use ExtUtils::MakeMaker;
use Env qw(XERCES_LIB 
	   XERCES_CONFIG
	   XERCES_INCLUDE
	   XERCESCROOT
	   XERCES_DEVEL
	   SWIG);
use strict;
use vars qw($INCLUDES $CXX $CFLAGS @LDFLAGS @OPTIMIZE);
use File::Basename;

eval {
  require 5.6.0;
};
if ($@) {
  die <<ERROR;


    !!!WHOA!!!

You are using an *ancient* version of Perl. Because of the need to
support Unicode, XML::Xerces requires you upgrade to at least
v5.6.0. If you plan on using Unicode in your XML, you should really
upgrade to 5.7.2.

ERROR
}


if (defined $XERCES_LIB || defined $XERCES_INCLUDE) {
  # this is the default, so do nothing
} elsif (defined $XERCESCROOT) {
  # they are instructing us to use the build directories
  $XERCES_INCLUDE = "$XERCESCROOT/include";
  $XERCES_LIB = "$XERCESCROOT/lib";
} 

my $LIBS = '-lpthread';
$INCLUDES = '-I. -IHandler';
if (defined $XERCES_LIB) {
  print STDERR "Using XERCES_LIB = $XERCES_LIB\n";
  $LIBS .= " -L$XERCES_LIB ";
}

if (defined $XERCES_INCLUDE) {
  print STDERR "Using XERCES_INCLUDE = $XERCES_INCLUDE\n";
  $INCLUDES .= " -I$XERCES_INCLUDE";
}

if (!defined $XERCES_LIB && !defined $XERCES_INCLUDE) {
  print STDERR <<EOW;

   WARNING

You have not defined any of the following environment variables:
   XERCESCROOT
   XERCES_LIB
   XERCES_INCLUDE

These instruct me how to locate the Xerces header files, and the
Xerces dynamic library. If they are installed in a standard system
directory, I will located them without those variables.

However, if they have been installed in a non-standard location
(e.g. '/usr/include/xerces'), then I will need help. See the README
for more info.

Proceeding ...
EOW
}

my $config_file = 'config.status';
my $CXXFLAGS;
my $LDFLAGS;
if (defined $XERCES_CONFIG) {
  unless (-f $XERCES_CONFIG) {
  print STDERR <<EOW;

   WARNING

You have defined the XERCES_CONFIG variable, but it does not seem to
point to the $config_file file that was used to build your
Xerces-C. Without that file, I may not be able to properly build the
C++ glue files that come with Xerces.pm.

Proceeding ...
EOW
  }
} elsif (defined $XERCESCROOT) {
  $XERCES_CONFIG = "$XERCESCROOT/src/xercesc/$config_file";
  unless (-f $XERCES_CONFIG) {
    print STDERR <<EOW;

   WARNING

You have defined the XERCESCROOT variable, but I am unable to locate
the $config_file file that was used to build your Xerces-C. It is
supposed to be located at: $XERCES_CONFIG

Without that file, I may not be able to properly build the C++ glue
files that come with Xerces.pm.

Proceeding ...
EOW
  }
} else {
  print STDERR <<EOW;

   WARNING

You have not defined any of the following environment variables:
   XERCESCROOT
   XERCES_CONFIG

Without these I cannot find the $config_file file that was used to
build your Xerces-C. Without that file, I may not be able to properly
build the C++ glue files that come with Xerces.pm.

Proceeding ...
EOW
}

if ($XERCES_CONFIG) {
  print STDERR "using config file: $XERCES_CONFIG\n";
  open(CONF,$XERCES_CONFIG)
    or die "Couldn't open $XERCES_CONFIG for reading";
  while (<CONF>) {
    if (/\@CXXFLAGS\@/) {
      my ($flags) = /%([^%]*)%g$/;
      my @flags = split /\s+/, $flags;
      my @new_flags;
      foreach my $flag (@flags) {
	if ($flag =~ /^(-(g|O).?)$/) {
	  @OPTIMIZE = (OPTIMIZE => $1);
	  next;
	} elsif ($flag =~ /^-DPROJ_/) {
	  next;
	}
	push(@new_flags,$flag);
      }
      ($CXXFLAGS) = join(' ',@new_flags);
    } elsif (/\@LDFLAGS\@/) {
      ($LDFLAGS) = /%([^%]*)%g$/;
      @LDFLAGS = ('LDFLAGS'     => $LDFLAGS)
	if $LDFLAGS !~ /^\s*$/;
    } elsif (/\@CXX\@/) {
      ($CXX) = /%([^%]*)%g$/
    }
  }
  print STDERR <<EOM;

