#!/bin/bash
#/**
#@file    importimage
#@usage   importimage [str_user] str_repo str_imagename
#@brief   Imports an image file from other repository
#@param   str_user      username to access the remote repository (local user, by default)
#@param   str_repo      repository IP address or hostaname
#@param   str_imagename image name to download
#@warning Program will request the repository REST token.
#@version 1.1.1 - Initial version
#@author  Ramón M. Gómez, ETSII Universidad de Sevilla
#@date    2017-10-08
#*/


# Variables.
PROG="$(basename "$0")"
OPENGNSYS="/opt/opengnsys"
REPODIR="$OPENGNSYS/images"
SERVERCONF="$OPENGNSYS/etc/ogAdmServer.cfg"
let BACKUP=0

# Functions.
source $OPENGNSYS/lib/ogfunctions.sh


# Main program.

# Error control.
[ "$USER" = "root" ] || raiseError access "Need to be root."
[ -w $REPODIR ] || raiseError access "Cannot write in local repository."
case $# in
    2)  USERNAME="$SUDO_USER"; REPO="$1"; IMAGE="$2" ;;
    3)  USERNAME="$1"; REPO="$2"; IMAGE="$3" ;;
    *)  [ "$*" == "help" ] && help || raiseError usage
esac
source $SERVERCONF &>/dev/null
[ "${REPO,,}" == "${HOSTNAME,,}" -o "${REPO,,}" == "localhost" -o "${REPO}" == "127.0.0.1" -o "${REPO,,}" == "${IPLocal,,}}" ] && raiseError access "Cannot import from local repository."

# Fetching image info from the repository.
read -rp "Enter repository API token: " APITOKEN
IMAGEINFO="$(curl -k -H "Authorization: $APITOKEN" "https://$REPO/opengnsys/rest/repository/image/$IMAGE" 2> /dev/null | jq -r .)"
IMAGENAME="$(jq -r '.name' <<< "$IMAGEINFO" 2>/dev/null)"
case "$IMAGEINFO" in
    "") # Connection error.
        raiseError access "Cannot connect to $REPO" ;;
    "[]") # Image not found.
        raiseError notfound "Image $IMAGE in remote repository $REPO" ;;
    *)  # Checking REST error.
        MESSAGE="$(jq -r '.message' <<< "$IMAGEINFO" 2>/dev/null)"
        [ -n "$MESSAGE" ] && raiseError access "$MESSAGE"
esac
IMAGETYPE="$(jq -r '.type' <<< "$IMAGEINFO" 2>/dev/null)"
IMAGELOCKED="$(jq -r '.locked' <<< "$IMAGEINFO" 2>/dev/null)"
[ "$IMAGELOCKED" == "true" ] && raiseError access "Image locked by remote repository."
IMAGESIZE="$(jq -r '.size' <<< "$IMAGEINFO" 2>/dev/null)"
[ -z "$IMAGESIZE" ] && raiseError access "Cannot retrieve image size"
# Checking if local image is locked.
LOCKFILE="$IMAGEPATH.lock"
[ -f "$LOCKFILE" ] && raiseError access "Local image is locked, cannot write."
# Checking if local image exists.
IMAGEPATH="$REPODIR/$IMAGENAME.$IMAGETYPE"
if [ -e "$IMAGEPATH" ]; then
    read -rp "Image $IMAGENAME exists in the local repository. Do you want to continue? (y/N): " ANSWER
    [ "${ANSWER,,}" = "y" ]  || exit
    BACKUP=1
    REMOTEDATE=$(jq -r '.modified' <<< "$IMAGEINFO" 2>/dev/null)
    LOCALDATE=$(stat -c "%y" "$IMAGEPATH" | cut -f1 -d.)
    if [[ "$REMOTEDATE" < "$LOCALDATE" ]]; then
        read -rp "Remote image seems older than the local one. Do you want to continue? (y/N): " ANSWER
        [ "${ANSWER,,}" = "y" ]  || exit
    fi
fi

# Trapping signal to unlock image before exit.
trap "rm -f $LOCKFILE" 1 2 3 6 9 15
# Creating lock file.
touch $LOCKFILE
# Backing up local image.
if [ $BACKUP -eq 1 ]; then
    mv -vf "$IMAGEPATH" "$IMAGEPATH.ant" 2>/dev/null
    mv -vf "$IMAGEPATH.torrent" "$IMAGEPATH.torrent.ant" 2>/dev/null
    mv -vf "$IMAGEPATH.sum" "$IMAGEPATH.sum.ant" 2>/dev/null
    mv -vf "$IMAGEPATH.full.sum" "$IMAGEPATH.full.sum.ant" 2>/dev/null
fi
# Downloading image file.
[[ $IMAGEPATH =~ / ]] && mkdir -p "$(dirname "$IMAGEPATH")"
scp $USERNAME@$REPO:$IMAGEPATH $REPODIR
ERRCODE=$?
if [ $ERRCODE -eq 0 ]; then
    # Storing creation info.
    jq -r '.clonator+":"+.compressor+":"+.filesystem+":"+(.datasize|tostring)+":"' <<<"$IMAGEINFO" > "$IMAGEPATH.info"
    #### Si no es backup de imagen y es repo con server,
    ####    crear objeto imagen asociado a nuevo perfil de software vacío.
    DOWNLOADSIZE=$(stat -c "%s" $IMAGEPATH)
    [ $IMAGESIZE -ne $DOWNLOADSIZE ] && echo "Warning: image sizes differ: source=$IMAGESIZE, target=$DOWNLOADSIZE."
else
    raiseError download "$USERNAME@$REPO:$IMAGEPATH"
    # Recovering back up, if needed.
    if [ $BACKUP -eq 1 ]; then
        mv -vf "$IMAGEPATH.ant" "$IMAGEPATH" 2>/dev/null
        mv -vf "$IMAGEPATH.torrent.ant" "$IMAGEPATH.torrent" 2>/dev/null
        mv -vf "$IMAGEPATH.sum.ant" "$IMAGEPATH.sum" 2>/dev/null
        mv -vf "$IMAGEPATH.full.sum.ant" "$IMAGEPATH.full.sum" 2>/dev/null
    fi
fi

# Unlocking image.
rm -f $LOCKFILE