File Coverage

lib/PAGI/Middleware/SSE/Retry.pm

Criterion	Covered	Total	%
statement	39	40	97.5
branch	7	10	70.0
condition	7	12	58.3
subroutine	7	7	100.0
pod	1	1	100.0
total	61	70	87.1

package PAGI::Middleware::SSE::Retry;

use strict;
use warnings;
use parent 'PAGI::Middleware';
use Future::AsyncAwait;

=head1 NAME

PAGI::Middleware::SSE::Retry - Add retry hints to SSE events

=head1 SYNOPSIS

    use PAGI::Middleware::Builder;

    my $app = builder {
        enable 'SSE::Retry',
            retry => 5000;  # 5 seconds
        $my_app;
    };

=head1 DESCRIPTION

PAGI::Middleware::SSE::Retry adds the C field to SSE events,
telling clients how long to wait before reconnecting after a disconnect.

=head1 CONFIGURATION

=over 4

=item * retry (default: 3000)

Default retry interval in milliseconds.

=item * include_on_start (default: 1)

If true, sends a retry hint immediately after sse.start.

=item * include_on_events (default: 0)

If true, includes retry in every sse.send event.

=back

=cut

sub _init {
    my ($self, $config) = @_;

    $self->{retry} = $config->{retry} // 3000;
    $self->{include_on_start} = $config->{include_on_start} // 1;
    $self->{include_on_events} = $config->{include_on_events} // 0;
}

sub wrap {
    my ($self, $app) = @_;

    return async sub  {
        my ($scope, $receive, $send) = @_;
        # Only apply to SSE connections
        if ($scope->{type} ne 'sse') {
            await $app->($scope, $receive, $send);
            return;
        }

        my $retry = $self->{retry};
        my $sent_initial = 0;

        # Wrap send to add retry field
        my $wrapped_send = async sub  {
        my ($event) = @_;
            if ($event->{type} eq 'sse.start') {
                await $send->($event);

                # Send initial retry hint
                if ($self->{include_on_start} && !$sent_initial) {
                    $sent_initial = 1;
                    await $send->({
                        type  => 'sse.send',
                        retry => $retry,
                    });
                }
                return;
            }

            if ($event->{type} eq 'sse.send') {
                # Add retry to event if configured and not already present
                if ($self->{include_on_events} && !defined $event->{retry}) {
                    $event = { %$event, retry => $retry };
                }
            }

            await $send->($event);
        };

        # Add retry info to scope
        my $new_scope = {
            %$scope,
            'pagi.sse.retry' => $retry,
        };

        await $app->($new_scope, $receive, $wrapped_send);
    };
}

1;

__END__