#!/usr/bin/perl
# -*- perl -*-
my $version_banner = <<END;
epsffit 2.04
Copyright (c) Reuben Thomas 2016.
Released under the GPL version 3, or (at your option) any later version.
END

use v5.10;
use warnings;
use strict;

BEGIN
{
# Relocatable header

if ("no" eq "yes") {
  my $exec_prefix = "/usr";
  my $orig_installdir = "/usr/bin"; # see Makefile.am's *_SCRIPTS variables
  my ($orig_installprefix, $curr_installprefix) = find_prefixes($orig_installdir, find_curr_installdir());
  sub relocate { # the subroutine is defined whether or not the enclosing block is executed
    my ($dir) = @_;
    if ("no" eq "yes") {
      $dir =~ s%^$orig_installprefix/%$curr_installprefix/%;
      $dir =~ s,/$,,;
    }
    return $dir;
  }
}

# Relocate the directory variables that we use.
my $pkgdatadir = &relocate("/usr/share/psutils");

# End of relocatable header; "real" Perl starts here.

  unshift (@INC, '/usr/share/psutils') unless $ENV{PSUTILS_UNINSTALLED};
}

use File::Basename;
use Getopt::Long;
use List::Util qw(min);

use PSUtils;

our $program_name = basename($0);
my ($help_flag, $version_flag, $center, $rotate, $aspect, $maximize, $showpage);

sub usage {
  my ($exit_code) = @_;
  print STDERR <<END;
Usage: $program_name [OPTION...] LLX LLY URX URY [INFILE [OUTFILE]]
Fit an Encapsulated PostScript file to a given bounding box.

  -c, --center         center the image in the given bounding box
  -r, --rotate         rotate the image by 90 degrees counter-clockwise
  -a, --aspect         adjust the aspect ratio to fit the bounding box
  -m, --maximize       rotate the image to fill more of the page if possible
  -s, --showpage       append a /showpage to the file to force printing
      --help           display this help and exit
      --version        display version information and exit

(LLX, LLY) are the coordinates of the lower left corner of the box, and
(URX, URY) the upper right.

If OUTFILE is not specified, writes to standard output.
If INFILE is not specified, reads from standard input.
END
  exit $exit_code;
}

# Get arguments
Getopt::Long::Configure("bundling");
# Having configured bundling, must give short option names explicitly
my $opts = GetOptions(
  "center|centre|c" => \$center,
  "rotate|r" => \$rotate,
  "aspect|a" => \$aspect,
  "maximize|maximise|m" => \$maximize,
  "showpage|s" => \$showpage,
  "help" => \$help_flag,
  "version" => \$version_flag,
 ) or usage(1);
if ($version_flag) {
  print STDERR $version_banner;
  exit 0;
}
usage(0) if $help_flag;
usage(1) if $#ARGV < 3 || $#ARGV > 5;

my $bbfound = 0;              # %%BoundingBox: found
my ($urx, $ury, $llx, $lly) = (0, 0, 0, 0);

my $fllx = singledimen(shift);
my $flly = singledimen(shift);
my $furx = singledimen(shift);
my $fury = singledimen(shift);

my ($infile, $outfile) = setup_input_and_output();
usage(1) if $#ARGV != -1; # Check no more arguments were given

while (<$infile>) {
  if (/^%[%!]/) {
    # still in comment section
    if (/^%%BoundingBox:/) {
      if (/^%%BoundingBox: +([\d.]+) +([\d.]+) +([\d.]+) +([\d.]+)$/) {
        $bbfound = 1;
        $llx = int($1); # accept doubles, but convert to int
        $lly = int($2);
        $urx = int($3 + 0.5);
        $ury = int($4 + 0.5);
      }
    } elsif (/^%%EndComments/) {
      # don't repeat %%EndComments
      last;
    } else {
      print $outfile $_;
    }
  } else {
    last;
  }
}

Die("no %%BoundingBox:", 2) unless $bbfound;

# put BB, followed by scale & translate
my ($xoffset, $yoffset) = ($fllx, $flly);
my ($width, $height) = ($urx - $llx, $ury - $lly);

$rotate = 1 if $maximize &&
  (($width > $height && $fury - $flly > $furx - $fllx) ||
   ($width < $height && $fury - $flly < $furx - $fllx));

my ($fwidth, $fheight) = ($furx - $fllx, $fury - $flly);
($fwidth, $fheight) = ($fheight, $fwidth) if $rotate;

my ($xscale, $yscale) = ($fwidth / $width, $fheight / $height);

$xscale = $yscale = min($xscale, $yscale) if !$aspect; # preserve aspect ratio?
$width *= $xscale; # actual width and height after scaling
$height *= $yscale;
if ($center) {
   if ($rotate) {
      $xoffset += ($fheight - $height) / 2;
      $yoffset += ($fwidth - $width) / 2;
   } else {
      $xoffset += ($fwidth - $width) / 2;
      $yoffset += ($fheight - $height) / 2;
   }
}
say $outfile "%%BoundingBox: " . int($xoffset) . " " . int($yoffset) . " " .
  int($xoffset + ($rotate ? $height : $width)) . " " .
  int($yoffset + ($rotate ? $width : $height));
if ($rotate) { # compensate for original image shift
   $xoffset += $height + $lly * $yscale; # displacement for rotation
   $yoffset -= $llx * $xscale;
} else {
   $xoffset -= $llx * $xscale;
   $yoffset -= $lly * $yscale;
}
say $outfile "%%EndComments";
if ($showpage) {
  say $outfile "save /showpage{}def /copypage{}def /erasepage{}def";
} else {
  say $outfile "%%BeginProcSet: epsffit 1 0";
}
say $outfile "gsave " . (sprintf "%.3f %.3f translate", $xoffset, $yoffset);
say $outfile "90 rotate" if $rotate;
say $outfile (sprintf "%.3f %.3f scale", $xscale, $yscale);
say $outfile "%%EndProcSet" unless $showpage;
while (<$infile>) {
   print $outfile $_;
}
say $outfile "grestore";
say $outfile "restore showpage" if $showpage; # just in case

1; # exit with a true value (value of previous statement may be false)