#!/usr/bin/env bash

usage()
{
cat << EOF
GAM installation script.

OPTIONS:
   -h      show help.
   -d      Directory where gam folder will be installed. Default is \$HOME/bin/
   -a      Architecture to install (i386, x86_64, x86_64_legacy, arm, arm64). Default is to detect your arch with "uname -m".
   -o      OS we are running (linux, macos). Default is to detect your OS with "uname -s".
   -b      OS version. Default is to detect on MacOS and Linux.
   -l      Just upgrade GAM to latest version. Skips project creation and auth.
   -p      Profile update (true, false). Should script add gam command to environment. Default is true.
   -u      Admin user email address to use with GAM. Default is to prompt.
   -r      Regular user email address. Used to test service account access to user data. Default is to prompt.
   -v      Version to install (latest, prerelease, draft, 3.8, etc). Default is latest.
   -s      Strip gamadv-xtd3 component from extracted files, files will be downloaded directly to $target_dir
EOF
}

target_dir="$HOME/bin"
target_gam="gamadv-xtd3/gam"
gamarch=$(uname -m)
gamos=$(uname -s)
osversion=""
update_profile=true
upgrade_only=false
gamversion="latest"
adminuser=""
regularuser=""
gam_x86_64_glibc_vers="2.39 2.35 2.31 2.27 2.23 2.19"
gam_arm64_glibc_vers="2.31 2.27 2.23"
strip_gam="--strip-components 0"

while getopts "hd:a:o:b:lp:u:r:v:s" OPTION
do
     case $OPTION in
         h) usage; exit;;
         d) target_dir="$OPTARG";;
         a) gamarch="$OPTARG";;
         o) gamos="$OPTARG";;
         b) osversion="$OPTARG";;
         l) upgrade_only=true;;
         p) update_profile="$OPTARG";;
         u) adminuser="$OPTARG";;
         r) regularuser="$OPTARG";;
         v) gamversion="$OPTARG";;
         s) strip_gam="--strip-components 1"; target_gam="gam";;
         ?) usage; exit;;
     esac
done

# remove possible / from end of target_dir
target_dir=${target_dir%/}

update_profile() {
        [ "$2" -eq 1 ] || [ -f "$1" ] || return 1

        grep -F "$alias_line" "$1" > /dev/null 2>&1
        if [ $? -ne 0 ]; then
                echo_yellow "Adding gam alias to profile file $1."
                echo -e "\n$alias_line" >> "$1"
        else
          echo_yellow "gam alias already exists in profile file $1. Skipping add."
        fi
}

echo_red()
{
echo -e "\x1B[1;31m$1"
echo -e '\x1B[0m'
}

echo_green()
{
echo -e "\x1B[1;32m$1"
echo -e '\x1B[0m'
}

echo_yellow()
{
echo -e "\x1B[1;33m$1"
echo -e '\x1B[0m'
}

version_gt()
{
# MacOS < 10.13 doesn't support sort -V
echo "" | sort -V > /dev/null 2>&1
vsort_failed=$?
echo "Check:${2}"
if [ "${1}" = "${2}" ]; then
  true
elif (( $vsort_failed != 0 )); then
  false
else
  test "$(printf '%s\n' "$@" | sort -V | head -n 1)" != "$1"
fi
}

case $gamos in
  [lL]inux)
    gamos="linux"
    if [ "$osversion" == "" ]; then
      this_glibc_ver=$(ldd --version | awk '/ldd/{print $NF}')
    else
      this_glibc_ver=$osversion
    fi
    echo "This Linux distribution uses glibc $this_glibc_ver"
    case $gamarch in
      x86_64)
        useglibc="legacy"
        for gam_glibc_ver in $gam_x86_64_glibc_vers; do
          if version_gt $this_glibc_ver $gam_glibc_ver; then
            useglibc="glibc$gam_glibc_ver"
            echo_green "Using GAM compiled against $useglibc"
            break
          fi
        done
        gamfile="linux-x86_64-$useglibc.tar.xz";;
      arm|arm64|aarch64)
        useglibc=""
        for gam_glibc_ver in $gam_arm64_glibc_vers; do
          if version_gt $this_glibc_ver $gam_glibc_ver; then
            useglibc="glibc$gam_glibc_ver"
            echo_green "Using GAM compiled against $useglibc"
            break
          fi
        done
        if [ "$useglibc" == "" ]; then
          echo_red "Sorry, you need to be running at least glibc $useglibc to run GAM"
          exit
        fi
        gamfile="linux-arm64-$useglibc.tar.xz";;
      *)
        echo_red "ERROR: this installer currently only supports x86_64 and arm64 Linux. Looks like you're running on $gamarch. Exiting."
        exit
    esac
    ;;
  [Mm]ac[Oo][sS]|[Dd]arwin)
    gamos="macos"
    fullversion=$(sw_vers -productVersion)
    osversion=${fullversion:0:2}
    case $gamarch in
      x86_64)
        gamfile="macos-x86_64.tar.xz"
	minimum_version=11
        ;;
      arm|arm64|aarch64)
        gamfile="macos-arm64.tar.xz"
	minimum_version=13
        ;;
      *)
        echo_red "ERROR: this installer currently only supports x86_64 and arm64 MacOS. Looks like you're running on $gamarch. Exiting."
        exit
	;;
    esac
    if [[ "$osversion" -ge "$minimum_version" ]]; then
      echo_green "You are running MacOS ${fullversion}, good. Using GAM with ${gamfile}."
    else
      echo_red "Sorry, you are running MacOS ${fullversion} but GAM on ${gamarch} requires MacOS ${minimum_version}. Exiting."
      exit
    fi
    ;;
  MINGW64_NT*)
    gamos="windows"
    echo "You are running Windows"
    gamfile="-windows-x86_64.zip"
    ;;
  *)
    echo_red "Sorry, this installer currently only supports Linux and MacOS. Looks like you're running on $gamos. Exiting."
    exit
    ;;
esac

