#!/usr/bin/env bash
set -eu

end="\033[0m"
red="\033[0;31m"
red() { echo -e "${red}${1}${end}"; }

usage() {
  red "Missing argument $1.\n"
  cat <<EOF
Usage:
    $0 <REGEX_PATTERN> <REPOSITORY_URL>

      Arguments:
        REGEX_PATTERN     Regular expression that "git grep" can search
        REPOSITORY_URL    URL address that "git clone" can download the repository from

Examples:
    Searching "make get-git" in cgit repository:
        git search 'make get-git' https://git.zx2c4.com/cgit/
        git search 'make get-git' https://git.zx2c4.com/cgit/ -- \$(git rev-list --all)
EOF
  exit 2
}


REGEX_PATTERN="${1:-}"
REPOSITORY_URL="${2:-}"
[[ -z "${REGEX_PATTERN}" ]] && usage 'REGEX_PATTERN'
[[ -z "${REPOSITORY_URL}" ]] && usage 'REPOSITORY_URL'

mkdir -p /tmp/git-search
DIRNAME="$(echo "${REPOSITORY_URL%/}" | rev | cut -d/ -f1 | rev)"
if [[ ! -d "/tmp/git-search/${DIRNAME}" ]]; then
  git clone "${REPOSITORY_URL}" "/tmp/git-search/${DIRNAME}"
fi
pushd "/tmp/git-search/${DIRNAME}"

shift 3 || shift 2 # when "--" is missing
git grep "${REGEX_PATTERN}" "${@}"