#!/bin/bash

# Load environment variables
source /PATH/TO/domains.env
source /PATH/TO/notification.env

# Read the list of domains
domains=$(cat "$DOMAINS_FILE")

# Initialize
declare -A whois_cache        # TLD → WHOIS server cache
expiring_domains=()
current_datetime=$(date +%Y-%m-%d_%H:%M:%S)

# --- Functions ---

# Get the authoritative WHOIS server for a TLD (with in-memory cache)
get_whois_server() {
    local domain=$1
    local tld="${domain##*.}"

    # Return cached entry if present
    if [[ -n "${whois_cache[$tld]}" ]]; then
        echo "${whois_cache[$tld]}"
        return
    fi

    # Query whois.iana.org for authoritative WHOIS server
    local server
    server=$(whois -h whois.iana.org "$tld" 2>/dev/null | grep -i "whois:" | awk '{print $2}' | head -n1)

    # Store result in cache (even if blank)
    whois_cache[$tld]="$server"

    echo "$server"
}

# Get the expiration date for a domain from the correct WHOIS server
get_expiration_date() {
    local domain=$1
    local whois_server=$2
    local whois_output

    if [[ -n "$whois_server" ]]; then
        whois_output=$(whois -h "$whois_server" "$domain" 2>/dev/null)
    else
        whois_output=$(whois "$domain" 2>/dev/null)
    fi

    echo "$whois_output" | grep -Ei 'Expiration Date|Expiry Date|Registry Expiry Date' | awk -F ':' '{print $2}' | head -n1
}

# --- Main Loop ---

for domain in $domains; do
    whois_server=$(get_whois_server "$domain")
    expiration_date=$(get_expiration_date "$domain" "$whois_server")

    # Calculate days left
    if [[ -n "$expiration_date" ]]; then
        expiration_timestamp=$(date -d "$expiration_date" +%s 2>/dev/null)
        if [[ -n "$expiration_timestamp" ]]; then
            days_left=$(( (expiration_timestamp - $(date +%s)) / 86400 ))
        else
            days_left=""
        fi
    fi

    # Check if expiring soon
    if [[ -n "$days_left" && "$days_left" -lt "$DAYS_WITHIN" ]]; then
        expiring_domains+=("$domain: $days_left days left (WHOIS: ${whois_server:-default})")
    fi
done

# --- Notifications ---

if [[ ${#expiring_domains[@]} -gt 0 ]]; then
    subject="Domain Expiration Alert - $current_datetime"
    body="The following domains are expiring within $DAYS_WITHIN days:\n\n${expiring_domains[@]/%/\\n}"

    # Email
    echo -e "$body" | mail -s "$subject" -a "From: $SENDER_EMAIL" "$RECEIVER_EMAIL"

    # Discord
    curl -H "Content-Type: application/json" \
         -X POST \
         --data "{\"content\": null, \"embeds\": [{\"title\": \"$subject\", \"description\": \"$body\"}]}" \
         "$WEBHOOK_URL"
fi