# PDL interface to  FFTW
# Makefile.PL for a package defined by PP code.

use ExtUtils::MakeMaker;

PDL::Core::Dev->import();

BEGIN {


	$msg = ""; $forcebuild=0;  # Note: forcebuild not used

	if (defined $PDL::Config{WITH_FFTW} && $PDL::Config{WITH_FFTW}==0) {
	   $msg = "\n   Will skip build of PDL::FFTW on this system   \n";
	   goto skip;
	}

	if (defined $PDL::Config{WITH_FFTW} && $PDL::Config{WITH_FFTW}==1) {
	   print "\n   Will forcibly try and build PDL::FFTW on this system   \n\n";
	   $forcebuild=1;
	}

	# Setup the FFTW library we will link to: (single/double precision)
	#  Default is double precision
	$want_float = 0;
	$want_double = 1;
	if (defined $PDL::Config{FFTW_TYPE} && $PDL::Config{FFTW_TYPE} =~ /single/i ) {
		$want_float = 1;
		$want_double = 0;
	}

	$found_float = $found_double = 'none';

	# Look for FFTW includes/libs
	# default locations:
	@FFTW_inc_locations = ('/usr/local/include'); 
	@FFTW_lib_locations = ('/lib','/usr/lib','/usr/local/lib');

	# get locations from perldl.conf, if specified there:
	@FFTW_inc_locations = @{$PDL::Config{FFTW_INC}} if( defined $PDL::Config{FFTW_INC} );
	@FFTW_lib_locations = @{$PDL::Config{FFTW_LIBS}} if( defined $PDL::Config{FFTW_LIBS} );

	foreach $i (@FFTW_inc_locations) {
	  if (-e "$i/dfftw.h") {
	    print  "Found FFTW2 double version in $i/dfftw.h !\n";
	    $double_rinclude = 'drfftw.h';
	    $double_lib = '-ldfftw -ldrfftw';

	    # Inc found, now try to find libs:
	    if( findLibs($double_lib, @FFTW_lib_locations)){
		    print " FFTW Libs also found.\n";
		    $found_double = 'dfftw.h';

	    }
	  }
	  if (-e "$i/sfftw.h") {
	    print  "Found FFTW2 single version $i/sfftw.h !\n";
	    $single_rinclude = 'srfftw.h';
	    $single_lib = '-lsfftw -lsrfftw';

	    # Inc found, now try to find libs:
	    if( findLibs($single_lib, @FFTW_lib_locations)){
		    print " FFTW Libs also found.\n";
		    $found_float = 'sfftw.h';
	    }
	  }
	  if (-e "$i/fftw.h") {
	    open F,"$i/fftw.h";
	    $is_float=0;
	    while (<F>) {
	      if (/define FFTW_ENABLE_FLOAT 1/) {$is_float=1;}
	    }
	    close F;
	    if ($is_float) {
		    print "Found FFTW2 single version in $i/fftw.h !\n";
		    $single_rinclude = 'rfftw.h';
		    $single_lib = '-lfftw -lrfftw';
		    # Inc found, now try to find libs:
		    if( findLibs($single_lib, @FFTW_lib_locations)){
			    print " FFTW Libs also found.\n";
			    $found_float = 'fftw.h';
		    }
	    }
	    else {
		    print  "Found FFTW2 double version in $i/fftw.h !\n";
		    $double_rinclude = 'rfftw.h';
		    $double_lib = '-lfftw -lrfftw';
		    if( findLibs($double_lib, @FFTW_lib_locations)){
			    print " FFTW Libs also found.\n";
			    $found_double = 'fftw.h';
		    }
	    }
	  }
	}

	$donot = 1;
	$wanted_not_found = 0;
	
        # want float, found float
        if ($found_float ne 'none' && $want_float ) {
            $include = $found_float;
            print "Building single version\n";
            $pdltype = 'PDL_F';
            $lib = $single_lib;
            $rinclude = $single_rinclude;
            $out = '$fftwtype=\'float\'';
            $donot = 0;
        }

        # want double, found double
        elsif ($found_double ne 'none' && $want_double ) {
            $include = $found_double;
            print "Building double version\n";
            $pdltype = 'PDL_D';
            $lib = $double_lib;
            $rinclude = $double_rinclude;
            $out = '$fftwtype=\'double\'';
            $donot = 0;
        }


        if ( $donot )   {

          $msg .= "\n Skipping build of PDL::FFTW.\n";

          # maybe we found something, but it wasn't what was wanted...
          if ( $found_double ne 'none' )
            { $msg .= "Found double version, wanted float!\n" }

          if ( $found_float ne 'none' )
            { $msg .= "Found float version, wanted double!\n" }
        }

skip:

	if ($msg ne "" && $forcebuild==0) {

	    warn $msg . "\n";
	    $msg =~ s/\n//g;
	    write_dummy_make( $msg );
	    $donot = 1;
	} else {
		print "\n   Building PDL::FFTW. Turn off WITH_FFTW if there are any problems\n\n";
	}

	# Sub to find libs
	sub findLibs {
		my ($libstring, @libdirs) = @_;
		# make a list of libs from the libstring
		my @libs = split ' ',$double_lib;
		grep s/\-l//g, @libs;
		grep $_ = "lib$_.a", @libs;
		my %libs;
		my $lib;
		foreach $libdir(@libdirs){
			foreach $lib(@libs){
				if( -e "$libdir/$lib"){
					$libs{$lib} = 1;
				}
			}
	
		}
		if( scalar(keys %libs) == scalar(@libs) ){
			return 1;	# all libs in the list were found
		}
		print "     Libs: '".join("', '",@libs)."' Not Found\n";
		print "     Looked in: '".join("', '",@libdirs)."'\n";
		return 0; # all libs in the list not found
	
	}
}
##############################################################################


return if $donot;

open F,'>typespec';
print F $out,";\n";
print F 'pp_addhdr(\'',"\n";
print F '#include "',$include,'"',"\n";
print F '#include "',$rinclude,'"',"\n";
print F '#define PDL_MYTYPE ',$pdltype,"\n";
print F '\');',"\n";
close F;

@pack = (["fftw.pd",FFTW,PDL::FFTW]);
%hash = pdlpp_stdargs_int(@::pack);
$hash{INC} .= " -I".join(' -I',@FFTW_inc_locations);
$hash{clean}->{FILES} .= ' typespec';
push @{$hash{LIBS}},"-lm -L".join(" -L",@FFTW_lib_locations)." $lib";
WriteMakefile(%hash);


sub MY::postamble {
        pdlpp_postamble_int(@::pack);
}  # Add genpp rule