#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2017-2023 OpenFOAM Foundation
#    \\/     M anipulation  |
#-------------------------------------------------------------------------------
# License
#     This program is free software: you can redistribute it and/or modify it
#     under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     This program is distributed in the hope that it will be useful, but
#     WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
#     or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     openfoam10-linux
#
# Description
#     Run script for an OpenFOAM 10 Docker image at:
#     https://hub.docker.com/r/openfoam
#
#------------------------------------------------------------------------------
Script=${0##*/}
ver=10

usage () {
    exec 1>&2
    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    cat <<USAGE

Usage: ${0##*/} [OPTIONS]
options:
  -d | -dir             host directory mounted (defaults to current directory)
  -h | -help            help
  -p | -paraview <vers> specify paraview version 56 | 510 (default)      
  -u | -upgrade         install latest upgrades to the Docker image
  -x | -xhost           use custom X authority and give container host network

Launches the OpenFOAM-$ver Docker image.
- Requires installation of docker-engine.
- Runs a "containerized" bash shell environment where the user can run OpenFOAM
  and, optionally, ParaView (see below).
- The container mounts the user's file system so that case files are stored
  permanently.  The container mounts the current directory by default, but the
  user can also specify a particular directory using the "-d" option.
- Mounting the user's HOME directory is disallowed.
- The '-xhost' option is useful when accessing the host via 'ssh -X'.
  This option should only be used when strictly necessary, as it relies on the
  option '--net=host' when launching the container in Docker, which will
  give to the container full access to the Docker host network stack and
  potentially the host's system services that rely on network communication,
  making it potentially insecure.

Example:
To store data in $HOME/OpenFOAM/$USER-$ver, the user can launch
$Script either by:
    cd $HOME/OpenFOAM/$USER-$ver && $Script
or
    $Script -d $HOME/OpenFOAM/$USER-$ver

Further Information:
http://openfoam.org/download/$ver-linux

Note:
The container user name appears as "openfoam" but it is just an alias.

USAGE
    exit 1
}

paraview_vers=510
mount_dir=$(pwd)
custom_xauth=""
docker_options=""

while [ "$#" -gt 0 ]
do
   case "$1" in
   -d | -dir)
       [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
       mount_dir=$2
       shift 2
       ;;
   -h | -help)
       usage
       ;;
   -p | -paraview)
       [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
       paraview_vers=$2
       case "$paraview_vers" in
           56|510) ;;
           *) usage "'$2' is not a valid ParaView version." \
		    "Valid versions are 56 | 510."
	      ;;
       esac
       shift 2
       ;;
   -u | -upgrade)
       upgrade=yes
       shift
       ;;
   -x | -xhost)
       custom_xauth=yes
       shift
       ;;
   *)
       usage "Invalid option '$1'"
       ;;
    esac
done

docker_image="openfoam/openfoam$ver-paraview$paraview_vers"

[ -d "$mount_dir" ] || usage "No directory exists: $mount_dir"
mount_dir=$(cd "$mount_dir" && pwd -P)

[ "$mount_dir" = "$(cd "$HOME" && pwd -P)" ] && \
    usage "Mount directory cannot be the user's home directory" \
          "Make a subdirectory and run from there, e.g." \
          "    mkdir -p $HOME/OpenFOAM/$(whoami)-$ver" \
          "    $Script -d $HOME/OpenFOAM/$(whoami)-$ver"

if [ -n "$custom_xauth" ]
then
    xauth_path="$mount_dir/.docker.xauth.$$"
    touch "$xauth_path"

    # Generate a custom X-authority file that allows any hostname
    xauth nlist "$DISPLAY" |  sed -e 's/^..../ffff/' | \
        xauth -f "$xauth_path" nmerge -

    docker_options="-e XAUTHORITY=$xauth_path
                    -v $xauth_path:$xauth_path
                    --net=host"
else
    docker_options="-e XAUTHORITY=/home/openfoam/.Xauthority \
                    -v $XAUTHORITY:/home/openfoam/.Xauthority"
fi

user_id=$(id -u 2> /dev/null)
[ -n "$user_id" ] || usage "Cannot determine current user ID"
group_id=$(id -g)

home_dir='/home/openfoam'

echo "Launching $0"
echo "User: \"$(id -un)\" (ID $user_id, group ID $group_id)"

[ "$upgrade" ] && docker pull "$docker_image"

# shellcheck disable=SC2086
docker run -it \
    --rm \
    -e DISPLAY="$DISPLAY" \
    -u "$user_id":"$group_id" \
    -v /tmp/.X11-unix:/tmp/.X11-unix \
    -v "$mount_dir":$home_dir \
    $docker_options \
    "$docker_image"

[ -n "$custom_xauth" ] && [ -e "$xauth_path" ] && rm "$xauth_path"