#!/usr/bin/env bash
set -Eeuo pipefail

# Display wait message
/run/server.sh 5000 install &

# Download the required files from the Synology website
DL="https://global.synologydownload.com/download/DSM"

if [ -z "$URL" ]; then

  URL="$DL/release/7.2/64551/DSM_VirtualDSM_64551.pat"
  #URL="$DL/release/7.0.1/42218/DSM_VirtualDSM_42218.pat"
  #URL="$DL/release/7.1.1/42962-1/DSM_VirtualDSM_42962.pat"

fi

# Check if output is to interactive TTY
if [ -t 1 ]; then
  PROGRESS="--progress=bar:noscroll"
else
  PROGRESS="--progress=dot:giga"
fi

BASE=$(basename "$URL" .pat)

rm -f "$STORAGE"/"$BASE".pat
rm -f "$STORAGE"/"$BASE".agent
rm -f "$STORAGE"/"$BASE".boot.img
rm -f "$STORAGE"/"$BASE".system.img

TMP="$STORAGE/tmp"
RDC="$STORAGE/dsm.rd"

rm -rf "$TMP" && mkdir -p "$TMP"

[[ "${DEBUG}" == [Yy1]* ]] && set -x

if [ ! -f "${RDC}" ]; then

  RD="$TMP/rd.gz"
  info "Install: Downloading installer..."
  LOC="$DL/release/7.0.1/42218/DSM_VirtualDSM_42218.pat"

  { curl -r 65627648-71021835 -sfk -o "$RD" "$LOC"; rc=$?; } || :
  (( rc != 0 )) && error "Failed to download $LOC, reason: $rc" && exit 60

  SUM=$(md5sum "$RD" | cut -f 1 -d " ")
  VERIFY="b4215a4b213ff5154db0488f92c87864"

  if [ "$SUM" != "$VERIFY" ]; then

    PAT="/install.pat"
    rm "$RD"
    rm -f "$PAT"

    { wget "$LOC" -O "$PAT" -q --no-check-certificate --show-progress "$PROGRESS"; rc=$?; } || :
    (( rc != 0 )) && error "Failed to download $LOC, reason: $rc" && exit 60

    tar --extract --file="$PAT" --directory="$TMP/." rd.gz
    rm "$PAT"

  fi

  cp "$RD" "$RDC"

fi

set +e
xz -dc <"$RDC" >"$TMP/rd" 2>/dev/null || true
(cd "$TMP" && cpio -idm <"$TMP/rd" 2>/dev/null)
set -e

mkdir -p /run/extract
for file in $TMP/usr/lib/libcurl.so.4 \
            $TMP/usr/lib/libmbedcrypto.so.5 \
            $TMP/usr/lib/libmbedtls.so.13 \
            $TMP/usr/lib/libmbedx509.so.1 \
            $TMP/usr/lib/libmsgpackc.so.2 \
            $TMP/usr/lib/libsodium.so \
            $TMP/usr/lib/libsynocodesign-ng-virtual-junior-wins.so.7 \
            $TMP/usr/syno/bin/scemd; do
  cp "$file" /run/extract/
done

mv /run/extract/scemd /run/extract/syno_extract_system_patch
chmod +x /run/extract/syno_extract_system_patch

rm -rf "$TMP" && mkdir -p "$TMP"

info "Install: Downloading $(basename "$URL")..."

PAT="/$BASE.pat"
rm -f "$PAT"

{ wget "$URL" -O "$PAT" -q --no-check-certificate --show-progress "$PROGRESS"; rc=$?; } || :
(( rc != 0 )) && error "Failed to download $URL, reason: $rc" && exit 69

[ ! -f "$PAT" ] && error "Failed to download $URL" && exit 69

SIZE=$(stat -c%s "$PAT")

if ((SIZE<250000000)); then
  error "The specified PAT file is probably an update pack as it's too small." && exit 62
fi

info "Install: Extracting downloaded image..."

if { tar tf "$PAT"; } >/dev/null 2>&1; then
   tar xpf "$PAT" -C "$TMP/."
else
   export LD_LIBRARY_PATH="/run/extract"
   { /run/extract/syno_extract_system_patch "$PAT" "$TMP/."; rc=$?; } || :
   (( rc != 0 )) && error "Failed to extract PAT file, reason $rc" && exit 63
   export LD_LIBRARY_PATH=""
fi

HDA="$TMP/hda1"
IDB="$TMP/indexdb"
PKG="$TMP/packages"
HDP="$TMP/synohdpack_img"

