#!/bin/bash

########################################################################################################################
#
#   Panhandler start up tool
#
#   This script will check for updates to the paloaltonetworks/panhandler:dev image and start / restart / recreate
#   the panhandler container as necessary
#
#   Feel free to leave feedback at: https://github.com/PaloAltoNetworks/panhandler/issues
#
########################################################################################################################

export IMAGE_TAG="${IMAGE_TAG:=latest}"
export DEFAULT_PORT="${DEFAULT_PORT:=8080}"
export FORCE_DEFAULT_PORT="${FORCE_DEFAULT_PORT:=false}"

export RESET_REPOSITORIES=false
export NEEDS_UPDATE=false
export CNC_VOLUME=pan_cnc_volume
export PANHANDLER_VOLUME=panhandler_volume

# used for filtering containers
export DEV_EXPOSED_PORT=8080
export LATEST_EXPOSED_PORT=8080

# used to check if the user has supplied a non-default port
export DEV_DEFAULT_PORT=8081
export LATEST_DEFAULT_PORT=8080

# default panhandler auth if not set from the environment
export CNC_USERNAME="${CNC_USERNAME:=paloalto}"
export CNC_PASSWORD="${CNC_PASSWORD:=panhandler}"

function ensure_docker_volume() {
  if [[ ! $(docker volume ls -q -f name=$CNC_VOLUME) ]]; then
    echo "Creating data volume"
    docker volume create $CNC_VOLUME
  fi

  if [[ ! $(docker volume ls -q -f name=$PANHANDLER_VOLUME) ]]; then
    echo "Creating home volume"
    docker volume create $PANHANDLER_VOLUME
  fi
}

function validate_container_id() {
  # container id will always be 13 characters. Anything is either blank or an error message along the way
  # example: b977b1401f9e
  PH_ID=$1
  echo " " >&2
  echo "  Checking ${PH_ID}" >&2
  if [[ -z $PH_ID ]]; then
    return 1
  fi

  len=$(echo $1 | wc -c | sed -e 's/ //g')
  if [[ $len -eq '13' ]]; then
    return 0
  else
    return 1
  fi
}

function find_panhandler_container_id() {

  # first check for a name and ancestor
  PANHANDLER_ID=$(docker ps -a -q -f name=panhandler -f ancestor="$PANHANDLER_IMAGE")
  if validate_container_id "${PANHANDLER_ID}"; then
    echo "${PANHANDLER_ID}"
    return 0
  fi
  # maybe name hasn't been set but we have the right image here
  PANHANDLER_ID=$(docker ps -a -q -f ancestor="$PANHANDLER_IMAGE")
  if validate_container_id "${PANHANDLER_ID}"; then
    echo "${PANHANDLER_ID}"
    return 0
  fi
  # in the following cases, maybe the user has pulled a new image in which case we can no longer see the ancestor image
  # we will have to filter images using the known exposed ports
  # ancestor is no longer available after a pull, check for a name being set and the exposed port
  PANHANDLER_ID=$(docker ps -a -q -l -f name=panhandler -f expose="${EXPOSED_PORT}")
  if validate_container_id "${PANHANDLER_ID}"; then
    # since the ancestor is incorrect, we know we're gonna need to stop, rm, and recreate
    NEEDS_UPDATE=true
    export NEEDS_UPDATE
    echo "${PANHANDLER_ID}"
    return 0
  fi
  # ok, no ancestor and no name is set either :-|
  # filter on known command string, known exposed port, and ensure a published port (grep tcp ensures this)
  # finally, only return the first match found in case we have more than 1 for some reason...
  PANHANDLER_ID=$(
    docker ps -a --format "{{.ID}} {{.Command}} {{ .Ports}}" -f expose="${EXPOSED_PORT}" |
      grep '/app/cnc/tools/ph.sh' |
      grep 'tcp' |
      head -1 |
      awk '{ print $1} '
  )
  if validate_container_id "${PANHANDLER_ID}"; then
    # since the ancestor is incorrect, we know we're gonna need to stop, rm, and recreate
    NEEDS_UPDATE=true
    export NEEDS_UPDATE
    echo "${PANHANDLER_ID}"
    return 0
  fi

  # at this point we can be reasonably sure panhandler does not exist on this instance in some form or fashion
  return 1
}

function container_has_correct_image() {
  FOUND=$(docker ps -a -q -f id="$PANHANDLER_ID" -f ancestor="$PANHANDLER_IMAGE")
  if validate_container_id "$FOUND"; then
    return 0
  fi
  # this container has an out of date image
  return 1
}

function create_panhandler_container() {
  echo "  Creating and running new Panhandler container"
  echo " "
  # shellcheck disable=SC2086
  ensure_docker_volume
  docker run -p ${DEFAULT_PORT}:${LATEST_EXPOSED_PORT} -t -d \
    -v "$PANHANDLER_VOLUME":/home/cnc_user \
    -v "$CNC_VOLUME":/home/cnc_user/.pan_cnc \
    -v "/var/run/docker.sock:/var/run/docker.sock" \
    -e CNC_USERNAME \
    -e CNC_PASSWORD \
    --name panhandler "${PANHANDLER_IMAGE}"

