#!/bin/sh

set -e

UNATTENDED="false"
if [ "$#" = "1" ] && [ "$1" = "-y" ]; then
  UNATTENDED="true"
elif [ "$#" -gt 1 ]; then
  echo "Usage: $0 [-y]" 1>&2
  exit 1
fi

detect_os () {
  RAW_OS=$(uname -s)
  OS="linux"
  case "$RAW_OS" in
    "Linux") OS="linux";;
    "Darwin") OS="osx";;
    *) echo "Unsupported operating system \"${RAW_OS}\"" 1>&2; exit 1;;
  esac
  echo "${OS}"
}

detect_architecture () {
  RAW_ARCH=$(uname -m)
  ARCH="x86_64"
  case "$RAW_ARCH" in
    "x86_64") ARCH="x86_64";;
    "i386") ARCH="x86_32";;
    *) echo "Unsupported architecture \"${RAW_ARCH}\"" 1>&2; exit 1;;
  esac
  echo "${ARCH}"
}

detect_platform () {
  OS=$(detect_os)
  ARCH=$(detect_architecture)
  echo "${OS}_${ARCH}"
}

confirm () {
  if [ "$UNATTENDED" = "true" ]; then
    return 0
  fi
  echo "$1"
  printf "[y/n]"
  read -r RESPONSE </dev/tty
  printf "\n"
  case "$RESPONSE" in
    "yes" | "y" | "YES" | "Y" ) return 0;;
    "no" | "n" | "NO" | "N" ) echo "Aborting." 1>&2; exit 1;;
    *) echo "Unrecognized response. Aborting." 1>&2; exit 1;;
  esac
}

ensure_command () {
  if command -v "$1" 1>/dev/null 2>&1; then
    return 0
  else
    echo "$1 is not installed. Please install it to proceed." 1>&2
    exit 1
  fi
}

modify_config_file () {
  FILE="$1"
  BIN_DIR="$2"
  BACKUP="${FILE}.bak.$(date | sed 's/ /-/g')"
  if ! stat "${FILE}" 1>/dev/null 2>&1; then
    return 1
  fi
  cp "${FILE}" "${BACKUP}"
  printf "\n# Added by https://grpc.io/get_grpcurl\nexport PATH=\"\$PATH:%s\"\n" "${BIN_DIR}" >> "${FILE}"
}

ensure_command "curl"
ensure_command "cut"
ensure_command "cp"
ensure_command "date"
ensure_command "grep"
ensure_command "mkdir"
ensure_command "sed"
ensure_command "stat"
ensure_command "uname"

GITHUB_URL="https://github.com"
GRPCURL_REPO="fullstorydev/grpcurl"

PLATFORM=$(detect_platform)

BIN_DIR="${HOME}/.grpcurl/bin"

confirm "This script will perform a user install of grpcurl. Would you like to proceed?"

mkdir -p "${BIN_DIR}"

curl -Ls "${GITHUB_URL}/${GRPCURL_REPO}/releases/latest" | \
  grep "href=.*${PLATFORM}.tar.gz" | \
  cut -d '"' -f 2 | \
  echo "${GITHUB_URL}$(cat -)" | \
  curl -sL "$(cat -)" --output - | \
  tar -C "${BIN_DIR}" -xzf - grpcurl

modify_config_file "${HOME}/.bashrc" "${BIN_DIR}" || \
modify_config_file "${HOME}/.bash_profile" "${BIN_DIR}" || \
modify_config_file "${HOME}/.profile" "${BIN_DIR}"

echo "${BIN_DIR} has been added to your PATH. Please open a new shell to use grpcurl."