package Catmandu::Fix::assoc;

use Catmandu::Sane;

our $VERSION = '1.0301';

use Moo;
use namespace::clean;
use Catmandu::Fix::Has;

has path      => (fix_arg => 1);
has keys_path => (fix_arg => 1);
has vals_path => (fix_arg => 1);

with 'Catmandu::Fix::Base';

sub emit {
    my ($self, $fixer) = @_;
    my $path      = $fixer->split_path($self->path);
    my $keys_path = $fixer->split_path($self->keys_path);
    my $vals_path = $fixer->split_path($self->vals_path);
    my $keys_key  = pop @$keys_path;
    my $vals_key  = pop @$vals_path;

    my $keys_var = $fixer->generate_var;
    my $vals_var = $fixer->generate_var;
    my $perl
        = $fixer->emit_declare_vars([$keys_var, $vals_var], ['[]', '[]']);

    $perl .= $fixer->emit_walk_path(
        $fixer->var,
        $keys_path,
        sub {
            my $var = shift;
            $fixer->emit_get_key(
                $var,
                $keys_key,
                sub {
                    my $var = shift;
                    "push(\@{${keys_var}}, ${var}) if is_value(${var});";
                }
            );
        }
    );
    $perl .= "if (\@{${keys_var}}) {" . $fixer->emit_walk_path(
        $fixer->var,
        $vals_path,
        sub {
            my $var = shift;
            $fixer->emit_get_key(
                $var,
                $vals_key,
                sub {
                    my $var = shift;
                    "push(\@{${vals_var}}, ${var});";
                }
            );
        }
        )
        . $fixer->emit_create_path(
        $fixer->var,
        $path,
        sub {
            my $var = shift;
            "if (is_hash_ref(${var} //= {})) {"
                . "while (\@{${keys_var}} && \@{${vals_var}}) {"
                . "${var}\->{shift(\@{${keys_var}})} = shift(\@{${vals_var}});"
                . "}" . "}";
        }
        ) . "}";

    $perl;
}

1;

__END__

=pod

=head1 NAME

Catmandu::Fix::assoc - associate two values as a hash key and value

=head1 SYNOPSIS

   # {pairs => [{key => 'year', val => 2009}, {key => 'subject', val => 'Perl'}]}
   assoc(fields, pairs.*.key, pairs.*.val)
   # {fields => {subject => 'Perl', year => 2009}, pairs => [...]}

=head1 SEE ALSO

L<Catmandu::Fix>

=cut