#!/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; }

# --- CLI argument parsing ---
_cli_user=""
_cli_is_dev=false
_cli_path=""
_cli_mgmt_pass=""
_cli_mgmt_user=""
_cli_mgmt_domain=""
_cli_force_venv=false
_cli_wan_iface=""
_cli_lan_ifaces=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        --user|-u)       _cli_user="$2"; shift 2 ;;
        --path|-p)       _cli_path="$2"; shift 2 ;;
        --dev)           _cli_is_dev=true; shift ;;
        --mgmt-pass)     _cli_mgmt_pass="$2"; shift 2 ;;
        --mgmt-user)     _cli_mgmt_user="$2"; shift 2 ;;
        --mgmt-domain)   _cli_mgmt_domain="$2"; shift 2 ;;
        --force-venv)    _cli_force_venv=true; shift ;;
        --wan-iface)     _cli_wan_iface="$2"; shift 2 ;;
        --lan-ifaces)    _cli_lan_ifaces="$2"; shift 2 ;;
        -h|--help)
            printf '%s\n' \
              "Usage: scripts/install.sh [OPTIONS]" \
              "" \
              "Options:" \
              "  --user, -u USER        WebUI user (created if it does not exist, required for non-dev mode)" \
              "  --path, -p DIR         Install directory (default: repo root)" \
              "  --dev                  Dev mode: auto-detect repo owner, skip safety warning" \
               "  --mgmt-pass PASS       Initial admin password (required)" \
               "  --mgmt-user USER       Initial admin username (default: admin)" \
               "  --mgmt-domain DOMAIN   Management domain (auto-detected)" \
                "  --wan-iface IFACE      WAN interface name (auto-detected)" \
              "  --lan-ifaces IFC,...   LAN interface names, comma-separated (auto-detected)" \
              "  -h, --help             Show this help" \
              "" \
              "All options also have environment variable equivalents:" \
               "  USER_NAME, INSTALL_DIR, MGMT_PASS, MGMT_USER," \
               "  MGMT_DOMAIN, WAN_IFACE, LAN_IFACES." \
              "  CLI flags take precedence over env vars." \
              "" \
               "Example (dev):" \
               "  ./scripts/install.sh --dev --mgmt-pass pass" \
              "" \
               "Example (prod):" \
               "  MGMT_PASS=pass ./scripts/install.sh --user vacuum-wall"
            exit 0
            ;;
        *)
            err "Unknown argument: $1 (use --help for usage)"
            ;;
    esac
done

# --- Resolve config: CLI flag > env var > default ---
REPO_DIR="$(cd "$(dirname "$0")/../" && pwd)"

# Optional settings with defaults
# MGMT_PASS is strictly required — admin user is created at install time
MGMT_PASS="${_cli_mgmt_pass:-${MGMT_PASS:-}}"
MGMT_USER="${_cli_mgmt_user:-${MGMT_USER:-admin}}"

# MGMT_DOMAIN — CLI > env > auto-detect from hostname
if [[ -n "$_cli_mgmt_domain" ]]; then
    DOMAIN="$_cli_mgmt_domain"
elif [[ -n "${MGMT_DOMAIN:-}" ]]; then
    DOMAIN="$MGMT_DOMAIN"
else
    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 or --mgmt-domain."
    fi
    DOMAIN="${HOSTNAME_F}.local"
fi

# Install directory (CLI > env > repo root)
INSTALL_DIR="${_cli_path:-${INSTALL_DIR:-}}"
if [[ -n "$INSTALL_DIR" ]]; then
    PROJECT_DIR="$INSTALL_DIR"
else
    PROJECT_DIR="$REPO_DIR"
fi

# Network interfaces (CLI > env — auto-detect happens later if still unset)
WAN_IFACE="${_cli_wan_iface:-${WAN_IFACE:-}}"
LAN_IFACES="${_cli_lan_ifaces:-${LAN_IFACES:-}}"

# --- 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."

# --- Validate required settings ---
[[ -n "$MGMT_PASS" ]] || err "MGMT_PASS is required (set --mgmt-pass or MGMT_PASS env var)"
ACME_HOME="$PROJECT_DIR/data/acme"

# Dev mode: auto-detect repo owner as service user
if [[ "$_cli_is_dev" == true ]]; then
    _repo_owner=$(stat -c '%U' "$REPO_DIR" 2>/dev/null) || true
    if [[ -n "$_repo_owner" && "$_repo_owner" != "root" ]]; then
        _cli_user="$_repo_owner"
        log "Dev mode: using repo owner '$_repo_owner' as service user"
    else
        err "Dev mode: cannot determine repo owner (root or unavailable)."
    fi
fi

