2 files changed, 44 insertions, 1 deletions
diff --git a/entity/dag/entity.go b/entity/dag/entity.go
index 8b561274..ca674ad7 100644
--- a/entity/dag/entity.go
+++ b/entity/dag/entity.go
@@ -361,7 +361,7 @@ func (e *Entity) Validate() error {
 		return fmt.Errorf("entity has no operations")
 	}
 
-	// check if each operations are valid
+	// check if each operation are valid
 	for _, op := range e.ops {
 		if err := op.Validate(); err != nil {
 			return err
diff --git a/entity/dag/interface.go b/entity/dag/interface.go
new file mode 100644
index 00000000..613f60e6
--- /dev/null
+++ b/entity/dag/interface.go
@@ -0,0 +1,43 @@
+package dag
+
+import (
+	"github.com/MichaelMure/git-bug/entity"
+	"github.com/MichaelMure/git-bug/repository"
+	"github.com/MichaelMure/git-bug/util/lamport"
+)
+
+// Interface define the extended interface of a dag.Entity
+type Interface[SnapT Snapshot, OpT Operation] interface {
+	entity.Interface
+
+	// Validate checks if the Entity data is valid
+	Validate() error
+
+	// Append an operation into the staging area, to be committed later
+	Append(op OpT)
+
+	// Operations returns the ordered operations
+	Operations() []OpT
+
+	// NeedCommit indicates that the in-memory state changed and need to be committed in the repository
+	NeedCommit() bool
+
+	// Commit writes the staging area in Git and move the operations to the packs
+	Commit(repo repository.ClockedRepo) error
+
+	// FirstOp lookup for the very first operation of the Entity.
+	FirstOp() OpT
+
+	// LastOp lookup for the very last operation of the Entity.
+	// For a valid Entity, should never be nil
+	LastOp() OpT
+
+	// Compile a bug in an easily usable snapshot
+	Compile() SnapT
+
+	// CreateLamportTime return the Lamport time of creation
+	CreateLamportTime() lamport.Time
+
+	// EditLamportTime return the Lamport time of the last edit
+	EditLamportTime() lamport.Time
+}