#!/bin/bash
set -euo pipefail
shopt -s extglob

DEBUG=${DEBUG:-''}
FORCE_DOWNLOAD=${FORCE_DOWNLOAD:-''}
declare UPDATE_TYPE=""
if [[ $# -gt 0 && $1 =~ talisman-binary.* ]]; then
  UPDATE_TYPE='talisman-binary'
fi

function run() {

  # Download appropriate (appropriate = based on OS and ARCH) talisman binary from github
  # Copy the talisman binary to $TALISMAN_SETUP_DIR ($HOME/.talisman/bin)

  declare TALISMAN_BINARY_NAME

  IFS=$'\n'
  VERSION=${VERSION:-'latest'}
  INSTALL_ORG_REPO=${INSTALL_ORG_REPO:-'thoughtworks/talisman'}

  TALISMAN_SETUP_DIR=${HOME}/.talisman/bin # location of central install: talisman binary and hook script

  TEMP_DIR=$(mktemp -d 2>/dev/null || mktemp -d -t 'talisman_setup')
  #trap "rm -r ${TEMP_DIR}" EXIT
  chmod 0700 ${TEMP_DIR}

  function echo_error() {
    echo -ne $(tput setaf 1) >&2
    echo "$1" >&2
    echo -ne $(tput sgr0) >&2
  }
  export -f echo_error

  function echo_debug() {
    [[ -z "${DEBUG}" ]] && return
    echo -ne $(tput setaf 3) >&2
    echo "$1" >&2
    echo -ne $(tput sgr0) >&2
  }
  export -f echo_debug

  function echo_success() {
    echo -ne $(tput setaf 2)
    echo "$1" >&2
    echo -ne $(tput sgr0)
  }
  export -f echo_success


  function operating_system() {
    OS=$(uname -s)
    case $OS in
    "Linux")
      echo "linux"
      ;;
    "Darwin")
      echo "darwin"
      ;;
    MINGW32_NT-10.0-WOW*)
      echo "windows"
      ;;
    MINGW64_NT-10.0*)
      echo "windows"
      ;;
    MSYS_NT-*)
      echo "windows"
      ;;
    *)
      echo_error "Talisman currently only supports Windows, Linux and MacOS(darwin) systems."
      echo_error "If this is a problem for you, please open an issue: https://github.com/${INSTALL_ORG_REPO}/issues/new"
      exit $E_UNSUPPORTED_ARCH
      ;;
    esac
  }

  function set_talisman_binary_name() {
    # based on OS (linux/darwin) and ARCH(32/64 bit)
    echo_debug "Running set_talisman_binary_name"
    declare OS
    OS=$(operating_system)
    ARCH=$(uname -m)
    case $ARCH in
    "x86_64")
      OS="${OS}_amd64"
      ;;
    "i686" | "i386")
      OS="${OS}_386"
      ;;
    "arm64")
      OS="${OS}_arm64"
      ;;
    *)
      echo_error "Talisman currently only supports x86 and x86_64 architectures."
      echo_error "If this is a problem for you, please open an issue: https://github.com/${INSTALL_ORG_REPO}/issues/new"
      exit $E_UNSUPPORTED_ARCH
      ;;
    esac

    TALISMAN_BINARY_NAME="talisman_${OS}"
    if [[ $OS == *"windows"* ]]; then
      TALISMAN_BINARY_NAME="${TALISMAN_BINARY_NAME}.exe"
    fi
  }

  function download() {
    echo_debug "Running download()"
    OBJECT=$1
    DOWNLOAD_URL=$(curl -Ls https://api.github.com/repos/"$INSTALL_ORG_REPO"/releases/latest |
       grep download_url | awk '{print $2}' | tr -d '"' | grep "$OBJECT")

    echo_debug "Downloading ${OBJECT} from ${DOWNLOAD_URL}"
    curl --location --silent ${DOWNLOAD_URL} >${TEMP_DIR}/${OBJECT}
  }

  function verify_checksum() {
    FILE_NAME=$1
    CHECKSUM_FILE_NAME='checksums'
    echo_debug "Verifying checksum for ${FILE_NAME}"
    download ${CHECKSUM_FILE_NAME}

