#!/usr/bin/perl -w

# Todo: Check for 0 gains that don't have to be.  Requires knowing the E21
# format.

# use strict;     # Can't use with Getopt::Long.
use Getopt::Long;
use IO::Seekable;

my $use = q {
Use: chkgains [-f|--fix] [-v|--verbose] gainfile1 gainfile2 ...

Checks selfcal solutions for amplitudes that are not 0 or inclusively within
0.2 of 1.

--fix: Replace 0 gains with 1
 -f:   in gainfile.fixed.

--verbose: Report finishing files
 -v:       even when they're OK.
};

GetOptions("fix" => \$dofix, "f" => \$dofix,
	   "verbose" => \$verbose, "v" => \$verbose) or die $use;

foreach my $gf ( @ARGV ){
  if($dofix){
    open(GF, "+< $gf") or die "Could not open $gf for reading";
  }
  else{
    open(GF, $gf) or die "Could not open $gf for reading and writing";
  }

  my $ob = "";
  my $day = 1;
  my $maxant = 7;
  my $maxvis = 480;
  my $ant = 0;

  my $scbuf;

  my @mingain = ();
  my @maxgain = ();

#  read(GF, $scbuf, 3840);	# First one is junk?

  while (read(GF, $scbuf, 3840)) {
    ++$ant;
    my @gains = unpack('f*', pack('N*', unpack('V*', $scbuf)));
    #  print "ant: $ant, day: $day\n";

    $maxgain[$ant] =  0.0;
    $mingain[$ant] = 10.0;
    for (my $ii = 0; $ii < $maxvis; ++$ii) {
      # nodata = -1.0e+38.
      if ($gains[$ii] > -1.0E+37 && $gains[$maxvis + $ii] > -1.0E+37) {
	my $gain = $gains[$ii]**2 + $gains[$maxvis + $ii]**2;

	if($gain > 0.0){
	  if ($gain > $maxgain[$ant]) {
	    $maxgain[$ant] = $gain;
	  }
	  elsif ($gain < $mingain[$ant]) {
	    $mingain[$ant] = $gain;
	  }
	}
	elsif($dofix){
	  $gains[$ii]           = 1.0;
	  $gains[$maxvis + $ii] = 0.0;
	}
      }
    }
    if($dofix){
      seek(GF, -3840, SEEK_CUR);
      print GF pack('V*', unpack('N*', pack('f*', @gains)));
    }

    if ($ant == 7) {
      $ant = 0;

      my $mig = 5.0;
      my $mag = 1.0;
      for (my $jj = 1; $jj <= $maxant; ++$jj) {
	if ($mingain[$jj] < $mig) {
	  $mig = $mingain[$jj];
	}
	if ($maxgain[$jj] > $mag) {
	  $mag = $maxgain[$jj];
	}
      }

      if ($mig < 0.64 || $mag > 1.44) {
	$ob .= "Day $day:";
	for (my $antnum = 1; $antnum <= 7; ++$antnum) {
	  if ($mingain[$antnum] < 0.64) {
	    $ob .= sprintf("\t%5.3f (%d)", sqrt($mingain[$antnum]), $antnum);
	  }
	  if ($maxgain[$antnum] > 1.44) {
	    $ob .= sprintf("\t%5.3f (%d)", sqrt($maxgain[$antnum]), $antnum);
	  }
	}
	$ob .= "\n";
      }

      ++$day;
    }
  }

  close(GF) or warn "Error $! closing $gf";

  if($ob ne ""){
    print "$gf\n";
    print "-" x length($gf);
    print "\n$ob\n";
  }
  elsif($verbose){
    print "$gf: OK\n\n";
  }
}