#!/bin/bash

# name:     citrix-update
# summary:  Startup script: Downloads and installs "Citrix Workspace"
# params:   none

########
# INIT #
########
# find all download links on update page
# find corresponding checksums

has_command() { # $command
  command -v "$1" &>/dev/null
}

needs_commands() { # $cmd1 $cmd2 ...
  local cmd
  for cmd in "${@}"; do
    if ! has_command "${cmd}"; then
      echo "Command '${cmd}' not available!" >&2
      return 1
    fi
  done
  return 0
}

needs_commands "xidel" "curl" || exit 1

echo -n "Downloading citrix update page ... " >&2
html_data="$(curl -sSfL 'https://www.citrix.com/downloads/workspace-app/linux/workspace-app-for-linux-latest.html')"
echo "OK!" >&2

# # XPath playground
# echo "${html_data}" | xidel - \
#   --silent \
#   --printed-node-format text \
#   --extract "links:=//div[contains(@class, 'ctx-dl-content')]//a[contains(@class, 'ctx-dl-link') and @rel]/@rel" \
#   --extract "csums:=//div[contains(@class, 'ctx-dl-content')]//ul[contains(@class, 'ctx-checksum-list')]/li[1]/text()"
# exit 0

# parse using XPath
declare -a links csums
eval "$( \
  echo "${html_data}" | xidel - \
    --silent \
    --output-format bash \
    --extract "links:=//div[contains(@class, 'ctx-dl-content')]//a[contains(@class, 'ctx-dl-link') and @rel]/@rel" \
    --extract "csums:=//div[contains(@class, 'ctx-dl-content')]//ul[contains(@class, 'ctx-checksum-list')]/li[1]/text()" \
)"

# ensure every link has a checksum
if [[ "${!links[*]}" != "${!csums[*]}" ]]; then
  echo "Links and Checksums don't match up!" >&2
  exit 1
fi

# postprocess data
declare -A citrix_data
for key in "${!links[@]}"; do
  link="${links["${key}"]}"

  # if link starts with "//" (no protocol), assume https
  if [[ "${link}" == "//"* ]]; then
    link="https:${link}"
  fi

  # extract checksum only (64 hex digits)
  csum="$(echo "${csums["${key}"]}" | grep -Eo "\<[[:xdigit:]]{64}\>")"

  citrix_data["${csum}"]="${link}"
done

# remove intermediate containers
unset links csums

#########
# FUNCS #
#########

find_link() { # $filename_regex
  local link_regex="://downloads\.citrix\.com/[[:digit:]]+/${1}\?__gda__=exp=[[:digit:]]+~acl=[^~]+~hmac=[[:digit:]a-f]{64}$"

  for key in "${!citrix_data[@]}"; do
    if echo "${citrix_data["${key}"]}" | grep -E "${link_regex}" &>/dev/null; then
      echo "${key} ${citrix_data["${key}"]}"
    fi
  done
}

find_link_deb() { # $name $arch
  case "${2}" in
    x86_64) local arch="amd64" ;;
    arm64) local arch="arm64" ;;
    *) local arch="${2}" ;;
  esac

  find_link "${1}_[[:digit:]\.]+_${arch}\.deb"
}

find_link_rpm() { # $name $flavor $arch
  find_link "${1}(:?-${2})?-[[:digit:]\.]+(:?-[[:digit:]]+)?.${3}\.rpm"
}

find_link_targz() { # $arch
  case "${1}" in
    x86_64) local arch="x64" ;;
    arm64) local arch="arm64" ;;
    *) local arch="${1}" ;;
  esac

  find_link "linux${arch}-[[:digit:]\.]+\.tar.gz"
}

# shellcheck disable=SC2155
list_all() {
  local debs="$(find_link_deb "[[:lower:]]+" "[[:alnum:]]+")"
  local debc="$(echo "${debs}" | wc -l)"
  echo "deb:"
  echo "${debs}"

  local rpms="$(find_link_rpm "[[:alpha:]]+" "[[:lower:]]+" "[[:alnum:]_]+")"
  local rpmc="$(echo "${rpms}" | wc -l)"
  echo "rpm:"
  echo "${rpms}"