  # check if on a mac - this is only needed on Linux
  if uname -a | grep -q -i darwin; then
    return 0
  fi
}

function get_existing_published_port() {
  FOUND_PORT=$(docker inspect "${PANHANDLER_ID}" |
    grep "HostPort" |
    head -1 |
    awk '{ print $2 }' |
    sed -e 's/"//g')
  if [[ -n $FOUND_PORT ]]; then
    echo "$FOUND_PORT"
  else
    echo "$DEFAULT_PORT"
  fi
}

while getopts ":t:r:p:w:u:h" opt; do
  case ${opt} in
  t)
    IMAGE_TAG="$OPTARG"
    ;;
  p)
    DEFAULT_PORT="$OPTARG"
    FORCE_DEFAULT_PORT=true
    ;;
  r)
    RESET_REPOSITORIES="$OPTARG"
    ;;
  w)
    CNC_PASSWORD="$OPTARG"
    ;;
  u)
    CNC_USERNAME="$OPTARG"
    ;;
  h)
    echo "Valid options are: "
    echo "-t Image tag (latest, dev, beta)"
    echo "-p local port binding, default is 8080 *note this will be ignored if the container is already running"
    echo "-r Reset Panhandler local settings (true, false)"
    echo "Reset will remove all imported repositories, local caches, and environments"
    exit 0
    ;;
  \?)
    echo "Invalid option -$OPTARG" >&2
    ;;
  :)
    echo "Option -$OPTARG requires an argument." >&2
    exit 1
    ;;
  esac
done

case ${IMAGE_TAG} in
latest) ;;

dev) ;;

beta) ;;

\?)
  echo "Invalid tag - Please use latest, dev, or beta"
  exit 1
  ;;
esac

if [[ ! $(command -v docker) ]]; then
  echo "Could not find the docker command, please ensure you have docker installed on this machine"
  exit 1
fi

echo "==================================================================================================="
echo " "
echo "  Welcome to Panhandler"
echo " "
echo "==================================================================================================="

if [[ ${IMAGE_TAG} == latest ]]; then
  EXPOSED_PORT=${LATEST_EXPOSED_PORT}
  export EXPOSED_PORT

  # now that we (maybe?) have the container ID, ensure we use the latest tag from here on out
  PANHANDLER_IMAGE=paloaltonetworks/panhandler:latest
  export PANHANDLER_IMAGE

  PANHANDLER_ID=$(find_panhandler_container_id)
  export PANHANDLER_ID

else
  EXPOSED_PORT=${DEV_EXPOSED_PORT}
  export EXPOSED_PORT

  PANHANDLER_IMAGE=paloaltonetworks/panhandler:${IMAGE_TAG}
  export PANHANDLER_IMAGE

  # fix for returning more than 1 container. This returns only the latest created container
  PANHANDLER_ID=$(find_panhandler_container_id)
  export PANHANDLER_ID

fi

echo " "
echo "  Checking for image updates ... (This may take some time while the image downloads)"

docker pull "${PANHANDLER_IMAGE}" | grep 'Image is up to date' >/dev/null

# shellcheck disable=SC2181
if [[ $? -eq 0 ]]; then
  echo " "
  echo "  ${PANHANDLER_IMAGE} is already up to date!"
else
  echo "  Panhandler is out of date, and will need to be restarted"
  echo " "
  NEEDS_UPDATE=true
fi

if [[ ${RESET_REPOSITORIES} == true ]]; then
  echo " "
  echo "  Moving Panhandler data directory to backup"
  DATESTRING=$(date "+%Y-%m-%d-%H:%M:%S")
  # shellcheck disable=SC2086
  mv ~/.pan_cnc/panhandler ~/.pan_cnc/panhandler.backup.${DATESTRING}
  mkdir ~/.pan_cnc/panhandler
fi

if [[ -z "${PANHANDLER_ID}" ]]; then
  echo " "
  echo "  ${PANHANDLER_IMAGE} has not been started..."
  create_panhandler_container

else
  echo " "
  echo "  Found container id of ${PANHANDLER_ID}"
  # we have a valid container id from a previous run, let's ensure it has the correct image as it's ancestor
  if container_has_correct_image; then
    echo " "
    echo "  This container is up-to-date!"
    NEEDS_UPDATE=false
  else
    echo " "
    echo "  This container is out-of-date"
    NEEDS_UPDATE=true
  fi

  if [[ ${NEEDS_UPDATE} == true ]]; then
    #
    # Set the port to the value the user is already using
    #
    if [[ ${FORCE_DEFAULT_PORT} == false ]]; then
      echo " "
      echo "  Getting existing port mapping for re-use"

      # check if the user has passed in a port that is not the default. If so
      # we should always use that one
      if [[ ${LATEST_DEFAULT_PORT} == {$DEFAULT_PORT} ]]; then
        DEFAULT_PORT=$(get_existing_published_port)
      fi

      echo " "
      echo "  Using ${DEFAULT_PORT} as local port mapping"
    fi
    echo " "
    echo "  Stopping Panhandler container"
    docker stop "${PANHANDLER_ID}"

    echo " "
    echo "  Removing old Panhandler container"
    docker rm -f "${PANHANDLER_ID}"

    create_panhandler_container

  else
    DEFAULT_PORT=$(get_existing_published_port)
    echo " "
    echo "  Panhandler is already up to date. Ensuring it's running"
    docker start "${PANHANDLER_ID}" >>/dev/null 2>&1
  fi
fi

echo " "
echo "  You may now use Panhandler by opening a web browser and browsing to http://localhost:${DEFAULT_PORT}"
echo " "
echo "==================================================================================================="