#!/bin/bash
# pdns-ddns - Updates both Infomaniak and PowerDNS with external IP
# Speichern als: /usr/local/bin/pdns-ddns

# Load config
source /etc/powerdns/ddns.conf

# IP History file
IP_HISTORY_FILE="/var/log/ddns-ip-history.log"

# ============================================================================
# LOGGING FUNCTIONS
# ============================================================================

log_info() {
    echo "$(date): $1"
}

log_error() {
    echo "$(date): ERROR: $1"
}

log_success() {
    echo "$(date): SUCCESS: $1"
}

log_change() {
    local message="$1"
    echo "$(date): $message"
    echo "$(date): $message" >> "$IP_HISTORY_FILE"
}

log_history() {
    echo "$(date): $1" >> "$IP_HISTORY_FILE"
}

# ============================================================================
# IP CHANGE DETECTION
# ============================================================================

check_ip_change() {
    # Get external IP
    EXTERNAL_IP=$(curl -s ifconfig.me)

    if [[ ! $EXTERNAL_IP =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
        log_error "Invalid IP address: $EXTERNAL_IP"
        exit 1
    fi

    # Read last known IP
    local last_ip=""
    if [[ -f "$IP_HISTORY_FILE" ]]; then
        last_ip=$(grep "IP changed from" "$IP_HISTORY_FILE" | tail -1 | sed 's/.*to \([0-9.]*\)$/\1/')
    fi

    # Check if IP changed
    if [[ -n "$last_ip" && "$last_ip" != "$EXTERNAL_IP" ]]; then
        log_info "External IP: $EXTERNAL_IP"
        log_change "IP changed from $last_ip to $EXTERNAL_IP"
        log_info "Previous IPs in last 10 changes:"
        grep "IP changed from" "$IP_HISTORY_FILE" | tail -10 | sed 's/.*from \([0-9.]*\) to \([0-9.]*\)$/Old: \1 -> New: \2/' || log_info "No previous changes found"
        return 1  # IP changed = update needed
    elif [[ -z "$last_ip" ]]; then
        log_info "External IP: $EXTERNAL_IP"
        log_info "First run or no history - checking DNS records"
        return 1  # First run = update needed
    else
        # IP unchanged - only return 1 if we need to check DNS consistency
        return 0  # No change needed
    fi
}

# ============================================================================
# EXTERNAL DNS (INFOMANIAK) FUNCTIONS
# ============================================================================

check_external_dns() {
    local current_record=$(curl -s -H "Authorization: Bearer $INFOMANIAK_TOKEN" \
        "https://api.infomaniak.com/2/zones/$INFOMANIAK_DOMAIN/records" | \
        jq -r '.data[] | select(.type=="A" and .source==".") | .target' | head -1)

    if [[ "$current_record" == "$EXTERNAL_IP" ]]; then
        return 0  # No update needed - silent success
    else
        log_info "Checking Infomaniak A record for $INFOMANIAK_DOMAIN..."
        if [[ -n "$current_record" ]]; then
            log_change "Infomaniak A record needs update: $current_record -> $EXTERNAL_IP"
        else
            log_change "Infomaniak A record does not exist, creating with IP: $EXTERNAL_IP"
        fi
        return 1  # Update needed
    fi
}

update_external_dns() {
    log_info "Updating Infomaniak DNS..."

    local record_id=$(curl -s -H "Authorization: Bearer $INFOMANIAK_TOKEN" \
        "https://api.infomaniak.com/2/zones/$INFOMANIAK_DOMAIN/records" | \
        jq -r '.data[] | select(.type=="A" and .source==".") | .id' | head -1)

    if [[ -z "$record_id" ]]; then
        log_info "Creating new Infomaniak A record..."
        if curl -s -X POST "https://api.infomaniak.com/2/zones/$INFOMANIAK_DOMAIN/records" \
             -H "Authorization: Bearer $INFOMANIAK_TOKEN" \
             -H "Content-Type: application/json" \
             -d "{\"type\": \"A\", \"source\": \".\", \"target\": \"$EXTERNAL_IP\", \"ttl\": $TTL}" > /dev/null; then
            log_success "Infomaniak A record created"
            log_history "Infomaniak created: -> $EXTERNAL_IP"
        else
            log_error "Failed to create Infomaniak A record"
            return 1
        fi
    else
        log_info "Updating existing Infomaniak A record..."
        if curl -s -X PUT "https://api.infomaniak.com/2/zones/$INFOMANIAK_DOMAIN/records/$record_id" \
             -H "Authorization: Bearer $INFOMANIAK_TOKEN" \
             -H "Content-Type: application/json" \
             -d "{\"target\": \"$EXTERNAL_IP\", \"ttl\": $TTL}" > /dev/null; then
            log_success "Infomaniak A record updated"
            log_history "Infomaniak change: -> $EXTERNAL_IP"
        else
            log_error "Failed to update Infomaniak A record"
            return 1
        fi
    fi
    return 0
}