  local tars="$(find_link_targz "[[:alnum:]]+")"
  local tarc="$(echo "${tars}" | wc -l)"
  echo "tar.gz:"
  echo "${tars}"

  local anys="$(find_link "[[:alnum:]\._-]+")"
  local anyc="$(echo "${anys}" | wc -l)"
  echo "any:"
  echo "${anys}"

  if [ $(( debc + rpmc + tarc )) -ne $(( anyc )) ]; then
    echo "Not all links matched!" >&2
    exit 1
  fi
}

download_gui() { # $link $csum $destfile
  needs_commands "curl" "zenity" "sha256sum" || return 1
  echo "Downloading '${1}' to '${3}'"

  curl -fL -o "${3}" "${1}" &
  local curlpid=$!

  yes | zenity \
    --progress --pulsate --auto-close \
    --title="Downloading" \
    --text="Downloading '${3}' ..." &
  local zenpid=$!

  while kill -0 "${curlpid}" 2>/dev/null; do
    if ! kill -0 "${zenpid}" 2>/dev/null; then
      # progress bar died; ask for abort
      if zenity \
        --question \
        --text="Abort Download?"; then
        kill "${curlpid}" 2>/dev/null || true
        echo "Download cancelled!" >&2
        break
      fi

      # restart progress bar
      yes | zenity \
        --progress --pulsate --auto-close \
        --title="Downloading" \
        --text="Downloading '${3}' ..." &
      zenpid=$!
    fi

    sleep 0.2
  done

  kill "${zenpid}" 2>/dev/null || true
  wait "${curlpid}"

  if [ "$( sha256sum "${3}" | cut -d' ' -f1 )" = "${2}" ]; then
    echo "SHA256 ${2} OK!" >&2
    return 0
  else
    echo "SHA256 ${2} mismatch!" >&2
    return 1
  fi
}

install_deb() { # $name
  needs_commands "dpkg-query" "zenity" "gdebi-gtk" || return 1

  local arch
  arch="$(uname -m)"
  echo "Trying to install ${1} DEB for ${arch}" >&2

  local link
  if ! link="$(find_link_deb "${1}" "${arch}")"; then
    echo "No DEB found!" >&2
    return 1
  elif [ "$(echo "${link}" | wc -l)" -ne 1 ]; then
    echo "More than one DEB found!" >&2
    return 1
  fi

  local csum
  csum="$(echo "${link}" | cut -d' ' -f1)"
  link="$(echo "${link}" | cut -d' ' -f2)"

  local version_available
  version_available="$(echo "${link}" | sed -r 's/^.*\/[^_]+_([[:digit:]\.]+)_[^\.]+\.deb.*$/\1/')"

  local version_installed
  if version_installed="$(dpkg-query --show --showformat='${Version}\n' "${1}")" \
  && [ "${version_available}" = "${version_installed}" ]; then
    echo "Newest version already installed!" >&2
    zenity \
        --notification \
        --window-icon="info" \
        --text="Citrix \"${1}\": Newest version is installed!"
    sleep 2

    return 0
  fi

  if ! zenity \
    --question \
    --title="New Version Available" \
    --text="<span size=\"xx-large\">Citrix Upgrade Available!</span>\n\nInstall ${1} version <b>${version_available}</b> now?"; then
    echo "Installation of ${1} cancelled!" >&2
    return 0
  fi

  local destfile
  destfile="$(mktemp --tmpdir "XXXXX_${1}_${version_available}.deb")"
  
  if download_gui "${link}" "${csum}" "${destfile}"; then
    echo "Download for ${1} successful!" >&2
    gdebi-gtk "${destfile}"
  fi

  rm -f "${destfile}"
  echo "Cleaned up '${destfile}'" >&2
  return 0
}

########
# MAIN #
########

list_all > /dev/null

if has_command "apt"; then
  install_deb "icaclient" || exit 1
  install_deb "ctxusb" || exit 1
fi

exit 0