#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2020-present Fewtarius

. /etc/profile


ORGANIZATION="${GIT_ORGANIZATION}"
BRANCH="$(get_setting updates.branch)"
case ${BRANCH} in
  dev)
    PROJECT="${GIT_REPO}-dev"
  ;;
  *)
    PROJECT="${GIT_REPO}"
  ;;
esac

FORCE="$(get_setting updates.force)"

GIT_REPO="https://github.com/${ORGANIZATION}/${PROJECT}"
GIT_API="https://api.github.com/repos/${ORGANIZATION}/${PROJECT}"
UPDATE_PATH="/storage/.update"
EXTENSION="tar"

function check_network() {
  GW=$(ip route | awk '/eth0/ {a=$0} END{print $1}')
  if [[ ${GW} =~ [0-9] ]]
  then
    echo true
  else
    echo false
  fi
}

get_available() {
  echo $(df | awk '/'$1'/ {printf $4; exit}')
}

get_size() {
  echo $(df | awk '/'$1'/ {printf $2; exit}')
}

check_space() {
  MYSIZE="$(get_$1 $2)"
  VOLNAME="$3"
  REQUIRED="$4"
  if [ "${MYSIZE}" -lt "${REQUIRED}" ]
  then
    NEEDED=$(( (${REQUIRED} - ${MYSIZE} ) / 1024 ))
    echo -e "There is not enough free space available ${VOLNAME} to install this update.  Free up an additional ${NEEDED}MB, or reflash the newer version."
    echo "Exiting in 5 seconds..." && sleep 5
    exit 1
  fi
}

get_changelog() {
  echo "Fetching change log."
  echo -e "Change Log\n" >/storage/.cache/changelog
  lynx --dump "${GIT_REPO}/releases/latest" | awk '/Assets [0-9]/ {exit}; /Change Log/{p++;if(p==1){next}}p;' >>/storage/.cache/changelog
}

ONLINE_STATUS=$(check_network)
if [ ! "${ONLINE_STATUS}" == true ]
then
  echo "System not online, cannot continue..."
  echo "Exiting in 5 seconds..."  && sleep 5
  exit 0
fi

echo -e "=> ${OS_NAME} UPGRADE UTILITY"


# Check storage
check_space size flash boot 2048000 2>/dev/null

if [ "$(mountpoint -q /storage/roms)" ]
then
  check_space available .update GAMES 4096000 2>/dev/null
fi

# Download
LATEST_RELEASE_TAG=$(curl -H 'Cache-Control: no-cache' -Ls "${GIT_API}/releases" | python -c "import sys, json; print(json.load(sys.stdin)[0]['tag_name'])")
if [ "${OS_VERSION}" -ge "${LATEST_RELEASE_TAG}" ] && [ ! "${FORCE}" = "1" ]
then
  echo "No new updates are available..."
  echo "Exiting in 5 seconds..." && sleep 5
  exit 0
fi

echo -e "\nFetching: ${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.${EXTENSION}"
curl -Lo "${UPDATE_PATH}/${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.${EXTENSION}" "${GIT_REPO}/releases/download/${LATEST_RELEASE_TAG}/${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.tar" 
echo -e "Fetching: ${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.${EXTENSION}.sha256"
curl -Lo "${UPDATE_PATH}/${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.${EXTENSION}.sha256" "${GIT_REPO}/releases/download/${LATEST_RELEASE_TAG}/${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.tar.sha256" 

echo -e "\nVerifying download, please wait..."
# Verify
MYSUM=$(sha256sum ${UPDATE_PATH}/${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.${EXTENSION} | awk '{print $1}')
DLSUM=$(cat ${UPDATE_PATH}/${OS_NAME}-${HW_DEVICE}.${HW_ARCH}-${LATEST_RELEASE_TAG}.${EXTENSION}.sha256 | awk '{print $1}')

if [ ! "${MYSUM}" == "${DLSUM}" ]
then
  echo "Verification failed, cleaning up and exiting..."
  rm -f ${UPDATE_PATH}/*
  sleep 5
  clear
  exit 1
else
  echo "Verification successful..."
fi

get_changelog

if [ "${FORCE}" == "1" ]
then
  set_setting updates.force 0
fi

echo -e "\nRebooting to complete OS upgrade..."
sync
sleep 3
reboot