#! /usr/bin/perl -w

=head1 NAME

to_html: Translate an atxt document to HTML

=head1 SYNOPSIS

to_html [-t template -o output] document.atxt

=head1 DESCRIPTION

to_html translates an augmented text (atxt) document to HTML using
HTML::Template and HTML::FromText.

to_html tries to use C<./template.tmpl> or a file specified by the
C<-t> option as an HTML::Template template, and writes to
C<./document.html> or a file specified by the C<-o> flag.

=head1 ATXT FORMAT

The atxt format is simple: a top block of headers (in key: value
form), an empty line, and the rest of the document, just like an
email.

=cut

use strict;
use vars qw($opt_t $opt_o);
use HTML::FromText;
use HTML::Template;
use Data::Dumper;

# symbolic constants
my $WEBROOT = "/var/www/infernus.net/";

my $doc      = shift @ARGV
  or die "Usage: to_html [-t template -o output] document\n";
  
my $template = HTML::Template->new
    (
    'filename' => $opt_t || "template.tmpl"
    )
  or die "Cannot create HTML::Template object: $!\n";

my $output   = $opt_o || $doc;
$output =~ s/\.\w+$/\.html/ unless $opt_o;

my ($headers, $body) = &grab_doc($doc);

my $html_body = &text2html
    ($body,
     'bold'       => 1,
     'underline'  => 1,
     'urls'       => 1,
     'paras'      => 1,
     'blockparas' => 1,
     'bullets'    => 1,
     'numbers'    => 1,
     'tables'     => 1,
    );

my $lastmod = (-M $doc) * 86400 + time;

# default template variables
$template->param('lastmod_date' => &make_time_str($lastmod));
$template->param('content'      => $html_body);
$template->param('sitenav'      => &make_sitenav());

# page-specific template variables
$template->param('dirnav'       => &make_dirnav())
  unless ((defined $headers->{'dirnav'}) and
          (! $headers->{'dirnav'}));


# set template variables based on headers
$template->param(%$headers);

&write_html($output, $template->output());

# make_sitenav 
# Make a site navigation link bar (top level)
# Links to /main.html and each dir in $WEBROOT
sub make_sitenav
{
  my @links = (qq(<a href="/main.html">main</a>));

  opendir WEBROOT, $WEBROOT
    or die "Can't opendir $WEBROOT: $!\n";

  my @dirs = grep { -d $_ } readdir WEBROOT;
  foreach (@dirs) {
    next if /^\.{1,2}$/;
    push @links, qq(<a href="/$_/">$_</a>);
  }

  closedir WEBROOT
    or die "Can't closedir $WEBROOT: $!\n";

  return join " | ", @links;
}

# make_dirnav
# Make links to the HTML versions of any files in the current directory.
# Pretty up the filenames a bit for the link text -- this should change 
#  to document titles in later versions
sub make_dirnav
{
  my @links = ();

  opendir CURRENT, '.'
    or die "Can't opendir .: $!\n";

  my @files = grep /\.atxt$/, readdir CURRENT;
  foreach (@files) {
    my ($file) = /^(.+)\.atxt$/;
    my $name = $file; $name =~ s/_/ /g;
    push @links, qq(<a href="$file.html">$name</a>);
  }
  closedir CURRENT
    or die "Can't closedir .: $!\n";

  return join " | ", @links;
}

# grab_doc(doc)
# Read in an atxt document, extract the headers, and grab the rest.
# Returns a ref to a headers hash and a scalar of the body text.
# Dies on file open error.
sub grab_doc
{
  my ($doc) = @_;

  open DOC, "<$doc"
    or die "Cannot open $doc: $!\n";

  my $headers = {};
  my $body = "";

  # get headers
  while(<DOC>) {
    last if /^\s*$/;
    # would use split here, but only want to break on the first :
    my ($key, $value) = /^([^:]+):\s*(.*)$/;
    $headers->{$key}  = $value;
  }

  # rest is body
  local $/ = undef;
  $body = <DOC>;

  close DOC
    or die "Cannot close $doc: $!\n";

  return ($headers, $body);
}

# make_time_str(time)
# Makes a pretty date string from an epoch time.
# Probably horribly redundant.
sub make_time_str
{ 
  my ($time) = @_;

  my ($sec, 
      $min, 
      $hour, 
      $day, 
      $mth, 
      $year,
      $wday,  
      $yearday,
      $isdst
      ) = localtime($time);

  # CHANGE if you're in a different time zone
  my $timezone = $isdst ? "MDT" : "MST";

  my @weekdays =
    qw(Sunday Monday Tuesday Wednesday Thursday Friday Saturday);
  my $weekday = $weekdays[$wday];
  my @months  =
    qw(Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec.);
  my $month   = $months[$mth];
  
  # bah to all of these.
  $year += 1900;
  $sec  = "0$sec" if $sec < 10;
  $min  = "0$min" if $min < 10;
  $hour = "0$hour" if $hour < 10;
  
  return "$weekday $day-$month-$year at $hour:$min:$sec $timezone";
}
  
# write_html(outfile, content)
# Writes content to a file named "outfile".  Simple.
sub write_html
{
  my ($outfile, $content) = @_;

  open OUT, ">$outfile"
    or die "Cannot open output file $outfile: $!\n";

  print OUT $content;

  close OUT
    or die "Cannot close output file $outfile: $!\n";
}