#!/bin/bash
################################################################################
# GCM VM Configuration Wizard
# Version: 1.0.0
# Date: 2026-06-11
#
# Purpose: Interactive wizard to configure VM network and system settings
#          for GCM OVF deployment
#
# Usage: ./configure_vm.sh
#
################################################################################

set -euo pipefail

# Color codes
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
MAGENTA='\033[0;35m'
NC='\033[0m'

# Logging functions
log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
log_success() { echo -e "${GREEN}[✓]${NC} $1"; }
log_warning() { echo -e "${YELLOW}[⚠]${NC} $1"; }
log_error() { echo -e "${RED}[✗]${NC} $1"; }
log_step() { echo -e "${MAGENTA}[STEP $1]${NC} $2"; }
log_section() {
    echo ""
    echo -e "${CYAN}╔════════════════════════════════════════════════════════════════╗${NC}"
    echo -e "${CYAN}║${NC} $1"
    echo -e "${CYAN}╚════════════════════════════════════════════════════════════════╝${NC}"
    echo ""
}

# Configuration directory
CONFIG_DIR="/etc/gcm"
CONFIG_FILE="$CONFIG_DIR/vm-config.env"
BACKUP_DIR="$CONFIG_DIR/backups"

# Ensure running as root
if [ "$EUID" -ne 0 ]; then
    log_error "This script must be run as root"
    exit 1
fi

# Create configuration directory
mkdir -p "$CONFIG_DIR"
mkdir -p "$BACKUP_DIR"

# Backup existing configuration if present
if [ -f "$CONFIG_FILE" ]; then
    BACKUP_FILE="$BACKUP_DIR/vm-config.env.$(date +%Y%m%d_%H%M%S)"
    cp "$CONFIG_FILE" "$BACKUP_FILE"
    log_info "Backed up existing configuration to $BACKUP_FILE"
fi

################################################################################
# Helper Functions
################################################################################

# Validate IP address format
validate_ip() {
    local ip=$1
    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
        IFS='.' read -ra ADDR <<< "$ip"
        for i in "${ADDR[@]}"; do
            if [ "$i" -gt 255 ]; then
                return 1
            fi
        done
        return 0
    fi
    return 1
}

# Convert subnet mask to CIDR notation
subnet_to_cidr() {
    local mask=$1
    local nbits=0
    IFS='.' read -ra octets <<< "$mask"
    for octet in "${octets[@]}"; do
        case $octet in
            255) ((nbits+=8));;
            254) ((nbits+=7));;
            252) ((nbits+=6));;
            248) ((nbits+=5));;
            240) ((nbits+=4));;
            224) ((nbits+=3));;
            192) ((nbits+=2));;
            128) ((nbits+=1));;
            0) ;;
            *) echo "24"; return;; # Default to /24 for invalid masks
        esac
    done
    echo "$nbits"
}

# Validate FQDN format
validate_fqdn() {
    local fqdn=$1
    if [[ $fqdn =~ ^[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$ ]]; then
        return 0
    fi
    return 1
}

# Get current network configuration
get_current_ip() {
    hostname -I | awk '{print $1}'
}

get_current_gateway() {
    ip route | grep default | awk '{print $3}' | head -1
}

get_current_dns() {
    grep "^nameserver" /etc/resolv.conf | head -1 | awk '{print $2}'
}

get_current_hostname() {
    hostname -s
}

get_current_domain() {
    hostname -d
}

# Prompt with default value
prompt_with_default() {
    local prompt=$1
    local default=$2
    local result
    
    if [ -n "$default" ]; then
        read -p "$prompt [$default]: " result
        echo "${result:-$default}"
    else
        read -p "$prompt: " result
        echo "$result"
    fi
}

# Test network connectivity
test_connectivity() {
    local target=$1
    local description=$2
    
    if ping -c 2 -W 2 "$target" &>/dev/null; then
        log_success "$description reachable"
        return 0
    else
        log_error "$description not reachable"
        return 1
    fi
}

