#!/bin/sh
# Bemmoly installer. Keep your work in-house.
#
#   curl -fsSL https://get.bemmoly.com | sh
#   curl -fsSL https://get.bemmoly.com | sh -s -- --domain bemmoly.example.com --yes
#   curl -fsSL https://get.bemmoly.com | sh -s -- --refresh-cli   # only the bemmoly command
#
# Three ways this file runs:
#   - from a checkout (sudo sh deploy/install.sh): it sources deploy/installer/lib;
#   - served by get.bemmoly.com and piped into sh: it fetches the bundled installer of the
#     matching GitHub release (bemmoly-installer.sh, which carries that release's Compose
#     file and Caddyfile), checks its SHA-256 and runs it with the same options;
#   - as part of that bundle (BEMMOLY_BUNDLED=1), built by deploy/scripts/bundle-installer.sh.
# Run with --help for the options. MIT licensed.
set -eu

# Everything runs from one function called on the last line, so a download cut short
# (`curl … | sh` still exits 0 when curl fails) defines nothing and runs nothing.
bemmoly_install() {
  BEMMOLY_BUNDLED="${BEMMOLY_BUNDLED:-}"
  RELEASES=https://github.com/bemmoly/bemmoly/releases

  bootstrap_fail() {
    printf '\n✗ %s\n  Fix: %s\n' "$1" "$2" >&2
    exit 1
  }

  latest_prerelease_tag() {
    curl -fsSL -H 'Accept: application/vnd.github+json' \
      'https://api.github.com/repos/bemmoly/bemmoly/releases?per_page=20' |
      awk -F'"' '/"tag_name":/ { tag = $4 } /"prerelease": *true/ && tag != "" { print tag; exit }'
  }

  # The release the options ask for: --version X.Y.Z, latest (default) or the beta channel.
  bootstrap() {
    want_version=""
    want_channel=stable
    previous=''
    for arg in "$@"; do
      case "${previous}" in --version) want_version="${arg#v}" ;; --channel) want_channel="${arg}" ;; esac
      case "${arg}" in
        --version=*) want_version="${arg#--version=}" && want_version="${want_version#v}" ;;
        --channel=*) want_channel="${arg#--channel=}" ;;
      esac
      previous="${arg}"
    done
    if [ "${want_version}" = beta ] || { [ -z "${want_version}" ] && [ "${want_channel}" = beta ]; }; then
      tag=$(latest_prerelease_tag) || tag=''
      [ -n "${tag}" ] || bootstrap_fail 'No beta release was found' 'Install a numbered version with --version X.Y.Z.'
      base="${RELEASES}/download/${tag}"
    elif [ -z "${want_version}" ] || [ "${want_version}" = latest ]; then
      base="${RELEASES}/latest/download"
    else
      base="${RELEASES}/download/v${want_version}"
    fi
    command -v curl >/dev/null 2>&1 || bootstrap_fail 'curl is not installed' 'Install curl, then run the installer again.'
    work=$(mktemp -d)
    if ! curl -fsSL -o "${work}/bemmoly-installer.sh" "${base}/bemmoly-installer.sh" ||
      ! curl -fsSL -o "${work}/bemmoly-installer.sh.sha256" "${base}/bemmoly-installer.sh.sha256"; then
      bootstrap_fail "Could not download the installer from ${base}" \
        'Check the version exists (https://github.com/bemmoly/bemmoly/releases) and outbound HTTPS to github.com.'
    fi
    expected=$(awk '{ print $1; exit }' "${work}/bemmoly-installer.sh.sha256")
    actual=$(sha256sum "${work}/bemmoly-installer.sh" | awk '{ print $1 }')
    if [ -z "${expected}" ] || [ "${expected}" != "${actual}" ]; then
      bootstrap_fail 'The downloaded installer does not match its checksum' 'Run the command again; if it repeats, report it.'
    fi
    exec sh "${work}/bemmoly-installer.sh" "$@"
  }

  if [ -z "${BEMMOLY_BUNDLED}" ]; then
    case "$0" in */*) DEPLOY_DIR=$(cd "$(dirname "$0")" && pwd) ;; *) DEPLOY_DIR='' ;; esac
    if [ -z "${DEPLOY_DIR}" ] || [ ! -f "${DEPLOY_DIR}/installer/lib/common.sh" ]; then
      bootstrap "$@"
    fi
    for lib in common args preflight bundle docker config start; do
      # shellcheck source=/dev/null
      . "${DEPLOY_DIR}/installer/lib/${lib}.sh"
    done
  fi

  # Files the installer writes, from the checkout or from the bundle.
  asset() {
    if [ -n "${BEMMOLY_BUNDLED}" ]; then
      bundled_asset "$1"
      return
    fi
    case "$1" in
      docker-compose.yml | Caddyfile | env.template) cat "${DEPLOY_DIR}/compose/$1" ;;
      common.sh | preflight.sh | bundle.sh) cat "${DEPLOY_DIR}/installer/lib/$1" ;;
      cli-*.sh) cat "${DEPLOY_DIR}/cli/lib/${1#cli-}" ;;
      bemmoly) cat "${DEPLOY_DIR}/cli/bemmoly" ;;
      completion.bash) cat "${DEPLOY_DIR}/cli/completion.bash" ;;
      bemmoly-backup.service | bemmoly-backup.timer) cat "${DEPLOY_DIR}/installer/systemd/$1" ;;
      *) die "Unknown installer asset $1" "This is a bug in the installer; please report it." ;;
    esac
  }

  main() {
    parse_args "$@"
    BEMMOLY_LOG="$(mktemp /tmp/bemmoly-install.XXXXXX)"
    export BEMMOLY_LOG
    : "${BEMMOLY_DEFAULT_VERSION:=}"
    if [ -n "${REFRESH_CLI}" ]; then
      refresh_cli
      rm -f "${BEMMOLY_LOG}"
      return 0
    fi
    # A bundle decides the version and the images, before preflight skips the DNS check.
    bundle_home=''
    [ ! -f "$0" ] || bundle_home=$(dirname "$0")
    prepare_bundle "${bundle_home}"
    if [ -z "${VERSION}" ]; then
      VERSION="${BEMMOLY_DEFAULT_VERSION}"
      [ -n "${VERSION}" ] || { [ "${CHANNEL}" = beta ] && VERSION=beta || VERSION=latest; }
    fi
    run_preflight "${INSTALL_DIR}"
    note "Detected $(describe_machine)"
    ensure_docker
    check_external_database
    configure
    # Before start-up, so the fixes printed on a failure (`bemmoly logs …`) work.
    install_cli
    start_stack
    request_certificate
    schedule_backups
    final_message
    as_root install -m 600 "${BEMMOLY_LOG}" "${INSTALL_DIR}/install.log"
    rm -f "${BEMMOLY_LOG}"
    [ -z "${BUNDLE_WORK:-}" ] || rm -rf "${BUNDLE_WORK}"
  }

  main "$@"
}

bemmoly_install "$@"