#!/usr/bin/env bash
# Vacuum Wall - SSL Proxy Firewall Appliance Installer
# Run as root on a fresh Debian 13 (trixie) system
set -euo pipefail

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

log() { echo -e "${GREEN}[OK]${NC} $*"; }
warn() { echo -e "${YELLOW}[!!]${NC} $*"; }
err() { echo -e "${RED}[!!]${NC} $*"; exit 1; }

# --- Configurable via environment ---
REPO_DIR="$(cd "$(dirname "$0")" && pwd)"
USER_NAME="${USER_NAME:-vacuum-wall}"

# --- Validate required env vars ---
missing=()
[[ -z "${MGMT_PASS:-}" ]]   && missing+=(MGMT_PASS)
[[ -z "${ACME_EMAIL:-}" ]]  && missing+=(ACME_EMAIL)

if (( ${#missing[@]} )); then
  echo -e "${RED}[!!]${NC} Missing required environment variables:"
  for v in "${missing[@]}"; do
    case "$v" in
      MGMT_PASS)   echo '  export MGMT_PASS="your-password"  # WebUI basic auth password';;
      ACME_EMAIL)  echo "  export ACME_EMAIL=\"you@example.com\"  # ACME (ZeroSSL) registration email";;
    esac
  done
  printf '\nTo run: MGMT_PASS=pass ACME_EMAIL=you@example.com ./install.sh\n'
  exit 1
fi

# Auto-detect MGMT_DOMAIN from system hostname if not provided
if [[ -z "${MGMT_DOMAIN:-}" ]]; then
    HOSTNAME_F=$(hostname -f 2>/dev/null || hostname 2>/dev/null || true)
    if [[ -z "$HOSTNAME_F" ]]; then
        err "Cannot determine system hostname — set MGMT_DOMAIN env var."
    fi
    DOMAIN="${HOSTNAME_F}.local"
else
    DOMAIN="$MGMT_DOMAIN"
fi
MGMT_USER="${MGMT_USER:-admin}"

# --- Pre-flight checks ---
[[ $EUID -eq 0 ]] || err "This script must be run as root."
[[ -f /etc/debian_version ]] || warn "This script is designed for Debian/Ubuntu."

# --- Deploy to /opt/vacuum-wall ---
INSTALL_DIR="/opt/vacuum-wall"

# Install rsync first if not available (needed for deploy)
if ! command -v rsync &>/dev/null; then
    apt-get update -qq
    apt-get install -y -qq rsync
fi

if [[ -d "$INSTALL_DIR" ]]; then
    if [[ -L "$INSTALL_DIR" ]]; then
        log "Symbolic link already exists at $INSTALL_DIR, skipping deploy."
    elif [[ "$INSTALL_DIR" == "$REPO_DIR" ]]; then
        log "Installed from repo location, skipping deploy."
    else
        err "Installation directory $INSTALL_DIR already exists."
    fi
else
    log "Deploying $REPO_DIR → $INSTALL_DIR"
    rsync -a --delete \
        --exclude='.venv' \
        --exclude='__pycache__' \
        --exclude='*.pyc' \
        --exclude='.git' \
        --exclude='build' \
        "$REPO_DIR/" "$INSTALL_DIR/"
    chown -R "$USER_NAME:$USER_NAME" "$INSTALL_DIR"
fi

PROJECT_DIR="$INSTALL_DIR"
ACME_HOME="$PROJECT_DIR/data/acme"

echo "============================================"
echo "  Vacuum Wall Appliance Installer"
echo "  Install dir:     $PROJECT_DIR"
echo "  System user:     $USER_NAME"
echo "  Management domain: $DOMAIN"
echo "============================================"

# --- 1. Install packages ---
log "Installing system packages..."
apt-get update -qq
apt-get install -y -qq \
    firewalld \
    nginx \
    dnsmasq \
    wireguard-tools \
    python3 \
    python3-pip \
    jq \
    curl \
    iptables \
    nftables \
    apache2-utils \
    avahi-daemon

