#!/bin/bash

# This script is called from our systemd unit file to mount or unmount
# a USB drive.

usage()
{
    echo "Usage: $0 {add|remove} device_name (e.g. sdb1)"
    exit 1
}

if [[ $# -ne 2 ]]; then
    usage
fi

ACTION=$1
DEVBASE=$2
DEVICE="/dev/${DEVBASE}"

# See if this drive is already mounted, and if so where
MOUNT_POINT=$(/bin/mount | /bin/grep ${DEVICE} | /usr/bin/awk '{ print $3 }')

do_mount()
{
    if [[ -n ${MOUNT_POINT} ]]; then
        echo "Warning: ${DEVICE} is already mounted at ${MOUNT_POINT}"
        exit 1
    fi

    # Get info for this drive: $ID_FS_LABEL, $ID_FS_UUID, and $ID_FS_TYPE
    eval $(/sbin/blkid -o udev ${DEVICE})

    # Figure out a mount point to use
    #LABEL=${ID_FS_LABEL}
    #if /bin/grep -q " /media/${LABEL} " /etc/mtab; then
    #    # Already in use, make a unique one
    #    LABEL+="-${DEVBASE}"
    #fi

    MOUNT_POINT="/media/usbhd-${DEVBASE}"

    if [ ! -d "$MOUNT_POINT" ]; then
      mkdir -p $MOUNT_POINT
    fi

    echo "Mount point: ${MOUNT_POINT}"

    /bin/mkdir -p ${MOUNT_POINT}

    # Global mount options
    OPTS="rw,relatime"

    # File system type specific mount options
    if [[ ${ID_FS_TYPE} == "vfat" ]]; then
        #OPTS+=",users,gid=100,umask=000,shortname=mixed,utf8=1,flush"
        #OPTS+=",umask=000,shortname=mixed,utf8=1,flush"
        OPTS+=",shortname=mixed,utf8=1,flush"
    fi

    echo "ID_FS_LABEL: ${ID_FS_LABEL}, ID_FS_UUID: ${ID_FS_UUID}, ID_FS_TYPE: ${ID_FS_TYPE}" >> /tmp/mount_log.txt

    if ! /bin/mount -o ${OPTS} ${DEVICE} ${MOUNT_POINT}; then
        echo "Error mounting ${DEVICE} (status = $?)"
        /bin/rmdir ${MOUNT_POINT}
        exit 1
    else
      if [[ ${ID_FS_TYPE} == "vfat" ]]; then
        # mouted with success, run a dosfsck on the mounted device
        echo "Will run dosfsck on ${DEVICE} (${MOUNT_POINT})..." >> /tmp/mount_log.txt
        dosfsck -a ${DEVICE} >> /tmp/mount_log.txt
        rm -f ${MOUNT_POINT}/FSCK*.REC
      fi
    fi

    echo "**** Mounted ${DEVICE} at ${MOUNT_POINT} ****"
}

do_unmount()
{
    if [[ -z ${MOUNT_POINT} ]]; then
        echo "Warning: ${DEVICE} is not mounted"
    else
        /bin/umount -l ${DEVICE}
        echo "**** Unmounted ${DEVICE}"
    fi

    # Delete all empty dirs in /media that aren't being used as mount
    # points. This is kind of overkill, but if the drive was unmounted
    # prior to removal we no longer know its mount point, and we don't
    # want to leave it orphaned...
    for f in /media/* ; do
        if [[ -n $(/usr/bin/find "$f" -maxdepth 0 -type d -empty) ]]; then
            if ! /bin/grep -q " $f " /etc/mtab; then
                echo "**** Removing mount point $f"
                /bin/rmdir "$f"
            fi
        fi
    done
}

case "${ACTION}" in
    add)
        do_mount
        ;;
    remove)
        do_unmount
        ;;
    *)
        usage
        ;;
esac

