#!/bin/bash
#  $HeadURL: https://svn.pasta.freemyip.com/main/miniade/trunk/bin/nop-sh $ $LastChangedRevision: 10100 $

#  Modules
. $(miniade) || { echo "${0##*/}: ERROR: miniade failed (hint: run 'miniade' to see error)" >&2; exit 1; }

#  Globals
#  Configurable stuff

#  Other globals
#MODROOT=$(cd $(dirname $(readlink -f $0))/.. && pwd)
MODROOT=/root/opt/virttools    #  Hard-coded 'cos invoked via hardlink that doesn't have rest of module close by

main()
{
    local MY_ARGS
    local PROGNAME VM STEP BEGIN_OR_END HYPHEN MODE PROGRAM XMLFILE DRYRUN
    local ASSIGNMENTS TYPE DEVICE FILE MNTPNT

    #  Process options
    miniade_process_options --help-handler=help MY_ARGS "$@" && set -- "${MY_ARGS[@]}"
    #miniade_set_verboselevel 10
    #miniade_set_progname "mounter"

    #  Process arguments 
    [ $# = 4 ] || miniade_bad_usage
    VM=$1
    STEP=$2
    BEGIN_OR_END=$3
    HYPHEN=$4
    miniade_debug 10 "main: VM=$VM, STEP=$STEP, BEGIN_OR_END=$BEGIN_OR_END, HYPHEN=$HYPHEN"

    #  Sanity checks and derivations
    [ "X$LOGNAME" = X ] || miniade_error "it looks like you are trying to call this script directly; it is not meant to be used like that"
    if [ $STEP = prepare -a $BEGIN_OR_END = begin ]; then
        MODE=mount
    elif [ $STEP = release -a $BEGIN_OR_END = end ]; then
        MODE=umount
    else
        miniade_debug 10 "main: ignoring step/begin_or_end combination '$STEP/$BEGIN_OR_END'"
        exit 0
    fi
    for PROGRAM in xmlstarlet; do
        type -p $PROGRAM > /dev/null || miniade_error "$PROGRAM: not found"
    done
    miniade_get_progname PROGNAME

    #  Guts
    XMLFILE=$(mktemp)
    cat > $XMLFILE

    for DRYRUN in true false; do
        miniade_debug 10 "main: DRYRUN=$DRYRUN"
        while read ASSIGNMENTS; do
            TYPE=; FILE=; DEVICE=; MNTPNT=
            eval "$ASSIGNMENTS"
            miniade_debug 10 "main: TYPE=$TYPE, DEVICE=$DEVICE, FILE=$FILE, MNTPNT=$MNTPNT"
            if [ $TYPE = loop ]; then
                $TYPE "$MODE" "$DRYRUN" "$FILE" "$MNTPNT"
            elif [ $TYPE = block ]; then
                $TYPE "$MODE" "$DRYRUN" "$DEVICE" "$MNTPNT"
            else
                miniade_error "$TYPE: unknown type"
            fi
        done < <(xmlstarlet select --template --match "//domain/metadata/*[local-name() = '$PROGNAME']/mounts/mount" --value-of "concat('TYPE=\"',@type,'\";FILE=\"',@file,'\";DEVICE=\"',@device,'\";MNTPNT=\"',@mntpnt,'\"')" -n < $XMLFILE)
    done

    rm -f $XMLFILE
} 

help()
{
    local PROGNAME

    miniade_get_progname PROGNAME
    echo "Usage: $PROGNAME [ <standard-options> ] <vm> <step> {begin|end} -"
    exit 0
}

loop()
{
    local MODE DRYRUN FILE MNTPNT

    [ $# = 4 ] || miniade_internal "loop: $#: bad argument count"
    MODE=$1
    DRYRUN=$2
    FILE=$3
    MNTPNT=$4
    miniade_debug 10 "loop: MODE=$MODE, DRYRUN=$DRYRUN, FILE=$FILE, MNTPNT=$MNTPNT"

