#!/usr/bin/env bash

_help() {
  cat <<END

USAGE

    $ ./install.sh [--version=<crystal-version>] [--channel=stable|unstable|nightly]

  - crystal-version: "latest", or a minor release version like 1.0 or 1.1 (Default: latest)
  - channel: "stable", "unstable", "nightly" (Default: stable)

REQUIREMENTS

  - Run as root
  - The following packages need to be installed already:
    - gnupg ca-certificates apt-transport-https (on Debian/Ubuntu)

NOTES

  The following files may be updated:

  - /etc/apt/sources.list.d/crystal.list (on Debian/Ubuntu)
  - /etc/yum.repos.d/crystal.repo (on CentOS/Fedora)

  The following packages may be installed:

  - wget (on Debian/Ubuntu when missing)
  - curl (on openSUSE when missing)
  - yum-utils (on CentOS/Fedora when using --version=x.y.z)

  This script source and issue-tracker can be found at:

  - https://github.com/crystal-lang/distribution-scripts/tree/master/packages/scripts/install.sh

END
}

set -eu

OBS_PROJECT=${OBS_PROJECT:-"devel:languages:crystal"}
DISTRO_REPO=${DISTRO_REPO:-}
CRYSTAL_VERSION=${CRYSTAL_VERSION:-"latest"}
CHANNEL="stable"
SCRIPT_COMMAND="$0 $@"

_error_reporting() {
  cat >&2 <<TXT
This installer script tries to identify your Linux distribution and install the
appropriate Crystal package from the Open Build Service repository. It supports
only DEB and RPM based package managers.
More options to install Crystal are listed on https://crystal-lang.org/install/
Please report issues to https://forum.crystal-lang.org/c/help-support/11
TXT
}

_error() {
  echo >&2 "ERROR: $*"
}

_warn() {
  echo >&2 "WARNING: $*"
}

_check_version_id() {
  if [[ -z "${VERSION_ID}" ]]; then
    _error "Unable to identify distribution repository for ${ID}."
    _error_reporting
    exit 1
  fi
}

_discover_distro_repo() {
  if [[ -r /etc/os-release ]]; then
    # shellcheck source=/dev/null
    source /etc/os-release
  elif [[ -r /usr/lib/os-release ]]; then
    # shellcheck source=/dev/null
    source /usr/lib/os-release
  else
    _error "Unable to identify distribution."
    _error_reporting
    exit 1
  fi

  case "$ID" in
    debian)
      if [[ -z "${VERSION_ID:-}" ]]; then
        VERSION_ID="Unstable"
      elif [[ "$VERSION_ID" == "9" ]]; then
        VERSION_ID="$VERSION_ID.0"
      fi
      _check_version_id

      DISTRO_REPO="Debian_${VERSION_ID}"
      ;;
    ubuntu)
      _check_version_id
      DISTRO_REPO="xUbuntu_${VERSION_ID}"
      ;;
    fedora)
      _check_version_id
      if [[ "${VERSION}" == *"Prerelease"* ]]; then
        DISTRO_REPO="Fedora_Rawhide"
      else
        DISTRO_REPO="Fedora_${VERSION_ID}"
      fi
      ;;
    centos)
      _check_version_id
      DISTRO_REPO="CentOS_${VERSION_ID}"
      ;;
    rhel)
      _check_version_id
      DISTRO_REPO="RHEL_${VERSION_ID}"
      ;;
    opensuse-tumbleweed)
      DISTRO_REPO="openSUSE_Tumbleweed"
      ;;
    opensuse-leap)
      _check_version_id
      DISTRO_REPO="${VERSION_ID}"
      ;;
    "")
      _error "Unable to identify distribution. You may specify one with environment variable DISTRO_REPO"
      _error_reporting
      exit 1
      ;;
    *)
      if [[ -n "${UBUNTU_CODENAME:-}" ]]; then
        # Map UBUNTU_CODENAME to the corresponding repo version for
        # distros that use Ubuntu package sources, such as Linux Mint.
        case "${UBUNTU_CODENAME}" in
          jammy)
            DISTRO_REPO="xUbuntu_22.04"
            return 0
            ;;
          noble)
            DISTRO_REPO="xUbuntu_24.04"
            return 0
            ;;
          resolute)
            DISTRO_REPO="xUbuntu_26.04"
            return 0
            ;;
        esac
      fi

      # If there's no dedicated repository for the distro, try to figure out
      # if the distro is apt, dnf or rpm based and use a default repository.
      _discover_package_manager

      _error "Unable to identify distribution type ($ID). You may specify a repository with the environment variable DISTRO_REPO."

      echo >&2 "See https://software.opensuse.org/download.html?project=devel%3Alanguages%3Acrystal&package=crystal for available repositories."

