#!/usr/bin/perl

use Getopt::Std;
use POSIX;

sub Usage {
  print STDERR <<EOF;

 Usage: rotate.pl -lStart -LEnd -c -d  [East|1]_Component_file_name

    rotate.pl rotates iris data(-d), trinet data and synthetics (with
    out -d option)
    -l -L specifies the start and end point of the traces to rotate
    -c check SAC output on screen
       ex. rotate.pl -d *.LHE.SAC for iris data
           rotate.pl PAS.*.MXE.sac for synthetics
    For iris data (with -d), the timing part of the name will be ignored
    and only the component part of the name will be changed correspondingly

EOF
exit(1)
}


if (!getopts('l:L:cdts')) {die('Check input arguments\n');}
@ARGV > 0 or Usage();
if (!$opt_l) {$opt_l = 0;}

$saclst = "saclst";
if (system("which $saclst >/dev/null") != 0) {die(" No $saclst file\n");}

$undef=-12345.0;
$eps=0.1;

foreach $file (@ARGV) {
  print "processing $file\n";
  if (! -f $file) {die (" check to see if $file exists or not\n");}

  (undef,$comp)=split(" ",`$saclst kcmpnm f $file`);
  if ($comp eq "-12345") {die("No component name defined in the file\n");}
  if (not ($comp=~/E/ or $comp=~/1/)) {die("Please input only E/1 comp\n");}

  $ecomp = $comp; $ncomp = $ecomp; $rcomp = $ecomp; $tcomp = $ecomp;
  $ncomp=~s/E/N/; $ncomp =~s/1/2/;
  $tcomp=~s/E/T/; $tcomp =~s/1/T/;
  $rcomp=~s/E/R/; $rcomp =~s/1/R/;
  ($dir) = split(" ",`dirname $file`);$east = $file;
  if ($opt_d) {
    #(undef,undef,undef,undef,undef,undef,$network,undef)=split(/\./,`basename $file`);
    ($network,$sta,undef,undef)=split(/\./,`basename $file`);
    (undef,$east1) = split(/\.$sta\./,$file);
    $east1 = "$sta.$east1";
    $north1 = $east1; $north1=~s/$ecomp/$ncomp/;
    ($north) = split(" ",`ls -1 $dir/*$north1`);
    $tang1=$east1;$radial1=$east1;
    $tang1=~s/$ecomp/$tcomp/; $radial1=~s/$ecomp/$rcomp/;
    $tang = "$dir/$tang1"; $radial = "$dir/$radial1";
  } else {
    $north = $east; $north =~s/$ecomp/$ncomp/;
    $tang = $east; $tang =~s/$ecomp/$tcomp/;
    $radial = $east; $radial =~s/$ecomp/$rcomp/;
}

#  print "   rotate $north $east \n   to $tang $radial\n";
  if (!-f $north or !-f $east ) {
    print " no such files: $north and $east, check if -d option is missing\n";
    next;}

# check some header variables
  @tmp=`$saclst b kcmpnm npts gcarc cmpinc cmpaz nzyear nzjday nzhour nzmin nzsec nzmsec f $north $east`;
  (undef,$nb,$ncomp,$npts_n,$gcarc_n,$ninc,$naz,$ny,$nj,$nh,$nm,$ns,$nms)=split(" ",$tmp[0]);
  (undef,$eb,$ecomp,$npts_e,$gcarc_e,$einc,$eaz,$ey,$ej,$eh,$em,$es,$ems)=split(" ",$tmp[1]);

  if (abs($ninc-$undef)<$eps or abs($einc-$undef)<$eps or abs($naz-$undef)<$eps or abs($eaz-$undef)<$eps ) {die("Check header cmpinc and cmpaz for $north and $east\n");}

  # allow n and e component .2 degrees from vertical
  $daz = abs($naz-$eaz);
  if ($daz > 180 and abs(abs($daz-270) >= 0.18) or $daz < 180 and abs(abs($daz-90) >=0.18) ) {
    print "cmpaz not properly set for $north and $east: $naz,$eaz, skip\n";
   next;}

  if ($ny != $ey or $nj != $ej or $nh != $eh or $nm != $em or $ns != $es or abs($nms-$ems)>1)
    {die(" Not the same reference time for $north and $east\n");}

  if (abs($gcarc_e-$undef)<$eps or abs($gcarc_n-$undef)<$eps )
    {die(" Check to see if GCARC is defined in the header\n");}

  # check if the reference time is the same or not!

  if ($opt_c) {open(SAC,"|sac");}
  else {open(SAC,"|sac > /dev/null");}
  print SAC "echo on\n";
  print SAC "r $north $east\n ";
  if ($opt_L or $npts_n != $npts_e or abs($nb-$eb) > $eps) { #cut properly
    if(!$opt_L){
      print SAC "setbb begin ( max &1,b &2,b ) \n";
      print SAC "setbb end   ( min &1,e &2,e ) \n";}
    else{
      print SAC "setbb begin ( max &1,b &2,b ( &1,o + $opt_l ) ( &2,o + $opt_l ) ) \n";
      print SAC "setbb end   ( min &1,e &2,e ( &1,o + $opt_L ) ( &2,o + $opt_L ) ) \n"; }
    print SAC "cut %begin% %end%\n r $north $east\n cut off\n";

  }
  print SAC "ch cmpinc 90.0\n";  # make sure both are horizontal comp.
  print SAC "rot\n";           # this is the default rotate to normal
  print SAC "ch file 1 kcmpnm $rcomp\n";
  print SAC "ch file 2 kcmpnm $tcomp\n";
  print SAC "w $radial $tang\nquit\n";
  close(SAC);
}

print "   Done !\n";