#!/bin/bash
# Generate index HTML page
#
#  Copyright (C) 2019 Mike Gerwitz
#
#  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/>.
#
# The index page consists of post abstracts, some static text, and the
# static header and footer.  All post metadata files must have been built,
# along with `post/list'.
#
# This script includes the static body (see `main').
##

set -euo pipefail


# Get the file name of the Nth most recent post.  This relies on the
# existence of `post/list'.
pnfile()
{
  local -ri n=${1?Missing relative post number}

  sed "${n}q;d" post/list
}


# Read field FIELD from post metadata recfile FILE.
pmeta()
{
  local -r file=${1?Missing file name}
  local -r field=${2?Missing field name}

  recsel -P "$field" "$file"
}


# Process each numeric argument using `abstract'.  Each argument must be a
# relative post number (see `pnfile').
abstracts()
{
  while [ $# -gt 0 ]; do
    abstract "$1"
    shift
  done
}


# Generate HTML for relative post number N (see `pnfile').
abstract()
{
  local -ri n=${1?Missing relative post number}

  local file title date slug body
  file=$( pnfile "$n" )
  title=$( pmeta "$file" subject )
  date=$( pmeta "$file" date )
  slug=$( pmeta "$file" slug )
  body=$( pmeta "$file" abstract )

  cat <<EOF
<article class="abstract">
  <h2 class="title"><a href="/$slug">$title</a></h2>
  $body
  <p class="date">Posted on $date.
    <a href="/$slug">Read more &raquo;</a>
  </p>
</article>
EOF
}


# Generate index HTML page.
# TODO: Factor out static sections.
main()
{
  src/mkheader index

  cat <<EOF
<h1 id="latest-posts">Latest Posts</h1>
<section class="asideable" aria-labelledby="latest-posts">
  $( abstracts {1..2} )
</section>

<aside>
  <ul class="links">
    <li><a class="box free-sw" href="#">What is Free/Libre Software?</a></li>
    <li><a class="box eff-privacy" href="#">EFF on Privacy</a></li>
  </ul>
</aside>

<section class="highlight">
  <h1 class="title">The Surreptitious Assault on Privacy, Security,
    and Freedom</h1>

  <aside>
    Each of these essential rights are being surreptitiously
    assaulted; only the most technical among us even know what to look
    for, let alone how to defend ourselves. Governments, corporations,
    and groups of ill-minded individuals are spying and preying upon
    both users and bystanders with unprecedented frequency and
    breadth.
  </aside>

  <a href="/talks#sapsf" class="lp-watch">Watch LibrePlanet&nbsp;2017 Talk</a>
  <br clear="both" />
</section>

<section class="compact sm">
  <h1 id="older-posts">Older Posts</h1>

  $( abstracts {3..8} )

  <a class="view-all" href="/posts">View all posts</a>
</section>
EOF

  cat src/footer.tpl.htm
}


main "$@"