use ExtUtils::MakeMaker;
use Config;
#require 5.008008;

our %args = map { split /\s*=\s*/ } @ARGV;
our $LIBS = $args{ LIBS } || "-lmpfr -lgmp";
our $INC = $args{ INC };

$use_64_bit_int  = 0;     # Let perl decide whether to include 64-bit 'long long' support
$use_long_double = 0;     # Let perl decide whether to include 'long double' support
$have_decimal64  = undef; # Default value
$have_float128   = undef; # Default value

#$use_64_bit_int  = -1; # Uncomment to Force exclusion of 64-bit 'long long' support
#$use_long_double = -1; # Uncomment to Force exclusion of 'long double' support
#$have_decimal64  = -1; # Uncomment to Force exclusion of _Decimal64 support
#$have_float128   = -1; # Uncomment to Force exclusion of __float128/_Float128 support

#$use_64_bit_int  = 1; # Uncomment to Force inclusion of 64-bit 'long long' support
#$use_long_double = 1; # Uncomment to Force inclusion of 'long double' support
#$have_decimal64  = 1; # Uncomment to Force inclusion of _Decimal64 support
#$have_float128   = 1; # Uncomment to Force inclusion of __float128/_Float128 support

$save = open SAVE, '>', 'save_config.txt';

warn "Couldn't open save_config.txt for writing: $!" unless $save;

############################################
# Whether to build with _Decimal64 support #
############################################

if($have_decimal64) {$have_decimal64++} # $have_decimal64 is now either 0 or 2, depending
                                        # upon which of the above lines was uncommented

else { # we still need to determine whether_Decimal64 should be supported

  for(@ARGV) {
    $have_decimal64 = 1 if $_ eq 'D64=1';
    $have_decimal64 = 0 if $_ eq 'D64=0';
  }

  if(!defined($have_decimal64)) { # _Decimal64 support still undetermined
    my($mycc, $mylibs, $myinc) = ('', '', '');

    if(@ARGV) {
      for my $arg(@ARGV) {
        $mycc   = (split /=/, $arg)[1] if $arg =~ /^cc=/i;
        $mylibs = (split /=/, $arg)[1] if $arg =~ /^libs=/i;
        $myinc  = (split /=/, $arg)[1] if $arg =~ /^inc=/i;
      }
    }

    unless($mycc) {
      $mycc = defined($Config{cc}) ? $Config{cc} : 'cc';
    }

    $mylibs = '-lmpfr -lgmp' unless $mylibs;

    my $out = `$mycc -o have_d64.exe -x c have_d64.in 2>&1`;

    if($out) {
      print "$out\n";
      if($save) {print SAVE "try_64 build: $out\n"}
    }

    unless(-e 'have_d64.exe') {$have_decimal64 = 0}

    else { # _Decimal64 support still undetermined

      my $out = `$mycc -o try_dec64.exe -x c try_dec64.in $myinc $mylibs 2>&1`;

      if($out) {
        print "$out\n";
        if($save) {print SAVE "try_dec64 build: $out\n"}
      }

      if(-e 'try_dec64.exe') {
        $out = $^O =~ /MSWin32/i ? `try_dec64.exe` : `./try_dec64.exe`;
        if($out == 42) {$have_decimal64 = 1}
        if($save) {print SAVE "try_dec64.exe: $out\n"}
      }
    }
  }
}

my $d64_message = $have_decimal64 ? "Attempting to build with _Decimal64 support\n"
                                  : "Building without _Decimal64 support\n";

###########################################
###########################################
# Whether to build with __foat128 support #
###########################################

if($have_float128) {$have_float128++} # $have_float128 is now either 0 or 2, depending
                                      # upon which of the above lines was uncommented

else { # we still need to determine whether__float128 should be supported.

  for(@ARGV) {
    $have_float128 = 1 if $_ eq 'F128=1';
    $have_float128 = 0 if $_ eq 'F128=0';
  }

  if(!defined($have_float128)) { # __float128 support still undetermined

    print SAVE "\n\n" if $save;
    my($mycc, $mylibs, $myinc) = ('', '', '');

    if(@ARGV) {
      for my $arg(@ARGV) {
        $mycc   = (split /=/, $arg)[1] if $arg =~ /^cc=/i;
        $mylibs = (split /=/, $arg)[1] if $arg =~ /^libs=/i;
        $myinc  = (split /=/, $arg)[1] if $arg =~ /^inc=/i;
      }
    }

    unless($mycc) {
      $mycc = defined($Config{cc}) ? $Config{cc} : 'cc';
    }

    $mylibs = '-lmpfr -lgmp -lquadmath' unless $mylibs;

    my $out = `$mycc -o have_f128.exe -x c have_f128.in 2>&1`;

    if($out) {
      print "$out\n";
      if($save) {print SAVE "have_f128 build: $out\n"}
    }

    unless(-e 'have_f128.exe') {$have_float128 = 0}

    else {
      my $out = `$mycc -o try_flt128.exe -x c try_flt128.in $myinc $mylibs 2>&1`;

      if($out) {
        print "$out\n";
        if($save) {print SAVE "try_flt128 build: $out\n"}
      }

      if(-e 'try_flt128.exe') {
        $out = $^O =~ /MSWin32/i ? `try_flt128.exe` : `./try_flt128.exe`;
        if($out == 42) {$have_float128 = 1}
        if($save) {print SAVE "try_flt128.exe: $out\n"}
      }
    }
  }
}

my $float128_message = $have_float128 ? "Attempting to build with __float128 support\n"
                                      : "Building without __float128 support\n";

