package Devel::REPL::Plugin::History;

use Devel::REPL::Plugin;
use namespace::clean -except => [ 'meta' ];

has 'history' => (
   isa => 'ArrayRef', is => 'rw', required => 1, lazy => 1,
   default => sub { [] }
);

# lazy so ReadLineHistory Plugin can set this
has 'have_readline_history' => (
   is => 'rw', required => 1, lazy => 1,
   default => sub { 0 }
);

sub push_history {
   my ($self, $line) = @_;
   # Push history is not needed if we have Term::ReadLine
   # support.  We put the test inside push_history() in case
   # someone has modified it in their code.
   if ($self->have_readline_history) {
      # update history to keep consistent with Term::ReadLine
      $self->history( [ $self->term->GetHistory ] );
   } else {
      # not used with Term::ReadLine history support
      push(@{$self->history}, $line);
   }
}

around 'read' => sub {
   my $orig = shift;
   my ($self, @args) = @_;
   my $line = $self->$orig(@args);
   if (defined $line) {
      if ($line =~ m/^!(.*)$/) {
         my $call = $1;
         $line = $self->history_call($call);
         if (defined $line) {
            $self->print($line."\n");
         } else {
            return "'Unable to find ${call} in history'";
         }
      }
      if ($line =~ m/\S/) {
         $self->push_history($line);
      }
   }
   return $line;
};

sub history_call {
   my ($self, $call) = @_;
   if ($call =~ m/^(-?\d+)$/) { # handle !1 or !-1
      my $idx = $1;
      $idx-- if ($idx > 0); # !1 gets history element 0
      my $line = $self->history->[$idx];
      return $line;
   }
   my $re = qr/^\Q${call}\E/;
   foreach my $line (reverse @{$self->history}) {
      return $line if ($line =~ $re);
   }
   return;
};

1;

__END__

=head1 NAME

Devel::REPL::Plugin::History - Keep track of all input, provide shortcuts !1, !-1

=cut