#!/bin/sh

die() {
  [ -n "$1" ] && echo ERROR "$1" >&2
  exit ${2:-1}
}

usage() {
  die "\
Usage: $0 [-s download_url] [-p packages_url_prefix] [-d destdir] [-u jet_user] [-S]

  -s - source download URL, env DOWNLOAD_URL (default: $DOWNLOAD_URL)
  -p - packages download URL prefix, env PACKAGER_URL_PREFIX (default: $PACKAGER_URL_PREFIX)
  -d - destination directory, env DESTDIR (default: $DESTDIR)
  -u - jet user, env JET_USER (default: $JET_USER)
  -S - don't start jet after downloading and installing
"
}

#
# Default values and check if running as root
#

: ${JET_ROOT:=/jet}
: ${DOWNLOAD_URL:='http://jetware.io/appliances/jetware/memcached14-170503/download/installer:nub_tgz'}
: ${PACKAGER_URL_PREFIX:='http://download.jetware.org/packager/'}
: ${DESTDIR:=$JET_ROOT}

if [ `id -u` = 0 ]; then
  running_root=yes
  : ${JET_USER:=jet}
else
  running_root=
  : ${JET_USER:=$USER}
fi


#
# Parse options
#

while getopts s:p:d:u:Slh? opt; do
  case $opt in
  s)
    DOWNLOAD_URL="$OPTARG" ;;
  p)
    PACKAGER_URL_PREFIX="$OPTARG" ;;
  d)
    DESTDIR="$OPTARG" ;;
  u)
    JET_USER="$OPTARG" ;;
  S)
    DONT_START=yes ;;
  *)
    usage
    ;;
  esac
done

shift $((OPTIND-1))

[ $# = 0 ] || usage


#
# Check permissions and setup privileged and user execution modes
# 

if [ -n "$running_root" ]; then
  run_priv() { "$@"; }
  user_sh() {
    su "$JET_USER" -s /bin/sh -- "$@"
  }
else
  command -v sudo >/dev/null || die "'sudo' command required or run install from root"
  sudo -l >/dev/null || die "Insufficient sudo permissions"
  run_priv() { sudo "$@"; }
  if [ "$USER" = "$JET_USER" ]; then
    user_sh() {
      sh "$@"
    }
  else
    user_sh() {
      sudo su "$JET_USER" -s /bin/sh -- "$@"
    }
  fi
fi

#
# Install required binaries using distribution's package manager
#
required_binaries="sudo su useradd curl tar gunzip setcap"

missing=
for cmd in $required_binaries; do
  command -v $cmd >/dev/null || missing="$missing $cmd"
done

if [ -n "$missing" ]; then
  if command -v apt-get >/dev/null; then
    # debian 7, 8; ubuntu 14.04, 16.04
    run_priv apt-get update || die "apt-get update"
    run_priv apt-get install -y login passwd sudo curl gzip libcap2-bin || die "apt-get install"
  elif command -v yum >/dev/null; then
    # redhat, centos, fedora
    run_priv yum install -y util-linux shadow-utils sudo curl tar gzip libcap || die "yum"
  else
    die "Missing binaries: $missing"
  fi
fi


#
# Set exit and cleanup handler
#

destdir_tmp=
new_user=
tmp_sudoers=

CLEANUP() {
  trap '' EXIT
  [ -n "$tmp_sudoers" -a -e "$tmp_sudoers" ] && run_priv rm -f "$tmp_sudoers"
  # delete temporary directory new user 
  if [ -d "$destdir_tmp" ]; then
    run_priv rm -rf "$destdir_tmp"
    [ -n "$new_user" ] && userdel $JET_USER
  fi
}