# Resolve USER_NAME: dev mode auto-detects, non-dev requires --user
USER_NAME="${_cli_user:-${USER_NAME:-}}"
if [[ -z "$USER_NAME" ]]; then
    err "WebUI user is required. Use --dev to auto-detect repo owner, or set --user / USER_NAME."
fi
# Daemon user name (derived from web UI user name)
USER_DAEMON_NAME="${USER_NAME}d"

# --- Safety check: running service as a regular user ---
if [[ "$_cli_is_dev" != true ]] && id "$USER_NAME" &>/dev/null; then
    _uid=$(id -u "$USER_NAME")
    _shell=$(getent passwd "$USER_NAME" | cut -d: -f7)
    if [[ "$_uid" -ge 1000 ]] && [[ "$_shell" != "/usr/sbin/nologin" && "$_shell" != "/bin/false" ]]; then
        warn "USER_NAME='$USER_NAME' is a regular user (UID=$_uid, shell=$_shell)!"
        warn "This runs the web service as your login account."
        warn "Sudo access is held only by the daemon user ($USER_DAEMON_NAME)."
    fi
fi
# Create WebUI user if it does not exist
if ! id "$USER_NAME" &>/dev/null; then
    log "Creating system user $USER_NAME..."
    useradd --system --home-dir "$PROJECT_DIR" --no-create-home --shell /usr/sbin/nologin "$USER_NAME"
fi
# Shared group: use the WebUI user's primary group
USER_GROUP=$(id -gn "$USER_NAME")

echo "============================================"
echo "  Vacuum Wall Appliance Installer"
echo "  Install dir:       $PROJECT_DIR"
echo "  WebUI user:        $USER_NAME"
echo "  Daemon user:       $USER_DAEMON_NAME"
echo "  Shared group:      $USER_GROUP"
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

# --- 1b. Vendored libraries ---
log "Downloading vendored libraries..."
bash "${PROJECT_DIR}/scripts/update-vendor.sh" || err "update-vendor.sh failed"

# --- 2. Setup users ---
log "WebUI user: $USER_NAME (group: $USER_GROUP)"

# --- 2a. Create daemon user (has sudo for privileged operations) ---
if ! id "$USER_DAEMON_NAME" &>/dev/null; then
    log "Creating system user $USER_DAEMON_NAME..."
    useradd --system --home-dir "$PROJECT_DIR" --no-create-home --shell /usr/sbin/nologin \
        --gid "$USER_GROUP" "$USER_DAEMON_NAME"
else
    log "User $USER_DAEMON_NAME already exists."
    usermod -g "$USER_GROUP" "$USER_DAEMON_NAME" 2>/dev/null || true
fi

# --- 2b. Setup Python venv ---
if [[ -x "${PROJECT_DIR}/.venv/bin/python3" ]] && [[ "$_cli_force_venv" != true ]]; then
    log "Python venv already exists, skipping (use --force-venv to recreate)."
else
    log "Setting up Python virtual environment..."
    rm -rf "${PROJECT_DIR}/.venv"
    python3 -m venv "${PROJECT_DIR}/.venv"
    "${PROJECT_DIR}/.venv/bin/pip" install -qe "${PROJECT_DIR}"
    chown -R "$USER_DAEMON_NAME:$USER_GROUP" "${PROJECT_DIR}/.venv"
    chmod -R g+x "${PROJECT_DIR}/.venv"
fi

# Install the deploy hook into acme.sh's deploy directory
# (acme.sh only resolves hooks from $ACME_HOME/deploy/)
mkdir -p "$ACME_HOME/deploy"
cp "${PROJECT_DIR}/system/acme-deploy.sh" "$ACME_HOME/deploy/acme-deploy.sh"
chown "$USER_DAEMON_NAME:$USER_GROUP" "$ACME_HOME/deploy/acme-deploy.sh"
chmod 0755 "$ACME_HOME/deploy/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
# Set ownership: daemon owns project dir in prod, repo owner keeps ownership in dev
if [[ "$_cli_is_dev" == true ]]; then
    _dev_owner="$USER_NAME"
else
    _dev_owner="$USER_DAEMON_NAME"
fi
chown -R "$_dev_owner:$USER_GROUP" "$PROJECT_DIR"
chmod -R g+rwX "$PROJECT_DIR"
find "$PROJECT_DIR" -type d -exec chmod g+s '{}' +

