#!/usr/bin/env bash

set -e
set -u
set -o pipefail

# Outputs a version name for the hasura servers and their components, given the
# checked out state of the repo:
#  - if HEAD has a tag, return that
#  - if VERSION_FALLBACK is set, return that
#  - else return a combination of branch and SHA hash
#
# In all of the above, we strip any characters invalid in a Docker image name
# (everything except alphanumeric characters, '.', '_', and '-').
#
# This is called in a compile time macro to bake the version into the server
# binaries, and also at various points during CI (and must agree every time).

# When 'ci/server-test-mode' label is present in a PR, the CI runs in a
# so-called "server test mode". In server test mode, a server from some other
# CI build is used to run all the server test jobs. This causes some tests,
# which assert the version from /v1/version to be equal to the one
# returned by this script, to fail. SERVER_TEST_MODE env var is used to
# force the version to be set to the value in /build/_server_output/version.txt.
# This is done only for test_oss_server_pg_* CI jobs in server test mode.
#
if [[ "${SERVER_TEST_MODE:-}" == 'true' ]]; then
  cat /build/_server_output/version.txt
  exit
fi

GIT_BRANCH="$(git rev-parse --abbrev-ref HEAD)"
GIT_SHA="$(git rev-parse --short=7 HEAD)"
# NOTE: a commit may have multiple tags; this should return the most recent
# result of `git tag` if any:
if GIT_TAG_EXACT="$(git describe --tags --exact-match --dirty 2>/dev/null)"; then
  VERSION="${GIT_TAG_EXACT}"
elif [[ "${VERSION_FALLBACK+is set}" ]]; then
  VERSION="$VERSION_FALLBACK"
else
  GIT_DIRTY=$(test -n "$(git status --porcelain)" && echo "-dirty" || echo '')
  # IMPORTANT: SHA hash needs to come first so we get a unique version string,
  # even in the presence of truncation below
  VERSION="dev-${GIT_SHA}${GIT_DIRTY}-${GIT_BRANCH}"
fi

VERSION="$(echo "$VERSION" | tr -cd '[[:alnum:]]._-')"
# Truncate to 50 chars, to ensure it fits in a Docker image name.
echo "${VERSION:0:50}"