#!/bin/sh


MOUNTPT=/tmp/mojo-jojo-iso

Die() {
    echo "$1" >> /dev/stderr
    exit 1
}


mount_iso_for_me() {
    [ -e "$1/$2.iso" ] || Die "ISO #$2 not found at $1. Terminating."
    mount $1/$2.iso -o loop,ro $MOUNTPT || Die "Cannot mount ISO $isoloc/$isono"
}



trap_me_here() {
    i=1
    while [ "$i" -le "50" ] ; do
        umount $isoloc/$i.iso 2> /dev/null
        i=$(($i+1))
    done
    echo "Terminating in reponse to a signal caught by the OS"
    exit 1
}



process_this_cd() {
    local restorepath res
    isono=$1
    restorepath=$2

    find $MOUNTPT/archives | grep "slice-" > /dev/null || Die "No bigfiles at $MOUNTPT"
    mkdir -p $restorepath
    cd $restorepath
    for slicename in `find $MOUNTPT/archives | grep "slice-" | sort` ; do
#        echo -en "Slice = $slicename    \r"
        echo -en "."
        if echo "$slicename" | grep "slice-[0-9]*.00000\.dat" 2> /dev/null; then
            CHECKSUM=`head -n1 $slicename | cut -f1`
            OUTFNAME=`head -n1 $slicename | cut -f2`
            OUTFNAME=`echo "$restorepath/$OUTFNAME" | tr -s '/' '/'`
            echo "Now restoring $OUTFNAME"
            [ "$OUTFNAME" ] || Die "No filename?! WTF?"
            rm -f "$OUTFNAME" 2> /dev/null
            mkdir -p "$OUTFNAME" 2> /dev/null
            rmdir "$OUTFNAME" 2> /dev/null
            > "$OUTFNAME" || Die "Cannot write to $OUTFNAME"
        elif [ ! -s "$slicename" ] ; then
            echo "Finished restoring $OUTFNAME"
            res=`md5sum "$OUTFNAME" | cut -d' ' -f1`
#            echo "Orig=$CHECKSUM. Disk=$res"
            if [ "$CHECKSUM" != "$res" ] ; then
                echo "Warning - checksums do not match"
            fi
            CHECKSUM=""
            OUTFNAME=""
        else
            [ "$OUTFNAME" = "" ] && Die "No filename to write to! Are you sure you inserted the _first_ ISO to begin with?"
            if echo "$slicename" | grep "bz2" > /dev/null ; then
                bzip2 -dc $slicename >> "$OUTFNAME" || Die "Failed to decompress slice $slicename"
            elif echo "$slicename" | grep "gz" > /dev/null ; then
                gzip -dc $slicename >> "$OUTFNAME" || Die "Failed to decompress slice $slicename"
            elif echo "$slicename" | grep "lzo" > /dev/null ; then
                lzop -dc $slicename >> "$OUTFNAME" || Die "Failed to decompress slice $slicename"
            else
                cat $slicename >> "$OUTFNAME" || Die "Failed to decompress slice $slicename"
            fi
        fi
    done
}




# ------------------- main ------------------- 

trap trap_me_here SIGTERM SIGHUP SIGQUIT SIGKILL SIGABRT SIGINT
[ "$#" -eq "1" ] || Die "restore-bigfiles-from-iso <location of ISOs> --- e.g. /storage/ISOs"
isoloc=$1
mkdir -p $MOUNTPT
isono=1
OUTFNAME=""
CHECKSUM=""

def="/RESTORED"
echo -en "Restore path (default is '$def') --> "
read restorepath
[ "$restorepath" ] || restorepath=$def
while [ ! -e "$isoloc/$isono.iso" ] ; do
    echo "Skipping CD #$isono (does not exist)"
    isono=$(($isono+1))
    [ "$isono" -gt "50" ] && Die "Ran out of ISOs to try"
done
while [ -e "$isoloc/$isono.iso" ] ; do
    echo "Processing CD #$isono"
    mount_iso_for_me $isoloc $isono
    process_this_cd $isono $restorepath
    umount $isoloc/$isono.iso || Die "Unable to unmount ISO $isono"
    isono=$(($isono+1))
done
echo "OK, done."
exit 0