unsubscribe_confirmation.go

package snshttp

import (
	"context"
	"fmt"
	"net/http"
	"strings"
)

// UnsubscribeConfirmation events are received when a subscription is canceled
// via the API. No unsubscribe event is fired when deleting a subscription
// through the AWS web console.
type UnsubscribeConfirmation struct {
	Type      string 
	MessageID string `json:"MessageId"`
	TopicARN  string `json:"TopicArn"`
	Timestamp string `json:"Timestamp"`

	Token          string `json:"Token"`
	Message        string `json:"Message"`
	SubscribeURL   string `json:"SubscribeURL"`
	Signature      string `json:"Signature"`
	SigningCertURL string `json:"SigningCertURL"`
}

// Resubscribe notifies Amazon to reinstate the subscription. A request is made
// to the SubscribeURL.
func (e *UnsubscribeConfirmation) Resubscribe(ctx context.Context) error {
	req, err := http.NewRequest("GET", e.SubscribeURL, nil)
	if err != nil {
		return err
	}

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	// Server is expected to return 200 OK but we can treat any 200 level code as
	// success.
	if !(200 <= resp.StatusCode && resp.StatusCode < 300) {
		return fmt.Errorf("server returned error status=%d", resp.StatusCode)
	}

	return nil
}

func (e *UnsubscribeConfirmation) SigningString() string {
	return strings.Join([]string{
		"Message", e.Message,
		"MessageId", e.MessageID,
		"SubscribeURL", e.SubscribeURL,
		"Timestamp", e.Timestamp,
		"Token", e.Token,
		"TopicArn", e.TopicARN,
		"Type", e.Type,
		"",
	}, "\n")
}