    if [ $MODE = umount ]; then
        miniade_debug 10 "loop: delegating to generic ..."
        generic "$MODE" "$DRYRUN" "$MNTPNT"
    elif ! $DRYRUN; then
        miniade_debug 10 "loop: calling [mount -o loop \"$FILE\" \"$MNTPNT\"] ..."
        if ! mount -o loop "$FILE" "$MNTPNT"; then
            miniade_internal "$MNTPNT: failed to mount despite dryrun thinking it would be okay"
        fi
    elif [ "X$FILE" = X ]; then
        miniade_error "file not specified"
    elif [[ $FILE =~ ^/dev/ ]]; then
        miniade_error "$FILE: looks like it might be a device rather than a file"
    elif [ "X$MNTPNT" = X ]; then
        miniade_error "mntpnt not specified"
    elif ! mkdir -p "$MNTPNT"; then
        miniade_error "$MNTPNT: failed to create it"
    elif ! mount --fake -o loop "$FILE" "$MNTPNT"; then
        miniade_error "$FILE: mount would fail (see messages above)"
    fi
}

block()
{
    local MODE DRYRUN DEVICE MNTPNT

    [ $# = 4 ] || miniade_internal "block: $#: bad argument count"
    MODE=$1
    DRYRUN=$2
    DEVICE=$3
    MNTPNT=$4
    miniade_debug 10 "block: MODE=$MODE, DRYRUN=$DRYRUN, DEVICE=$DEVICE, MNTPNT=$MNTPNT"

    if [ $MODE = umount ]; then
        miniade_debug 10 "block: delegating to generic ..."
        generic "$MODE" "$DRYRUN" "$MNTPNT"
    elif ! $DRYRUN; then
        miniade_debug 10 "block: calling [mount \"$DEVICE\" \"$MNTPNT\"] ..."
        if ! mount "$DEVICE" "$MNTPNT"; then
            miniade_internal "$MNTPNT: failed to mount despite dryrun thinking it would be okay"
        fi
    elif [ "X$DEVICE" = X ]; then
        miniade_error "device not specified"
    elif ! [[ $DEVICE =~ ^/dev/ ]]; then
        miniade_error "$DEVICE: looks like it might not be a device"
    elif [ ! -b "$DEVICE" ]; then
        miniade_error "$DEVICE: not a block device"
    elif [ "X$MNTPNT" = X ]; then
        miniade_error "mntpnt not specified"
    elif ! mkdir -p "$MNTPNT"; then
        miniade_error "$MNTPNT: failed to create it"
    elif ! mount --fake "$DEVICE" "$MNTPNT"; then
        miniade_error "$DEVICE: mount would fail (see messages above)"
    fi
}

generic()
{
    local DRYRUN MNTPNT

    [ $# = 3 ] || miniade_internal "generic: $#: bad argument count"
    MODE=$1
    DRYRUN=$2
    MNTPNT=$3

    if [ $MODE != umount ]; then
        miniade_internal "generic: $MODE: invalid mode (hint: the generic handler can only handle mode 'umount')"
    elif ! $DRYRUN; then
        miniade_debug 10 "generic: calling [umount \"$MNTPNT\"] ..."
        if ! umount "$MNTPNT"; then
            miniade_internal "$MNTPNT: failed to mount despite dryrun thinking it would be okay"
        fi
    elif [ "X$MNTPNT" = X ]; then
        miniade_error "mntpnt not specified"
    elif [ ! -d "$MNTPNT" ]; then
        miniade_error "$MNTPNT: does not exist"
    elif ! umount --fake "$MNTPNT"; then
        miniade_error "$MNTPNT: umount would fail (see messages above)"
    fi
}

#  At the time of writing, miniade did not support changing the 
#  writer functions dynamically. Since, I needed the logfile writer
#  I redefined the existing writer function.
#eval "$(echo "orig__miniade_msg_writer()"; declare -f _miniade_msg_writer | tail -n +2)"
#_miniade_msg_writer() { orig__miniade_msg_writer "$@"; _miniade_msg_writer_logfile "$3"; }

main "$@"