#!/usr/bin/env bash

# Repository configuration
REPO_OWNER="railwayapp"
REPO_NAME="railpack"
REPO_URL="https://github.com/${REPO_OWNER}/${REPO_NAME}"

help_text="Options

   -V, --verbose
   Enable verbose output for the installer

   -f, -y, --force, --yes
   Skip the confirmation prompt during installation

   -p, --platform
   Override the platform identified by the installer

   -b, --bin-dir
   Override the bin installation directory

   -a, --arch
   Override the architecture identified by the installer

   -B, --base-url
   Override the base URL used for downloading releases

   -r, --remove
   Uninstall railpack

   -h, --help
   Get some help

"

set -eu
printf '\n'

BOLD="$(tput bold 2>/dev/null || printf '')"
GREY="$(tput setaf 0 2>/dev/null || printf '')"
UNDERLINE="$(tput smul 2>/dev/null || printf '')"
RED="$(tput setaf 1 2>/dev/null || printf '')"
GREEN="$(tput setaf 2 2>/dev/null || printf '')"
YELLOW="$(tput setaf 3 2>/dev/null || printf '')"
BLUE="$(tput setaf 4 2>/dev/null || printf '')"
MAGENTA="$(tput setaf 5 2>/dev/null || printf '')"
NO_COLOR="$(tput sgr0 2>/dev/null || printf '')"


SUPPORTED_TARGETS="x86_64-apple-darwin arm64-apple-darwin \
                  x86_64-unknown-linux-musl arm64-unknown-linux-musl \
                  x86_64-pc-windows-msvc arm64-pc-windows-msvc"

info() {
  printf '%s\n' "${BOLD}${GREY}>${NO_COLOR} $*"
}

debug() {
  if [[ -n "${VERBOSE}" ]]; then
    printf '%s\n' "${BOLD}${GREY}>${NO_COLOR} $*"
  fi
}

warn() {
  printf '%s\n' "${YELLOW}! $*${NO_COLOR}"
}

error() {
  printf '%s\n' "${RED}x $*${NO_COLOR}" >&2
}

completed() {
  printf '%s\n' "${GREEN}✓${NO_COLOR} $*"
}

has() {
  command -v "$1" 1>/dev/null 2>&1
}

get_tmpfile() {
  local suffix
  suffix="$1"
  if has mktemp; then
    printf "%s%s.%s.%s" "$(mktemp)" "-railpack" "$(date +%s)" "${suffix}"
  else
    printf "/tmp/railpack.%s" "${suffix}"
  fi
}

# Test if a location is writeable by trying to write to it. Windows does not let
# you test writeability other than by writing: https://stackoverflow.com/q/1999988
test_writeable() {
  local path
  path="${1:-}/test.txt"
  if touch "${path}" 2>/dev/null; then
    rm "${path}"
    return 0
  else
    return 1
  fi
}

download() {
 file="$1"
  url="$2"
  touch "$file"

  if has curl; then
    cmd="curl --fail --silent --location --output $file $url"
  elif has wget; then
    cmd="wget --quiet --output-document=$file $url"
  elif has fetch; then
    cmd="fetch --quiet --output=$file $url"
  else
    error "No HTTP download program (curl, wget, fetch) found, exiting…"
    return 1
  fi

  $cmd && return 0 || rc=$?

  error "Command failed (exit code $rc): ${BLUE}${cmd}${NO_COLOR}"
  printf "\n" >&2
  info "This is likely due to railpack not yet supporting your configuration."
  info "If you would like to see a build for your configuration,"
  info "please create an issue requesting a build for ${MAGENTA}${TARGET}${NO_COLOR}:"
  info "${BOLD}${UNDERLINE}${REPO_URL}/issues/new/${NO_COLOR}"
  return $rc
}

unpack() {
  local archive=$1
  local bin_dir=$2
  local sudo=${3-}

  case "$archive" in
    *.tar.gz)
      flags=$(test -n)
      ${sudo} tar "${flags}" -xzf "${archive}" -C "${bin_dir}"
      return 0
      ;;
    *.zip)
      flags=$(test -z)
      UNZIP="${flags}" ${sudo} unzip "${archive}" -d "${bin_dir}"
      return 0
      ;;
  esac

  error "Unknown package extension."
  printf "\n"
  info "This almost certainly results from a bug in this script--please file a"
  info "bug report at ${REPO_URL}/issues"
  return 1
}

elevate_priv() {
  if ! has sudo; then
    error 'Could not find the command "sudo", needed to get permissions for install.'
    info "If you are on Windows, please run your shell as an administrator, then"
    info "rerun this script. Otherwise, please run this script as root, or install"
    info "sudo."
    exit 1
  fi
  if ! sudo -v; then
    error "Superuser not granted, aborting installation"
    exit 1
  fi
}

install() {
  local msg
  local sudo
  local archive
  local ext="$1"

  if test_writeable "${BIN_DIR}"; then
    sudo=""
    msg="Installing railpack, please wait…"
  else
    warn "Escalated permissions are required to install to ${BIN_DIR}"
    elevate_priv
    sudo="sudo"
    msg="Installing railpack as root, please wait…"
  fi
  info "$msg"

  archive=$(get_tmpfile "$ext")

