#!/bin/sh
# Copyright 2024-2025, Lime Technology
# Copyright 2024-2025, Christoph Hummer
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 2,
# as published by the Free Software Foundation.
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

exec_entrypoint() {
  echo "Starting container..."
  echo
  echo "======================="
  echo
  eval "exec ${ORG_ENTRYPOINT} ${ORG_CMD} ${ORG_POSTARGS}"
}

error_handler() {
  if [ "${DISABLE_ERROR_HANDLER}" != "true" ]; then
    echo "ERROR: Unraid Docker Hook script throw an error!"
    echo "       Starting container without Tailscale!"
    echo
    exec_entrypoint
  fi
}

echo "======================="
echo
echo "Executing Unraid Docker Hook for Tailscale"
echo

if [ "$(id -u)" != "0" ]; then
  echo "ERROR: No root privileges!"
  error_handler
fi

if [ "${OFFICIAL_TAILSCALE_SIDECAR}" = "true" ]; then
  echo "Official Tailscale Sidecar container routine enabled!"
  echo
  OFFICIAL_TS_SIDECAR="true"
  apk update >/dev/null 2>&1
  apk add jq >/dev/null 2>&1
elif [ ! -f /usr/bin/tailscale ] || [ ! -f /usr/bin/tailscaled ]; then
  OFFICIAL_TS_SIDECAR="false"
  if [ ! -z "${TAILSCALE_EXIT_NODE_IP}" ]; then
    if [ ! -c /dev/net/tun ]; then
      echo "ERROR: Device /dev/net/tun not found!"
      echo "       Make sure to pass through /dev/net/tun to the container."
      error_handler
    fi
    INSTALL_IPTABLES="iptables "
  fi

  echo "Detecting Package Manager..."
  if which apt-get >/dev/null 2>&1; then
    echo "Detected Advanced Package Tool!"
    PACKAGES_UPDATE="apt-get update"
    PACKAGES_INSTALL="apt-get -y install --no-install-recommends"
  elif which apk >/dev/null 2>&1; then
    echo "Detected Alpine Package Keeper!"
    PACKAGES_UPDATE="apk update"
    PACKAGES_INSTALL="apk add"
  elif which pacman >/dev/null 2>&1; then
    echo "Detected pacman Package Manager!"
    PACKAGES_INSTALL="pacman -Syu --noconfirm"
  else
    echo "ERROR: Detection from Package Manager failed!"
    error_handler
  fi

  if [ "${TAILSCALE_TROUBLESHOOTING}" = "true" ]; then
    if which apt-get >/dev/null 2>&1; then
      PACKAGES_TROUBLESHOOTING="curl dnsutils iputils-ping speedtest-cli "
    elif which apk >/dev/null 2>&1; then
      PACKAGES_TROUBLESHOOTING="curl bind-tools iputils-ping speedtest-cli "
    elif which pacman >/dev/null 2>&1; then
      PACKAGES_TROUBLESHOOTING="curl dnsutils iputils speedtest-cli "
    fi
    echo "Tailscale Troubleshooting enabled!"
    echo "Installing additional packages: $(echo "${PACKAGES_TROUBLESHOOTING}" | sed 's/[[:blank:]]*$//' | sed 's/ /, /g')"
  fi

  echo "Installing packages..."
  echo "Please wait..."
  if [ ! -z "${PACKAGES_UPDATE}" ]; then
    UPDATE_LOG=$(${PACKAGES_UPDATE} 2>&1)
  fi
  INSTALL_LOG=$(${PACKAGES_INSTALL} jq wget ca-certificates ${INSTALL_IPTABLES}${PACKAGES_TROUBLESHOOTING} 2>&1)
  INSTALL_RESULT=$?

  if [ "${INSTALL_RESULT}" -eq 0 ]; then
    echo "Packages installed!"
    unset INSTALL_LOG
  else
    echo "ERROR: Installing packages!"
    echo "${UPDATE_LOG}"
    echo "${INSTALL_LOG}"
    error_handler
  fi

  if [ "${INSTALL_IPTABLES}" = "iptables " ]; then
    if ! iptables -L >/dev/null 2>&1; then
      echo "ERROR: Cap: NET_ADMIN not available!"
      echo "       Make sure to add --cap-add=NET_ADMIN to the Extra Parameters"
      error_handler
    fi
  fi

  echo "Tailscale not found, downloading..."
  echo "Please wait..."

