#!/bin/bash

DEV=/dev/sdb2
MNT=/media/esata
DELAY=5
SCSIDEV=1 # This can change based on OS, etc.

registered() {
    if [ -b "$DEV" ]; then
	[ -n "$VERBOSE" ] && echo "registered"
	return 0
    else
	[ -n "$VERBOSE" ] && echo "not registered"
	return 1
    fi
}

mounted() {
    if mount | grep -q "$MNT"; then
	[ -n "$VERBOSE" ] && echo "mounted"
	return 0
    else
	[ -n "$VERBOSE" ] && echo "not mounted"
	return 1
    fi
}

doregister() {
    registered && return 0
    [ -n "$VERBOSE" ] && echo "register SATA device"
    scsiadd -a $SCSIDEV 0 0 0 >/dev/null || return 1
    sleep $DELAY
    registered || return 1
    [ -n "$VERBOSE" ] && echo "register ok"
    return 0
}

domount() {
    mounted && return 0
    doregister || return 1
    [ -n "$VERBOSE" ] && echo "mount SATA $DEV"
    mkdir -p "$MNT" || return 1
    mount "$DEV" "$MNT" || return 1
    [ -n "$VERBOSE" ] && echo "mount ok"
    return 0
}

dounregister() {
    registered || return 0
    [ -n "$VERBOSE" ] && echo "unregister SATA device"
    scsiadd -r $SCSIDEV 0 0 0 >/dev/null || return 1
    sleep $DELAY
    registered && return 1
    [ -n "$VERBOSE" ] && echo "unregister ok"
    return 0
}

doumount() {
    if mounted; then
	[ -n "$VERBOSE" ] && echo "unmount SATA $DEV"
	umount "$MNT" || return 1
	mounted && return 1
	[ -n "$VERBOSE" ] && echo "unmount ok"
    fi
    dounregister || return 1
    return 0
}

# MAIN

unset VERBOSE
if [ "$1" = "-v" ]; then
    VERBOSE=1
    shift
fi
if [ "$1" = "mount" ]; then
    if domount; then
	echo "esata mounted on $MNT"
    else
	echo "$0: cannot mount esata" >&2
	dounregister
    fi
elif [ "$1" = "umount" -o "$1" = "unmount" ]; then
    if doumount; then
	echo "esata is unmounted"
    else
	echo "$0: cannot unmount esata" >&2
	exit 1
    fi
elif [ "$1" = "register" ]; then
    if doregister; then
	echo "esata registered as $DEV"
    else
	echo "$0: cannot register esata" >&2
	exit 1
    fi
elif [ "$1" = "status" ]; then
    if mounted; then
	echo "esata mounted on $MNT"
    elif registered; then
	echo "esata registered as $DEV but not mounted"
    else
	echo "esata is unregistered"
    fi
    #mount | grep "$DEV"
    #scsiadd -p | grep "scsi1"
else
    echo "usage: $0 [-v] <mount|umount|register|status>"
fi
exit 0