Found CXX      = $CXX
Found CXXFLAGS = $CXXFLAGS
Found LDFLAGS  = $LDFLAGS
EOM
}

$CFLAGS .= " $CXXFLAGS ";

# We need to know which version of libxerces we are to use.
# As of Xerces-C 1.5.1, minor version numbers are used
my $XERCES_MAJOR_VERSION = '2.5';
my $XERCES_MINOR_VERSION = '0';
my $XERCES_LIB_VERSION = "$XERCES_MAJOR_VERSION.$XERCES_MINOR_VERSION";
my $XERCES_PERL_VERSION = $XERCES_LIB_VERSION . '-0';
my $XERCES_VERSION = "$XERCES_LIB_VERSION";

# find the version of Xerces-C we are using
my $file_name = 'XercesVersion.hpp';
my $file = "$XERCES_INCLUDE/xercesc/util/$file_name";
open(VERSION,$file)
  or die "Couldn't find $file_name in your include directory $XERCES_INCLUDE";
print STDERR "Using Xerces-C version info from $file\n";
my ($major,$minor,$rev);
while (<VERSION>) {
  next unless /^\#define\s+XERCES_VERSION_/;
  if (/MAJOR\s+(\d)/) {
    $major = $1;
  } elsif (/MINOR\s+(\d)/) {
    $minor = $1;
  } elsif (/REVISION\s(\d)/) {
    $rev = $1;
  }
}
die "Couldn't find Xerces-C MAJOR version"
  unless defined $major;
die "Couldn't find Xerces-C MINOR version"
  unless defined $minor;
die "Couldn't find Xerces-C REVISION version"
  unless defined $rev;

my $XERCES_C_VERSION = "$major.$minor.$rev";

die <<EOE if $XERCES_VERSION ne $XERCES_C_VERSION;
      *** Version Mismatch ***

You are attempt to build XML::Xerces-$XERCES_PERL_VERSION using Xerces-C-$XERCES_C_VERSION,
this will most likely fail, so I am aborting. 

You must use Xerces-C-$XERCES_LIB_VERSION

EOE

# this substitution will yield '1_4' from '1.4' to be used by 'LIBS'
# $XERCES_LIB_VERSION =~ s/\./_/g;
my $LIBXERCES = "-lxerces-c";
if ($^O eq 'cygwin') {
  $LIBXERCES .= "$major$minor.dll";
} elsif ($^O eq 'MSWin32') {
  $LIBXERCES = "-lxerces-c_2";
}
$LIBS .= " $LIBXERCES";

# now we ensure that libxerces is in the library path
# if not we die()
print STDERR "Checking to see if libxerces is in your library path...";
my $lib = 1;
#($lib) = MM->new->ExtUtils::Liblist::ext($LIBS);

die <<EOE unless $lib;


    !!!WHOA!!!

I couldn\'t find $LIBXERCES anywhere in your library path. Begging to
differ with perl, this is most assuredly *NOT* harmless. This is a
critical error that will prevent you from running Xerces.pm.