  TAILSCALE_VERSION=$(wget -qO- 'https://pkgs.tailscale.com/stable/?mode=json' | jq -r '.TarballsVersion')

  if [ -z "${TAILSCALE_VERSION}" ]; then
    echo "ERROR: Can't get Tailscale JSON"
    error_handler
  fi

  if [ ! -d /tmp/tailscale ]; then
    mkdir -p /tmp/tailscale
  fi

  if wget -q -nc --show-progress --progress=bar:force:noscroll -O /tmp/tailscale/tailscale.tgz "https://pkgs.tailscale.com/stable/tailscale_${TAILSCALE_VERSION}_amd64.tgz" ; then
    echo "Download from Tailscale version ${TAILSCALE_VERSION} successful!"
  else
    echo "ERROR: Download from Tailscale version ${TAILSCALE_VERSION} failed!"
    rm -rf /tmp/tailscale
    error_handler
  fi

  tar -C /tmp/tailscale -xf /tmp/tailscale/tailscale.tgz
  cp /tmp/tailscale/tailscale_${TAILSCALE_VERSION}_amd64/tailscale /usr/bin/tailscale
  cp /tmp/tailscale/tailscale_${TAILSCALE_VERSION}_amd64/tailscaled /usr/bin/tailscaled
  rm -rf /tmp/tailscale

  echo "Installation Done!"
else
  OFFICIAL_TS_SIDECAR="false"
  echo "Tailscale found, continuing..."
fi

unset TSD_PARAMS
unset TS_PARAMS

if [ "${OFFICIAL_TS_SIDECAR}" = "true" ]; then
  if [ -z "${TS_STATE_DIR}" ]; then
    echo "No Tailscale State Directory specified, falling back to: /var/lib/tailscale"
    export TS_STATE_DIR="/var/lib/tailscale"
  else
    export TS_STATE_DIR="${TS_STATE_DIR}"
  fi
  TSD_STATE_DIR="${TS_STATE_DIR}"
elif [ ! -z "${TAILSCALE_STATE_DIR}" ]; then
  TSD_STATE_DIR="${TAILSCALE_STATE_DIR}"
elif [ ! -z "${SERVER_DIR}" ]; then
  TSD_STATE_DIR="${SERVER_DIR}/.tailscale_state"
elif [ ! -z "${DATA_DIR}" ]; then
  TSD_STATE_DIR="${DATA_DIR}/.tailscale_state"
elif [ ! -z "${USER_HOME}" ]; then
  TSD_STATE_DIR="${USER_HOME}/.tailscale_state"
elif [ -d "/config" ]; then
  TSD_STATE_DIR="/config/.tailscale_state"
elif [ -d "/data" ]; then
  TSD_STATE_DIR="/data/.tailscale_state"
elif [ ! -z "${CA_TS_FALLBACK_DIR}" ]; then
  TSD_STATE_DIR="${CA_TS_FALLBACK_DIR}/.tailscale_state"
else
  echo "ERROR: Couldn't detect persistent Docker directory for .tailscale_state!"
  echo "       Please enable Tailscale Advanced Settings in the Docker template and set the Tailscale State Directory manually!"
  sleep infinity
fi
echo "Settings Tailscale state dir to: ${TSD_STATE_DIR}"

if [ ! -z "${TSD_STATE_DIR}" ] && [ ! -d "${TSD_STATE_DIR}" ]; then
  mkdir -p ${TSD_STATE_DIR}
fi

