#!/bin/sh -eu
#
# Interactive bulk file rename using $EDITOR.
#
# Copyright (c) 2026 Dylan Araps
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#

case $# in 0) exit; esac
f=${TMPDIR:=/tmp}/.dfm-brn-$$-$#
e() { rm -f "$f" || :; exit "$1"; }
(
  printf '%s\n' "$@" > "$f" &&
  "${EDITOR:=vi}" "$f" &&
  exec 3<"$f" &&
  for _ do
    IFS= read -r l <&3
    case ${l:?line mismatch in rename file} in
      "$1") set -- "$@" "# not modified: '$1'" ;;
         *) set -- "$@" "mv -f -- '$1' '$l'"
    esac
    shift
  done && {
  read -r l <&3 && {
    echo "$0: 39: line mismatch in rename file" >&2
    return 1
  }
  printf '%s\n' '# This file will be executed when the editor is closed.' \
                '# Clear the file to abort.' "$@"
  } > "$f" &&
  "$EDITOR" "$f" && . "$f" && e 0
) || e 1