# --- 2. Create system user (home set to PROJECT_DIR for env, no-create) ---
if ! id "$USER_NAME" &>/dev/null; then
    log "Creating system user $USER_NAME..."
    useradd --system --home-dir "$PROJECT_DIR" --no-create-home --shell /usr/sbin/nologin "$USER_NAME"
else
    log "User $USER_NAME already exists."
fi

# --- 2b. Setup Python venv ---
log "Setting up Python virtual environment..."
python3 -m venv "${PROJECT_DIR}/.venv"
"${PROJECT_DIR}/.venv/bin/pip" install -q "${PROJECT_DIR}"

# --- 2c. Install acme.sh ---
if [[ ! -d "$ACME_HOME" ]]; then
    log "Installing acme.sh..."
    mkdir -p "$ACME_HOME"
    chown "$USER_NAME:$USER_NAME" "$ACME_HOME"
    sudo -u "$USER_NAME" env ACME_HOME="$ACME_HOME" HOME="$PROJECT_DIR" \
        sh -c 'curl -sS https://get.acme.sh | sh'
else
    log "acme.sh already installed."
fi

# Ensure the acme deploy hook script has correct permissions
chmod 0755 "${PROJECT_DIR}/system/acme-deploy.sh"

# --- 3. Setup directories ---
log "Creating config and data directories..."
mkdir -p "${PROJECT_DIR}/config"/{dnsmasq,nginx,wireguard,firewall}
mkdir -p "${PROJECT_DIR}/data"/{nginx/sites-enabled,dnsmasq,firewall,wireguard,acme}
mkdir -p /etc/wireguard
mkdir -p /etc/dnsmasq

# --- 4. Template rendering function ---
render_template() {
    export USER_NAME PROJECT_DIR ACME_HOME
    "${PROJECT_DIR}/.venv/bin/python3" -c "
import sys, os
from jinja2 import Template
text = open(sys.argv[1]).read()
env = {
    'USER_NAME': os.environ['USER_NAME'],
    'PROJECT_DIR': os.environ['PROJECT_DIR'],
    'ACME_HOME': os.environ['ACME_HOME'],
}
print(Template(text).render(**env), end='')
" "$1"
}

# --- 5. Install sudoers ---
log "Installing sudoers whitelist..."
render_template "${PROJECT_DIR}/system/sudoers.d/vacuum-wall" \
    | install -m 0440 /dev/stdin /etc/sudoers.d/vacuum-wall

visudo -cf /etc/sudoers.d/vacuum-wall || err "Invalid sudoers file!"

# --- 6. Install systemd units ---
log "Installing systemd units..."
render_template "${PROJECT_DIR}/system/systemd/vacuum-wall.service" \
    | install -m 0644 /dev/stdin /etc/systemd/system/vacuum-wall.service

render_template "${PROJECT_DIR}/system/systemd/vacuum-wall-acme.service" \
    | install -m 0644 /dev/stdin /etc/systemd/system/vacuum-wall-acme.service

install -m 0644 "${PROJECT_DIR}/system/systemd/vacuum-wall-acme.timer" /etc/systemd/system/vacuum-wall-acme.timer
systemctl daemon-reload

# --- 7. Enable IP forwarding ---
log "Enabling IP forwarding..."
if ! grep -q "^net.ipv4.ip_forward=1" /etc/sysctl.conf 2>/dev/null; then
    echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
fi
sysctl -w net.ipv4.ip_forward=1 2>/dev/null || warn "Could not enable IP forwarding (may need kernel access)"

# --- 8. Start and configure firewalld ---
log "Enabling firewalld..."
systemctl enable firewalld >/dev/null 2>&1 || warn "Could not enable firewalld (already running?)"
systemctl start firewalld >/dev/null 2>&1 || warn "Could not start firewalld (may need D-Bus)"

firewall-cmd --permanent --add-service=http >/dev/null 2>&1 || true
log "Added service http to public zone"
firewall-cmd --permanent --add-service=https >/dev/null 2>&1 || true
log "Added service https to public zone"
firewall-cmd --permanent --add-service=ssh >/dev/null 2>&1 || true
log "Added service ssh to public zone"
firewall-cmd --reload >/dev/null 2>&1 || true
log "Firewalld rules reloaded"

