#! /usr/local/bin/perl
#
#  slides.pl
#
#  Generate HTML for slides based on a set of images
#
#  Example:
#
#     perl slides.pl -thumbs -slides -template
#
#  Creates thumbnails, html "slides" incorporating captions, and
#  a template file to copy image links from.
#
#  Slides live in a 'slides' directory at the same level in
#  the hierarchy as the images directory that they are based on.
#
#  Captions and image order are specified by the file images/idb.txt.
#  Running slides.pl generates a default version of that file which
#  can then be edited by the user.  Typically, you'll run slides
#  twice, once to thumbnail and create images/idb.txt, then, after
#  editing images/idb.txt, once to generate the slides with captions
#

%options =
(
   '-thumbs', 0,           # generate thumbnails
   '-template', 0,         # generate general purpose HTML template
   '-gallery', 0,          # generate a gallery template
   '-slides', 0,           # generate links to slides instead of image files
   '-imageDir', 'images',  # where to find images
   '-slideDir', 'slides',  # where to put slides
   '-home', 'index.htm'    # start/finish of slide show (in .)
);

for ($i = 0; $i < @ARGV; $i++)
{
   die( "Undefined option: $ARGV[$i]" )
      unless (defined( $options{$ARGV[$i]} ));
   if ($ARGV[$i] eq '-imageDir')
   {
      $options{'-imageDir'} = $ARGV[++$i];
   }
   elsif ($ARGV[$i] eq '-home')
   {
      $options{'-home'} = $ARGV[++$i];
   }
   elsif ($ARGV[$i] eq '-slideDir')
   {
      $options{'-slideDir'} = $ARGV[++$i];
   }
   else
   {
      $options{$ARGV[$i]} = 1;
   }
}

$options{'-template'} = 1
   if ($options{'-gallery'});

$ImageDir = $options{'-imageDir'};
$SlideDir = $options{'-slideDir'};
$Home = $options{'-home'};

$DefaultTitle = 'title here';
$IDBFile = "$ImageDir/idb.txt";

LoadFiles();
GenIDB();

GenThumbs() if ($options{'-thumbs'});
GenTemplateHTML() if ($options{'-template'});
GenSlides() if ($options{'-slides'});

exit( 0 );



sub ReadIDB
{
   undef %IDB;   # maps name to title
   undef @IDBFiles;   # preserves idb.txt ordering

   my @filesInOrder;
   if (-f $IDBFile)
   {
      open( T, "<$IDBFile" ) || die( "Unable to open $IDBFile" );
      while (<T>)
      {
         chop;
         my ($file, $title) = split /\s*\|\s*/;
         $IDB{$file} = $title;
         push @filesInOrder, $file;
      }
      close( T );
   }

   my $file;
   my %currentImageFiles;
   foreach $file (@ImageFiles)   # add any new files
   {
      if (!defined( $IDB{$file} ))
      {
         $IDB{$file} = $DefaultTitle;
         push @filesInOrder, $file;
      }
      $currentImageFiles{$file} = 1;
   }

   foreach $file (keys( %IDB ))   # remove missing files
   {
      delete ( $IDB{$file} )
         unless ($currentImageFiles{$file});
   }
   
   foreach $file (@filesInOrder)
   {
      push @IDBFiles, $file
         if (defined( $IDB{$file} ));
   }
}



sub GenIDB
{
   ReadIDB();

   open( T, ">$IDBFile" ) || die( "Unable to open: $IDBFile" );
   foreach $file (@IDBFiles)
   {
      print T $file, " | ", $IDB{$file}, "\n";
   }
   close( T );
}



sub ReadImageFiles
{
   my( $dir ) = @_;
   opendir( D, $dir) || die( "unable to open $dir" );
   my @files = readdir( D );
   closedir( D );

   return grep( /\.([Jj][Pp][Gg])|([Gg][Ii][Ff])$/, sort( @files ) );
}



sub LoadFiles
{
   @ImageFiles = ReadImageFiles( $ImageDir );

   die ( "No images" ) unless (@ImageFiles);
}



sub GenThumbs
{
   if (! -d "$ImageDir/thumbs")
   {
      mkdir( "$ImageDir/thumbs", 0777 ) || die( "Unable to create thumbs directory" );
   }

