#!/bin/bash

# Read the list of domains from a file
domains=$(cat /www/cert_check/domains.txt)

# Email settings
sender_email="SENDER_EMAIL"
receiver_email="RECEIVER_EMAIL"

# Discord Webhook
WEBHOOK_URL="DISCORD_WEBHOOK_URL"

# Initialize an empty array to store the expiring domains and their days left
expiring_domains=()

# Set number of days to search within
days_within=30

# Set time and date of search
current_datetime=$(date +%Y-%m-%d_%H:%M:%S)

# Iterate over the list of domains
for domain_entry in $domains; do
    # Split the domain and port
    IFS=':' read -r domain port <<< "$domain_entry"

    # Set default port to 443 if not specified
    if [ -z "$port" ]; then
        port=443
    fi

    # Get SSL certificate expiration date
    expiration_date=$(echo | openssl s_client -servername $domain -connect $domain:$port 2>/dev/null | openssl x509 -noout -dates | grep 'notAfter' | cut -d'=' -f2)

    # Calculate the number of days left until the SSL certificate expires
    if [ ! -z "$expiration_date" ]; then
        expiration_timestamp=$(date -d "$expiration_date" +%s 2>/dev/null)
        if [ ! -z "$expiration_timestamp" ]; then
            days_left=$((($expiration_timestamp - $(date +%s)) / 86400))
        fi
    fi

    # Check if the SSL certificate is expiring within set days time
    if [ ! -z "$days_left" ] && [ "$days_left" -lt $days_within ]; then
        # Add the expiring domain and its days left to the array
        expiring_domains+=("$domain:$port: $days_left days left")
    fi
done

# Send an email with the expiring domains and their days left (if any)
if [ ${#expiring_domains[@]} -gt 0 ]; then
    # Email content
    subject="SSL Certificate Expiration Alert - $current_datetime"
    body="The following domains have SSL certificates expiring within $days_within days:\n\n${expiring_domains[@]/%/\\n}"

    # Send the email
    echo -e "$body" | mail -s "$subject" -a "From: $sender_email" "$receiver_email"
    
    # Send the notification to Discord
    curl -H "Content-Type: application/json" -X POST --data "{\"content\": null, \"embeds\": [{\"title\": \"$subject\", \"description\": \"$body\", \"color\": null}], \"attachments\": []}" $WEBHOOK_URL
fi