# --- 9. Configure dnsmasq ---
log "Configuring dnsmasq..."
systemctl enable dnsmasq >/dev/null 2>&1 || true
systemctl start dnsmasq >/dev/null 2>&1 || warn "Could not start dnsmasq (no interfaces configured yet)"
log "dnsmasq configured (will fully start after DHCP ranges are set)"

# --- 10. Setup nginx management proxy ---
log "Generating self-signed certificate for management domain..."
mkdir -p "$ACME_HOME/$DOMAIN"

openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
    -keyout "$ACME_HOME/$DOMAIN/$DOMAIN.key" \
    -out "$ACME_HOME/$DOMAIN/fullchain.cer" \
    -subj "/CN=$DOMAIN" \
    -addext "subjectAltName=DNS:$DOMAIN"

chown -R "$USER_NAME:$USER_NAME" "$ACME_HOME"

# Generate htpasswd directly in data/nginx/
htpasswd -cb "${PROJECT_DIR}/data/nginx/.htpasswd" "$MGMT_USER" "$MGMT_PASS" 2>/dev/null || \
    MGMT_USER="$MGMT_USER" MGMT_PASS="$MGMT_PASS" HTFILE="${PROJECT_DIR}/data/nginx/.htpasswd" python3 -c "
import os, crypt, base64
password = os.environ['MGMT_PASS']
user = os.environ['MGMT_USER']
salt = '\$6\$' + base64.b64encode(os.urandom(16)).decode().rstrip('=')[:16]
hashed = crypt.crypt(password, salt)
with open(os.environ['HTFILE'], 'w') as f:
    f.write(user + ':' + hashed + '\n')
" 2>/dev/null || \
    warn "Could not generate htpasswd (install apache2-utils or python3-crypt)"

chown "$USER_NAME:$USER_NAME" "${PROJECT_DIR}/data/nginx/.htpasswd"

# Remove default nginx site so vacuum-wall management config takes precedence
rm -f /etc/nginx/sites-enabled/default

# Write WebSocket upgrade map (nginx conf.d/ is already inside http {} context)
cat > /etc/nginx/conf.d/vacuum-wall-map.conf <<'MAPEOF'
# Vacuum Wall - WebSocket upgrade map
map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}
MAPEOF

# Write the management site block (conf.d/ is inside http {}, no extra http {} needed)
cat > /etc/nginx/conf.d/vacuum-wall-mgmt.conf <<MGMTSITEEOF
# Vacuum Wall - Management Proxy
# Auto-generated by install.sh

server {
    listen 80;
    server_name $DOMAIN;
    return 301 https://\$host\$request_uri;
}

server {
    listen 443 ssl;
    server_name $DOMAIN;

    ssl_certificate $ACME_HOME/$DOMAIN/fullchain.cer;
    ssl_certificate_key $ACME_HOME/$DOMAIN/$DOMAIN.key;

    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;
    ssl_prefer_server_ciphers off;

    auth_basic "Vacuum Wall";
    auth_basic_user_file ${PROJECT_DIR}/data/nginx/.htpasswd;

    location / {
        proxy_pass http://127.0.0.1:9090;
        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;

        # WebSocket support
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection \$connection_upgrade;
    }
}
MGMTSITEEOF

