#!/usr/bin/env bash

GO_PACKAGE_VERSION="$1"
LIB_DIR="$2"
LIBEXEC_DIR="$3"

# ############################################################
# Package Go within netdata (TBD: Package it separately)
safe_sha256sum() {
  # Within the context of the installer, we only use -c option that is common between the two commands
  # We will have to reconsider if we start non-common options
  if command -v sha256sum >/dev/null 2>&1; then
    sha256sum $@
  elif command -v shasum >/dev/null 2>&1; then
    shasum -a 256 $@
  else
    fatal "I could not find a suitable checksum binary to use"
  fi
}

download_go() {
  url="${1}"
  dest="${2}"

  if command -v curl >/dev/null 2>&1; then
    curl -sSL --connect-timeout 10 --retry 3 "${url}" >"${dest}"
  elif command -v wget >/dev/null 2>&1; then
    wget -T 15 -O - "${url}" >"${dest}"
  else
    echo >&2
    echo >&2 "Downloading go.d plugin from '${url}' failed because of missing mandatory packages."
    echo >&2 "Either add packages or disable it by issuing '--disable-go' in the installer"
    echo >&2
    exit 1
  fi
}

install_go() {
  ARCH_MAP=(
    'i386::386'
    'armhf::arm'
  )
  if [ -z "${NETDATA_DISABLE_GO+x}" ]; then
    ARCH="${DEB_TARGET_ARCH}"

    for index in "${ARCH_MAP[@]}" ; do
      KEY="${index%%::*}"
      VALUE="${index##*::}"
      if [ "$KEY" = "$ARCH" ]; then
        ARCH="${VALUE}"
        break
      fi
    done

    OS=$(uname -s | tr '[:upper:]' '[:lower:]')

    echo >&2 "Install go.d.plugin (ARCH=${ARCH}, OS=${OS})"

    tmp=$(mktemp -d /tmp/netdata-go-XXXXXX)
    GO_PACKAGE_BASENAME="go.d.plugin-${GO_PACKAGE_VERSION}.${OS}-${ARCH}.tar.gz"
    download_go "https://github.com/netdata/go.d.plugin/releases/download/${GO_PACKAGE_VERSION}/${GO_PACKAGE_BASENAME}" "${tmp}/${GO_PACKAGE_BASENAME}"
    download_go "https://github.com/netdata/go.d.plugin/releases/download/${GO_PACKAGE_VERSION}/config.tar.gz" "${tmp}/config.tar.gz"

    if [ ! -f "${tmp}/${GO_PACKAGE_BASENAME}" ] || [ ! -f "${tmp}/config.tar.gz" ] || [ ! -s "${tmp}/config.tar.gz" ] || [ ! -s "${tmp}/${GO_PACKAGE_BASENAME}" ]; then
      echo >&2 "Either check the error or consider disabling it by issuing '--disable-go' in the installer"
      echo >&2
      return 1
    fi

    grep "${GO_PACKAGE_BASENAME}\$" "packaging/go.d.checksums" >"${tmp}/sha256sums.txt" 2>/dev/null
    grep "config.tar.gz" "packaging/go.d.checksums" >>"${tmp}/sha256sums.txt" 2>/dev/null

    # Checksum validation
    if ! (cd "${tmp}" && safe_sha256sum -c "sha256sums.txt"); then

      echo >&2 "go.d plugin checksum validation failure."
      echo >&2 "Either check the error or consider disabling it by issuing '--disable-go' in the installer"
      echo >&2

      echo "go.d.plugin package files checksum validation failed."
      exit 1
    fi

    # Install files
    tar -xf "${tmp}/config.tar.gz" -C "${LIB_DIR}/conf.d/"
    tar xf "${tmp}/${GO_PACKAGE_BASENAME}"
    mv "${GO_PACKAGE_BASENAME/\.tar\.gz/}" "${LIBEXEC_DIR}/plugins.d/go.d.plugin"

    rm -rf "${tmp}"
  fi
  return 0
}

install_go