add mastodon service

go.mod

@@ -36,6 +36,7 @@ require (
 require (
 	github.com/appleboy/go-fcm v0.1.5
 	github.com/google/go-cmp v0.5.8
+	github.com/mattn/go-mastodon v0.0.4
 )
 
 require (
@@ -77,6 +78,7 @@ require (
 	github.com/tidwall/gjson v1.14.1 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.0 // indirect
+	github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80 //indirect
 	golang.org/x/crypto v0.0.0-20220411220226-7b82a4e95df4 // indirect
 	golang.org/x/net v0.0.0-20220225172249-27dd8689420f // indirect
 	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8 // indirect

service/mastodon/mastodon.go

@@ -0,0 +1,66 @@
+package mastodon
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/mattn/go-mastodon"
+	"github.com/pkg/errors"
+)
+
+type Mastodon struct {
+	client      *mastodon.Client
+	mastodonIDs []string
+}
+
+type Credentials struct {
+	Server       string
+	ClientID     string
+	ClientSecret string
+	AccessToken  string
+}
+
+func New(credentials Credentials) (*Mastodon, error) {
+	config := mastodon.Config(credentials)
+	client := mastodon.NewClient(&config)
+
+	// Verify Credentials
+	_, err := client.GetAccountCurrentUser(context.Background())
+	if err != nil {
+		return nil, err
+	}
+
+	t := &Mastodon{
+		client:      client,
+		mastodonIDs: []string{},
+	}
+
+	return t, nil
+}
+
+func (t *Mastodon) AddReceivers(mastodonIDs ...string) {
+	t.mastodonIDs = append(t.mastodonIDs, mastodonIDs...)
+}
+
+func (t Mastodon) Send(ctx context.Context, subject, message string) error {
+
+	for _, mastodonID := range t.mastodonIDs {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+			directMessage := &mastodon.Toot{
+				Status:     fmt.Sprintf("@%s, %s: %s", mastodonID, subject, message),
+				Visibility: "direct",
+			}
+
+			_, err := t.client.PostStatus(ctx, directMessage)
+			if err != nil {
+				return errors.Wrapf(err, "failed to send direct message to mastodon ID '%s'", mastodonID)
+			}
+
+		}
+	}
+
+	return nil
+}