# --- 11. Write initial nginx config.json ---
log "Writing initial nginx configuration..."
MGMT_DOMAIN="$DOMAIN" \
MGMT_USER="$MGMT_USER" \
INSTALL_DIR="$PROJECT_DIR" \
"${PROJECT_DIR}/.venv/bin/python3" -c "
import json, os
d = os.environ['MGMT_DOMAIN']
u = os.environ['MGMT_USER']
p = os.environ['INSTALL_DIR']
cfg = {
    'domains': {},
    'management': {
        'domain': d,
        'backend': {
            'host': '127.0.0.1',
            'port': 9090,
            'proto': 'http'
        },
        'auth': {
            'user': u,
            'htpasswd': p + '/data/nginx/.htpasswd'
        }
    },
    'ssl': {
        'protocols': 'TLSv1.2 TLSv1.3',
        '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',
        'prefer_server_ciphers': False
    }
}
with open(os.path.join(p, 'config/nginx/config.json'), 'w') as f:
    json.dump(cfg, f, indent=4)
    f.write('\n')
"

# --- 12. Auto-detect interfaces and setup initial firewalld zones ---
log "Detecting network interfaces..."

# Auto-detect WAN (interface with default gateway)
WAN_IFACE="${WAN_IFACE:-}"
if [[ -z "$WAN_IFACE" ]]; then
    DETECTED_WAN=$(ip route show default 2>/dev/null | awk '/default/ {print $5; exit}')
    if [[ -n "$DETECTED_WAN" ]]; then
        WAN_IFACE="$DETECTED_WAN"
        log "Auto-detected WAN interface: $WAN_IFACE"
    else
        warn "Could not auto-detect WAN interface — set WAN_IFACE env var"
    fi
fi

# Auto-detect LAN (all non-loopback, non-Docker, non-WAN, non-virtual interfaces)
LAN_IFACES="${LAN_IFACES:-}"
if [[ -z "$LAN_IFACES" ]]; then
    DETECTED_LANS=$(ls /sys/class/net/ 2>/dev/null \
        | grep -vE "^(lo|docker|br-|virbr|${WAN_IFACE})$")
    if [[ -n "$DETECTED_LANS" ]]; then
        LAN_IFACES=$(echo "$DETECTED_LANS" | paste -sd ',' -)
        log "Auto-detected LAN interfaces: $LAN_IFACES"
    else
        warn "Could not auto-detect LAN interfaces — set LAN_IFACES env var"
    fi
fi

# Generate config/firewall/config.json
log "Writing initial firewall configuration..."
WAN_IFACE="$WAN_IFACE" \
LAN_IFACES="$LAN_IFACES" \
INSTALL_DIR="$PROJECT_DIR" \
"${PROJECT_DIR}/.venv/bin/python3" -c "
import json, os

wan = os.environ.get('WAN_IFACE', '').strip() or None
lan = os.environ.get('LAN_IFACES', '').strip() or None
p = os.environ['INSTALL_DIR']

cfg = {'zones': {}}

if wan:
    cfg['zones']['public'] = {
        'target': 'DEFAULT',
        'interfaces': [i for i in wan.split(',') if i],
        'services': ['http', 'https', 'ssh'],
        'masquerade': True,
    }

if lan:
    cfg['zones']['internal'] = {
        'target': 'ACCEPT',
        'interfaces': [i for i in lan.split(',') if i],
        'services': ['dhcp', 'dns', 'ntp'],
        'masquerade': False,
    }

# Always create vpn zone skeleton for later WireGuard setup
cfg['zones']['vpn'] = {
    'target': 'ACCEPT',
    'interfaces': [],
    'services': [],
    'masquerade': False,
}

with open(os.path.join(p, 'config/firewall/config.json'), 'w') as f:
    json.dump(cfg, f, indent=2)
    f.write('\n')
"

# Apply zones via firewall-cmd (Python venv not yet fully available for apply_config)
firewall-cmd --permanent --new-zone=internal >/dev/null 2>&1 || true
log "Created firewalld zone: internal"
firewall-cmd --permanent --zone=internal --set-target=ACCEPT >/dev/null 2>&1 || true
firewall-cmd --permanent --zone=internal --add-service=dhcp >/dev/null 2>&1 || true
log "Added service dhcp to internal zone"
firewall-cmd --permanent --zone=internal --add-service=dns >/dev/null 2>&1 || true
log "Added service dns to internal zone"
firewall-cmd --permanent --zone=internal --add-service=ntp >/dev/null 2>&1 || true
log "Added service ntp to internal zone"

firewall-cmd --permanent --new-zone=vpn >/dev/null 2>&1 || true
log "Created firewalld zone: vpn"
firewall-cmd --permanent --zone=vpn --set-target=ACCEPT >/dev/null 2>&1 || true

