#!/usr/bin/env bash
# Setup provisioning LXC: DHCP + DNS on eth1, extra LAN IPs, VLAN eth1.40, NAT so LAN uses eth0 for internet.
# Network boot (TFTP, PXE, initrd) sections are commented out; uncomment if you need PXE/netboot.
# Run inside the LXC (as root), or from your machine: ./setup-network-boot-on-lxc.sh root@10.130.60.141 [SUBNET]
# SUBNET optional: A.B.C.D/PREFIX (e.g. 10.100.1.1/24). When run with ssh target, writes lan-subnet.conf on LXC if SUBNET given.
# When run with ssh target, rsyncs lxc/ and runs this script inside the container. Subnet is read from /opt/cm4-provisioning/lan-subnet.conf.

set -e
TARGET="${1:-}"
SUBNET_ARG="${2:-}"

if [[ -n "$TARGET" ]]; then
  # Run remotely: sync lxc/ and script, then execute inside LXC
  SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
  REPO_DIR="$(dirname "$SCRIPT_DIR")"
  echo "Syncing lxc config and script to $TARGET ..."
  rsync -a "$REPO_DIR/lxc/" "$TARGET:/tmp/cm4-network-boot-lxc/" --exclude='.git'
  # Network boot: copy initrd.img for TFTP
  # if [[ -f "$REPO_DIR/network-boot-initramfs/initrd.img" ]]; then
  #   echo "Copying initrd.img to $TARGET ..."
  #   scp "$REPO_DIR/network-boot-initramfs/initrd.img" "$TARGET:/tmp/cm4-network-boot-lxc/initrd.img"
  # else
  #   echo "Note: network-boot-initramfs/initrd.img not found (run build.sh first); skipping."
  # fi
  scp "$SCRIPT_DIR/setup-network-boot-on-lxc.sh" "$TARGET:/tmp/cm4-network-boot-lxc/setup.sh"
  # If SUBNET_ARG given, write lan-subnet.conf on LXC so inner script uses the set subnet
  if [[ -n "$SUBNET_ARG" ]]; then
    if [[ "$SUBNET_ARG" =~ ^([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)/([0-9]+)$ ]]; then
      LAN_GW="${BASH_REMATCH[1]}"
      PREFIX="${BASH_REMATCH[2]}"
      BASE_3="${LAN_GW%.*}"
      LAN_CIDR="${BASE_3}.0/${PREFIX}"
      DHCP_RANGE_START="${BASE_3}.100"
      DHCP_RANGE_END="${BASE_3}.200"
      ssh "$TARGET" "mkdir -p /opt/cm4-provisioning && echo 'LAN_GW=$LAN_GW' > /opt/cm4-provisioning/lan-subnet.conf && echo 'LAN_CIDR=$LAN_CIDR' >> /opt/cm4-provisioning/lan-subnet.conf && echo 'DHCP_RANGE_START=$DHCP_RANGE_START' >> /opt/cm4-provisioning/lan-subnet.conf && echo 'DHCP_RANGE_END=$DHCP_RANGE_END' >> /opt/cm4-provisioning/lan-subnet.conf"
      echo "Wrote lan-subnet.conf on LXC (LAN_GW=$LAN_GW, DHCP ${DHCP_RANGE_START}-${DHCP_RANGE_END})."
    else
      echo "Warning: SUBNET must be A.B.C.D/PREFIX (e.g. 10.100.1.1/24); ignoring '$SUBNET_ARG'."
    fi
  fi
  ssh "$TARGET" "bash /tmp/cm4-network-boot-lxc/setup.sh"
  echo "Done."
  exit 0
fi

# --- Running inside the LXC from here ---
# LAN subnet: use /opt/cm4-provisioning/lan-subnet.conf (written by deploy-to-proxmox.sh or passed as SUBNET when running remotely)
# Optional first arg when running locally: A.B.C.D/PREFIX to set/write lan-subnet.conf
LAN_CONF="/opt/cm4-provisioning/lan-subnet.conf"
if [[ "$1" =~ ^([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)/([0-9]+)$ ]]; then
  LAN_GW="${BASH_REMATCH[1]}"
  PREFIX="${BASH_REMATCH[2]}"
  BASE_3="${LAN_GW%.*}"
  LAN_CIDR="${BASE_3}.0/${PREFIX}"
  DHCP_RANGE_START="${BASE_3}.100"
  DHCP_RANGE_END="${BASE_3}.200"
  mkdir -p /opt/cm4-provisioning
  echo "LAN_GW=$LAN_GW" > "$LAN_CONF"
  echo "LAN_CIDR=$LAN_CIDR" >> "$LAN_CONF"
  echo "DHCP_RANGE_START=$DHCP_RANGE_START" >> "$LAN_CONF"
  echo "DHCP_RANGE_END=$DHCP_RANGE_END" >> "$LAN_CONF"
  echo "Using set subnet: $LAN_CIDR (gateway $LAN_GW), DHCP ${DHCP_RANGE_START}-${DHCP_RANGE_END}."
elif [[ -f "$LAN_CONF" ]]; then
  source "$LAN_CONF"
else
  LAN_GW="10.20.50.1"
  LAN_CIDR="10.20.50.0/24"
  DHCP_RANGE_START="10.20.50.100"
  DHCP_RANGE_END="10.20.50.200"
  echo "No lan-subnet.conf and no SUBNET argument; using defaults: $LAN_CIDR."
fi
echo "Configuring LAN (DHCP + DNS on eth1, NAT via eth0) — LAN $LAN_CIDR (gateway $LAN_GW), DHCP ${DHCP_RANGE_START}-${DHCP_RANGE_END} ..."