[ ! -f "$HDA.tgz" ] && error "The PAT file contains no OS image." && exit 64
[ ! -f "$HDP.txz" ] && error "The PAT file contains no HD pack." && exit 65
[ ! -f "$IDB.txz" ] && error "The PAT file contains no IndexDB." && exit 66
[ ! -d "$PKG" ] && error "The PAT file contains no packages." && exit 68

BOOT=$(find "$TMP" -name "*.bin.zip")

[ ! -f "$BOOT" ] && error "The PAT file contains no boot file." && exit 67

BOOT=$(echo "$BOOT" | head -c -5)
unzip -q -o "$BOOT".zip -d "$TMP"

[[ "${ALLOCATE}" == [Zz]* ]] && info "Install: Allocating diskspace..."

SYSTEM="$TMP/sys.img"
SYSTEM_SIZE=4954537983

# Check free diskspace
SPACE=$(df --output=avail -B 1 "$TMP" | tail -n 1)

if (( SYSTEM_SIZE > SPACE )); then
  error "Not enough free space to create a 4 GB system disk." && exit 87
fi

if ! fallocate -l "${SYSTEM_SIZE}" "${SYSTEM}"; then
  rm -f "${SYSTEM}"
  error "Could not allocate a file for the system disk." && exit 88
fi

if [[ "${ALLOCATE}" == [Zz]* ]]; then
  info "Install: Preallocating 4 GB of diskspace..."
  dd if=/dev/urandom of="${SYSTEM}" count="${SYSTEM_SIZE}" bs=1M iflag=count_bytes status=none
fi

# Check if file exists
if [ ! -f "${SYSTEM}" ]; then
    error "System disk does not exist ($SYSTEM)" && exit 89
fi

# Check the filesize
SIZE=$(stat -c%s "${SYSTEM}")

if [[ SIZE -ne SYSTEM_SIZE ]]; then
  rm -f "${SYSTEM}"
  error "System disk has the wrong size: ${SIZE}" && exit 90
fi

PART="$TMP/partition.fdisk"

{	echo "label: dos"
	echo "label-id: 0x6f9ee2e9"
	echo "device: ${SYSTEM}"
	echo "unit: sectors"
	echo "sector-size: 512"
	echo ""
	echo "${SYSTEM}1 : start=        2048, size=     4980480, type=83"
	echo "${SYSTEM}2 : start=     4982528, size=     4194304, type=82"
} > "$PART"

sfdisk -q "$SYSTEM" < "$PART"

info "Install: Extracting system partition..."

MOUNT="$TMP/system"

rm -rf "$MOUNT" && mkdir -p "$MOUNT"

mv -f "$HDA.tgz" "$HDA.txz"

tar xpfJ "$HDP.txz" --absolute-names -C "$MOUNT/"
tar xpfJ "$HDA.txz" --absolute-names -C "$MOUNT/"
tar xpfJ "$IDB.txz" --absolute-names -C "$MOUNT/usr/syno/synoman/indexdb/"

# Install Agent

LOC="$MOUNT/usr/local"
mkdir -p "$LOC"
mv "$PKG/" "$LOC/"

LOC="$MOUNT/usr/local/bin"
mkdir -p "$LOC"
cp /agent/agent.sh "$LOC/agent.sh"
chmod 755 "$LOC/agent.sh"

LOC="$MOUNT/usr/local/etc/rc.d"
mkdir -p "$LOC"
cp /agent/service.sh "$LOC/agent.sh"
chmod 755 "$LOC/agent.sh"

# Store agent version
echo "7" > "$STORAGE"/"$BASE".agent

info "Install: Installing system partition..."

LABEL="1.44.1-42218"
OFFSET="1048576" # 2048 * 512
NUMBLOCKS="622560" # (4980480 * 512) / 4096

mke2fs -q -t ext4 -b 4096 -d "$MOUNT/" -L "$LABEL" -F -E "offset=$OFFSET" "$SYSTEM" "$NUMBLOCKS"

rm -rf "$MOUNT"

echo "$BASE" > "$STORAGE"/dsm.ver
mv -f "$PAT" "$STORAGE"/"$BASE".pat
mv -f "$BOOT" "$STORAGE"/"$BASE".boot.img
mv -f "$SYSTEM" "$STORAGE"/"$BASE".system.img

rm -rf "$TMP"

{ set +x; } 2>/dev/null
[[ "${DEBUG}" == [Yy1]* ]] && echo

return 0