####################################

close SAVE or warn "Couldn't close save_config.txt";

my $defines = $] < 5.008 ? "-DOLDPERL" : "-DNEWPERL";

if($use_64_bit_int == -1) {}
elsif($use_64_bit_int == 1) {$defines .= " -DMATH_MPFR_NEED_LONG_LONG_INT -DIVSIZE_BITS=" . (8 * $Config{ivsize})}
else {
  unless($Config{ivsize} < 8 || $Config{ivtype} eq 'long') {
    $defines .= " -DMATH_MPFR_NEED_LONG_LONG_INT -DIVSIZE_BITS=" . (8 * $Config{ivsize});
  }
}

if($use_long_double == -1) {}
elsif($use_long_double == 1) {
  $defines .= " -DNV_IS_FLOAT128" if $Config{nvtype} eq '__float128';
  $defines .= " -DNV_IS_LONG_DOUBLE" if $Config{nvtype} eq 'long double';
}
else {
  if($Config::Config{nvsize} > 8 ) {
    $defines .= " -DNV_IS_FLOAT128" if $Config{nvtype} eq '__float128';
    $defines .= " -DNV_IS_LONG_DOUBLE" if $Config{nvtype} eq 'long double';
  }
}

$defines .= " -DMPFR_WANT_DECIMAL_FLOATS" if $have_decimal64;
$defines .= " -DMPFR_WANT_FLOAT128" if $have_float128;

print "\nThis module requires the following C libraries:\n";
print " gmp-4.2.0 (or later)\n mpfr-2.4.0 (or later)\n\n";
$defines =~ /\-DMATH_MPFR_NEED_LONG_LONG_INT/ ? print "Building with 'long long' support\n" :
                                 print "Building without 'long long' support\n";

print "If this is wrong, see the \"64-bit support\" section in the README\n\n";

($defines =~ /\-DNV_IS_LONG_DOUBLE/ || $defines =~ /\-DNV_IS_FLOAT128/)
                                    ? print "Building with 'long double' support\n"
                                    : print "Building without 'long double' support\n";

print "If this is wrong, see the \"64-bit support\" section in the README\n\n";

($defines =~ /\-DNV_IS_FLOAT128/) ? print "Building with support for a __float128 NV\n"
                                  : print "Building without support for a __float128 NV\n";

print "If this is wrong, see the \"__float128 NV\" conversion section in the README\n\n";

print "\n$d64_message";
print "If this is wrong, see the \"Decimal64 conversion\" section in the README\n\n";

print "\n$float128_message";
print "If this is wrong, see the \"Math::Float128 conversion\" section in the README\n\n";

$defines .= $Config::Config{byteorder} =~ /^1234/ ? " -DMPFR_HAVE_LENDIAN" : " -DMPFR_HAVE_BENDIAN";

if(defined $Config{longdblkind}) {
  if($Config{longdblkind} == 1 || $Config{longdblkind} == 2) {
    $defines .= " -DHAVE_IEEE_754_LONG_DOUBLE";
  }
  if($Config{longdblkind} == 3 || $Config{longdblkind} == 4) {
    $defines .= " -DHAVE_EXTENDED_PRECISION_LONG_DOUBLE";
  }
}

$defines .= " -DNV_IS_DOUBLE"
  if $Config{nvtype} eq 'double';

if($^O =~ /MSWin32/i && $] < 5.022) {
  $defines .= " -D_WIN32_BIZARRE_INFNAN";
}

# NOTE: The '-lquadmath' link we provide below
#       to 'LIBS' is generally not needed.
#       It is, however, currently needed on at
#       least some quadmath Cygwin builds.
#             Jan 8 2018.

my %options = (
  NAME => 'Math::MPFR',
  AUTHOR => 'Sisyphus (sisyphus at (@) cpan dot (.) org)',
  ABSTRACT => 'Perl interface to the MPFR (floating point) library',
  DEFINE   => $defines,
  LIBS => [
    '-lmpfr -lgmp -lquadmath'
  ],
  LICENSE  => 'perl',
  VERSION_FROM => 'MPFR.pm',
  clean   => { FILES => '*.exe *.txt' },
  META_MERGE => {
   'meta-spec' => { version => 2 },
    resources => {
      repository => {
        type => 'git',
        url => 'https://github.com/sisyphus/math-mpfr.git',
        web => 'https://github.com/sisyphus/math-mpfr',
      },
    },
  },
);

my %prereq = ();
$prereq{'Math::Decimal64'} = '0.01' if $have_decimal64;
$prereq{'Math::Float128'}  = '0.01' if ($have_float128 && $Config{nvtype} ne '__float128');

$options{PREREQ_PM} = \%prereq;

WriteMakefile(%options);

# Remove the Makefile dependency. Causes problems on a few systems.
sub MY::makefile { '' }