"""
This module contains a Lambda function that checks if domains are reachable and retrieves SSL information.
Amazon will bill for the wait time of this function, timeout is set to 10 seconds.
TODO: Implement a loop with asynchronous checking of multiple domains.
"""

import requests
import ssl
import socket
from datetime import datetime

def lambda_handler(event, context):
    """
    Args:
        event (dict):
            The event data passed to the Lambda function. Expects a dictionary
            with a "hostnames" key containing a list of all hosts to be checked.
        context (LambdaContext):
            The runtime information of the Lambda function.
    """
    max_timeout = 10
    remaining_time_in_seconds = context.get_remaining_time_in_millis() / 1000
    timeout_in_seconds = min(remaining_time_in_seconds - 1, max_timeout)
    results = {}
    for hostname in event["hostnames"]:
        url = f"https://{hostname}/"
        host_result = {}
        host_result["https_get_request"] = get_request(url, timeout=timeout_in_seconds)
        if host_result["https_get_request"].get("reachable"):
            host_result["ssl"] = ssl_info(hostname)
        results[hostname] = host_result
    return results


def get_request(url, timeout=10):
    result = {}
    try:
        resp = requests.get(url, timeout=timeout)
        result["status_code"] = resp.status_code
        result["reason"] = resp.reason
        result["reachable"] = resp.status_code == 200
    except requests.exceptions.RequestException as e:
        result["error"] = str(e)
        result["reachable"] = False
    return result


def ssl_info(hostname, port=443):
    try:
        ctx = ssl.create_default_context()
        with socket.create_connection((hostname, port), timeout=10) as sock:
            with ctx.wrap_socket(sock, server_hostname=hostname) as ssock:
                cert = ssock.getpeercert()
                issuer = dict(x[0] for x in cert['issuer'])
                not_after = datetime.strptime(cert['notAfter'], "%b %d %H:%M:%S %Y %Z")
                return {
                    "issuer": issuer.get("organizationName", "Unknown"),
                    "expiry": not_after.strftime("%Y-%m-%d %H:%M:%S"),
                    "valid": not_after > datetime.utcnow()
                }
    except Exception as e:
        return {"error": str(e)}