# 1) Install dnsmasq and vlan (for eth1.40)
if ! command -v dnsmasq >/dev/null 2>&1; then
  apt-get update -qq && DEBIAN_FRONTEND=noninteractive apt-get install -y -qq dnsmasq
fi
if ! command -v vconfig >/dev/null 2>&1; then
  apt-get update -qq && DEBIAN_FRONTEND=noninteractive apt-get install -y -qq vlan
fi

# 2) dnsmasq config for eth1 only (DHCP + DNS). PXE/TFTP in network-boot-pxe.conf when needed (toggle-network-boot-dhcp.sh)
mkdir -p /etc/dnsmasq.d
cat > /etc/dnsmasq.d/network-boot.conf << DNSMASQ
# DHCP + DNS on eth1 only (provisioning LAN)
# (TFTP/PXE options in network-boot-pxe.conf when network boot is enabled)
interface=eth1
bind-interfaces
dhcp-range=${DHCP_RANGE_START},${DHCP_RANGE_END},12h
# DNS: file.server resolves to this host (eth1) so scripts can use http://file.server/...
address=/file.server/${LAN_GW}
# Explicitly send this host as DNS server to DHCP clients (option 6) so they use LXC DNS and resolve file.server
dhcp-option=6,${LAN_GW}
# Other DNS queries forwarded via LXC's resolv.conf
log-dhcp
log-queries
DNSMASQ
mkdir -p /opt/cm4-provisioning
# Network boot: install toggle script and enable PXE/TFTP
# if [ -f /tmp/cm4-network-boot-lxc/toggle-network-boot-dhcp.sh ]; then
#   cp /tmp/cm4-network-boot-lxc/toggle-network-boot-dhcp.sh /opt/cm4-provisioning/
#   chmod +x /opt/cm4-provisioning/toggle-network-boot-dhcp.sh
#   /opt/cm4-provisioning/toggle-network-boot-dhcp.sh enable
# fi

# 3) Network boot: TFTP root — fetch Raspberry Pi 4 boot files from GitHub if missing
# mkdir -p /srv/tftpboot
# if [[ ! -f /srv/tftpboot/start4cd.elf ]]; then
#   echo "Fetching Raspberry Pi firmware boot files from GitHub ..."
#   if ! command -v curl >/dev/null 2>&1 && ! command -v wget >/dev/null 2>&1; then
#     apt-get update -qq && DEBIAN_FRONTEND=noninteractive apt-get install -y -qq curl
#   fi
#   tmpdir=$(mktemp -d)
#   trap "rm -rf $tmpdir" EXIT
#   if command -v curl >/dev/null 2>&1; then
#     curl -sL "https://github.com/raspberrypi/firmware/archive/refs/heads/master.tar.gz" -o "$tmpdir/firmware.tar.gz"
#   else
#     wget -q -O "$tmpdir/firmware.tar.gz" "https://github.com/raspberrypi/firmware/archive/refs/heads/master.tar.gz"
#   fi
#   tar xzf "$tmpdir/firmware.tar.gz" -C "$tmpdir"
#   cp -a "$tmpdir/firmware-master/boot/." /srv/tftpboot/
#   rm -rf "$tmpdir"
#   echo "Copied RPi boot files to /srv/tftpboot"
# else
#   echo "TFTP root already has boot files (start4cd.elf present), skipping fetch."
# fi

# 3b) Network boot: copy provisioning initrd.img to TFTP root if provided
# if [[ -f /tmp/cm4-network-boot-lxc/initrd.img ]]; then
#   cp /tmp/cm4-network-boot-lxc/initrd.img /srv/tftpboot/initrd.img
#   echo "Copied initrd.img to /srv/tftpboot"
#   if [[ -f /srv/tftpboot/config.txt ]] && ! grep -q 'initramfs initrd.img' /srv/tftpboot/config.txt 2>/dev/null; then
#     echo "" >> /srv/tftpboot/config.txt
#     echo "# Provisioning initramfs (network-boot-initramfs)" >> /srv/tftpboot/config.txt
#     echo "initramfs initrd.img followkernel" >> /srv/tftpboot/config.txt
#     echo "Added initramfs line to config.txt"
#   fi
# fi