TERMINATE() {
  local err=$?
  trap '' INT TERM
  exit $err
}

trap CLEANUP EXIT
trap TERMINATE INT TERM


#
# Check and prepare directories
#

[ -e "$DESTDIR" ] && die "Destination directory $DESTDIR already exists"

destdir_tmp=${DESTDIR}.jet.$$

[ -e "$destdir_tmp" ] && die "Temporary directory $destdir_tmp already exists"

run_priv mkdir -p "$destdir_tmp" || die

#
# Create user if running as root, and grant him temporary sudo to allow admin privileges during fasten process
#

if [ -n "$running_root" ]; then
  id $JET_USER >/dev/null 2>&1 && die "User $JET_USER already exists"

  new_user=yes
  run_priv useradd --system --home "$DESTDIR" --shell "$DESTDIR/login" $JET_USER || die

  tmp_sudoers=/etc/sudoers.d/99-tmp-$$
  run_priv sh <<_EOF_
echo "\
$JET_USER ALL=NOPASSWD: ALL
Defaults:$JET_USER !requiretty
" > "$tmp_sudoers"
_EOF_

fi

run_priv chown $JET_USER "$destdir_tmp" || die

#
# Download
#

user_sh <<_EOF_ || exit

if command -v curl >/dev/null; then
  download() {
    : \${COLUMNS:=80}
    [ -t 2 ] && printf "\\033[\$((COLUMNS/2+1))C" >&2
    printf "\${1##*/}" >&2
    COLUMNS=\$((COLUMNS/2)) curl --progress-bar -L "\$1" 
  }
elif command -v wget >/dev/null; then
  download() {
    wget --quiet --show-progress --progress=bar -O - "\$1"
  }
fi

echo Downloading and extracting "$DOWNLOAD_URL" ... >&2

download "$DOWNLOAD_URL" | tar xpzf - -C "$destdir_tmp" || exit

while read PACKAGE ROLE NAME VERSION; do
  [ -e "$destdir_tmp/use/\$ROLE" ] && continue
  [ -h "$destdir_tmp/use/\$ROLE" ] && rm -f "$destdir_tmp/use/\$ROLE"
  mkdir "$destdir_tmp/use/\$ROLE"
  download "$PACKAGER_URL_PREFIX/\$PACKAGE.tgz" | tar xpzf - -C "$destdir_tmp/use/\$ROLE" || exit
done < "$destdir_tmp/own/packages"

_EOF_

#
# Setup and start jet running with user credentials
#

sudo mv "$destdir_tmp" "$DESTDIR" || exit

user_sh <<_EOF_ || exit

"$DESTDIR"/own/bin/run "$JET_ROOT"/own/bin/config \
           appliance.author="jetware" \
           appliance.name="memcached14" \
           appliance.title="Memcached 1.4" \
           appliance.version="170503" \
           appliance.url="http://jetware.io/appliances/jetware/memcached14-170503" \
           appliance.support_url="http://jetware.io/contacts/submit?contacts_form%5Bsubject%5D=Appliance%3A+jetware%2Fmemcached14-170503"

echo Setting up ... >&2
"$DESTDIR"/own/bin/run "$JET_ROOT"/own/bin/fasten || exit

if [ -z "$DONT_START" ]; then
  echo Starting ... >&2
  "$DESTDIR"/enter start
fi

echo Done >&2

exit 0

_EOF_

#
# Show quick start manual
#

if [ -n "$new_user" ]; then
  echo -n "\
-----------------------------------------------------------------------------

To enter the runtime environment, log in as the user '$JET_USER'.

" >&2
else
  echo -n "\
-----------------------------------------------------------------------------

To enter the runtime environment, run:

  $DESTDIR/enter

" >&2
fi

quick_start=
for file in usage config_show; do
  if [ -e "$DESTDIR/bin/$file" ]; then
    quick_start="$file"
    break
  fi
done

if [ -n "$quick_start" ]; then
  if [ -n "$new_user" ]; then
    echo -n "\
To execute a command, i.e. show quick start configuration
via '$quick_start' command, log in as the user '$JET_USER':

  su -l $JET_USER

and run:

  $quick_start

or run from root:

  su -l $JET_USER -c $quick_start

" >&2
  else
    echo -n "\
To execute a command, i.e. show quick start configuration
via '$quick_start' command, run:

  $DESTDIR/enter $quick_start

" >&2
  fi
fi