package messaging

import (
	"context"
	"errors"
	"fmt"
	"strings"
	"time"

	"github.com/Azure/go-amqp"
)

const amqpTopicPrefix = "topic://"

type AmqpSender interface {
	Send(ctx context.Context, msg *amqp.Message, opts *amqp.SendOptions) error
	Close(ctx context.Context) error
}

type AmqpSenderSession struct {
	Session AmqpSession
	Sender  AmqpSender
}

func (s *AmqpSenderSession) Send(
	topic string,
	data [][]byte,
	contentType string,
	applicationProperties map[string]any,
) error {
	// check topic name
	if !strings.HasPrefix(topic, amqpTopicPrefix) {
		return fmt.Errorf(
			"topic %q name lacks mandatory prefix %q",
			topic,
			amqpTopicPrefix,
		)
	}

	if contentType == "" {
		return errors.New("content-type is required")
	}

	// prepare the amqp message
	message := amqp.Message{
		Header: &amqp.MessageHeader{
			Durable: true,
		},
		Properties: &amqp.MessageProperties{
			To:          &topic,
			ContentType: &contentType,
		},
		ApplicationProperties: applicationProperties,
		Data:                  data,
	}

	// send
	ctx, cancelFn := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancelFn()
	return s.Sender.Send(ctx, &message, nil)
}

func (s *AmqpSenderSession) Close() error {
	ctx, cancelFn := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancelFn()

	var closeErrors []error
	senderErr := s.Sender.Close(ctx)
	if senderErr != nil {
		closeErrors = append(closeErrors, senderErr)
	}
	sessionErr := s.Session.Close(ctx)
	if sessionErr != nil {
		closeErrors = append(closeErrors, sessionErr)
	}

	if len(closeErrors) > 0 {
		return errors.Join(closeErrors...)
	}
	return nil
}