  # download to the temp file
  download "${archive}" "${URL}"

  # unpack the temp file to the bin dir, using sudo if required
  unpack "${archive}" "${BIN_DIR}" "${sudo}"

  # remove tempfile
  # rm "${archive}"
}

# Simplify platform detection
detect_platform() {
  local platform
  platform="$(uname -s | tr '[:upper:]' '[:lower:]')"

  case "${platform}" in
    msys_nt*|cygwin_nt*|mingw*) platform="pc-windows-msvc" ;;
    linux) platform="unknown-linux-musl" ;;
    darwin) platform="apple-darwin" ;;
  esac

  printf '%s' "${platform}"
}

detect_arch() {
  local arch
  arch="$(uname -m | tr '[:upper:]' '[:lower:]')"

  case "${arch}" in
    amd64|x86_64) printf 'x86_64' ;;
    arm64|aarch64) printf 'arm64' ;;
    *) printf 'x86_64' ;;
  esac
}

detect_target() {
  local arch="$1"
  local platform="$2"
  local target="$arch-$platform"

  if [ "${target}" = "arm-unknown-linux-musl" ]; then
    target="${target}eabihf"
  fi

  printf '%s' "${target}"
}


confirm() {
  if [ -t 0 ]; then
    if [ -z "${FORCE-}" ]; then
      printf "%s " "${MAGENTA}?${NO_COLOR} $* ${BOLD}[y/N]${NO_COLOR}"
      set +e
      read -r yn </dev/tty
      rc=$?
      set -e
      if [ $rc -ne 0 ]; then
        error "Error reading from prompt (please re-run with the '--yes' option)"
        exit 1
      fi
      if [ "$yn" != "y" ] && [ "$yn" != "yes" ]; then
        error 'Aborting (please answer "yes" to continue)'
        exit 1
      fi
    fi
  fi
}

check_bin_dir() {
  local bin_dir="$1"

  if [ ! -d "$BIN_DIR" ]; then
    error "Installation location $BIN_DIR does not appear to be a directory"
    info "Make sure the location exists and is a directory, then try again."
    exit 1
  fi

  # https://stackoverflow.com/a/11655875
  local good
  good=$(
    IFS=:
    for path in $PATH; do
      if [ "${path}" = "${bin_dir}" ]; then
        printf 1
        break
      fi
    done
  )

  if [ "${good}" != "1" ]; then
    warn "Bin directory ${bin_dir} is not in your \$PATH"
  fi
}

is_build_available() {
  local arch="$1"
  local platform="$2"
  local target="$3"

  local good

  good=$(
    IFS=" "
    for t in $SUPPORTED_TARGETS; do
      if [ "${t}" = "${target}" ]; then
        printf 1
        break
      fi
    done
  )

  if [ "${good}" != "1" ]; then
    error "${arch} builds for ${platform} are not yet available for nixpacks"
    printf "\n" >&2
    info "If you would like to see a build for your configuration,"
    info "please create an issue requesting a build for ${MAGENTA}${target}${NO_COLOR}:"
    info "${BOLD}${UNDERLINE}${REPO_URL}/issues/new/${NO_COLOR}"
    printf "\n"
    exit 1
  fi
}

UNINSTALL=0
HELP=0

DEFAULT_VERSION=$(curl --fail --silent --show-error ${GITHUB_TOKEN:+-H "Authorization: Bearer $GITHUB_TOKEN"} "https://api.github.com/repos/${REPO_OWNER}/${REPO_NAME}/releases/latest" | grep -o '"tag_name": "v.*"' | cut -d'"' -f4 | cut -c2-)