# Test DNS resolution
test_dns() {
    local hostname=$1
    
    if host "$hostname" &>/dev/null; then
        local resolved_ip=$(host "$hostname" | grep "has address" | awk '{print $4}' | head -1)
        log_success "DNS resolution: $hostname -> $resolved_ip"
        return 0
    else
        log_error "DNS resolution failed for $hostname"
        return 1
    fi
}

################################################################################
# Main Configuration Wizard
################################################################################

log_section "GCM VM Configuration Wizard"

log_info "This wizard will configure your VM for GCM deployment."
log_info "Current configuration will be detected and offered as defaults."
echo ""

# Get current configuration
CURRENT_IP=$(get_current_ip)
CURRENT_GATEWAY=$(get_current_gateway)
CURRENT_DNS=$(get_current_dns)
CURRENT_HOSTNAME=$(get_current_hostname)
CURRENT_DOMAIN=$(get_current_domain)

################################################################################
# STEP 1: Network Configuration
################################################################################

log_step "1/6" "Network Configuration"
echo "────────────────────────────────────────────────────────────────"

log_info "Current IP: $CURRENT_IP"
echo ""

# Ask if they want static IP
USE_STATIC=$(prompt_with_default "Configure static IP? (yes/no)" "yes")

if [[ "$USE_STATIC" =~ ^[Yy] ]]; then
    # IP Address
    while true; do
        VM_IP_ADDRESS=$(prompt_with_default "Enter IP address" "$CURRENT_IP")
        if validate_ip "$VM_IP_ADDRESS"; then
            break
        else
            log_error "Invalid IP address format"
        fi
    done
    
    # Subnet Mask
    VM_SUBNET_MASK=$(prompt_with_default "Enter subnet mask" "255.255.255.0")
    
    # Gateway
    while true; do
        VM_GATEWAY=$(prompt_with_default "Enter gateway" "$CURRENT_GATEWAY")
        if validate_ip "$VM_GATEWAY"; then
            break
        else
            log_error "Invalid gateway IP address"
        fi
    done
    
    # DNS Servers
    while true; do
        VM_DNS_PRIMARY=$(prompt_with_default "Enter primary DNS" "$CURRENT_DNS")
        if validate_ip "$VM_DNS_PRIMARY"; then
            break
        else
            log_error "Invalid DNS IP address"
        fi
    done
    
    VM_DNS_SECONDARY=$(prompt_with_default "Enter secondary DNS (optional)" "")
else
    # Use DHCP
    VM_IP_ADDRESS="$CURRENT_IP"
    VM_SUBNET_MASK="255.255.255.0"
    VM_GATEWAY="$CURRENT_GATEWAY"
    VM_DNS_PRIMARY="$CURRENT_DNS"
    VM_DNS_SECONDARY=""
    log_info "Using DHCP configuration"
fi

echo ""

################################################################################
# STEP 2: Hostname Configuration
################################################################################

log_step "2/6" "Hostname Configuration"
echo "────────────────────────────────────────────────────────────────"

if [ -n "$CURRENT_HOSTNAME" ] && [ "$CURRENT_HOSTNAME" != "localhost" ]; then
    log_info "Current hostname: $CURRENT_HOSTNAME"
fi

if [ -n "$CURRENT_DOMAIN" ]; then
    log_info "Current domain: $CURRENT_DOMAIN"
fi

echo ""

# Hostname
while true; do
    VM_HOSTNAME=$(prompt_with_default "Enter hostname (short name)" "${CURRENT_HOSTNAME:-gcm-server}")
    if [[ $VM_HOSTNAME =~ ^[a-zA-Z0-9-]+$ ]]; then
        break
    else
        log_error "Invalid hostname (use only letters, numbers, and hyphens)"
    fi
done

# Domain
while true; do
    VM_DOMAIN=$(prompt_with_default "Enter domain name" "${CURRENT_DOMAIN:-example.com}")
    if [[ $VM_DOMAIN =~ ^[a-zA-Z0-9.-]+$ ]]; then
        break
    else
        log_error "Invalid domain name"
    fi
done

# Construct FQDN
VM_FQDN="${VM_HOSTNAME}.${VM_DOMAIN}"

echo ""
log_info "FQDN will be: $VM_FQDN"
echo ""