    pushd ${TEMP_DIR} >/dev/null 2>&1
    grep ${TALISMAN_BINARY_NAME} ${CHECKSUM_FILE_NAME} >${CHECKSUM_FILE_NAME}.single

    if ! command -v shasum &> /dev/null; then
      sha256sum -c ${CHECKSUM_FILE_NAME}.single
    else
      shasum -a 256 -c ${CHECKSUM_FILE_NAME}.single
    fi
    popd >/dev/null 2>&1
    echo_debug "Checksum verification successful!"
    echo
  }

  function download_talisman_binary() {
    #download talisman binary
    echo_debug "Running download_talisman_binary"
    download ${TALISMAN_BINARY_NAME}
    verify_checksum ${TALISMAN_BINARY_NAME}
  }

  function verify_binary_is_working() {
    chmod +x ${TEMP_DIR}/${TALISMAN_BINARY_NAME}
    if ! ${TEMP_DIR}/${TALISMAN_BINARY_NAME} --version; then
        echo_error "Binary is not working, SKIPPING UPGRADE, Please open issue on github with your OS name and version"
        exit 0
    fi
  }

  function download_talisman_hook_script() {
    echo_debug "Running download_talisman_hook_script"
    curl --silent https://raw.githubusercontent.com/${INSTALL_ORG_REPO}/master/global_install_scripts/talisman_hook_script.bash >${TEMP_DIR}/talisman_hook_script
  }

  function setup_talisman() {
    # copy talisman binary from TEMP folder to the central location
    rm -f ${TALISMAN_SETUP_DIR}/${TALISMAN_BINARY_NAME}
    cp ${TEMP_DIR}/${TALISMAN_BINARY_NAME} ${TALISMAN_SETUP_DIR}
    chmod +x ${TALISMAN_SETUP_DIR}/${TALISMAN_BINARY_NAME}
    echo_success "Talisman binary updated successfully!"
  }

  function setup_talisman_hook_script() {
    BINARY_PATH=${TALISMAN_SETUP_DIR}/${TALISMAN_BINARY_NAME}
    rm -f ${TALISMAN_SETUP_DIR}/talisman_hook_script
    sed "s@\${TALISMAN_BINARY}@$BINARY_PATH@g" ${TEMP_DIR}/talisman_hook_script >${TALISMAN_SETUP_DIR}/talisman_hook_script
    chmod +x ${TALISMAN_SETUP_DIR}/talisman_hook_script
    echo_success "Talisman hook script updated successfully!"
  }

  function set_talisman_env_variables_properly() {
    FILE_PATH="$1"
    if [ -f $FILE_PATH ] && grep -q "TALISMAN_HOME" $FILE_PATH; then
      if ! grep -q ">>> talisman >>>" $FILE_PATH; then
        sed -i'-talisman.bak' '/TALISMAN_HOME/d' $FILE_PATH
        echo -e "\n" >>${ENV_FILE}
        echo "# >>> talisman >>>" >>$FILE_PATH
        echo "# Below environment variables should not be modified unless you know what you are doing" >>$FILE_PATH
        echo "export TALISMAN_HOME=${TALISMAN_SETUP_DIR}" >>$FILE_PATH
        echo "alias talisman=\$TALISMAN_HOME/${TALISMAN_BINARY_NAME}" >>$FILE_PATH
        echo "# <<< talisman <<<" >>$FILE_PATH
      fi
    fi
  }

  set_talisman_binary_name
  echo "Downloading latest talisman binary..."
  download_talisman_binary
  verify_binary_is_working
  setup_talisman
  if [ -z "$UPDATE_TYPE" ]; then
    echo "Downloading latest talisman hook script..."
    download_talisman_hook_script
    setup_talisman_hook_script
  fi
  # Correcting talisman env variables if they are not in proper format
  if [ -n "${TALISMAN_HOME:-}" ]; then
    set_talisman_env_variables_properly ~/.bashrc
    set_talisman_env_variables_properly ~/.bash_profile
    set_talisman_env_variables_properly ~/.profile
  fi

}

run $0 $@