#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2016, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

# ln fe:SOURCE host:remote_system_ds/disk.i vmid dsid
#   - fe is the front-end hostname
#   - SOURCE is the path of the disk image in the form DS_BASE_PATH/disk
#   - host is the target host to deploy the VM
#   - remote_system_ds is the path for the system datastore in the host
#   - vmid is the id of the VM
#   - dsid is the target datastore (0 is the system datastore)

SRC=$1
DST=$2

VMID=$3
DSID=$4

if [ -z "${ONE_LOCATION}" ]; then
    TMCOMMON=/var/lib/one/remotes/tm/tm_common.sh
else
    TMCOMMON=$ONE_LOCATION/var/remotes/tm/tm_common.sh
fi

. $TMCOMMON

DRIVER_PATH=$(dirname $0)

#-------------------------------------------------------------------------------
# Set dst path and dir
#-------------------------------------------------------------------------------
DST_PATH=`arg_path $DST`
DST_HOST=`arg_host $DST`
DST_DIR=`dirname $DST_PATH`

SRC_ARG_PATH=`arg_path $SRC`

DST_DS_PATH="$(dirname $(dirname $(dirname $DST_PATH)))"
SRC_DS_PATH="$(dirname $(dirname $SRC_ARG_PATH))"

SRC_PATH="${DST_DS_PATH}${SRC_ARG_PATH##$SRC_DS_PATH}"
SNAP_DIR="${SRC_PATH}.snap"
SNAP_NAME="$(basename $SNAP_DIR)"

#-------------------------------------------------------------------------------
# Get Image information
#-------------------------------------------------------------------------------

XPATH="${DRIVER_PATH}/../../datastore/xpath.rb --stdin"

unset i j XPATH_ELEMENTS

while IFS= read -r -d '' element; do
    XPATH_ELEMENTS[i++]="$element"
done < <(onevm show -x $VMID| $XPATH \
                    /VM/HISTORY_RECORDS/HISTORY[last\(\)]/TM_MAD)

TM_MAD="${XPATH_ELEMENTS[j++]}"

if [ "$TM_MAD" = "ssh" ]; then
    MONITOR="monitor"
else
    MONITOR=""
fi

#-------------------------------------------------------------------------------
# Create DST path
#-------------------------------------------------------------------------------

ssh_make_path $DST_HOST $DST_DIR $MONITOR

#-------------------------------------------------------------------------------
# Link (ln) SRC into DST
#-------------------------------------------------------------------------------
log "Linking $SRC_PATH in $DST"

type="$(file -b --mime-type $SRC_PATH)"

if [ "$type" == "application/x-iso9660-image" ]; then
    CMD="ln -sf ${SRC_PATH} ${DST_PATH}"
else
    CMD=$(cat <<EOT
set -ex

mkdir -p "${SNAP_DIR}"

if [ ! -L "${SNAP_DIR}/${SNAP_NAME}" ]; then
    ln -s "${SNAP_DIR}" "${SNAP_DIR}/${SNAP_NAME}"
fi

SNAP="\$(ls ${SNAP_DIR} | grep '^[[:digit:]]*$' | sort -n | tail -n 1)"

if [ -z "\${SNAP}" ]; then
    SNAP=0
    ln -sf "$SRC_PATH" "$SNAP_DIR/0"
fi

ln -sf "$SNAP_DIR/\$SNAP" "$DST_PATH"

$RM -f "${DST_PATH}.snap"
ln -sf "$SNAP_DIR" "${DST_PATH}.snap"
EOT
)
fi

ssh_exec_and_log $DST_HOST "$CMD" "Error linking $SRC to $DST"

exit 0
