#!/bin/bash
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | Copyright (C) 2017 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
#     openfoam-macos-file-system
#
# Description
#     Creates a disk image with a case-sensitive filing system on a macOS
#     formatted disk (with a case-insensitive filing system)
#
#------------------------------------------------------------------------------
Script=${0##*/}

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

Usage: ${0##*/} [OPTIONS] <command>

commands:
  create       Initialize case-sensitive volume (only needed first time)
  automount    Configure macOS to mount the volume automatically on restart
  mount        Attach the case-sensitive volume
  unmount      Detach the case-sensitive volume
  compact      Remove any uneeded reserved space in the volume
  delete       Delete the disk image

options:
  -d | -dir <dir>      mount directory, default "$HOME/<volume-name>"
  -h | -help           help
  -n | -no-run         do not create the "run" directory
  -s | -size <size>    size of volume in GB, default 10, minimum 2
  -v | -volume <name>  name of volume, default "openfoam"

Creates a volume (disk image) with a case-sensitive filing system on a
macOS formatted disk (with a case-insensitive filing system) for use with
the Docker builds of OpenFOAM for macOS: http://openfoam.org/version/macos

Commands exist to create, mount, unmount, delete and compact the volume, and
to mount it automatically when the machine starts up.

By default, the volume is named "openfoam" with size of 10GB, mounted at
"\$HOME/openfoam", and includes a "run" directory corresponding to the
\$FOAM_RUN environment variable in the Docker container.  There are options to
override all these defaults.

USAGE
    exit 1
}

create() {
    hdiutil create \
        -type SPARSE \
        -fs 'Case-sensitive Journaled HFS+' \
        -size "$VOLUME_SIZE"g \
        -volname "$VOLUME" \
        "$WORKSPACE"
}

automount() {
    attach
    cat << EOF > /tmp/com.workspace.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>RunAtLoad</key>
        <true/>
        <key>Label</key>
        <string>com.workspace</string>
        <key>ProgramArguments</key>
        <array>
            <string>hdiutil</string>
            <string>attach</string>
            <string>-notremovable</string>
            <string>-nobrowse</string>
            <string>-mountpoint</string>
            <string>$MOUNT_DIR</string>
            <string>$WORKSPACE</string>
        </array>
    </dict>
</plist>
EOF
    sudo cp /tmp/com.workspace.plist /Library/LaunchDaemons/com.workspace.plist
    rm /tmp/com.workspace.plist
}

detach() {
    MOUNTED=$(hdiutil info | grep "$MOUNT_DIR" | cut -f1)
    [ "$MOUNTED" ] && \
        sudo hdiutil detach "$MOUNTED" && \
        return 0

    usage "Volume is not currently mounted at $MOUNT_DIR"
}

attach() {
    MOUNTED=$(hdiutil info | grep "$MOUNT_DIR" | cut -f1)
    [ "$MOUNTED" ] && \
        usage "Volume is already mounted at $MOUNT_DIR"
    if [ -d "$MOUNT_DIR" ]
    then
        [ "$(ls -A "$MOUNT_DIR")" ] && \
            usage "Mount directory is not empty, exiting"
    else
        mkdir -p "$MOUNT_DIR"
    fi
    sudo hdiutil attach -mountpoint "$MOUNT_DIR" "$WORKSPACE"
    RUN=$MOUNT_DIR/run
    { [ -d "$RUN" ] || [ "$NO_RUN" ] ; } || mkdir "$RUN"
}

compact() {
    detach
    hdiutil compact "$WORKSPACE" -batteryallowed
    attach
}

confirm () {
    read -r -p "$* " response
    case $response in
         [yY][eE][sS]|[yY])
            true
            ;;
        *)
            false
            ;;
    esac
}

delete() {
    confirm "This operation will delete ALL FILES on disk image $VOLUME." \
            "Are you sure? (y/N)" && \
        echo "Detaching $VOLUME" && detach && \
        echo "Deleting $VOLUME" && rm "$WORKSPACE"
}

# ARGUMENT HANDLING
VOLUME=openfoam
VOLUME_SIZE=10

while [ "$#" -gt 0 ]
do
   case "$1" in
   -d | -dir)
      [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
      MOUNT_DIR=$2
      shift 2
      ;;
   -h | -help)
      usage
      ;;
   -n | -no-run)
      NO_RUN="yes"
      shift
      ;;
   -s | -size)
      [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
      VOLUME_SIZE=$2
      [ "$VOLUME_SIZE" -eq "$VOLUME_SIZE" ] || \
          usage "Specified volume size, in GB, must be an integer, e.g. \"-s 20\""
      [ "$VOLUME_SIZE" -lt 2 ] && \
          usage "Specified volume size, in GB, must be greater than 2 (GB)"
      shift 2
      ;;
   -v | -volume)
      [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
      VOLUME=$2
      shift 2
      ;;
   -*)
      usage "Invalid option '$1'"
      ;;
   *)
      break
      ;;
    esac
done

[ "$#" -eq 1 ] || usage "Script requires 1 command, e.g. \"$Script create\""

case "$1" in
    create)    CMD=create ;;
    automount) CMD=automount ;;
    mount)     CMD=attach ;;
    unmount)   CMD=detach ;;
    compact)   CMD=compact ;;
    delete)    CMD=delete ;;
    *)         usage "$1 is not a valid command" ;;
esac

WORKSPACE="$HOME/.$VOLUME.dmg.sparseimage"
[ "$MOUNT_DIR" ] || MOUNT_DIR="$HOME/$VOLUME"

# Run the command
echo $CMD

$CMD