#!/usr/bin/env perl
# +-======-+ 
#  Copyright (c) 2003-2007 United States Government as represented by 
#  the Admistrator of the National Aeronautics and Space Administration.  
#  All Rights Reserved.
#  
#  THIS OPEN  SOURCE  AGREEMENT  ("AGREEMENT") DEFINES  THE  RIGHTS  OF USE,
#  REPRODUCTION,  DISTRIBUTION,  MODIFICATION AND REDISTRIBUTION OF CERTAIN 
#  COMPUTER SOFTWARE ORIGINALLY RELEASED BY THE UNITED STATES GOVERNMENT AS 
#  REPRESENTED BY THE GOVERNMENT AGENCY LISTED BELOW ("GOVERNMENT AGENCY").  
#  THE UNITED STATES GOVERNMENT, AS REPRESENTED BY GOVERNMENT AGENCY, IS AN 
#  INTENDED  THIRD-PARTY  BENEFICIARY  OF  ALL  SUBSEQUENT DISTRIBUTIONS OR 
#  REDISTRIBUTIONS  OF THE  SUBJECT  SOFTWARE.  ANYONE WHO USES, REPRODUCES, 
#  DISTRIBUTES, MODIFIES  OR REDISTRIBUTES THE SUBJECT SOFTWARE, AS DEFINED 
#  HEREIN, OR ANY PART THEREOF,  IS,  BY THAT ACTION, ACCEPTING IN FULL THE 
#  RESPONSIBILITIES AND OBLIGATIONS CONTAINED IN THIS AGREEMENT.
#  
#  Government Agency: National Aeronautics and Space Administration
#  Government Agency Original Software Designation: GSC-15354-1
#  Government Agency Original Software Title:  GEOS-5 GCM Modeling Software
#  User Registration Requested.  Please Visit http://opensource.gsfc.nasa.gov
#  Government Agency Point of Contact for Original Software:  
#  			Dale Hithon, SRA Assistant, (301) 286-2691
#  
# +-======-+ 
########################################################################
#
#  Name: g5_modules_perl_wrapper
#
#  Purposes - This is a perl wrapper for the g5_modules csh script.
#
#  Notes:
#  1. You cannot "source" the csh file, g5_modules, from a perl
#     script.
#  2. Instead use the following in your perl script:
#     #--------------------------------
#        do "g5_modules_perl_wrapper";
#     #--------------------------------
#  3. The environment variable, FVROOT, must be set prior to calling script.
#
#  REVISION HISTORY
#  17Dec2007  Stassi  Initial version of code
#  23Apr2009  Stassi  Broke scripts into subprograms 
#
########################################################################
use strict;
use warnings;

my ($scriptname, $g5_modules);
my ($BASEDIR, @libmods, $modinit, $loadmodules);
my (@fields, $LD_LIBRARY_PATH);
my ($arch, $node);
my ($baselib, $status);

# main program
#-------------
{
    init();
    get_expected_values();
    set_env_variables();
}

#=======================================================================
# name - init
#=======================================================================
sub init {
    my ($FVROOT);
    
    # NOTE: Spell out scriptname--DO NOT USE $0 here!
    #------------------------------------------------
    $scriptname = "g5_modules_perl_wrapper";

    # get architecture and node
    #--------------------------
    chomp($arch = `uname -s`);
    chomp($node = `uname -n`);

    # get FVROOT
    #-----------
    $FVROOT = $ENV{"FVROOT"};
    die ">> Error << Environment variable, FVROOT not defined. " unless $FVROOT;

    # find g5_modules csh script
    #---------------------------
    $g5_modules = "$FVROOT/bin/g5_modules";
    die ">> Error << Cannot find $g5_modules. " unless (-e $g5_modules);
}

#=======================================================================
# name - get_expected_values
#=======================================================================
sub get_expected_values {

    # get expected values from g5_modules
    #------------------------------------
    chomp( $BASEDIR     = `$g5_modules basedir` );
    chomp( @libmods     = (`$g5_modules modules`) );
    chomp( $loadmodules = `$g5_modules loadmodules` );
    chomp( $modinit     = `$g5_modules modinit` );

    # convert modinit script to perl
    #-------------------------------
    @fields = split "/", $modinit;
    pop @fields;
    push @fields, "perl";
    $modinit = join "/", @fields;
}

#=======================================================================
# name - set_env_variables
#=======================================================================
sub set_env_variables {

    # setenv BASEDIR
    #---------------
    print "$scriptname: Setting BASEDIR";
    $ENV{"BASEDIR"} = $BASEDIR;

    # add BASEDIR lib to LD_LIBRARY_PATH, if not already there
    #---------------------------------------------------------
    $LD_LIBRARY_PATH = $ENV{"LD_LIBRARY_PATH"};
    $baselib = "$BASEDIR/$arch/lib";
    $status = index($LD_LIBRARY_PATH, $baselib);
    if ($status < 0) { $ENV{"LD_LIBRARY_PATH"} .= ":$baselib" };
 
    # load library modules
    #---------------------
    if (-e $modinit) {
        print " and modules";
        do $modinit;
        module ("purge");

        if ($loadmodules) { module ("load modules") };
        foreach ( @libmods ) { module ("load $_") };
        print " for $node\n";
    }
}