#!/bin/bash
# shellcheck disable=SC2016
# set -e

 # golang_install remove
 # golang_ install -e m

function get_platform () {

 local OS
 local ARCH
 local PLATFORM

  OS="$(uname -s)"
  ARCH="$(uname -m)"

  case $OS in
      "Linux")
          case $ARCH in
          "x86_64")
              ARCH=amd64
              ;;
          "aarch64")
              ARCH=arm64
              ;;
          "armv6")
              ARCH=armv6l
              ;;
          "armv8")
              ARCH=arm64
              ;;
          .*386.*)
              ARCH=386
              ;;
          esac
          PLATFORM="linux-$ARCH"
      ;;
      "Darwin")
          PLATFORM="darwin-amd64"
      ;;
  esac

  echo $PLATFORM
}

golang_install () {

## START INSTALL
PLATFORM=$(get_platform)
if [ -z "$PLATFORM" ]; then
    echo "Your operating system is not supported by this install script."
    return 1
fi

module_load block
[ ! "$(module_loaded block)" ] && echo unable to load block module, exiting && return 1
module_load confirm

declare ENV_TYPE="u" # Which shell repo for the block
declare ENV_FILE  # override shell repo location
# u=user h=host n=network b=base
# by default it is installed in userspace
# local versions of these
declare goroot
declare gopath
local force

declare OPTION
declare OPTARG
declare OPTIND

while getopts 're:f:r:p:' OPTION; do
    # echo $OPTION $OPTARG
  case "$OPTION" in
    r)
    force=true
    ;;
    f)
      ENV_FILE=$OPTARG
      echo explicing setting block to $ENV_FILE
      ;;
    e)
      ENV_TYPE=$OPTARG
      echo
      ;;
    r)
      goroot=$OPTARG
      echo setting root $goroot
      ;;
    p)
      gopath=$OPTARG
      echo setting path $gopath
      ;;
    *)
      echo unknown option $OPTION
      ;;
  esac
done

shift $(( OPTIND - 1 ))

if [[ ! $ENV_FILE ]]; then
  FILE=lang/go
  case $ENV_TYPE in
  # h=host m=machine n=network b=base
  "h")
     [[ -d $BASH_SHELL_HOST/$(hostname) ]] && ENV_FILE=$BASH_SHELL_HOST/$(hostname)/$FILE
     ;&
  "m")
    [[ -d $BASH_SHELL_HOST/all ]] && ENV_FILE=$BASH_SHELL_HOST/all/$FILE
    ;&
  "n")
      ([[ -d $BASH_SHELL_NETWORK/$NETWORKNAME ]] && [[ ! $ENV_FILE ]]) && ENV_FILE=$BASH_SHELL_NETWORK/$NETWORKNAME/$FILE
    ;&
  "b")
    ([[ -d $BASH_SHELL_BASE ]] && [[ ! $ENV_FILE ]]) && ENV_FILE=$BASH_SHELL_BASE/$FILE
      ;;
  esac
    [[ ! $ENV_FILE ]] && ENV_FILE=$HOME/.bashrc # default is userspace
    ENV_TYPE="u"
fi

if [[ ! $goroot ]]; then
  goroot=$GOROOT
  if [[ ! $goroot ]]; then
    [[ $ENV_TYPE = "u" ]] && goroot="$HOME/go" || goroot="/opt/go"
  fi
fi

if [[ ! $gopath ]]; then
  gopath=$GOPATH
  if [[ ! $gopath ]]; then
    [[ $ENV_TYPE = "u" ]] && gopath="$HOME/go/apps" || gopath="/opt/go/apps"
  fi
fi

echo --- go environment settings are -----
echo GOROOT: $goroot
echo GOPATH: $gopath
echo ---------------------------------------

goenv=('export GOROOT='"$goroot"'\n'
'export PATH=$PATH:'"$goroot"'/bin\n'
'export GOPATH='"$gopath"'\n'
'export PATH=$PATH:'"$gopath"'/bin')

echo ==== envionrment block is ====
printf "${goenv[*]}\n"
echo =========================================
echo environment block file is $ENV_FILE
confirm Do you want to continue || return 1

set_block -f $ENV_FILE -n "Go Language Environment"

if [[ $1 = remove ]]; then
   confirm Do you really want to remove the go installation? || return 1
   remove_block
   confirm Delete directory $gopath??? && rm -rf $gopath
   confirm Delete directory $goroot??? && rm -rf $goroot
   return 1
fi

  # the github api doesn't show any release records to had to grab this way
VERSION=$(echo "$(wget -qO- https://github.com/golang/go/tags)" | sed -e 's/<[^>]*>//g'| sed '/^\s*$/d'| grep release-branch| awk '{ print $2 }'|grep -v runtime|sort -V|tail -1|cut -c 3-)
if [[ $(which go) ]]; then
  INSTALLED_VERSION=$(echo $(go version)| awk '{print $3}' | cut -c 3-)
  # INSTALLED_VERSION=1.15.2 # this is for testing, comment out for production
  echo installed: $INSTALLED_VERSION available: $VERSION
  if [ "$INSTALLED_VERSION" == "$VERSION" ]; then
    if [[ ! $force ]]; then 
    echo Installed Version $INSTALLED_VERSION is current nothing to do, exiting
    echo use -r flag to force reinstall
    return 2
    fi
  fi
fi

if [ -d "$goroot" ]; then
    echo "The Go install directory ($goroot) already exists. "
    confirm Do you want to upgrade to $VERSION? || return 0
fi

echo installing version $VERSION ......

PACKAGE_NAME="go$VERSION.$PLATFORM.tar.gz"
TEMP_DIRECTORY=$(mktemp -d)

echo "Downloading $PACKAGE_NAME ..."
if hash wget 2>/dev/null; then
    wget https://storage.googleapis.com/golang/$PACKAGE_NAME -O "$TEMP_DIRECTORY/go.tar.gz"
else
    curl -o "$TEMP_DIRECTORY/go.tar.gz" https://storage.googleapis.com/golang/$PACKAGE_NAME
fi

if [ $? -ne 0 ]; then
    echo "Download failed! Exiting."
    return 1
fi

echo "Extracting File..."
mkdir -p "$goroot"
# TODO set correct permissions here if necessary

sudo tar -C "$goroot" --strip-components=1 -xzf "$TEMP_DIRECTORY/go.tar.gz"


echo done installing go binary and support files
rm -rf $TEMP_DIRECTORY
echo making go workspace directories

mkdir -p "${gopath}/"{src,pkg,bin}
# TODO set correct permission if all have access

echo "Configuring GO environment in: $ENV_FILE"

mkdir -p "$(dirname $ENV_FILE)"
touch "$ENV_FILE"
add_block
block_add_line "${goenv[*]}"
# echo ---------contents of $ENV_FILE------------------
# cat $ENV_FILE
# echo ------------------------------------------------

echo -e "\nGo $VERSION was installed into $goroot.\n(re)start a new shell environment to take effect"
echo NOTE: all files have root:root user:group, run a chown/chmod/setfacl commands if need be
return 0
}