#!/usr/bin/perl

use strict;
use Getopt::Long;
use File::Basename;
use FileHandle;

use lib ".";
use SAC;

my $version = "2009.129";

#my $gnuplot = "gnuplot";
my $gnuplot = "/Applications/Gnuplot.app/Contents/Resources/bin/gnuplot";

my $usage     = undef;
my $verbose   = undef;
my $title     = undef;
my $outfile   = undef;

my $getoptsret = GetOptions ( 'help|usage|h|?' => \$usage,
                              'verbose|v+'     => \$verbose,
			      'title|t=s'      => \$title,
			      'outfile|o=s'    => \$outfile,
			    );

if ( ! $getoptsret || $#ARGV < 0 || $usage ) {
  &usage();
  exit 1;
}

# Read each file and put references to SAC objects in @timeseries
my @timeseries = ();
foreach my $infile ( @ARGV ) {
  if ( ! -f "$infile" ) {
    print "Cannot find input file $infile\n";
    next;
  }
  
  my $sac = new SAC->new ($infile);
  
  push (@timeseries, \$sac) if ( $sac );
}

# Open pipe to gnuplot
open GP, "|$gnuplot -persist" || die "Cannot open pipe to gnuplot ($gnuplot)\n";
GP->autoflush(1);

# Set output to file if specified otherwise to X11 display
if ( defined $outfile ) {
  print GP "set terminal png size 800,400\n";
  print GP "set output \"$outfile\"\n";
}
else {
  # Redefine STDIN as the terminal ouput, since gnuplot inherits
  # the STDIN filehandler from his parent, the perl script.
  open (STDIN, "</dev/tty") or die "Cannot open /dev/tty";
  print GP "set terminal x11\n";
}

# Set up plot parameters
print GP "set title \"$title\"\n" if ( defined $title );
print GP "set xdata time\n";
print GP "set timefmt \"%s\"\n";
print GP "set format x \"%Y/%m/%d\"\n";
print GP "set key box\n";
print GP "set xlabel \"Time\"\n";

my $plotcmd = "plot ";
my $plotdata = "";

# Build plot commands and data for each time series
foreach my $sacref (@timeseries) {
  $$sacref->print;

  my $srcname = $$sacref->sourceName;
  my $stime = $$sacref->startTimeDepoch;

  print "Gathering plot data for $srcname\n" if ( $verbose > 0 );
  
  $plotcmd .= "'-' using (\$0*$$sacref->{delta}+$stime):1 title '$srcname' with lines,";

  foreach my $sample ( @{$$sacref->{datasamples}} ) {
    $plotdata .= "$sample\n";
  }
  #my $stime = $$sacref->startTimeDepoch;
  #foreach my $sample ( @{$$sacref->{datasamples}} ) {
  #  $plotdata .= "$stime $sample\n";
  #  $stime += $$sacref->{delta};
  #}
  $plotdata .= "e\n";
}

# Replace last comma with semi-colon in plot command
$plotcmd =~ s/,$/\n/;

# Add plot data to plot command
$plotcmd .= $plotdata;

print "Sending plot data to gnuplot\n" if ( $verbose > 0 );

print GP "$plotcmd;";

#print "PLOTCMD:\n'$plotcmd'\n";

# If not priting to an output file pause after drawing to X11 display
#if ( ! defined $outfile ) {
#  print GP "pause -1\n";
#}

close GP;

## End of main

sub usage {
  my $basename = basename $0;
  print STDERR "$basename version $version\n\n";
  print STDERR "Plot time-series data in SAC format using gnuplot\n\n";
  print STDERR "Usage: $basename [options] [inputfile]\n\n";
  print STDERR " -h -? --help         Print this help message\n";
  print STDERR " -v --verbose         Be verbose\n";
  print STDERR "\n";
  print STDERR "If no input file is specified, standard input is opened for, um, input.\n";
  print STDERR "\n";
}