use strictures 1;

use Benchmark qw/:hireswallclock cmpthese/;
use Getopt::Long::Descriptive;

use Config;
$ENV{PERL5LIB} = join ($Config{path_sep}, @INC);


my ($opts, $usage);
BEGIN {
  ($opts, $usage) = describe_options(
    '%c: %o' =>
    [ 'help|h'          => 'Print usage message and exit' ],
    [ 'classes|c:i'     => 'How many classes to create per benchmark cycle (def 10)', { default => 10 } ],
    [ 'accessors|a:i'   => 'How many accessors/attributes of each type to create per class (def 10)', { default => 10 } ],
    [ 'subprocess|startup|s' => 'Run the code in a subprocess to benchmark actual time spent on compilation' ],
    [ 'pregenerate|p:i' => 'How many bench-runs to pre-generate for compilation in case --subprocess is not used (def 1000)', { default => 1000} ],
    [ 'run|r'           => 'Use each accessor at runtime (get/set/get cycle)' ],
    [ 'unique|u'        => 'Make accessor names globally unique (instead of just per class)' ],
    [ 'bench|b:s'       => 'Which benchmarks to run (all|xs|pp)', { default => 'all', regex => qr/^(?:all|xs|pp)$/ } ],
    { getopt_conf => [qw/gnu_getopt bundling_override no_ignore_case/] },
  );

  # can not change this runtime, thus in-block
  $ENV{MOUSE_PUREPERL} = 1 if $opts->{bench} eq 'pp';

  my @missing;
  for (qw/
    Moose
    Moo
    Mouse
  /) {
    eval "require $_" or push @missing, $_;
  }

  if (@missing) {
    die sprintf "Missing modules necessary for benchmark:\n\n%s\n\n",
      join ("\n", @missing);
  }
}

use Method::Generate::Accessor; # need to pre-load for the XS shut-off to work

$usage->die if $opts->{help};

$opts->{pregenerate} = 1 if $opts->{subprocess};

my $counters;
my $tasks = {};

my $attrs_to_bench = {
  plain =>              q|is => 'rw'|,
  lazy_default =>       q|is => 'rw', lazy => 1, default => sub { {} }|,
  lazy_default_qsub =>  q|is => 'rw', lazy => 1, default => Sub::Quote::quote_sub q{ {} }|,
};

for (keys %$attrs_to_bench) {
  if ($opts->{bench} =~ /all|pp/) {
    {
      local $Method::Generate::Accessor::CAN_HAZ_XS = 0;
      _add_moosey_has (moo => 'Moo', $_);
    }

    _add_moosey_has (moose => 'Moose', $_);
    _add_moosey_has (mouse => 'Mouse', $_)
      if $ENV{MOUSE_PUREPERL};
  }

  if ($opts->{bench} =~ /all|xs/) {
    {
      local $Method::Generate::Accessor::CAN_HAZ_XS = 1;
      _add_moosey_has (moo_XS => 'Moo', $_);
    }
    _add_moosey_has (mouse_XS => 'Mouse', $_)
      unless $ENV{MOUSE_PUREPERL};
  }
}

# run each task once, prime whatever caches there may be
$_->() for values %$tasks;

# Actual Benchmarking
for (1, 2) {
  print "Perl $], take $_:\n";

  # if forking must run for certain number of cycles, cputime doesn't work
  foreach my $type (sort keys %$attrs_to_bench) {
    print "Benchming ${type}:\n";
    my %these = map { (split ' ', $_)[0] => $tasks->{$_} }
      grep /${type}$/, keys %$tasks;
    cmpthese ( $opts->{subprocess} ? 15 : -1 , \%these );
  }
  print "\n";
}

exit 0; # the end

sub _add_moosey_has {
  my ($name, $base, $attr_type) = @_;

  my @to_eval;

  for (1 .. $opts->{pregenerate} ) {
    my $perl = 'use Sub::Quote;';

    for ( 1.. $opts->{classes} ) {
      my $class = "Bench::${base}_" . ++$counters->{class};
      $perl .= "package $class; use $base;";

      my @attr_names;
      for ( 1.. $opts->{accessors} ) {
        my $attr = "attribute_${attr_type}" . ++$counters->{acc};
        push @attr_names, $attr;
        $perl .= "has $attr => ($attrs_to_bench->{$attr_type});";
      }

      $perl .= '__PACKAGE__->meta->make_immutable;'
        if $name !~ /^moo(_XS)?$/;

      $counters->{accessors} = 0
        unless $opts->{unique};

      if ($opts->{run}) {
        $perl .= "\$::obj = $class->new;";
        $perl .= "\$::foo = \$::obj->$_; \$::obj->$_(1); \$::foo = \$::obj->$_;"
          for @attr_names;
      }
    }

    push @to_eval, $perl;
  }

  $tasks->{"$name $attr_type"} = $opts->{subprocess}
    ? sub {
      open (my $subproc, '|-', $^X, '-');
      print $subproc $to_eval[0];
      close $subproc;
    }
    : sub {
      eval shift @to_eval;
    }
  ;
}