#!/usr/bin/env zsh

# Diffs two PDF files using pdftotext and wdiff.

emulate -LR zsh

if [[ $# -lt 2 ]] then
  echo "Usage: pdfwdiff [diff_options] file1.pdf file2.pdf" >&2
  return 1
fi

# The user may prefer his own cwdiff function (or external command) rather
# than the following one, provided in case cwdiff is not available.
# Changing '30;41' to 97;41' and '30;42' to '97;48;5;28' makes text more
# readable (tested on various devices), but needs a 256-color terminal,
# which are common nowadays.
cwdiff_fallback()
{
  wdiff -n -w $'\033[30;41m' -x $'\033[0m' \
           -y $'\033[30;42m' -z $'\033[0m' -d "$@"
  return $(( $? == 1 ? 0 : $? ))
}

eval "autoload -R cwdiff 2> /dev/null"
if [[ $? == 0 ]] || whence -p cwdiff > /dev/null; then
  cmd=cwdiff
else
  cmd=cwdiff_fallback
fi

diff -u "$@[1,-3]" <(pdftotext "$@[-2]" -) \
                   <(pdftotext "$@[-1]" -) | $cmd

# $Id: pdfwdiff 150114 2022-07-13 13:29:25Z vinc17/zira $