Timeline improvements (#41)

Tidying up.
Parent/child statuses now display correctly in status/id/context.

internal/visibility/filter.go

@@ -0,0 +1,33 @@
+package visibility
+
+import (
+	"github.com/sirupsen/logrus"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+// Filter packages up a bunch of logic for checking whether given statuses or accounts are visible to a requester.
+type Filter interface {
+	// StatusVisible returns true if targetStatus is visible to requestingAccount, based on the
+	// privacy settings of the status, and any blocks/mutes that might exist between the two accounts
+	// or account domains, and other relevant accounts mentioned in or replied to by the status.
+	StatusVisible(targetStatus *gtsmodel.Status, requestingAccount *gtsmodel.Account) (bool, error)
+
+	// StatusHometimelineable returns true if targetStatus should be in the home timeline of the requesting account.
+	//
+	// This function will call StatusVisible internally, so it's not necessary to call it beforehand.
+	StatusHometimelineable(targetStatus *gtsmodel.Status, requestingAccount *gtsmodel.Account) (bool, error)
+}
+
+type filter struct {
+	db  db.DB
+	log *logrus.Logger
+}
+
+// NewFilter returns a new Filter interface that will use the provided database and logger.
+func NewFilter(db db.DB, log *logrus.Logger) Filter {
+	return &filter{
+		db:  db,
+		log: log,
+	}
+}