if [ "$gamversion" == "latest" ]; then
  release_url="https://api.github.com/repos/taers232c/GAMADV-XTD3/releases/latest"
elif [ "$gamversion" == "prerelease" -o "$gamversion" == "draft" ]; then
  release_url="https://api.github.com/repos/taers232c/GAMADV-XTD3/releases"
else
  release_url="https://api.github.com/repos/taers232c/GAMADV-XTD3/releases/tags/v$gamversion"
fi

if [ -z ${GHCLIENT+x} ]; then
  check_type="unauthenticated"
  echo_yellow "Checking GitHub URL $release_url for $gamversion GAM release ($check_type)..."
  release_json=$(curl -s "$release_url" 2>&1 /dev/null)
else
  check_type="authenticated"
  echo_yellow "Checking GitHub URL $release_url for $gamversion GAM release ($check_type)..."
  release_json=$(curl -s "$GHCLIENT" "$release_url" 2>&1 /dev/null)
fi

echo_yellow "Getting file and download URL..."
# Python is sadly the nearest to universal way to safely handle JSON with Bash
# At least this code should be compatible with just about any Python version ever
# unlike GAM itself. If some users don't have Python we can try grep / sed / etc
# but that gets really ugly
pycode="import json
import sys

attrib = sys.argv[1]
gamversion = sys.argv[2]

release = json.load(sys.stdin)
if type(release) is list:
  for a_release in release:
    if a_release['prerelease'] and gamversion != 'prerelease':
      continue
    elif a_release['draft'] and gamversion != 'draft':
      continue
    release = a_release
    break
try:
  for asset in release['assets']:
    if asset[attrib].endswith('$gamfile'):
      print(asset[attrib])
      break
  else:
    print('ERROR: Attribute: {0} for $gamfile version {1} not found'.format(attrib, gamversion))
except KeyError:
  print('ERROR: assets value not found in JSON value of:\n\n%s' % release)"

pycmd="python3"
$pycmd -V >/dev/null 2>&1
rc=$?
if (( $rc != 0 )); then
  pycmd="python"
fi
$pycmd -V >/dev/null 2>&1
rc=$?
if (( $rc != 0 )); then
  pycmd="/usr/bin/python3"
fi
$pycmd -V >/dev/null 2>&1
rc=$?
if (( $rc != 0 )); then
  pycmd="python2"
fi
$pycmd -V >/dev/null 2>&1
rc=$?
if (( $rc != 0 )); then
  echo_red "ERROR: No version of python installed."
  exit
fi

browser_download_url=$(echo "$release_json" | $pycmd -c "$pycode" browser_download_url "$gamversion")
if [[ ${browser_download_url:0:5} = "ERROR" ]]; then
  echo_red "${browser_download_url}"
  exit
fi
name=$(echo "$release_json" | $pycmd -c "$pycode" name "$gamversion")
if [[ ${name:0:5} = "ERROR" ]]; then
  echo_red "${name}"
  exit
fi
# Temp dir for archive
#temp_archive_dir=$(mktemp -d)
temp_archive_dir=$(mktemp -d 2>/dev/null || mktemp -d -t 'mytmpdir')

# Clean up after ourselves even if we are killed with CTRL-C
trap "rm -rf $temp_archive_dir" EXIT

echo_yellow "Downloading file $name from $browser_download_url to $temp_archive_dir ($check_type)..."
# Save archive to temp w/o losing our path
if [ -z ${GHCLIENT+x} ]; then
  (cd "$temp_archive_dir" && curl -O -L $browser_download_url)
else
  (cd "$temp_archive_dir" && curl -O -L $GHCLIENT $browser_download_url)
fi

mkdir -p "$target_dir"

echo_yellow "Extracting archive to $target_dir"
if [[ "${name}" == *.tar.xz ]]; then
  tar $strip_gam -xf "$temp_archive_dir"/"$name" -C "$target_dir"
elif [[ "${name}" == *.tar ]]; then
  tar $strip_gam -xf "$temp_archive_dir"/"$name" -C "$target_dir"
else
  unzip "${temp_archive_dir}/${name}" -d "${target_dir}"
fi
rc=$?
if (( $rc != 0 )); then
  echo_red "ERROR: extracting the GAM archive with tar failed with error $rc. Exiting."
  exit
else
  echo_green "Finished extracting GAM archive."
fi