# --- 4. Template rendering function ---
# Renders Jinja2 templates by injecting env vars as template context.
# Used for systemd units and sudoers files.
render_template() {
    export USER_NAME USER_DAEMON_NAME USER_GROUP 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'],
    'USER_DAEMON_NAME': os.environ.get('USER_DAEMON_NAME', ''),
    'USER_GROUP': os.environ.get('USER_GROUP', ''),
    '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..."
export USER_DAEMON_NAME
render_template "${PROJECT_DIR}/system/sudoers.d/vacuum-walld" \
    | install -m 0440 /dev/stdin /etc/sudoers.d/vacuum-walld

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

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

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 (persistent via sysctl.conf + runtime apply) ---
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
# Apply immediately so NAT works without reboot
if [ "$(cat /proc/sys/net/ipv4/ip_forward 2>/dev/null)" != "1" ]; then
    sysctl -w net.ipv4.ip_forward=1 >/dev/null 2>&1 && log "IP forwarding enabled at runtime" || \
        warn "Could not enable IP forwarding at runtime"
fi

# --- 8. Detect network interfaces ---
log "Detecting network interfaces..."

# Auto-detect WAN (interface with default gateway)
WAN_IFACE="${WAN_IFACE:-}"
if [[ -z "$WAN_IFACE" ]]; then
    # Strip @if<port> suffix — physical port index can change on reboot
    DETECTED_WAN=$(ip route show default 2>/dev/null | awk '/default/ {print $5; exit}' | cut -d'@' -f1)
    if [[ -n "$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

# --- 9. Enable and start core services ---
log "Enabling services..."
systemctl enable firewalld >/dev/null 2>&1 && log "Enabled firewalld" || warn "Could not enable firewalld"
systemctl enable nginx >/dev/null 2>&1 && log "Enabled nginx" || warn "Could not enable nginx"
systemctl enable dnsmasq >/dev/null 2>&1 && log "Enabled dnsmasq" || warn "Could not enable dnsmasq"
systemctl enable vacuum-walld >/dev/null 2>&1 && log "Enabled vacuum-walld" || warn "Could not enable vacuum-walld"
systemctl enable vacuum-wall >/dev/null 2>&1 && log "Enabled vacuum-wall" || warn "Could not enable vacuum-wall"
systemctl enable vacuum-wall-acme.timer >/dev/null 2>&1 && log "Enabled vacuum-wall-acme.timer" || warn "Could not enable vacuum-wall-acme.timer"
systemctl enable avahi-daemon >/dev/null 2>&1 && log "Enabled avahi-daemon" || warn "Could not enable avahi-daemon"

# Clean up old nginx bootstrap configs (replaced by daemon-generated config)
rm -f /etc/nginx/conf.d/vacuum-wall-map.conf /etc/nginx/conf.d/vacuum-wall-mgmt.conf

# Stop all services to ensure clean start order
systemctl stop vacuum-wall >/dev/null 2>&1 || true
systemctl stop vacuum-walld >/dev/null 2>&1 || true

# Start services in dependency order
systemctl start firewalld >/dev/null 2>&1 && log "Started firewalld" || warn "Could not start firewalld"
systemctl start avahi-daemon >/dev/null 2>&1 && log "Started avahi-daemon" || warn "Could not start avahi-daemon"
systemctl start dnsmasq >/dev/null 2>&1 || warn "Could not start dnsmasq (no interfaces configured yet)"

# Start daemon and wait for socket
systemctl start vacuum-walld >/dev/null 2>&1 && log "Started vacuum-walld daemon" || warn "Could not start vacuum-walld daemon"

_SOCKET="$PROJECT_DIR/data/daemon.sock"
for _i in $(seq 1 30); do
    [[ -S "$_SOCKET" ]] && break
    sleep 0.5
done
if [[ ! -S "$_SOCKET" ]]; then
    warn "Daemon socket not found at $_SOCKET — skipping API configuration"
else
    chown "$USER_DAEMON_NAME:$USER_GROUP" "$_SOCKET" 2>/dev/null || true
    chmod 0660 "$_SOCKET" 2>/dev/null || true

    echo ""
    echo "  Setting up initial management configuration..."