if [ ! -z "${TAILSCALE_EXIT_NODE_IP}" ]; then
  echo "Disabling userspace networking! Tailscale DNS available"
  echo "Using ${TAILSCALE_EXIT_NODE_IP} as Exit Node! See https://tailscale.com/kb/1103/exit-nodes"
  TS_PARAMS=" --exit-node=${TAILSCALE_EXIT_NODE_IP}"
  if [ "${TAILSCALE_ALLOW_LAN_ACCESS}" = "true" ]; then
    echo "Enabling local LAN Access to the container!"
    TS_PARAMS="${TS_PARAMS} --exit-node-allow-lan-access"
  fi
else
  if [ -z "${TAILSCALE_USERSPACE_NETWORKING}" ] || [ "${TAILSCALE_USERSPACE_NETWORKING}" = "true" ]; then
    echo "Enabling userspace networking! Tailscale DNS not available"
    TSD_PARAMS="-tun=userspace-networking "
  else
    if [ ! -c /dev/net/tun ]; then
      echo "ERROR: Device /dev/net/tun not found!"
      echo "       Make sure to pass through /dev/net/tun to the container and add the"
      echo "       parameter --cap-add=NET_ADMIN to the Extra Parameters!"
      error_handler
    fi
  fi
fi

if [ ! -z "${TAILSCALE_ADVERTISE_ROUTES}" ]; then
  TAILSCALE_ADVERTISE_ROUTES="$(echo ${TAILSCALE_ADVERTISE_ROUTES} | sed 's/ //g')"
  echo "Advertising custom routes! See https://tailscale.com/kb/1019/subnets#advertise-subnet-routes"
  TS_PARAMS="${TS_PARAMS} --advertise-routes=${TAILSCALE_ADVERTISE_ROUTES}"
fi

if [ "${TAILSCALE_ACCEPT_ROUTES}" = "true" ]; then
  echo "Accepting subnet routes! See https://tailscale.com/kb/1019/subnets#use-your-subnet-routes-from-other-devices"
  TS_PARAMS="${TS_PARAMS} --accept-routes"
fi

if [ "${TAILSCALE_USE_SSH}" = "true" ]; then
  echo "Enabling SSH! See https://tailscale.com/kb/1193/tailscale-ssh"
  TS_PARAMS="${TS_PARAMS} --ssh"
fi

if [ "${OFFICIAL_TS_SIDECAR}" != "true" ]; then
  if [ "${TAILSCALE_LOG}" != "false" ]; then
    TSD_PARAMS="${TSD_PARAMS} >>/var/log/tailscaled 2>&1 "
    TSD_MSG=" with log file location: /var/log/tailscaled"
  else
    TSD_PARAMS="${TSD_PARAMS} >/dev/null 2>&1 "
    TSD_MSG=" with logging disabled"
  fi
fi

if [ ! -z "${TAILSCALE_HOSTNAME}" ]; then
  echo "Setting host name to \"${TAILSCALE_HOSTNAME}\""
  TAILSCALE_HOSTNAME="$(echo "$TAILSCALE_HOSTNAME" | tr -d ' ')"
  TS_PARAMS="${TS_PARAMS} --hostname=${TAILSCALE_HOSTNAME}"
fi

if [ "${OFFICIAL_TS_SIDECAR}" = "true" ]; then
  if [ ! -z "${TAILSCALE_HOSTNAME}" ]; then
    export TS_STATE_DIR="${TS_STATE_DIR}/${TAILSCALE_HOSTNAME}"
    TSD_STATE_DIR="${TS_STATE_DIR}/${TAILSCALE_HOSTNAME}"
  else
    export TS_STATE_DIR="${TS_STATE_DIR}/$(hostname)"
    TSD_STATE_DIR="${TS_STATE_DIR}/$(hostname)"
  fi
fi

if [ "${TAILSCALE_EXIT_NODE}" = "true" ]; then
  echo "Configuring container as Exit Node! See https://tailscale.com/kb/1103/exit-nodes"
  TS_PARAMS="${TS_PARAMS} --advertise-exit-node"
fi

if [ "${OFFICIAL_TS_SIDECAR}" = "true" ]; then
  if [ ! -z "${TAILSCALED_PARAMS}" ]; then
    export TS_TAILSCALED_EXTRA_ARGS="${TAILSCALED_PARAMS} ${TSD_PARAMS}"
  else
    export TS_TAILSCALED_EXTRA_ARGS="${TSD_PARAMS}"
  fi
  if [ ! -z "${TAILSCALE_PARAMS}" ]; then
    export TS_EXTRA_ARGS="${TAILSCALE_PARAMS}${TS_PARAMS}"
  else
    export TS_EXTRA_ARGS="${TS_PARAMS}"
  fi
  exec_entrypoint &
  TAILSCALE_PID=$!
else
  if [ ! -z "${TAILSCALED_PARAMS}" ]; then
    TSD_PARAMS="${TAILSCALED_PARAMS} ${TSD_PARAMS}"
  fi
  if [ ! -z "${TAILSCALE_PARAMS}" ]; then
    TS_PARAMS="${TAILSCALE_PARAMS}${TS_PARAMS}"
  fi
fi