# Update profile to add gam command
if [ "$update_profile" = true ]; then
  alias_line="alias gam=\"${target_dir// /\\ }/$target_gam\""
  if [ "$gamos" == "linux" ]; then
    update_profile "$HOME/.bash_aliases" 0 || update_profile "$HOME/.bash_profile" 0 || update_profile "$HOME/.bashrc" 0
    update_profile "$HOME/.zshrc" 0
  elif [ "$gamos" == "macos" ]; then
    update_profile "$HOME/.bash_aliases" 0 || update_profile "$HOME/.bash_profile" 0 || update_profile "$HOME/.bashrc" 0 || update_profile "$HOME/.profile" 1
    update_profile "$HOME/.zshrc" 1
  fi
else
  echo_yellow "skipping profile update."
fi

if [ "$upgrade_only" = true ]; then
  echo_green "Here's information about your GAM upgrade:"
  "$target_dir/$target_gam" version extended
  rc=$?
  if (( $rc != 0 )); then
    echo_red "ERROR: Failed running GAM for the first time with return code $rc. Please report this error to GAM mailing list. Exiting."
    exit
  fi

  echo_green "GAM upgrade complete!"
  exit
fi

# Set config command
config_cmd="config no_browser false"

while true; do
  read -p "Can you run a full browser on this machine? (usually Y for MacOS, N for Linux if you SSH into this machine) " yn
  case $yn in
    [Yy]*)
      break
      ;;
    [Nn]*)
      config_cmd="config no_browser true"
      break
      ;;
    *)
      echo_red "Please answer yes or no."
      ;;
  esac
done
echo

project_created=false
while true; do
  read -p "GAM is now installed. Are you ready to set up a Google API project for GAM? (yes or no) " yn
  case $yn in
    [Yy]*)
      if [ "$adminuser" == "" ]; then
        read -p "Please enter your Google Workspace admin email address: " adminuser
      fi
      "$target_dir/$target_gam" $config_cmd create project $adminuser
      rc=$?
      if (( $rc == 0 )); then
        echo_green "Project creation complete."
        project_created=true
        break
      else
        echo_red "Project creation failed. Trying again. Say N to skip project creation."
      fi
      ;;
    [Nn]*)
      echo -e "\nYou can create an API project later by running:\n\ngam create project\n"
      break
      ;;
    *)
      echo_red "Please answer yes or no."
      ;;
  esac
done

admin_authorized=false
while $project_created; do
  read -p "Are you ready to authorize GAM to perform Google Workspace management operations as your admin account? (yes or no) " yn
  case $yn in
    [Yy]*)
      "$target_dir/$target_gam" $config_cmd oauth create $adminuser
      rc=$?
      if (( $rc == 0 )); then
        echo_green "Admin authorization complete."
        admin_authorized=true
        break
      else
        echo_red "Admin authorization failed. Trying again. Say N to skip admin authorization."
      fi
      ;;
     [Nn]*)
       echo -e "\nYou can authorize an admin later by running:\n\ngam oauth create\n"
       break
       ;;
     *)
       echo_red "Please answer yes or no."
       ;;
  esac
done

service_account_authorized=false
while $admin_authorized; do
  read -p "Are you ready to authorize GAM to manage Google Workspace user data and settings? (yes or no) " yn
  case $yn in
    [Yy]*)
      if [ "$regularuser" == "" ]; then
        read -p "Please enter the email address of a regular Google Workspace user: " regularuser
      fi
      echo_yellow "Great! Checking service account scopes.This will fail the first time. Follow the steps to authorize and retry. It can take a few minutes for scopes to PASS after they've been authorized in the admin console."
      "$target_dir/$target_gam" $config_cmd user $regularuser check serviceaccount
      rc=$?
      if (( $rc == 0 )); then
        echo_green "Service account authorization complete."
        service_account_authorized=true
        break
      else
        echo_red "Service account authorization failed. Confirm you entered the scopes correctly in the admin console. It can take a few minutes for scopes to PASS after they are entered in the admin console so if you're sure you entered them correctly, go grab a coffee and then hit Y to try again. Say N to skip admin authorization."
      fi
      ;;
     [Nn]*)
       echo -e "\nYou can authorize a service account later by running:\n\ngam user $adminuser check serviceaccount\n"
       break
       ;;
     *)
       echo_red "Please answer yes or no."
       ;;
  esac
done

echo_green "Here's information about your new GAM installation:"
"$target_dir/$target_gam" $config_cmd save version extended
rc=$?
if (( $rc != 0 )); then
  echo_red "ERROR: Failed running GAM for the first time with $rc. Please report this error to GAM mailing list. Exiting."
  exit
fi

echo_green "GAM installation and setup complete!"
if [ "$update_profile" = true ]; then
  echo_green "Please restart your terminal shell or to get started right away run:\n\n$alias_line"
fi