########################################################################
# Copyright ( C ) 2007 ERG Limited, All rights reserved
#
# Module name   : jats.sh
# Module type   : Makefile system
# Compiler(s)   : n/a
# Environment(s): jats build system
#
# Description   : Provide access to information from the Makefile.gbe file
#
#                 Designed to be called by utilities that process
#                 makefile data.
#
# Interface     : CreateMakeInfo            - Create MAkefile.gbe
#                 ReadMakeInfo              - Read Makefile.gbe
#                 TestMachType              - Validate Machine Type
#
#......................................................................#

require 5.006_001;
use strict;
use warnings;

#===============================================================================


package JatsMakeInfo;

use JatsError;
use ConfigurationFile;

# automatically export what we need into namespace of caller.
use Exporter();
our (@ISA, @EXPORT, %EXPORT_TAGS, @EXPORT_OK, @EXPORT_BASIC);
@ISA         = qw(Exporter);
@EXPORT      = qw(  TestMachType
                    ReadMakeInfo
                    $ScmBuildMachType
                    $ScmRoot
                    $ScmInterface
                    $ScmBuildFilter
                );
@EXPORT_OK =  qw(
                    CreateMakeInfo
                    TestMachType
                );
@EXPORT_BASIC = qw(
                    TestMachType
                  );

%EXPORT_TAGS = (create => [@EXPORT_OK],
                basic  => [@EXPORT_BASIC]);

#-------------------------------------------------------------------------------
#   Global variables
#
#our $GBE_HOSTMACH;                          # Current machine type
our $ScmBuildMachType;                      # from Makefile.gbe
our $ScmRoot;                               # Built Root
our $ScmInterface;                          # Interface (relative to root)

#-------------------------------------------------------------------------------
# Function        : BEGIN
#
# Description     : Global initialisation
#                   Ensure required environment variables are present
#
# Inputs          : 
#
# Returns         : 
#
BEGIN
{
    $::GBE_HOSTMACH = $ENV{ GBE_HOSTMACH };
    Error( "Environment Variable 'GBE_HOSTMACH' not defined." )
            unless( defined $::GBE_HOSTMACH );
}


#-------------------------------------------------------------------------------
# Function        : CreateMakeInfo
#
# Description     : Create the Makefile.gbe file
#                   This contains sufficient info to locate:
#                       The build root
#                       The interface
#                   Designed to be required directly into a script
#
# Inputs          : EnvVars
#
# Returns         : 
#
sub CreateMakeInfo
{
    #
    #   Validate globals that are used
    #
    Error ("JatsMakeInfo - ScmRoot not defined") unless ( $::ScmRoot  );
    Error ("JatsMakeInfo - ScmInterface not defined") unless ( $::ScmInterface  );
    Error ("JatsMakeInfo - GBE_HOSTMACH not defined") unless ( $::GBE_HOSTMACH  );

    #
    #   Create Makefile.gbe in the current directory
    #
    my $fh = ConfigurationFile::New( "Makefile.gbe" );
    $fh->Header( $::ScmMakelib , 'Make Control Files');
    $fh->Write("\$ScmBuildMachType = \"$::GBE_HOSTMACH\";\n") ;
    $fh->Write("\$ScmRoot          = \"$::ScmRoot\";\n") ;
    $fh->Write("\$ScmInterface     = \"$::ScmInterface\";\n") ;
    $fh->Write("\$ScmBuildFilter   = \"$::GBE_BUILDFILTER\";\n") if ($::GBE_BUILDFILTER) ;
    $fh->Close();

    ::ToolsetFile ("Makefile.gbe");
}


#-------------------------------------------------------------------------------
# Function        : ReadMakeInfo
#
# Description     : Reads in Makefile.gbe data in the current directory
#                   This is used to provide basic information including
#                   The path to the build root
#                   The path to the interface directory
#
# Inputs          :
#
# Returns         : Reference to a structure that contains the data
#
#
sub ReadMakeInfo
{
    #
    #   Read in the file
    #   Reads some global variables directly into the global variable space
    #
    my $tag_file = "Makefile.gbe";
    Error ("Expected config file not found: $tag_file") unless ( -f $tag_file );
    require $tag_file;

    #
    #   Sanity tests
    #
    Error ("Bad Makefile.gbe file. Rebuild required") unless ( $ScmBuildMachType );
    TestMachType ( $ScmBuildMachType, "Makefile.gbe" );

}

#-------------------------------------------------------------------------------
# Function        : TestMachType
#
# Description     : Validate the current machine type
#
# Inputs          : MachType to test
#                   Source of test
#
# Returns         : May not return
#
sub TestMachType
{
    my ($MachType, $src) = @_;

    Error ("Incorrect Machine Type in $src",
           "The build has been construct for a Machine Type of: $MachType",
           "Current Machine Type is: $::GBE_HOSTMACH",
           ) unless ( $MachType eq $::GBE_HOSTMACH );
}

#------------------------------------------------------------------------------
1;