#!/usr/bin/env bash
#
# Silo IPA Enrollment and Nginx Setup Script
# Enrolls host in FreeIPA, obtains certificates, and configures nginx reverse proxy
#
# Usage:
#   sudo ./scripts/setup-ipa-nginx.sh
#
# Prerequisites:
#   - FreeIPA server at ipa.example.internal
#   - DNS configured for the silo host (set SILO_HOSTNAME to override default)
#   - Admin credentials for IPA enrollment

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# Configuration
IPA_SERVER="${IPA_SERVER:-ipa.example.internal}"
IPA_DOMAIN="${IPA_DOMAIN:-example.internal}"
IPA_REALM="${IPA_REALM:-KINDRED.INTERNAL}"
SILO_HOSTNAME="${SILO_HOSTNAME:-silo.example.internal}"
CERT_DIR="/etc/ssl/silo"
SILO_PORT="${SILO_PORT:-8080}"

log_info() { echo -e "${BLUE}[INFO]${NC} $*"; }
log_success() { echo -e "${GREEN}[OK]${NC} $*"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $*"; }
log_error() { echo -e "${RED}[ERROR]${NC} $*" >&2; }
die() { log_error "$*"; exit 1; }

# Check root
if [[ $EUID -ne 0 ]]; then
    die "This script must be run as root (use sudo)"
fi

log_info "============================================"
log_info "Silo IPA Enrollment and Nginx Setup"
log_info "============================================"
echo ""

# Detect package manager
if command -v apt-get >/dev/null 2>&1; then
    PKG_MANAGER="apt"
elif command -v dnf >/dev/null 2>&1; then
    PKG_MANAGER="dnf"
elif command -v yum >/dev/null 2>&1; then
    PKG_MANAGER="yum"
else
    die "Unsupported package manager"
fi

log_info "Detected package manager: ${PKG_MANAGER}"

#
# Step 1: Install IPA client and nginx
#
log_info "Installing packages..."

case ${PKG_MANAGER} in
    apt)
        apt-get update -qq
        apt-get install -y -qq freeipa-client nginx certmonger
        ;;
    dnf|yum)
        ${PKG_MANAGER} install -y -q freeipa-client nginx certmonger
        ;;
esac

log_success "Packages installed"

#
# Step 2: Set hostname
#
log_info "Setting hostname to ${SILO_HOSTNAME}..."
hostnamectl set-hostname "${SILO_HOSTNAME}"
log_success "Hostname set"

#
# Step 3: Enroll in FreeIPA
#
if ipa-client-install --version >/dev/null 2>&1 && klist -k /etc/krb5.keytab >/dev/null 2>&1; then
    log_info "Host appears to already be enrolled in IPA"
else
    log_info "Enrolling in FreeIPA domain..."
    log_warn "You will be prompted for IPA admin credentials"
    echo ""

    ipa-client-install \
        --server="${IPA_SERVER}" \
        --domain="${IPA_DOMAIN}" \
        --realm="${IPA_REALM}" \
        --hostname="${SILO_HOSTNAME}" \
        --mkhomedir \
        --enable-dns-updates \
        --unattended \
        --force-join || {
            log_warn "Unattended enrollment failed, trying interactive mode..."
            ipa-client-install \
                --server="${IPA_SERVER}" \
                --domain="${IPA_DOMAIN}" \
                --realm="${IPA_REALM}" \
                --hostname="${SILO_HOSTNAME}" \
                --mkhomedir \
                --enable-dns-updates
        }

    log_success "Enrolled in FreeIPA"
fi

#
# Step 4: Create certificate directory
#
log_info "Setting up certificate directory..."
mkdir -p "${CERT_DIR}"
chmod 750 "${CERT_DIR}"
chown root:nginx "${CERT_DIR}" 2>/dev/null || chown root:www-data "${CERT_DIR}"
log_success "Certificate directory created: ${CERT_DIR}"

#
# Step 5: Request certificate from IPA CA
#
log_info "Requesting SSL certificate from IPA CA..."

# Check if certificate already exists and is managed by certmonger
if getcert list | grep -q "${CERT_DIR}/silo.crt"; then
    log_info "Certificate already managed by certmonger"
else
    # Request new certificate
    ipa-getcert request \
        -f "${CERT_DIR}/silo.crt" \
        -k "${CERT_DIR}/silo.key" \
        -K "HTTP/${SILO_HOSTNAME}" \
        -D "${SILO_HOSTNAME}" \
        -N "CN=${SILO_HOSTNAME}" \
        -C "systemctl reload nginx"

    log_info "Waiting for certificate to be issued..."