CONFIRM_FQDN=$(prompt_with_default "Confirm FQDN? (yes/no)" "yes")
if [[ ! "$CONFIRM_FQDN" =~ ^[Yy] ]]; then
    log_error "Configuration cancelled by user"
    exit 0
fi

echo ""

################################################################################
# STEP 3: Time Configuration
################################################################################

log_step "3/6" "Time Configuration"
echo "────────────────────────────────────────────────────────────────"

CURRENT_TIMEZONE=$(timedatectl show -p Timezone --value 2>/dev/null || echo "UTC")
log_info "Current timezone: $CURRENT_TIMEZONE"

VM_TIMEZONE=$(prompt_with_default "Enter timezone" "$CURRENT_TIMEZONE")

VM_NTP_SERVER=$(prompt_with_default "Enter NTP server (optional)" "pool.ntp.org")

echo ""

################################################################################
# STEP 4: Firewall Configuration
################################################################################

log_step "4/6" "Firewall Configuration"
echo "────────────────────────────────────────────────────────────────"

log_info "GCM requires ports 30443 (OIDC) and 31443 (App) to be open"
echo ""

VM_FIREWALL_AUTO=$(prompt_with_default "Configure firewall automatically? (yes/no)" "yes")

echo ""

################################################################################
# STEP 5: Configuration Summary
################################################################################

log_step "5/6" "Configuration Summary"
echo "────────────────────────────────────────────────────────────────"

echo ""
log_info "Network:"
log_info "  IP Address:    $VM_IP_ADDRESS"
log_info "  Subnet Mask:   $VM_SUBNET_MASK"
log_info "  Gateway:       $VM_GATEWAY"
log_info "  DNS Primary:   $VM_DNS_PRIMARY"
if [ -n "$VM_DNS_SECONDARY" ]; then
    log_info "  DNS Secondary: $VM_DNS_SECONDARY"
fi
echo ""
log_info "System:"
log_info "  Hostname:      $VM_HOSTNAME"
log_info "  Domain:        $VM_DOMAIN"
log_info "  FQDN:          $VM_FQDN"
log_info "  Timezone:      $VM_TIMEZONE"
if [ -n "$VM_NTP_SERVER" ]; then
    log_info "  NTP:           $VM_NTP_SERVER"
fi
echo ""
log_info "Firewall:"
if [[ "$VM_FIREWALL_AUTO" =~ ^[Yy] ]]; then
    log_info "  Auto-configure: Yes"
    log_info "  Ports:         30443, 31443"
else
    log_info "  Auto-configure: No (manual configuration required)"
fi
echo ""

while true; do
    ACTION=$(prompt_with_default "Apply this configuration? (yes/no/edit)" "yes")
    case "$ACTION" in
        [Yy]*)
            break
            ;;
        [Nn]*)
            log_info "Configuration cancelled by user"
            exit 0
            ;;
        [Ee]*)
            log_info "Restarting configuration wizard..."
            exec "$0"
            ;;
        *)
            log_error "Please answer yes, no, or edit"
            ;;
    esac
done

echo ""

################################################################################
# STEP 6: Apply Configuration and Test
################################################################################

log_step "6/6" "Applying Configuration"
echo "────────────────────────────────────────────────────────────────"
echo ""

# Save configuration file
log_info "Saving configuration to $CONFIG_FILE..."

cat > "$CONFIG_FILE" << EOF
# GCM VM Configuration
# Generated: $(date '+%Y-%m-%d %H:%M:%S')

# Network Configuration
VM_IP_ADDRESS="$VM_IP_ADDRESS"
VM_SUBNET_MASK="$VM_SUBNET_MASK"
VM_GATEWAY="$VM_GATEWAY"
VM_DNS_PRIMARY="$VM_DNS_PRIMARY"
VM_DNS_SECONDARY="$VM_DNS_SECONDARY"

# Hostname Configuration
VM_HOSTNAME="$VM_HOSTNAME"
VM_DOMAIN="$VM_DOMAIN"
VM_FQDN="$VM_FQDN"

# Time Configuration
VM_TIMEZONE="$VM_TIMEZONE"
VM_NTP_SERVER="$VM_NTP_SERVER"

# Firewall Configuration
VM_FIREWALL_AUTO="$VM_FIREWALL_AUTO"
VM_FIREWALL_PORTS="30443,31443"
EOF

chmod 600 "$CONFIG_FILE"
log_success "Configuration saved"