if [ "${OFFICIAL_TS_SIDECAR}" != "true" ]; then
  echo "Starting tailscaled${TSD_MSG}"
  eval tailscaled -statedir=${TSD_STATE_DIR} ${TSD_PARAMS}&

  echo "Starting tailscale"
  eval tailscale up ${TS_PARAMS} --reset
  EXIT_STATUS="$?"

  if [ "${EXIT_STATUS}" != "0" ]; then
    echo "ERROR: Connecting to Tailscale not successful!"
    if [ -f /var/log/tailscaled ]; then
      echo "Please check the logs:"
      tail -20 /var/log/tailscaled
    fi
    error_handler
  fi
  unset EXIT_STATUS
else
  DISABLE_ERROR_HANDLER="true"
  sleep 2
fi

while true; do
  TAILSCALE_ONLINE=$(tailscale status --json | jq '.Self.Online')
  if [ "${TAILSCALE_ONLINE}" = "true" ]; then
    break
  fi
  sleep 2
done

if [ ! -z "${TAILSCALE_SERVE_PORT}" ] && [ "$(tailscale status --json | jq -r '.CurrentTailnet.MagicDNSEnabled')" != "false" ] && [ -z "$(tailscale status --json | jq -r '.Self.Capabilities[] | select(. == "https")')" ]; then
  echo "ERROR: Enable MagicDNS and HTTPS on your Tailscale account to use Tailscale Serve/Funnel."
  echo "See: https://tailscale.com/kb/1153/enabling-https"
  error_handler
fi

if [ "${TAILSCALE_EXIT_NODE}" = "true" ]; then
  if [ "$(tailscale status --json | jq -r '.Self.ExitNodeOption')" = "false" ]; then
    TSIP=$(tailscale status --json | jq -r '.Self.TailscaleIPs[0]')
    echo "WARNING: Exit Node not yet approved."
    echo "         Navigate to https://login.tailscale.com/admin/machines/${TSIP} and approve it."
  fi
fi

KEY_EXPIRY=$(tailscale status --json | jq -r '.Self.KeyExpiry')
if [ "${KEY_EXPIRY}" != "null" ]; then
  EXPIRY_EPOCH=$(date -d "${KEY_EXPIRY}" +"%s" 2>/dev/null)
  if [ -z "${EXPIRY_EPOCH}" ]; then
    EXPIRY_EPOCH=$(date -d "$(echo "${KEY_EXPIRY}" | sed 's/T/ /; s/Z//')" +"%s")
  fi
  CUR_EPOCH=$(date -u +%s)
  DIFF_EPOCH=$((EXPIRY_EPOCH - CUR_EPOCH))
  DIFF_DAYS=$((DIFF_EPOCH / 86400))
  HOST=$(tailscale status --json | jq -r '.Self.HostName')
  if [ -z "${EXPIRY_EPOCH}" ]; then
    echo "WARNING: An error occurred while retrieving the Tailscale key expiry!"
  elif [ -n "${DIFF_DAYS}" ] && echo "${DIFF_DAYS}" | grep -Eq '^[0-9]+$'; then
    echo "WARNING: Tailscale Key will expire in ${DIFF_DAYS} days."
    echo "         Navigate to https://login.tailscale.com/admin/machines and 'Disable Key Expiry' for ${HOST}"
  else
    echo "ERROR: Tailscale Key expired!"
    echo "       Navigate to https://login.tailscale.com/admin/machines and Renew/Disable Key Expiry for ${HOST}"
  fi
  echo "See: https://tailscale.com/kb/1028/key-expiry"
fi

