Notifications (#34)

Notifications working for:

* Mentions
* Faves
* New follow requests
* New followers

internal/federation/federatingdb/followers.go

@@ -0,0 +1,55 @@
+package federatingdb
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+
+	"github.com/go-fed/activity/streams"
+	"github.com/go-fed/activity/streams/vocab"
+	"github.com/sirupsen/logrus"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+// Followers obtains the Followers Collection for an actor with the
+// given id.
+//
+// If modified, the library will then call Update.
+//
+// The library makes this call only after acquiring a lock first.
+func (f *federatingDB) Followers(c context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	l := f.log.WithFields(
+		logrus.Fields{
+			"func":     "Followers",
+			"actorIRI": actorIRI.String(),
+		},
+	)
+	l.Debugf("entering FOLLOWERS function with actorIRI %s", actorIRI.String())
+
+	acct := &gtsmodel.Account{}
+	if err := f.db.GetWhere([]db.Where{{Key: "uri", Value: actorIRI.String()}}, acct); err != nil {
+		return nil, fmt.Errorf("db error getting account with uri %s: %s", actorIRI.String(), err)
+	}
+
+	acctFollowers := []gtsmodel.Follow{}
+	if err := f.db.GetFollowersByAccountID(acct.ID, &acctFollowers); err != nil {
+		return nil, fmt.Errorf("db error getting followers for account id %s: %s", acct.ID, err)
+	}
+
+	followers = streams.NewActivityStreamsCollection()
+	items := streams.NewActivityStreamsItemsProperty()
+	for _, follow := range acctFollowers {
+		gtsFollower := &gtsmodel.Account{}
+		if err := f.db.GetByID(follow.AccountID, gtsFollower); err != nil {
+			return nil, fmt.Errorf("db error getting account id %s: %s", follow.AccountID, err)
+		}
+		uri, err := url.Parse(gtsFollower.URI)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing %s as url: %s", gtsFollower.URI, err)
+		}
+		items.AppendIRI(uri)
+	}
+	followers.SetActivityStreamsItems(items)
+	return
+}