      echo >&2
      echo >&2 "         Example:"
      case "$PACKAGE_MANAGER" in
      dnf)
        echo >&2 "         DISTRO_REPO=Fedora_Rawhide $SCRIPT_COMMAND"
        ;;
      *)
        echo >&2 "         DISTRO_REPO=Debian_Unstable $SCRIPT_COMMAND"
        ;;
      esac
      echo >&2

      exit 1
  esac
}

_discover_package_manager() {
  [[ $(command -v apt-get) ]] && PACKAGE_MANAGER="apt" && return
  [[ $(command -v dnf) ]]     && PACKAGE_MANAGER="dnf" && return
  [[ $(command -v yum) ]]     && PACKAGE_MANAGER="yum" && return
  PACKAGE_MANAGER="unknown"
}

if [[ $EUID -ne 0 ]]; then
  _error "This script must be run as root"
  exit 1
fi

# Parse --version=<VERSION> and --channel=<CHANNEL> arguments

for i in "$@"
do
case $i in
    --crystal=*)
    CRYSTAL_VERSION="${i#*=}"
    shift
    echo "The argument --crystal= has been deprecated, please use --version= instead." >&2
    ;;
    --version=*)
    CRYSTAL_VERSION="${i#*=}"
    shift
    ;;
    --channel=*)
    CHANNEL="${i#*=}"
    shift
    ;;
    --help)
    _help
    exit 0
    ;;
    *)
    _warn "Invalid option $i"
    ;;
esac
done

case $CHANNEL in
  stable)
    ;;
  nightly | unstable)
    OBS_PROJECT="${OBS_PROJECT}:${CHANNEL}"
    ;;
  *)
    _error "Unsupported channel $CHANNEL"
    exit 1
    ;;
esac

if [[ -z "${DISTRO_REPO}" ]]; then
  _discover_distro_repo
fi

_install_apt() {
  if ! command -v wget &> /dev/null || ! command -v gpg &> /dev/null; then
    [[ -f /etc/apt/sources.list.d/crystal.list ]] && rm -f /etc/apt/sources.list.d/crystal.list
    apt-get update
    apt-get install -y wget gpg
  fi

  # Add repo signing key
  wget -qO- "https://download.opensuse.org/repositories/${OBS_PROJECT//:/:\/}/${DISTRO_REPO}/Release.key" | gpg --dearmor | tee /etc/apt/trusted.gpg.d/devel_languages_crystal.gpg > /dev/null
  echo "deb http://download.opensuse.org/repositories/${OBS_PROJECT//:/:\/}/${DISTRO_REPO}/ /" | tee /etc/apt/sources.list.d/crystal.list
  apt-get update

  if [[ "$CRYSTAL_VERSION" == "latest" ]]; then
    apt-get install -y crystal
  else
    apt-get install -y "crystal${CRYSTAL_VERSION}"
  fi
}

_install_rpm_key() {
  rpm --verbose --import "https://build.opensuse.org/projects/${OBS_PROJECT}/signing_keys/download?kind=gpg"
}

_add_yum_repo() {
  cat > /etc/yum.repos.d/crystal.repo <<EOF
[crystal]
name=Crystal (${DISTRO_REPO})
type=rpm-md
baseurl=https://download.opensuse.org/repositories/${OBS_PROJECT//:/:\/}/${DISTRO_REPO}/
gpgcheck=1
gpgkey=https://download.opensuse.org/repositories/${OBS_PROJECT//:/:\/}/${DISTRO_REPO}/repodata/repomd.xml.key
enabled=1
EOF
}

_install_yum() {
  _install_rpm_key
  _add_yum_repo

  if [[ "$CRYSTAL_VERSION" == "latest" ]]; then
    yum install -y crystal
  else
    yum install -y "crystal${CRYSTAL_VERSION}"
  fi
}

_install_dnf() {
  _install_rpm_key
  _add_yum_repo

  if [[ "$CRYSTAL_VERSION" == "latest" ]]; then
    dnf install -y crystal
  else
    dnf install -y "crystal${CRYSTAL_VERSION}"
  fi
}

_install_zypper() {
  if ! command -v curl &> /dev/null; then
    zypper refresh
    zypper install -y curl
  fi

  _install_rpm_key
  zypper --non-interactive addrepo "https://download.opensuse.org/repositories/${OBS_PROJECT//:/:\/}/$DISTRO_REPO/${OBS_PROJECT}.repo"
  zypper --non-interactive refresh

  if [[ "$CRYSTAL_VERSION" == "latest" ]]; then
    zypper --non-interactive install crystal
  else
    zypper --non-interactive install "crystal${CRYSTAL_VERSION}"
  fi
}

# Add repo
case $DISTRO_REPO in
  Debian*)
    _install_apt
    ;;
  xUbuntu*)
    _install_apt
    ;;
  Fedora*)
    _install_dnf
    ;;
  RHEL*)
    _install_yum
    ;;
  CentOS*)
    _install_yum
    ;;
  15.* | openSUSE*)
    _install_zypper
    ;;
  *)
    _error "Unable to install for $DISTRO_REPO"
    _error_reporting
    exit 1
    ;;
esac