#!/usr/bin/env bash

#
# sue(8) -- Run sudoedit(8) with an appropriate user on a set of files
#
# Author: Tom Ryder
# Copyright: 2015
# License: Public domain
#

# Name self
self=sue

# Define a function to show usage
usage() {
    printf 'USAGE: %s FILE1 [FILE2 ...]\n' \
        "$self"
}

# Test the first argument
case $1 in

    # Give help on stdout if requested
    -h|--help|-\?)
        usage
        exit
        ;;

    # If no file was given, give help on stderr and bail
    '')
        usage >&2
        exit 1
        ;;
esac

# Iterate through the files and check they all have the same owner
user=
for file ; do

    # Use stat(1) to get the file owner
    if ! file_owner=$(stat -c %U -- "$file") ; then
        printf '%s: Failed to run stat(1) on file %s\n' \
            "$self" "$file" >&2
        exit 1
    fi

    # If this is the first file, we'll use its owner as our user
    if [[ -z $user ]] ; then
        user=$file_owner

    # If not, and the user we're going to use and this file's owner don't
    # match, bail with an error
    elif [[ $user != $file_owner ]] ; then
        printf '%s: Files do not share a common owner\n' \
            "$self" >&2
        exit 1
    fi
done

# If we got this far, there's at least one file and all the files are owned by
# the same user; we can safely edit them
exec sudoedit -u "$user" -- "$@"