# defaults
if [ -z "${RAILPACK_VERSION-}" ]; then
  RAILPACK_VERSION="$DEFAULT_VERSION"
fi

if [ -z "${RAILPACK_PLATFORM-}" ]; then
  PLATFORM="$(detect_platform)"
fi

if [ -z "${RAILPACK_BIN_DIR-}" ]; then
  BIN_DIR=/usr/local/bin
fi

if [ -z "${RAILPACK_ARCH-}" ]; then
  ARCH="$(detect_arch)"
fi

if [ -z "${RAILPACK_BASE_URL-}" ]; then
  BASE_URL="${REPO_URL}/releases"
fi

while [ "$#" -gt 0 ]; do
  case "$1" in
  -p | --platform)
    PLATFORM="$2"
    shift 2
    ;;
  -b | --bin-dir)
    BIN_DIR="$2"
    shift 2
    ;;
  -a | --arch)
    ARCH="$2"
    shift 2
    ;;
  -B | --base-url)
    BASE_URL="$2"
    shift 2
    ;;

  -V | --verbose)
    VERBOSE=1
    shift 1
    ;;
  -f | -y | --force | --yes)
    FORCE=1
    shift 1
    ;;
  -r | --remove | --uninstall)
    UNINSTALL=1
    shift 1
    ;;
  -h | --help)
    HELP=1
    shift 1
    ;;
  -p=* | --platform=*)
    PLATFORM="${1#*=}"
    shift 1
    ;;
  -b=* | --bin-dir=*)
    BIN_DIR="${1#*=}"
    shift 1
    ;;
  -a=* | --arch=*)
    ARCH="${1#*=}"
    shift 1
    ;;
  -B=* | --base-url=*)
    BASE_URL="${1#*=}"
    shift 1
    ;;
  -V=* | --verbose=*)
    VERBOSE="${1#*=}"
    shift 1
    ;;
  -f=* | -y=* | --force=* | --yes=*)
    FORCE="${1#*=}"
    shift 1
    ;;

  *)
    error "Unknown option: $1"
    exit 1
    ;;
  esac
done

if [ -n "${VERBOSE-}" ]; then
  VERBOSE=v
else
  VERBOSE=
fi

if [ $UNINSTALL == 1 ]; then
  confirm "Are you sure you want to uninstall railpack?"

  msg=""
  sudo=""

  if test_writeable "$(dirname "$(which ${REPO_NAME})")"; then
    sudo=""
    msg="Removing railpack, please wait…"
  else
    warn "Escalated permissions are required to install to ${BIN_DIR}"
    elevate_priv
    sudo="sudo"
    msg="Removing railpack as root, please wait…"
  fi

  info "$msg"
  ${sudo} rm -f "$(which ${REPO_NAME})"
  ${sudo} rm -rf /tmp/${REPO_NAME}

  info "Removed railpack"
  exit 0
fi

if [ $HELP == 1 ]; then
    echo "${help_text}"
    exit 0
fi
TARGET="$(detect_target "${ARCH}" "${PLATFORM}")"

is_build_available "${ARCH}" "${PLATFORM}" "${TARGET}"

print_configuration () {
  if [[ -n "${VERBOSE}" ]]; then
    printf "  %s\n" "${UNDERLINE}Configuration${NO_COLOR}"
    debug "${BOLD}Bin directory${NO_COLOR}: ${GREEN}${BIN_DIR}${NO_COLOR}"
    debug "${BOLD}Platform${NO_COLOR}:      ${GREEN}${PLATFORM}${NO_COLOR}"
    debug "${BOLD}Arch${NO_COLOR}:          ${GREEN}${ARCH}${NO_COLOR}"
    debug "${BOLD}Version${NO_COLOR}:       ${GREEN}${RAILPACK_VERSION}${NO_COLOR}"
    printf '\n'
  fi
}

print_configuration

EXT=tar.gz
if [ "${PLATFORM}" = "pc-windows-msvc" ]; then
  EXT=zip
fi

URL="${BASE_URL}/download/v${RAILPACK_VERSION}/${REPO_NAME}-v${RAILPACK_VERSION}-${TARGET}.${EXT}"
debug "Tarball URL: ${UNDERLINE}${BLUE}${URL}${NO_COLOR}"
confirm "Install railpack ${GREEN}${RAILPACK_VERSION}${NO_COLOR} to ${BOLD}${GREEN}${BIN_DIR}${NO_COLOR}?"
check_bin_dir "${BIN_DIR}"

install "${EXT}"

printf "$GREEN"
cat <<'EOF'

   ____       _ _                  _
  |  _ \ __ _(_) |_ __   __ _  ___| | __
  | |_) / _` | | | '_ \ / _` |/ __| |/ /
  |  _ < (_| | | | |_) | (_| | (__|   <
  |_| \_\__,_|_|_| .__/ \__,_|\___|_|\_\
                  |_|

  Railpack is now installed!
  Run 'railpack --help' to get started

EOF
printf "$NO_COLOR"