   my( $iFile );
   foreach $iFile (@ImageFiles)
   {
      if (! -f "$ImageDir/thumbs/$iFile")
      {
         print STDERR "Thumbnail: $iFile\n";
         system( "convert -size 128x128 $ImageDir/$iFile -resize 128x128 $ImageDir/thumbs/$iFile" );
      }
   }
}



sub imageFileSizeInK
{
   my( $filename ) = @_;
   my( $dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks ) =
      stat( $filename );

   return int( $size / 1024 );
}



sub altOrTitleText
{
   my( $iFile, $iPath ) = @_;
   my $fileSize = imageFileSizeInK( $iPath );

   return
      $IDB{$iFile} ne $DefaultTitle ?
         "\"$IDB{$iFile} (${fileSize}K)\"" :
         "\"$iFile (${fileSize}K)\"";
}



sub GenTemplateHTML
{
   open( T, ">template.htm" ) || die( "unable to open template HTML file" );
   print T <<"End_Of_HTML";
<html>
<head>
   <title>Template HTML Links</title>
</head>
<body>
<h1>Template HTML Links</h1>
End_Of_HTML

   my( $iFile, $tText );
   if ($options{'-slides'})
   {
      for ($i = 0; $i < @IDBFiles; $i++)
      {
         $iFile = $IDBFiles[$i];
         my $iPath = "$ImageDir/$iFile";
         my $sFile = "$SlideDir/". slideName( $iFile );
         my $tPath = "$ImageDir/thumbs/" . $iFile;
         my ($tWidth, $tHeight) = GetSize( $tPath );
         my ($iWidth, $iHeight ) = GetSize( $iPath );
         $tText = altOrTitleText( $iFile, $iPath );
         print T "<!-- $iFile -->\n";
         print T "\t<a name=\"$iFile\" href=\"$sFile\" title=$tText><img src=\"$tPath\" width=$tWidth height=$tHeight></a>\n";
         print T "\t<img src=\"$iPath\" alt=$tText width=$iWidth height=$iHeight>\n\n";
      }
   }
   else
   {
      foreach $iFile (@IDBFiles)
      {
         my $iPath = "$ImageDir/$iFile";
         my $tPath = "$ImageDir/thumbs/$iFile";
         my ($tWidth, $tHeight ) = GetSize( $tPath )
            if (-f $tPath );
         my ($iWidth, $iHeight ) = GetSize( $iPath );
         $tText = altOrTitleText( $iFile, $iPath );
         if ($options{'-gallery'})
         {
            print T "<!-- $iFile --> ";
         }
         else
         {
            print T "<!-- $iFile -->\n\t";
         }
         print T "<a name=\"$iFile\" href=\"$iPath\" title=$tText><img src=\"$tPath\" width=$tWidth height=$tHeight></a>\n"
            if (-f $tPath );
         print T "\t<img src=\"$iPath\" alt=$tText width=$iWidth height=$iHeight></a>\n\n"
            if (!$options{'-gallery'})
      }
   }

   print T "</body>\n</html>\n";

   close( T );
}



sub slideTD
{
   my( $i ) = @_;
   my $iFile = $IDBFiles[$i];
   my $iPath = "$ImageDir/$iFile";
   my $sFile = slideName( $iFile );
   my $tFile = "$ImageDir/thumbs/" . $iFile;
   $tText = altOrTitleText( $iFile, $iPath );
   my ($width, $height) = GetSize( $tFile );
   my $link = "<a href=\"$sFile\" title=$tText><img src=\"../$ImageDir/thumbs/$iFile\" width=$width height=$height></a>";

   return <<"End_of_HTML";
      <td width="20%" align="center">
         $link
      </td>
End_of_HTML
}



sub GenSlideIndex
{
   open( S, ">$SlideDir/index.htm" ) || die( "unable to open slide index file" );

   print S <<"End_Of_HTML";
<html>
<head>
   <title>Slide Index</title>
</head>
<body>