if [ ! -z "${TAILSCALE_ADVERTISE_ROUTES}" ]; then
  APPROVED_ROUTES="$(tailscale status --json | jq -r '.Self.PrimaryRoutes')"
  IFS=','
  set -- ${TAILSCALE_ADVERTISE_ROUTES}
  ROUTES="$@"
  for route in ${ROUTES}; do
    if ! echo "${APPROVED_ROUTES}" | grep -q "${route}"; then
        NOT_APPROVED="$NOT_APPROVED ${route}"
    fi
  done
  if [ ! -z "${NOT_APPROVED}" ]; then
    TSIP="$(tailscale status --json | jq -r '.Self.TailscaleIPs[0]')"
    echo "WARNING: The following route(s) are not approved:${NOT_APPROVED}"
    echo "         Navigate to https://login.tailscale.com/admin/machines/${TSIP} and approve it."
  fi
fi

if [ ! -z "${TAILSCALE_SERVE_PORT}" ]; then
  if [ ! -z "${TAILSCALE_SERVE_PATH}" ]; then
    TAILSCALE_SERVE_PATH="=${TAILSCALE_SERVE_PATH}"
  fi
  if [ -z "${TAILSCALE_SERVE_PROTOCOL}" ]; then
    TAILSCALE_SERVE_PROTOCOL="https"
  fi
  if [ -z "${TAILSCALE_SERVE_PROTOCOL_PORT}" ]; then
    TAILSCALE_SERVE_PROTOCOL_PORT="=443"
  fi
  if [ -z "${TAILSCALE_SERVE_TARGET}" ]; then
    TAILSCALE_SERVE_TARGET="http://localhost"
  fi
  if [ "${TAILSCALE_FUNNEL}" = "true" ]; then
    echo "Enabling Funnel! See https://tailscale.com/kb/1223/funnel"
    eval tailscale funnel --bg --"${TAILSCALE_SERVE_PROTOCOL}"${TAILSCALE_SERVE_PROTOCOL_PORT}${TAILSCALE_SERVE_PATH} ${TAILSCALE_SERVE_TARGET}:"${TAILSCALE_SERVE_PORT}${TAILSCALE_SERVE_LOCALPATH}" | grep -v "To disable the proxy"
  else
    echo "Enabling Serve! See https://tailscale.com/kb/1312/serve"
    eval tailscale serve --bg --"${TAILSCALE_SERVE_PROTOCOL}"${TAILSCALE_SERVE_PROTOCOL_PORT}${TAILSCALE_SERVE_PATH} ${TAILSCALE_SERVE_TARGET}:"${TAILSCALE_SERVE_PORT}${TAILSCALE_SERVE_LOCALPATH}" | grep -v "To disable the proxy"
  fi
  if [ "${TAILSCALE_SERVE_PROTOCOL}" = "https" ]; then
    TS_DNSNAME="$(tailscale status --json | jq -r '.Self.DNSName' | sed 's/\.$//')"
    if [ ! -f "${TSD_STATE_DIR}/certs/${TS_DNSNAME}.crt" ] || [ ! -f "${TSD_STATE_DIR}/certs/${TS_DNSNAME}.key" ]; then
      if [ ! -d "${TSD_STATE_DIR}/certs" ]; then
        mkdir -p "${TSD_STATE_DIR}/certs"
      fi
      echo "Generating Tailscale certs! This can take some time, please wait..."
      timeout 30 tailscale cert --cert-file="${TSD_STATE_DIR}/certs/${TS_DNSNAME}.crt" --key-file="${TSD_STATE_DIR}/certs/${TS_DNSNAME}.key" "${TS_DNSNAME}" >/dev/null 2>&1
      EXIT_STATUS="$?"
      if [ "${EXIT_STATUS}" != "0" ] && [ "${OFFICIAL_TS_SIDECAR}" != "true" ]; then
        echo "ERROR: Can't generate certificates!"
        echo "Please check the logs:"
        tail -10 /var/log/tailscaled
      else
        echo "Done!"
      fi
      unset EXIT_STATUS
    fi
  fi
fi

if [ "${OFFICIAL_TS_SIDECAR}" != "true" ]; then
  exec_entrypoint
else
  trap "kill -SIGTERM ${TAILSCALE_PID}; exit 0" SIGTERM
  wait "${TAILSCALE_PID}"
fi