# Apply hostname
log_info "Applying hostname configuration..."
hostnamectl set-hostname "$VM_FQDN"
log_success "Hostname set to $VM_FQDN"

# Apply timezone
if [ -n "$VM_TIMEZONE" ]; then
    log_info "Setting timezone to $VM_TIMEZONE..."
    timedatectl set-timezone "$VM_TIMEZONE"
    log_success "Timezone configured"
fi

# Configure NTP if specified
if [ -n "$VM_NTP_SERVER" ]; then
    log_info "Configuring NTP server..."
    if command -v chronyc &>/dev/null; then
        if ! grep -q "^server $VM_NTP_SERVER" /etc/chrony.conf; then
            echo "server $VM_NTP_SERVER iburst" >> /etc/chrony.conf
            systemctl restart chronyd
            log_success "NTP configured"
        fi
    fi
fi

# Apply network configuration if static IP
if [[ "$USE_STATIC" =~ ^[Yy] ]]; then
    # Check if IP is changing
    if [ "$VM_IP_ADDRESS" != "$CURRENT_IP" ]; then
        echo ""
        log_warning "═══════════════════════════════════════════════════════════════"
        log_warning "IMPORTANT: IP address will change from $CURRENT_IP to $VM_IP_ADDRESS"
        log_warning "You will lose SSH connectivity and need to reconnect to the new IP"
        log_warning "═══════════════════════════════════════════════════════════════"
        echo ""
        read -p "Press ENTER to continue or Ctrl+C to cancel..."
        echo ""
    fi
    
    log_info "Applying network configuration..."
    
    # Detect network interface
    INTERFACE=$(ip route | grep default | awk '{print $5}' | head -1)
    
    if [ -n "$INTERFACE" ]; then
        # Use NetworkManager if available
        if command -v nmcli &>/dev/null; then
            log_info "Configuring network via NetworkManager..."
            log_info "Detected interface: $INTERFACE"
            
            # Try to get connection name - try multiple methods
            CONNECTION=$(nmcli -t -f NAME,DEVICE connection show --active | grep ":$INTERFACE$" | cut -d: -f1 | head -1)
            
            # If not found in active connections, try all connections
            if [ -z "$CONNECTION" ]; then
                CONNECTION=$(nmcli -t -f NAME,DEVICE connection show | grep ":$INTERFACE$" | cut -d: -f1 | head -1)
            fi
            
            # If still not found, use the interface name itself (common in many systems)
            if [ -z "$CONNECTION" ]; then
                CONNECTION="$INTERFACE"
                log_info "Using interface name as connection name: $CONNECTION"
            else
                log_info "Found connection name: $CONNECTION"
            fi
            
            # Convert subnet mask to CIDR notation
            CIDR=$(subnet_to_cidr "$VM_SUBNET_MASK")
            log_info "Using CIDR notation: /$CIDR for subnet mask $VM_SUBNET_MASK"
            
            # Set all network parameters in one command to avoid errors
            log_info "Configuring connection '$CONNECTION'..."
            if [ -n "$VM_DNS_SECONDARY" ]; then
                nmcli connection modify "$CONNECTION" \
                    ipv4.method manual \
                    ipv4.addresses "$VM_IP_ADDRESS/$CIDR" \
                    ipv4.gateway "$VM_GATEWAY" \
                    ipv4.dns "$VM_DNS_PRIMARY $VM_DNS_SECONDARY" 2>&1
            else
                nmcli connection modify "$CONNECTION" \
                    ipv4.method manual \
                    ipv4.addresses "$VM_IP_ADDRESS/$CIDR" \
                    ipv4.gateway "$VM_GATEWAY" \
                    ipv4.dns "$VM_DNS_PRIMARY" 2>&1
            fi
            