<table cellspacing=8>
End_Of_HTML

   my( $i );
   my( $fullRows ) = int( @IDBFiles / 5 );

   for ($i = 0; $i < $fullRows; $i++)
   {
      print S "   <tr>\n";
      my( $j );
      for ($j = 0; $j < 5; $j++)
      {
         print S slideTD( $i * 5 + $j );
      }
      print S "   </tr>\n";
   }

   my( $lastRow ) = @IDBFiles % 5;
   print S "   <tr>\n";
   for ($j = 0; $j < $lastRow; $j++)
   {
      print S slideTD( $i * 5 + $j );
   }
   print S "   </tr>\n";

   print S <<"End_Of_HTML";
</table>

</body>
</html>
End_Of_HTML

   close( S );
}



sub GetSize
{
   my( $fnm ) = @_;

   die( "invalid image file: $fnm" ) unless (-f $fnm);
   open( ID, "identify $fnm |" ) || die( "Unable to identify $fnm" );
   my $line = <ID>;
   chop( $line );
   close( ID );

   my ($name, $type, $size) = split( /\s+/, $line );

   return split( /x/, $size )
}



sub OutputSlide
{
   my( $sFile, $iFile, $next, $prev, $title ) = @_;

   my( $width, $height ) = GetSize( "$ImageDir/$iFile" );

   open( S, ">$SlideDir/$sFile" ) || die( "unable to open slide HTML file" );
   print S <<"End_Of_HTML";
<html>
<head>
   <title>$title</title>
</head>
<body>
<center>
<a href="../$Home#$iFile"><img src="../$ImageDir/$iFile" width=$width height=$height><h2>$title</h2></a>
<p>
$prev $next
</center>
</body>
</html>
End_Of_HTML

   close( S );
}


sub slideName
{
   my( $fnm ) = @_;

   $fnm =~ s/(\.[Jj][Pp][Gg])|(\.[Gg][Ii][Ff])$/\.htm/;
   return $fnm;
}



sub GenSlides
{
   if (! -d $SlideDir)
   {
      mkdir( $SlideDir, 0777 ) || die( "Unable to create $SlideDir directory" );
   }

   my( $i, $sFile, $next, $prev, $title );

   if(1 == @IDBFiles)
   {
      $title = 
         $IDB{$IDBFiles[0]} ne $DefaultTitle ?
            $IDB{$IDBFiles[0]} :
            undef;
      OutputSlide(
         slideName( $IDBFiles[0] ),
         $IDBFiles[0],
         "<a href=\"../$Home\">Next (home)</a>",
         "<a href=\"../$Home\">Prev (home)</a>",
         $title );
   }
   else
   {
      $title = 
         $IDB{$IDBFiles[0]} ne $DefaultTitle ?
            $IDB{$IDBFiles[0]} :
            undef;
         $next = slideName( $IDBFiles[1] );
         $next = "<a href=\"$next\">Next</a>";
      OutputSlide(
         slideName( $IDBFiles[0] ),
         $IDBFiles[0],
         $next,
         "<a href=\"../$Home\">Prev (home)</a>",
         $title );

      for ($i = 1; $i < $#IDBFiles; $i++)
      {
         $sFile = slideName( $IDBFiles[$i] );
         $title = 
            $IDB{$IDBFiles[$i]} ne $DefaultTitle ?
               $IDB{$IDBFiles[$i]} :
               undef;

         $next = slideName( $IDBFiles[$i + 1] );
         $next = "<a href=\"$next\">Next</a>";
         $prev = slideName( $IDBFiles[$i - 1] );
         $prev = "<a href=\"$prev\">Previous</a>";
         OutputSlide( $sFile, $IDBFiles[$i], $next, $prev, $title );
      }

      $prev = slideName( $IDBFiles[$i - 1] );
      $prev = "<a href=\"$prev\">Previous</a>";
      $title = 
         $IDB{$IDBFiles[$i]} ne $DefaultTitle ?
            $IDB{$IDBFiles[$i]} :
            undef;
      OutputSlide(
         slideName( $IDBFiles[$i] ),
         $IDBFiles[$i],
         "<a href=\"../$Home\">Next (home)</a>",
         $prev,
         $title );
   }

   GenSlideIndex();
}