#!/usr/bin/env bash

shopt -s nullglob

usage() {
    echo "Usage: $(basename "$0") [ -x <exclude> ]*"
    exit 1
}

word_in_list() {
    local a word=$1

    shift
    for a in "$@"; do
	[ "$word" = "$a" ] && return 0
    done
    return 1
}

remove_empty_directories() {
    find . -depth -type d |
        sed 's|^\./||' |
        grep -Ev '^\.$|^\.svn/|/\.svn/|/\.svn$|^\.hg/|^\.hg$|^\.git/|^\.git$' |
        while read -r d; do
	    for f in "$d"/{*,.*}; do
		if ! [ -e "$f" ]; then
		    rmdir "$d"
		fi
		break
	    done
	done
}

exclude=("TAGS")
git_options=(-e TAGS)

while [ "${1#-}" != "$1" ]; do
    case "$1" in
	-x)
	    exclude+=("$2")
	    git_options+=(-e "$2")
	    shift; shift;;
	*)
	    usage;;
    esac
done

for d in "${@-.}"; do
  (
    if cd "$d"; then
      if [ -e .svn ]; then
        if ! type -p svn >&/dev/null; then
          echo "$0: svn: not found."
          exit 0
        fi
        "$(dirname "$0")"/list-non-source-files |
          while read -r f; do
	    if ! word_in_list "$f" "${exclude[@]}"; then rm -rf -- "$f"; fi;
	  done
      elif [ -e .git ] || [ -e ../.git ]; then
        if ! type -p git >&/dev/null; then
          echo "$0: git: not found."
          exit 0
        fi
        git clean -f -d -x "${git_options[@]}" >/dev/null
        remove_empty_directories
      elif [ -e .hg ] || [ -e ../.hg ]; then
        if ! type -p hg >&/dev/null; then
          echo "$0: hg: not found."
          exit 0
        fi
        hg purge --all
      else
        echo "$0: $d: not administered by Subversion, Git or Mercurial."
      fi
    fi
  )
done