#!/bin/bash
#
# Formats a Git commit message
#
#  Copyright (C) 2012  Mike Gerwitz
#
#  This file is part of repo2html.
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
# #

# HTML replacements (default)
lquo='\&ldquo;'
rquo='\&rdquo;'
mdash='\&mdash;'

# redefines replacements to yield plain text (instead of HTML entities)
nohtml()
{
  lquo=\"
  rquo=\"
  mdash=---
}


while getopts n opt; do
  case "$opt" in
    n) nohtml;;
  esac
done


# format the commit message, stopping at the diff (if any)
awk '/^diff --git/ { exit } { print }' \
  | sed ':a;N;$!ba;
    # handle <>-delimited links (strip delimiters)
    s#<\([fh]ttps\?://[^ ]\+\)>#\1#g;

    # escaping
    s/\&/\&amp;/g;
    s/</\&lt;/g;
    s/>/\&gt;/g;

    # quoting (initiated by an indented paragraph and terminated by a new
    # paragraph, unless that paragraph is also indented)
    s#\n\n  \+\(\([^\n]\+\n\(\n  \+\)\?\)\+\)#<blockquote>\1</blockquote>#g

    # unfortunately, non-greedy matches make it difficult to exclude punctuation
    # at the end of a link, so we will handle it in a separate expression
    s#[fh]ttps\?://[^]\n )]\+#<a href="&">&</a>#g;
    s#<a href="\([^"]\+\)\([.;,!]\)">\([^<]\+\).</a>#<a href="\1">\3</a>\2#g;

    # reference definitions (footnotes)
    s#\n\[\([0-9]\+\)\]#</p><p id="ref-\1">&#g;

    # references in text
    s|\[\([^]]\+\)\]\[\([0-9]\+\)\]|<a href="#ref-\2">\1</a>\[\2\]|g
    s|\[\([0-9]\+\)\]|<sup><a href="#ref-\1">&</a></sup>|g

    # paragraphs
    s#\n\n#</p>&<p>#g;

    # basic formatting
    s/---/'"$mdash"'/g;
    s#``#'"$lquo"'#g;
    s#'\'\''#'"$rquo"'#g;
    s#\(\W\)\*\([^\*]\+\)\*\(\W\)#<em>\1\2\3</em>#g;
  '