    # Wait for certificate (up to 60 seconds)
    for i in {1..12}; do
        if [[ -f "${CERT_DIR}/silo.crt" ]] && [[ -s "${CERT_DIR}/silo.crt" ]]; then
            log_success "Certificate issued"
            break
        fi
        sleep 5
        echo -n "."
    done
    echo ""

    if [[ ! -f "${CERT_DIR}/silo.crt" ]]; then
        log_warn "Certificate not yet issued. Check with: getcert list"
    fi
fi

# Set certificate permissions
if [[ -f "${CERT_DIR}/silo.key" ]]; then
    chmod 640 "${CERT_DIR}/silo.key"
    chown root:nginx "${CERT_DIR}/silo.key" 2>/dev/null || chown root:www-data "${CERT_DIR}/silo.key"
fi

#
# Step 6: Get IPA CA certificate for trust
#
log_info "Installing IPA CA certificate..."
if [[ -f /etc/ipa/ca.crt ]]; then
    cp /etc/ipa/ca.crt "${CERT_DIR}/ca.crt"
    log_success "CA certificate installed"
else
    log_warn "IPA CA certificate not found at /etc/ipa/ca.crt"
fi

#
# Step 7: Configure nginx
#
log_info "Configuring nginx..."

# Backup existing config
if [[ -f /etc/nginx/sites-enabled/default ]]; then
    mv /etc/nginx/sites-enabled/default /etc/nginx/sites-available/default.bak 2>/dev/null || true
fi

# Create silo nginx config
cat > /etc/nginx/sites-available/silo << NGINX_EOF
# Silo API Server - Nginx Reverse Proxy Configuration

# Redirect HTTP to HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name ${SILO_HOSTNAME};

    # Allow certmonger/ACME challenges
    location /.well-known/ {
        root /var/www/html;
    }

    location / {
        return 301 https://\\$server_name\\$request_uri;
    }
}

# HTTPS server
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name ${SILO_HOSTNAME};

    # SSL certificates (managed by certmonger/IPA)
    ssl_certificate ${CERT_DIR}/silo.crt;
    ssl_certificate_key ${CERT_DIR}/silo.key;

    # SSL configuration
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;

    # OCSP stapling
    ssl_stapling on;
    ssl_stapling_verify on;
    ssl_trusted_certificate ${CERT_DIR}/ca.crt;

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

    # Logging
    access_log /var/log/nginx/silo_access.log;
    error_log /var/log/nginx/silo_error.log;

    # Proxy settings
    location / {
        proxy_pass http://127.0.0.1:${SILO_PORT};
        proxy_http_version 1.1;

        # Headers
        proxy_set_header Host \\$host;
        proxy_set_header X-Real-IP \\$remote_addr;
        proxy_set_header X-Forwarded-For \\$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \\$scheme;
        proxy_set_header X-Forwarded-Host \\$host;
        proxy_set_header X-Forwarded-Port \\$server_port;

        # WebSocket support (for future use)
        proxy_set_header Upgrade \\$http_upgrade;
        proxy_set_header Connection "upgrade";

        # Timeouts
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;

        # Buffering
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;

        # File uploads (for CAD files)
        client_max_body_size 100M;
    }

    # Health check endpoint (bypass proxy for monitoring)
    location /nginx-health {
        access_log off;
        return 200 "OK\n";
        add_header Content-Type text/plain;
    }
}
NGINX_EOF

# Enable the site
ln -sf /etc/nginx/sites-available/silo /etc/nginx/sites-enabled/silo

# Test nginx configuration
log_info "Testing nginx configuration..."
if nginx -t; then
    log_success "Nginx configuration valid"
else
    die "Nginx configuration test failed"
fi

#
# Step 8: Start/restart services
#
log_info "Starting services..."

# Enable and start certmonger
systemctl enable certmonger
systemctl start certmonger

# Enable and restart nginx
systemctl enable nginx
systemctl restart nginx

log_success "Services started"

#
# Step 9: Configure firewall
#
log_info "Configuring firewall..."

if command -v ufw >/dev/null 2>&1; then
    ufw allow 80/tcp
    ufw allow 443/tcp
    log_success "UFW rules added"
elif command -v firewall-cmd >/dev/null 2>&1; then
    firewall-cmd --permanent --add-service=http
    firewall-cmd --permanent --add-service=https
    firewall-cmd --reload
    log_success "Firewalld rules added"
else
    log_warn "No firewall detected. Manually open ports 80 and 443"
fi

#
# Summary
#
echo ""
log_info "============================================"
log_info "Setup Complete!"
log_info "============================================"
echo ""
echo "Certificate status:"
getcert list -f "${CERT_DIR}/silo.crt" 2>/dev/null || echo "  Check with: getcert list"
echo ""
echo "Nginx status:"
systemctl status nginx --no-pager -l | head -5
echo ""
echo "Next steps:"
echo ""
echo "1. Verify certificate was issued:"
echo "   getcert list"
echo ""
echo "2. Update silo config to use correct base URL:"
echo "   sudo nano /etc/silo/config.yaml"
echo "   # Change base_url to: https://${SILO_HOSTNAME}"
echo ""
echo "3. Restart silo service:"
echo "   sudo systemctl restart silod"
echo ""
echo "4. Test the setup:"
echo "   curl -k https://${SILO_HOSTNAME}/health"
echo "   curl https://${SILO_HOSTNAME}/health  # after trusting IPA CA"
echo ""
echo "5. Trust IPA CA on client machines:"
echo "   # The CA cert is at: ${CERT_DIR}/ca.crt"
echo "   # Or fetch from: https://${IPA_SERVER}/ipa/config/ca.crt"
echo ""