0.0.0", PORT), WebhookHandler)
    print(f"🚀 GitHub Webhook listener running on http://0.0.0.0:{PORT}/webhook")
    server.serve_forever()

if __name__ == "__main__":
    main()