# 4) Extra LAN IPs on eth1 (192.168.30.1, 192.168.127.1) and VLAN eth1.40 (192.168.0.1/24)
EXTRA_LAN_CONF="/etc/network/interfaces.d/70-cm4-extra-lan"
if [[ -f /tmp/cm4-network-boot-lxc/70-cm4-extra-lan ]]; then
  mkdir -p /etc/network/interfaces.d
  cp /tmp/cm4-network-boot-lxc/70-cm4-extra-lan "$EXTRA_LAN_CONF"
  # Ensure main interfaces includes interfaces.d (Debian)
  if [[ -f /etc/network/interfaces ]] && ! grep -q 'interfaces.d' /etc/network/interfaces 2>/dev/null; then
    echo 'source /etc/network/interfaces.d/*' >> /etc/network/interfaces
  fi
  # Apply immediately: secondary IPs on eth1
  ip addr add 192.168.30.1/24 dev eth1 2>/dev/null || true
  ip addr add 192.168.127.1/24 dev eth1 2>/dev/null || true
  # Create and bring up eth1.40 (VLAN 40)
  ip link add link eth1 name eth1.40 type vlan id 40 2>/dev/null || true
  ip addr add 192.168.0.1/24 dev eth1.40 2>/dev/null || true
  ip link set eth1.40 up 2>/dev/null || true
  echo "Extra LAN: eth1 + 192.168.30.1/24, 192.168.127.1/24; eth1.40 192.168.0.1/24 (persisted in $EXTRA_LAN_CONF)"
fi

# 5) IP forwarding (LAN clients use WAN)
echo 'net.ipv4.ip_forward=1' > /etc/sysctl.d/99-cm4-network-boot.conf
sysctl -p /etc/sysctl.d/99-cm4-network-boot.conf 2>/dev/null || sysctl -w net.ipv4.ip_forward=1

# 6) NAT: primary LAN + extra LAN subnets + VLAN 40 -> eth0 (masquerade)
# Subnets: primary (from lan-subnet.conf), 192.168.30.0/24, 192.168.127.0/24, 192.168.0.0/24 (eth1.40)
if command -v nft >/dev/null 2>&1; then
  mkdir -p /etc/nftables.d
  cat > /etc/nftables.d/nat-lan.conf << NFT
table ip nat {
	chain postrouting {
		type nat hook postrouting priority srcnat; policy accept;
		ip saddr ${LAN_CIDR} oifname "eth0" masquerade
		ip saddr 192.168.30.0/24 oifname "eth0" masquerade
		ip saddr 192.168.127.0/24 oifname "eth0" masquerade
		ip saddr 192.168.0.0/24 oifname "eth0" masquerade
	}
}
NFT
  if ! nft list table ip nat 2>/dev/null | grep -q postrouting; then
    nft -f /etc/nftables.d/nat-lan.conf
  else
    nft -f /etc/nftables.d/nat-lan.conf
  fi
  # Ensure main config includes our drop-in (Debian)
  if [[ -f /etc/nftables.conf ]] && ! grep -q 'nftables.d/nat-lan' /etc/nftables.conf 2>/dev/null; then
    echo 'include "/etc/nftables.d/nat-lan.conf"' >> /etc/nftables.conf
  fi
  echo "NAT rules added (nftables): ${LAN_CIDR}, 192.168.30.0/24, 192.168.127.0/24, 192.168.0.0/24 -> eth0"
else
  # Fallback iptables
  for cidr in "${LAN_CIDR}" 192.168.30.0/24 192.168.127.0/24 192.168.0.0/24; do
    iptables -t nat -C POSTROUTING -s "$cidr" -o eth0 -j MASQUERADE 2>/dev/null || \
      iptables -t nat -A POSTROUTING -s "$cidr" -o eth0 -j MASQUERADE
  done
  echo "NAT rules added (iptables) for primary LAN and extra subnets."
fi

# 7) Enable and start dnsmasq
systemctl enable dnsmasq
systemctl restart dnsmasq

echo "Setup done."
echo "  - DHCP + DNS on eth1 ($LAN_GW), range ${DHCP_RANGE_START}-${DHCP_RANGE_END}"
echo "  - NAT: ${LAN_CIDR}, 192.168.30.0/24, 192.168.127.0/24, 192.168.0.0/24 -> eth0 (internet)"
echo "  - Extra LAN: eth1 also 192.168.30.1, 192.168.127.1; eth1.40 192.168.0.1/24 (VLAN 40)"
# echo "  - TFTP root: /srv/tftpboot (RPi boot files; initrd.img if provided)"  # when network boot enabled
