#!/bin/bash
# Copyright Cédric Picard 2014 -- License DWTFYW -- inspired by Ranger's

set -e

if [ $# -ne 0 ] ; then
    for i in "$@" ; do printf "%s\n" "$i" ; done | "$0"
    exit
fi

[ -x "$(which "$EDITOR" 2>/dev/null)" ] || EDITOR=vi

file=/tmp/blkrn-$$
cat > ${file}.1
exec </dev/tty >/dev/tty

cp ${file}.1 ${file}.2
"$EDITOR" ${file}.2

line_count=$(wc -l < ${file}.1)
if [ $line_count -ne $(wc -l < ${file}.2) ] ; then
    rm ${file}.1 ${file}.2
    echo "Wrong number of lines" >&2
    exit 1
fi

paste -d "\n" ${file}.1 ${file}.2 | while [ $line_count -ne 0 ] ; do
    line_count=$(($line_count - 1))
    read -r input  ;  input="$(printf "%s" "$input"  | sed "s/'/'\"'\"'/")"
    read -r output ; output="$(printf "%s" "$output" | sed "s/'/'\"'\"'/")"

    if [ "$input" != "$output" ] ; then
        echo "mv -v -- '$input' '$output'"
    fi
done > ${file}.sh

if [ "$(stat --printf="%s" ${file}.sh)" -ne 0 ] ; then
    "$EDITOR" ${file}.sh
    sh ${file}.sh
fi

rm ${file}.1 ${file}.2 ${file}.sh