#!/usr/bin/env bash
set -o errexit -o pipefail
DIR=$(dirname "${0}")
MAIN_DIR=$(readlink -f "${DIR}/..")
if [ -L "${MAIN_DIR}/.git/config" ]; then
    # Support git-new-workdir
    GIT_DIR="$(dirname "$(realpath "${MAIN_DIR}/.git/config")")"
else
    # Support git-worktree
    GIT_DIR="$(cd "${MAIN_DIR}" && git rev-parse --no-flags --git-common-dir)"
fi
# shellcheck disable=SC2016
IMAGE=$(grep ^image: "${MAIN_DIR}/.gitlab-ci.yml" | \
        sed -e 's,^image: ,,g' | sed -e 's,\$CI_REGISTRY,registry.gitlab.com,g')

declare -a docker_opts=(
    -i
    --rm
    --user "$(id -u):$(id -g)"
    --mount "type=bind,src=${MAIN_DIR},dst=${MAIN_DIR}"
    --workdir "${MAIN_DIR}"
)

# Empty GIT_DIR means that we are not in a workdir, *and* git is too old
# to know about worktrees, so we're not in a worktree either. So it means
# we're in the main git working copy, and thus we don't need to mount the
# .git directory.
if [ "${GIT_DIR}" ]; then
    # GIT_DIR in the main working copy (when git supports worktrees) will
    # be just '.git', but 'docker run' needs an absolute path. If it's an
    # absolute path already (in a wordir), then that's a noop.
    GIT_DIR="$(readlink -e "${GIT_DIR}")"
    docker_opts+=( --mount "type=bind,src=${GIT_DIR},dst=${GIT_DIR}" )
fi

if tty -s; then
    docker_opts+=( -t )
fi

exec docker run "${docker_opts[@]}" "${IMAGE}" "${@}"