generate-go

#!/usr/bin/env sh

set -e

show_help() {
  cat << EOF >&2
generate-go v1.0.0

Compile all .proto definitions into importable .go files

Usage: generate-go [options] LND_VERSION

Where LND_VERSION is in a form: [v]MAJOR.MINOR.PATCH (ex: v0.9.0), or "all" to generate for all versions

Options:

  -h, --help, help      Show this help message
  -S, --strip-version   Don't include lnd version in the path (only works if LND_VERSION != "all")
  -o, --output          Save generated files to a specified dir (created, if doesn't exist)

Examples:

  ./generate-go all
  ./generate-go  -o /tmp/last/  v0.9.0

github: github.com/lncm/lnd-rpc/

EOF
}

# If no arguments passed, show help and exit
if [ "$#" -le 0 ]; then
  show_help
  exit 1
fi


#
##  UTILS;  General purpose utility fns
#
## Define logging utility fns as early as possible
log() {
  # shellcheck disable=SC2059
  >&2 printf "$*\n"
}
log_pad() {
  log "\t$*"
}
log_arrow() {
  log_pad "-> $*"
}
log_err() {
  log
  log_pad  "ERR: $*"
  log
}
log_ok() {
  log_arrow "${*:-ok}" # if nothing passed, write "ok"
}
log_err_input() {
  log_err "$*"
  show_help
}

check_dependencies() {
  log "Checking dependencies…"
  for  cmd  in  "$@"; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
      log_err "This script requires \"$cmd\" to be installed"
      exit 1
    fi
  done
  log_ok
}



#
##  DEFINITIONS;  Globally-scoped variables
#
DIR=
STRIP_VER=false



#
##  LOGIC;  `generate-go` logic
#
generate_go_for_tag() {
  tag=$1

  tmp_dir="$(mktemp -d)"

  log "Generating .go for ${tag}…"
  for  proto  in  "$tag"/*/*.proto; do
    log_arrow "${proto}…"
    protoc --go_out=plugins=grpc,paths=source_relative:"$tmp_dir"  -I.  -I"./$tag"  "$proto"
  done

  log_pad "Moving files to final destination…"
  (
    cd "$tmp_dir"

    if [ "$STRIP_VER" = "true" ]; then
      cd "$tag"
    fi

    find . -name '*.go' | cpio -pdmu "$DIR" 2>/dev/null
  )

  log_ok "done"
}



#
##  MAIN;  This is where the execution begins
#
while :; do
  opt="$1"

  # Handle fmt: `--output=/tmp/` or `-o=/tmp/`;  Split `opt` on `=` into `opt` & `value`
  # NOTE: prepended with `=`, because if `-d` isn't found, `cut` ignores `-f`, and returns the whole string regardless…
  value="$(echo "=$opt" | cut -d= -f3)"
  if [ -n "$value" ]; then
    opt="$(echo "=$opt" | cut -d= -f2)"
  fi

  case "$opt" in
    -h|--help|help)
      show_help
      exit 0
      ;;

    -S|--strip-version) STRIP_VER=true ;;

    -o|--output)
      if [ -z "$value" ] && [ "$2" = "${2#-}" ]; then
        value="$2"
        shift
      fi

      if [ -z "$value" ]; then
        log_err_input "$opt requires a non-empty argument"
        exit 1
      fi

      DIR="$value"
      ;;

    --) shift ; break ;;

    -?*)
      log_err_input "Unknown option: $1"
      exit 1
      ;;

    *) break
  esac

  shift
done


# If DIR is already set, use it
# If not, use `pwd`
DIR="${DIR:-$(pwd)}"

if [ -z "$1" ]; then
  log_err_input 'LND_VERSION has to be provided (ex: v0.9.0), or "all"'
  exit 1
fi

TAG="$1"
shift

if [ "$TAG" = "all" ] && [ "$STRIP_VER" = "true" ]; then
  log_err_input '--strip-version cannot be set together with "all"'
  exit 1
fi

if [ "$TAG" !=  "all" ]; then
  # Make sure version always starts with v
  TAG="v${TAG#v}"

  # Remove possible`-beta` suffix
  TAG="${TAG%-beta}"
else
  TAG=
fi

# Parsing args done, log start
log "Generating ${TAG:-all} into ${DIR}…"

check_dependencies protoc

# Make sure output directory exists
mkdir -p "$DIR"

# Use TAG, if provided, otherwise loop through all ./v*/ directories
for  dir  in  ./${TAG:-v**}; do
  generate_go_for_tag "${dir#./}"
done