#!/usr/bin/env bash
# Print the ref a build is named after: <branch>-<sha12>, plus -dirty when the
# tree has uncommitted changes. Slashes and anything else awkward in an S3
# prefix become dashes; a detached HEAD contributes no branch. Callers may set
# BUILD_REF instead.
#
# The same shape headquarters and arena name their artifacts with, on purpose:
# what is deployed is one id per repo, and reading three of them in
# releases.auto.tfvars.json should not mean learning three conventions.
set -euo pipefail

ref=$(git rev-parse --short=12 HEAD)
branch=$(git rev-parse --abbrev-ref HEAD)
if [ "$branch" != HEAD ]; then
  ref="$(printf '%s' "$branch" | tr -c 'A-Za-z0-9_.-' '-')-$ref"
fi
if [ -n "$(git status --porcelain)" ]; then
  ref="$ref-dirty"
  echo "working tree is dirty; ref is $ref" >&2
fi
printf '%s\n' "$ref"