            # Check if the command succeeded
            if [ $? -eq 0 ]; then
                log_success "Network configuration updated"
                log_info "Bringing up connection (you may lose connectivity)..."
                nmcli connection up "$CONNECTION" &
                sleep 2
                log_success "Network configuration applied"
            else
                log_error "Failed to modify network connection '$CONNECTION'"
                log_info "Available connections:"
                nmcli connection show
                log_info ""
                log_info "You may need to configure the network manually using:"
                log_info "  nmcli connection modify <connection-name> ipv4.method manual ipv4.addresses $VM_IP_ADDRESS/$CIDR ipv4.gateway $VM_GATEWAY ipv4.dns $VM_DNS_PRIMARY"
            fi
        else
            log_warning "NetworkManager not available - manual network configuration required"
        fi
    else
        log_warning "Could not detect network interface"
    fi
fi

# Configure firewall if requested
if [[ "$VM_FIREWALL_AUTO" =~ ^[Yy] ]]; then
    if command -v firewall-cmd &>/dev/null; then
        if systemctl is-active --quiet firewalld; then
            log_info "Configuring firewall..."
            
            firewall-cmd --permanent --add-port=30443/tcp &>/dev/null
            firewall-cmd --permanent --add-port=31443/tcp &>/dev/null
            firewall-cmd --reload &>/dev/null
            
            log_success "Firewall configured (ports 30443, 31443 opened)"
        else
            log_info "Firewalld not active - skipping firewall configuration"
        fi
    else
        log_info "Firewalld not installed - skipping firewall configuration"
    fi
fi

echo ""
log_section "Testing Configuration"

# Test gateway connectivity
log_info "Testing gateway connectivity..."
if test_connectivity "$VM_GATEWAY" "Gateway ($VM_GATEWAY)"; then
    GATEWAY_OK=true
else
    GATEWAY_OK=false
    log_warning "Gateway not reachable - check network configuration"
fi

# Test DNS
log_info "Testing DNS resolution..."
if test_dns "google.com"; then
    DNS_OK=true
else
    DNS_OK=false
    log_warning "DNS resolution failed - check DNS configuration"
fi

# Test internet connectivity
log_info "Testing internet connectivity..."
if test_connectivity "8.8.8.8" "Internet (8.8.8.8)"; then
    INTERNET_OK=true
else
    INTERNET_OK=false
    log_warning "Internet not reachable - check gateway and routing"
fi

# Test FQDN resolution (if DNS is working)
if [ "$DNS_OK" = true ]; then
    log_info "Testing FQDN resolution..."
    if test_dns "$VM_FQDN"; then
        FQDN_OK=true
    else
        FQDN_OK=false
        log_warning "FQDN not resolvable - you may need to add DNS record"
        log_info "  Add A record: $VM_FQDN -> $VM_IP_ADDRESS"
    fi
fi

echo ""
log_section "Configuration Complete!"

log_success "VM configuration has been applied and saved"
echo ""
log_info "Configuration file: $CONFIG_FILE"
log_info "Hostname: $VM_FQDN"
log_info "IP Address: $VM_IP_ADDRESS"
echo ""

# Summary of test results
log_info "Connectivity Tests:"
if [ "$GATEWAY_OK" = true ]; then
    log_success "  Gateway: OK"
else
    log_error "  Gateway: FAILED"
fi

if [ "$DNS_OK" = true ]; then
    log_success "  DNS: OK"
else
    log_error "  DNS: FAILED"
fi

if [ "$INTERNET_OK" = true ]; then
    log_success "  Internet: OK"
else
    log_error "  Internet: FAILED"
fi

if [ "${FQDN_OK:-false}" = true ]; then
    log_success "  FQDN Resolution: OK"
elif [ "$DNS_OK" = true ]; then
    log_warning "  FQDN Resolution: Not configured (add DNS record)"
fi

echo ""

if [ "$GATEWAY_OK" = true ] && [ "$DNS_OK" = true ] && [ "$INTERNET_OK" = true ]; then
    log_success "All connectivity tests passed!"
    echo ""
    log_info "Next step: Run ./02-configure_gcm.sh to configure GCM settings"
else
    log_warning "Some connectivity tests failed - please review and fix before proceeding"
    echo ""
    log_info "You can re-run this script to reconfigure: ./configure_vm.sh"
fi

echo ""

# Made with Bob