# ============================================================================
# INTERNAL DNS (POWERDNS) FUNCTIONS
# ============================================================================

ensure_zone_exists() {
    local domain="$1"

    if ! pdnsutil list-zone "$domain" >/dev/null 2>&1; then
        log_info "Zone $domain does not exist, creating..."
        log_history "PowerDNS $domain zone created"
        pdnsutil create-zone "$domain"
        return 1  # Zone was created, needs update
    fi
    return 0  # Zone exists
}

check_powerdns_record() {
    local domain="$1"
    local record_type="$2"  # "@" for root, "*" for wildcard
    local display_name="$3"

    local current_ip
    if [[ "$record_type" == "@" ]]; then
        current_ip=$(pdnsutil list-zone "$domain" 2>/dev/null | grep -E "^${domain}\s+[0-9]+\s+IN\s+A\s+" | awk '{print $5}' | head -1)
    else
        current_ip=$(pdnsutil list-zone "$domain" 2>/dev/null | grep -E "^\*\.${domain}\s+[0-9]+\s+IN\s+A\s+" | awk '{print $5}' | head -1)
    fi

    if [[ "$current_ip" == "$EXTERNAL_IP" ]]; then
        return 0  # No update needed - silent success
    else
        if [[ -n "$current_ip" ]]; then
            log_change "PowerDNS A record for $display_name needs update: $current_ip -> $EXTERNAL_IP"
        else
            log_change "PowerDNS A record for $display_name does not exist, creating with IP: $EXTERNAL_IP"
        fi
        return 1  # Update needed
    fi
}

update_powerdns_record() {
    local domain="$1"
    local record_type="$2"  # "@" for root, "*" for wildcard
    local display_name="$3"

    log_info "Updating PowerDNS A record for $display_name..."

    if pdnsutil replace-rrset "$domain" "$record_type" A "$TTL" "$EXTERNAL_IP" 2>/dev/null; then
        log_success "PowerDNS A record updated for $display_name"
        log_history "PowerDNS $display_name updated: -> $EXTERNAL_IP"
        pdnsutil rectify-zone "$domain" 2>/dev/null
        pdnsutil increase-serial "$domain" 2>/dev/null
        return 0
    else
        log_error "Failed to update PowerDNS A record for $display_name"
        return 1
    fi
}

check_internal_dns() {
    local needs_update=false
    local needs_logging=false

    for domain in $POWERDNS_DOMAINS; do
        # Ensure zone exists (this might need logging)
        if ! pdnsutil list-zone "$domain" >/dev/null 2>&1; then
            if [[ "$needs_logging" == "false" ]]; then
                log_info "Checking PowerDNS A records..."
                needs_logging=true
            fi
            log_info "Zone $domain does not exist, creating..."
            log_history "PowerDNS $domain zone created"
            pdnsutil create-zone "$domain"
            needs_update=true
        fi

        # Check root A record
        if ! check_powerdns_record "$domain" "@" "$domain"; then
            if [[ "$needs_logging" == "false" ]]; then
                log_info "Checking PowerDNS A records..."
                needs_logging=true
            fi
            needs_update=true
        fi

        # Check wildcard A record
        if ! check_powerdns_record "$domain" "*" "*.${domain}"; then
            if [[ "$needs_logging" == "false" ]]; then
                log_info "Checking PowerDNS A records..."
                needs_logging=true
            fi
            needs_update=true
        fi
    done

    if [[ "$needs_update" == "true" ]]; then
        return 1  # Update needed
    else
        return 0  # No update needed - was completely silent
    fi
}

update_internal_dns() {
    log_info "Updating PowerDNS records..."

    for domain in $POWERDNS_DOMAINS; do
        log_info "Processing zone $domain..."

        # Ensure zone exists
        ensure_zone_exists "$domain"

        # Update root A record if needed
        if ! check_powerdns_record "$domain" "@" "$domain"; then
            update_powerdns_record "$domain" "@" "$domain"
        fi

        # Update wildcard A record if needed
        if ! check_powerdns_record "$domain" "*" "*.${domain}"; then
            update_powerdns_record "$domain" "*" "*.${domain}"
        fi
    done
}

# ============================================================================
# MAIN EXECUTION
# ============================================================================

main() {
    # Check if IP changed
    if ! check_ip_change; then
        # IP unchanged - check if DNS is consistent
        local external_needs_update=false
        local internal_needs_update=false

        if ! check_external_dns; then
            external_needs_update=true
        fi

        if ! check_internal_dns; then
            internal_needs_update=true
        fi

        # If everything is consistent, exit silently
        if [[ "$external_needs_update" == "false" && "$internal_needs_update" == "false" ]]; then
            exit 0
        fi

        # If we reach here, something needs fixing
        log_info "External IP: $EXTERNAL_IP"
        log_info "No IP change detected, but DNS inconsistencies found"

        if [[ "$external_needs_update" == "true" ]]; then
            update_external_dns
        fi

        if [[ "$internal_needs_update" == "true" ]]; then
            update_internal_dns
        fi
    else
        # IP changed - do full update
        log_info "Starting DDNS check/update process"

        # Check and update external DNS (Infomaniak)
        if ! check_external_dns; then
            update_external_dns
        fi

        # Check and update internal DNS (PowerDNS)
        if ! check_internal_dns; then
            update_internal_dns
        fi
    fi

    log_info "DDNS check/update completed"

    # Show recent IP history summary
    if [[ -f "$IP_HISTORY_FILE" ]]; then
        log_info "Recent changes (last 5):"
        tail -5 "$IP_HISTORY_FILE" | grep -E "(change:|created:|updated:)" || log_info "No recent changes"
    fi
}

# Run main function
main