#!/usr/bin/env bash

# Setup script environment
set -o errexit  #Exit immediately if a pipeline returns a non-zero status
set -o errtrace #Trap ERR from shell functions, command substitutions, and commands from subshell
set -o nounset  #Treat unset variables as an error
set -o pipefail #Pipe will exit with last non-zero status if applicable
shopt -s expand_aliases
alias die='EXIT=$? LINE=$LINENO error_exit'
trap die ERR
trap cleanup EXIT

function error_exit() {
  trap - ERR
  local DEFAULT='Unknown failure occured.'
  local REASON="\e[97m${1:-$DEFAULT}\e[39m"
  local FLAG="\e[91m[ERROR] \e[93m$EXIT@$LINE"
  msg "$FLAG $REASON"
  [ ! -z ${VMID-} ] && cleanup_vmid
  exit $EXIT
}
function warn() {
  local REASON="\e[97m$1\e[39m"
  local FLAG="\e[93m[WARNING]\e[39m"
  msg "$FLAG $REASON"
}
function info() {
  local REASON="$1"
  local FLAG="\e[36m[INFO]\e[39m"
  msg "$FLAG $REASON"
}
function msg() {
  local TEXT="$1"
  echo -e "$TEXT"
}
function cleanup_vmid() {
  if $(qm status $VMID &>/dev/null); then
    if [ "$(qm status $VMID | awk '{print $2}')" == "running" ]; then
      qm stop $VMID
    fi
    qm destroy $VMID
  fi
}
function cleanup() {
  popd >/dev/null
  rm -rf $TEMP_DIR
}
TEMP_DIR=$(mktemp -d)
pushd $TEMP_DIR >/dev/null

# Select storage location
while read -r line; do
  TAG=$(echo $line | awk '{print $1}')
  TYPE=$(echo $line | awk '{printf "%-10s", $2}')
  FREE=$(echo $line | numfmt --field 4-6 --from-unit=K --to=iec --format %.2f | awk '{printf( "%9sB", $6)}')
  ITEM="  Type: $TYPE Free: $FREE "
  OFFSET=2
  if [[ $((${#ITEM} + $OFFSET)) -gt ${MSG_MAX_LENGTH:-} ]]; then
    MSG_MAX_LENGTH=$((${#ITEM} + $OFFSET))
  fi
  STORAGE_MENU+=( "$TAG" "$ITEM" "OFF" )
done < <(pvesm status -content images | awk 'NR>1')
if [ $((${#STORAGE_MENU[@]}/3)) -eq 0 ]; then
  warn "'Disk image' needs to be selected for at least one storage location."
  die "Unable to detect valid storage location."
elif [ $((${#STORAGE_MENU[@]}/3)) -eq 1 ]; then
  STORAGE=${STORAGE_MENU[0]}
else
  while [ -z "${STORAGE:+x}" ]; do
    STORAGE=$(whiptail --title "Storage Pools" --radiolist \
    "Which storage pool you would like to use for the container?\n\n" \
    16 $(($MSG_MAX_LENGTH + 23)) 6 \
    "${STORAGE_MENU[@]}" 3>&1 1>&2 2>&3) || exit
  done
fi
info "Using '$STORAGE' for storage location."

# Get the next guest VM/LXC ID
VMID=$(pvesh get /cluster/nextid)
info "Container ID is $VMID."

# Get latest Home Assistant disk image archive URL
msg "Getting URL for latest Home Assistant disk image..."
RELEASE_TYPE=vmdk
URL=$(cat<<EOF | python3
import requests
url = "https://api.github.com/repos/home-assistant/operating-system/releases"
r = requests.get(url).json()
if "message" in r:
    exit()
for release in r:
    if release["prerelease"]:
        continue
    for asset in release["assets"]:
        if asset["name"].find("$RELEASE_TYPE") != -1:
            image_url = asset["browser_download_url"]
            print(image_url)
            exit()
EOF
)
if [ -z "$URL" ]; then
  die "Github has returned an error. A rate limit may have been applied to your connection."
fi

# Download Home Assistant disk image archive
msg "Downloading disk image..."
wget -q --show-progress $URL
echo -en "\e[1A\e[0K" #Overwrite output from wget
FILE=$(basename $URL)

# Extract Home Assistant disk image
msg "Extracting disk image..."
case $FILE in
  *"gz") gunzip -f $FILE;;
  *"xz") xz -d $FILE;;
  *) die "Unable to handle file extension '${FILE##*.}'.";;
esac

# Create variables for container disk
STORAGE_TYPE=$(pvesm status -storage $STORAGE | awk 'NR>1 {print $2}')
if [ "$STORAGE_TYPE" = "dir" ]; then
  DISK_EXT=".qcow2"
  DISK_REF="$VMID/"
  IMPORT_OPT="-format qcow2"
fi
for i in {0,1}; do
  disk="DISK$i"
  eval DISK${i}=vm-${VMID}-disk-${i}${DISK_EXT:-}
  eval DISK${i}_REF=${STORAGE}:${DISK_REF:-}${!disk}
done

# Create VM
msg "Creating VM..."
VM_NAME=$(sed -e "s/\_//g" -e "s/.${RELEASE_TYPE}.*$//" <<< $FILE)
qm create $VMID -agent 1 -bios ovmf -name $VM_NAME -net0 virtio,bridge=vmbr0 \
  -onboot 1 -ostype l26 -scsihw virtio-scsi-pci
pvesm alloc $STORAGE $VMID $DISK0 128 1>&/dev/null
qm importdisk $VMID ${FILE%.*} $STORAGE ${IMPORT_OPT:-} 1>&/dev/null
qm set $VMID \
  -efidisk0 ${DISK0_REF},size=128K \
  -scsi0 ${DISK1_REF},size=6G > /dev/null
qm set $VMID \
  -boot order=scsi0 > /dev/null

# Add serial port and enable console output
set +o errtrace
(
  msg "Adding serial port and configuring console..."
  trap '
    warn "Unable to configure serial port. VM is still functional."
    if [ "$(qm config $VMID | sed -n ''/serial0/p'')" != "" ]; then
      qm set $VMID --delete serial0 >/dev/null
    fi
    exit
  ' ERR
  if [ "$(command -v kpartx)" = "" ]; then
    msg "Installing 'kpartx'..."
    apt-get update >/dev/null
    apt-get -qqy install kpartx &>/dev/null
  fi
  DISK1_PATH="$(pvesm path $DISK1_REF)"
  DISK1_PART1="$(kpartx -al $DISK1_PATH | awk 'NR==1 {print $1}')"
  DISK1_PART1_PATH="/dev/mapper/$DISK1_PART1"
  TEMP_MOUNT="${TEMP_DIR}/mnt"
  trap '
    findmnt $TEMP_MOUNT >/dev/null && umount $TEMP_MOUNT
    command -v kpartx >/dev/null && kpartx -d $DISK1_PATH
  ' EXIT
  kpartx -a $DISK1_PATH
  mkdir $TEMP_MOUNT
  mount $DISK1_PART1_PATH $TEMP_MOUNT
  sed -i 's/$/ console=ttyS0/' ${TEMP_MOUNT}/cmdline.txt
  qm set $VMID -serial0 socket >/dev/null
)

info "Completed Successfully! New VM ID is \e[1m$VMID\e[0m."