package com.ankurm.rabbit;

import com.rabbitmq.client.GetResponse;
import org.junit.jupiter.api.Test;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.QueueBuilder;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;
import java.util.Map;

import static org.assertj.core.api.Assertions.assertThat;

/**
 * The third dead-letter trigger: a queue that is full.
 *
 * <p>Included because the article states all three triggers in one table, and this was the only
 * row not produced by a run. It is now.
 *
 * @see <a href="../../../../../docs/04-dead-lettering.md">docs/04-dead-lettering.md</a>
 */
@SpringBootTest
class MaxLengthTest {

	static final String Q_BOUNDED = "orders.bounded";

	@Autowired
	RabbitTemplate template;

	@Autowired
	RabbitAdmin admin;

	@Test
	@SuppressWarnings("unchecked")
	void exceedingMaxLengthDeadLettersTheOldestWithReasonMaxlen() throws Exception {
		this.admin.deleteQueue(Q_BOUNDED);
		Queue bounded = QueueBuilder.durable(Q_BOUNDED)
				.maxLength(2)
				.deadLetterExchange(Topology.DLX)
				.deadLetterRoutingKey("failed")
				.build();
		this.admin.declareQueue(bounded);
		Binding binding = BindingBuilder.bind(bounded)
				.to(new DirectExchange(Topology.DIRECT)).with("bounded");
		this.admin.declareBinding(binding);
		this.admin.purgeQueue(Topology.Q_DLQ, false);

		// Three messages into a queue that holds two. RabbitMQ drops from the HEAD, so the
		// FIRST message is the one dead-lettered - the oldest, not the newest.
		for (String id : List.of("m-1", "m-2", "m-3")) {
			this.template.convertAndSend(Topology.DIRECT, "bounded", OrderMessage.of(id));
		}

		var message = this.template.receive(Topology.Q_DLQ, 10_000);
		assertThat(message).isNotNull();
		List<Map<String, Object>> deaths =
				(List<Map<String, Object>>) message.getMessageProperties().getHeader("x-death");
		System.out.println("=== x-death after x-max-length overflow ===");
		deaths.get(0).forEach((k, v) -> System.out.printf("  %-16s %s%n", k, v));
		System.out.println("  body            " + new String(message.getBody()));

		assertThat(deaths.get(0)).containsEntry("reason", "maxlen");
		assertThat(deaths.get(0)).containsEntry("queue", Q_BOUNDED);
		assertThat(new String(message.getBody())).contains("m-1");
	}

}