    # Bootstrap auth: generate config + seed admin user
    if [[ ! -f "${PROJECT_DIR}/config/auth/config.json" ]]; then
        echo ""
        echo "  Bootstrapping auth (creating admin user: $MGMT_USER)..."

        "${PROJECT_DIR}/.venv/bin/python3" "${PROJECT_DIR}/scripts/bootstrap_auth.py" \
            --project-dir "$PROJECT_DIR" \
            --username "$MGMT_USER" \
            --password "$MGMT_PASS" \
            --domain "$DOMAIN"

        chown -R "$USER_DAEMON_NAME:$USER_GROUP" "${PROJECT_DIR}/config/auth"
        chown -R "$USER_DAEMON_NAME:$USER_GROUP" "${PROJECT_DIR}/data/auth.db" 2>/dev/null || true
    fi

    # Helper: POST JSON to daemon API over Unix socket
    _daemon_post() {
        local endpoint="$1"
        local json="$2"
        local label="${3:-POST $endpoint}"
        local resp
        if resp=$(curl -s -f --unix-socket "$_SOCKET" \
              "http://localhost${endpoint}" \
              -H "Content-Type: application/json" \
              -d "$json" 2>&1); then
            log "$label"
            return 0
        else
            warn "$label: $resp"
            return 1
        fi
    }

    # 1A. Self-signed certificate for management domain
    _daemon_post "/acme/self-signed" "{\"domain\":\"$DOMAIN\"}" "Self-signed certificate"

    # 1C. Management proxy domain (no auth — JWT auth is handled by Flask)
    local mgmt_json
    mgmt_json="$(jq -n \
      --arg domain "$DOMAIN" \
      '{
        domain: $domain,
        backend: "webui",
        cert: "selfsigned",
        force_ssl: true
      }')"
    _daemon_post "/nginx/domains/update" "$mgmt_json" "Management domain configured" || \
      _daemon_post "/nginx/domains/add" "$mgmt_json" "Management domain configured"

    _daemon_post "/nginx/apply" "{}" "Nginx config applied"

    # Firewall zone assignment
    if [[ -n "$WAN_IFACE" ]]; then
      _daemon_post "/firewall/zones/interfaces" \
        "$(jq -n --arg zone "public" --arg iface "$WAN_IFACE" \
          '{zone: $zone, interfaces: [$iface]}')" \
        "WAN interface assigned to public zone"
    fi

    if [[ -n "$LAN_IFACES" ]]; then
      # Convert comma-separated list to JSON array
      LAN_JSON=$(echo "$LAN_IFACES" | tr ',' '\n' | sed 's/^[[:space:]]*//;s/[[:space:]]*$//' | jq -R . | jq -s '.')
      _daemon_post "/firewall/zones/interfaces" \
        "$(jq -n --arg zone "internal" --argjson ifaces "$LAN_JSON" \
          '{zone: $zone, interfaces: $ifaces}')" \
        "LAN interfaces assigned to internal zone"
    fi

    unset _daemon_post
fi

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

nginx -t 2>/dev/null && nginx -s reload 2>/dev/null && log "Reloaded nginx" || \
    systemctl restart nginx >/dev/null 2>&1 && log "Restarted nginx" || \
    warn "Could not restart nginx (check config)"

# --- Done ---
echo ""
echo "============================================"
echo -e "  ${GREEN}Vacuum Wall installed successfully!${NC}"
echo "============================================"
echo ""
echo "  Management UI: https://$DOMAIN"
echo "  Admin user: $MGMT_USER"
echo "  Daemon service:  vacuum-walld.service"
echo "  WebUI service:   vacuum-wall.service"
echo "  ACME renewal:    vacuum-wall-acme.timer"
echo ""
echo "  Firewall zones:"
if [[ -n "$WAN_IFACE" ]]; then
    echo "    public   (WAN) → $WAN_IFACE"
else
    echo "    public   (WAN) → not assigned"
fi
if [[ -n "$LAN_IFACES" ]]; then
    echo "    internal (LAN) → $LAN_IFACES"
else
    echo "    internal (LAN) → not assigned"
fi
echo ""
echo "  Next steps:"
echo "  1. Register your ACME account at https://$DOMAIN/certs"
echo "  2. Verify zone assignments at https://$DOMAIN/interfaces"
echo "  3. Configure DHCP ranges for your LAN"
echo "  4. Add proxy domains with ACME certificates"
echo "  5. Set up WireGuard tunnel (optional)"
echo ""