package t::Util;
use strict;
use warnings;
use Carp;
use Exporter 'import';
our @EXPORT = qw(
   respond_json
   next_pending_not_sync
   next_pending_sync
   send_sync
   matrix_login
   matrix_join_room
);
use HTTP::Response;
use JSON::MaybeXS qw( encode_json );
use constant SYNC_PATH => "/_matrix/client/r0/sync";
sub respond_json
{
   my ( $p, $content ) = @_;
   ref $content or
      croak "respond_json() called with non-reference";
   $p->respond(
      HTTP::Response->new( 200, "OK", [ "Content-Type" => "application/json" ],
         encode_json $content
      )
   );
}
my $sync_p;
sub next_pending_not_sync
{
   my ( $ua ) = @_;
   while(1) {
      my $p = $ua->next_pending or return;
      my $req = $p->request;
      return $p if $req->method ne "GET" or
                   $req->uri->path ne SYNC_PATH;
      die "Received a second /sync request before the first finished" if $sync_p;
      $sync_p = $p;
      $sync_p->response->on_cancel( sub { undef $sync_p } );
   }
}
sub next_pending_sync
{
   my ( $ua ) = @_;
   if( $sync_p ) {
      my $p = $sync_p; undef $sync_p;
      return $p;
   }
   my $p = $ua->next_pending;
   my $req = $p->request;
   return $p if $req->method eq "GET" and
                $req->uri->path eq SYNC_PATH;
   die "Received a different request while waiting for an /sync request";
}
my $next_event_token = 0;
sub send_sync
{
   my ( $ua, %fields ) = @_;
   respond_json( next_pending_sync( $ua ), {
      next_batch => $next_event_token,
      %fields,
   });
   $next_event_token++;
}
sub matrix_login
{
   my ( $matrix, $ua ) = @_;
   my $login_f = $matrix->login(
      user_id => '@my-test-user:localserver.test',
      access_token => "0123456789ABCDEF",
   );
   # respond to initial /sync request
   if( my $p = $ua->next_pending ) {
      respond_json( $p, {
         next_batch => "next_token_here",
         presence   => { events => [] },
         rooms      => {},
      });
   }
   $login_f->get;
}
sub matrix_join_room
{
   my ( $matrix, $ua, @initial_state ) = @_;
   my $join_f = $matrix->join_room( "!room:localserver.test" );
   my $p = next_pending_not_sync( $ua );
   respond_json( $p, { room_id => "!room:localserver.test" } );
   # Server sends new room initial state in the next /sync response
   send_sync( $ua,
      rooms => {
         join => {
            "!room:localserver.test" => {
               timeline => {},
               state => {
                  events => [ @initial_state ],
               },
            },
         },
      },
   );
   return $join_f->get;
}
0x55AA;