Check your settings of \$XERCES_INCLUDE and \$XERCES_LIB, and rerun
'perl Makefile.PL'

EOE

print STDERR "Success!!\n";

# give some nice feedback for the user
print STDERR "Using Xerces-C version: $XERCES_VERSION\n";

my $HANDLER_LIB = '$(INST_ARCHLIB)/auto/Handler/Handler$(LIB_EXT)';

sub MY_postamble {
qq[

$HANDLER_LIB:
	\$(MAKE) -C Handler static
];

}
*MY::postamble = \&MY_postamble;

my @MACRO;
$CFLAGS .= '-D_REENTRANT';

# we only consider using SWIG if we are a Xerces Developer
if ($XERCES_DEVEL) {
  # replace this with the path to your Unix compatible find application
  my $FIND = 'find';

  # set up the custom headers
  my @header_files;
  my @handler_headers;
  chomp(@handler_headers = `$FIND Handler -name "*.swig.hpp"`);

  sub Xerces_postamble {
    chomp(my @import_files = `$FIND Handler -name "*.i"`);
    push(@header_files,@handler_headers,@import_files);
    local $" = ' ';
    my $OS_DEF;
    my $CC_DEF;
    if ($^O eq 'linux') {
      $OS_DEF = '-DXML_LINUX';
    } elsif($^O eq 'darwin') {
      $OS_DEF = '-DXML_MACOSX';
    } else {
      die 'unsupported operating system';
    }
    if ($CXX =~ /g\+\+/) {
      $CC_DEF = '-DXML_GCC';
    } else {
      die 'unsupported compiler';
    }
    my $SWIG_ARGS = qq[-Wall $OS_DEF $CC_DEF -DXERCES_VERSION="$XERCES_PERL_VERSION" \$(INC) -perl5 -c++ -shadow];

    my $MAKE = '	\$(MAKE) -C Handler static';
    if ($^O eq 'MSWin32') {
      # nmake doesn't not honor '-C'
      $MAKE =  '	cd Handler && \$(MAKE) static';
    }

    my $retval = <<TERMINUS;
Xerces.cpp: Xerces.i typemaps.i @header_files postSource.pl 
	\$(SWIG) $SWIG_ARGS -o Xerces.cpp Xerces.i
	perl postSource.pl Xerces.cpp
	perl postModule.pl Xerces.pm


Xerces.pm: Xerces.cpp postModule.pl Xerces-extra.pm
	if [[ postModule.pl -nt Xerces.pm || Xerces-extra.pm -nt Xerces.pm ]] ; then \\
\$(SWIG) $SWIG_ARGS -o foo.C Xerces.i ; \\
rm foo.C ; \\
perl postModule.pl Xerces.pm ; \\
cp -f Xerces.pm blib/lib/XML ; \\
	fi

$HANDLER_LIB:
$MAKE
TERMINUS
    return $retval;
  }

  print STDERR "Welcome Xerces Developer!\n";
  # if we're to use SWIG, we need to know which version is available
  my $swig = $SWIG || 'swig';
  @MACRO = ('macro'       => {
    'SWIG'         => "$swig",
  });

  # we'll assume that we want -g as a default
  #  @OPTIMIZE = (OPTIMIZE => '-g');

  # we want all warnings
  $CFLAGS .= ' -Wall';
#  print STDERR "Using SWIG version: SWIG_$ {sv_maj}_$ {sv_min}\n";
  *MY::postamble = \&Xerces_postamble;
}

# set up the list of object files to include in Xerces\$(OBJ_EXT)
my $OBJS = 'Xerces$(OBJ_EXT)';

# write the makefile
# see the hints/ directory for architecture specific stuff!
WriteMakefile(
  'NAME'        => 'XML::Xerces',
  'AUTHOR'      => 'The Xerces-P developers: xerces-p-dev@xml.apache.org',
  'ABSTRACT'    => 'Perl Interface for Xerces XML API',
  'CC'          => $CXX,
  'CCFLAGS'     => $CFLAGS,
  'PM'          => {
    'Xerces.pm' => '$(INST_LIB)/XML/Xerces.pm',
  },
  'INC'         => $INCLUDES,
  'MYEXTLIB'    => $HANDLER_LIB,
  'LIBS'        => [$LIBS],
  'OBJECT'      => $OBJS,
  'VERSION'     => "$XERCES_PERL_VERSION",
  @OPTIMIZE,
  @MACRO,
  @LDFLAGS,
);