# Apply masquerade on public/WAN
if [[ -n "$WAN_IFACE" ]]; then
    firewall-cmd --permanent --zone=public --add-masquerade >/dev/null 2>&1 || true
    log "Enabled masquerade on public zone ($WAN_IFACE)"
    firewall-cmd --permanent --zone=public --add-interface="$WAN_IFACE" >/dev/null 2>&1 || true
    log "Assigned $WAN_IFACE to public zone"
fi

# Assign LAN interfaces to internal zone
if [[ -n "$LAN_IFACES" ]]; then
    IFS=',' read -ra LAN_ARRAY <<< "$LAN_IFACES"
    for iface in "${LAN_ARRAY[@]}"; do
        iface=$(echo "$iface" | xargs)
        [[ -z "$iface" ]] && continue
        firewall-cmd --permanent --zone=internal --add-interface="$iface" >/dev/null 2>&1 || true
        log "Assigned $iface to internal zone"
    done
fi

firewall-cmd --reload >/dev/null 2>&1 || true
log "Firewalld rules reloaded"

# --- 13. Enable and start services ---
log "Enabling services..."
systemctl enable nginx >/dev/null 2>&1 || true
log "Enabled nginx"
systemctl enable vacuum-wall >/dev/null 2>&1 || true
log "Enabled vacuum-wall"
systemctl enable vacuum-wall-acme.timer >/dev/null 2>&1 || true
log "Enabled vacuum-wall-acme.timer"

systemctl enable avahi-daemon >/dev/null 2>&1 || true
log "Enabled avahi-daemon"
systemctl start avahi-daemon >/dev/null 2>&1 && log "Started avahi-daemon" || warn "Could not start avahi-daemon"

systemctl start nginx >/dev/null 2>&1 && log "Started nginx" || warn "Could not start nginx (check config)"
systemctl start vacuum-wall >/dev/null 2>&1 && log "Started vacuum-wall WebUI" || warn "Could not start vacuum-wall WebUI"

# --- 14. Configure acme.sh default email ---
log "Configuring acme.sh default email..."
sudo -u "$USER_NAME" env ACME_HOME="$ACME_HOME" HOME="$PROJECT_DIR" \
    "$ACME_HOME/acme.sh" --register-account -m "$ACME_EMAIL" 2>/dev/null || \
    warn "Could not register acme.sh account (will be done from WebUI)"

# --- Done ---
echo ""
echo "============================================"
echo -e "  ${GREEN}Vacuum Wall installed successfully!${NC}"
echo "============================================"
echo ""
echo "  Management UI: https://$DOMAIN"
echo "  User: $MGMT_USER"
echo "  WebUI service: vacuum-wall.service"
echo "  ACME renewal:  vacuum-wall-acme.timer"
echo ""
echo "  Firewall zones:"
if [[ -n "$WAN_IFACE" ]]; then
    echo "    public   (WAN) → $WAN_IFACE"
else
    echo "    public   (WAN) → not assigned"
fi
if [[ -n "$LAN_IFACES" ]]; then
    echo "    internal (LAN) → $LAN_IFACES"
else
    echo "    internal (LAN) → not assigned"
fi
echo ""
echo "  Next steps:"
echo "  1. Verify zone assignments at https://$DOMAIN/interfaces"
echo "  2. Configure DHCP ranges for your LAN"
echo "  3. Add proxy domains with ACME certificates"
echo "  4. Set up WireGuard tunnel (optional)"
echo ""
echo "  NOTE: A self-signed certificate was generated."
echo "  From the WebUI, issue a real certificate for $DOMAIN"
echo "  when DNS points to this appliance."
echo ""