how can I use event and listener to handle the booking ?

I have rooms in hospital each of one has number of beds ( 1 or 2 or 3) I want to reserve bed to certain patient how can I handle this in my project in easy way

rooms migration :

 $table->increments('id');
            $table->string('name');
            $table->integer('floor');
            $table->text('description');
            $table->timestamps();

beds migration

Schema::create('beds', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('quality');
            $table->string('charge');
            $table->integer('room_id')->unsigned();;
            $table->foreign('room_id')->references('id')->on('rooms')
                  ->onUpdate('cascade')->onDelete('cascade');
            $table->boolean('status');
            $table->timestamps(); 
        });

reservation migration

Schema::create('reservations', function (Blueprint $table) {
            $table->increments('id');
            $table->date('date_in');
            $table->date('date_out');
            $table->boolean('status');
            $table->integer('patient_id')->unsigned();
            $table->foreign('patient_id')->references('id')->on('patients');
            $table->integer('bed_id')->unsigned();
            $table->foreign('bed_id')->references('id')->on('beds');
            $table->timestamps();
        });

how can I check available beds , get Available beds and ensure that the bed is booked or not ?? how can I use event and listener to handle the booking ?