1 files changed, 130 insertions, 0 deletions
diff --git a/entities/bug/op_edit_comment.go b/entities/bug/op_edit_comment.go
new file mode 100644
index 00000000..b0897b0a
--- /dev/null
+++ b/entities/bug/op_edit_comment.go
@@ -0,0 +1,130 @@
+package bug
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+
+	"github.com/MichaelMure/git-bug/entities/identity"
+	"github.com/MichaelMure/git-bug/entity"
+	"github.com/MichaelMure/git-bug/entity/dag"
+	"github.com/MichaelMure/git-bug/repository"
+	"github.com/MichaelMure/git-bug/util/timestamp"
+
+	"github.com/MichaelMure/git-bug/util/text"
+)
+
+var _ Operation = &EditCommentOperation{}
+var _ dag.OperationWithFiles = &EditCommentOperation{}
+
+// EditCommentOperation will change a comment in the bug
+type EditCommentOperation struct {
+	dag.OpBase
+	Target  entity.Id         `json:"target"`
+	Message string            `json:"message"`
+	Files   []repository.Hash `json:"files"`
+}
+
+func (op *EditCommentOperation) Id() entity.Id {
+	return dag.IdOperation(op, &op.OpBase)
+}
+
+func (op *EditCommentOperation) Apply(snapshot *Snapshot) {
+	// Todo: currently any message can be edited, even by a different author
+	// crypto signature are needed.
+
+	// Recreate the combined Id to match on
+	combinedId := entity.CombineIds(snapshot.Id(), op.Target)
+
+	var target TimelineItem
+	for i, item := range snapshot.Timeline {
+		if item.CombinedId() == combinedId {
+			target = snapshot.Timeline[i]
+			break
+		}
+	}
+
+	if target == nil {
+		// Target not found, edit is a no-op
+		return
+	}
+
+	comment := Comment{
+		combinedId: combinedId,
+		targetId:   op.Target,
+		Message:    op.Message,
+		Files:      op.Files,
+		unixTime:   timestamp.Timestamp(op.UnixTime),
+	}
+
+	switch target := target.(type) {
+	case *CreateTimelineItem:
+		target.Append(comment)
+	case *AddCommentTimelineItem:
+		target.Append(comment)
+	default:
+		// somehow, the target matched on something that is not a comment
+		// we make the op a no-op
+		return
+	}
+
+	snapshot.addActor(op.Author())
+
+	// Updating the corresponding comment
+
+	for i := range snapshot.Comments {
+		if snapshot.Comments[i].CombinedId() == combinedId {
+			snapshot.Comments[i].Message = op.Message
+			snapshot.Comments[i].Files = op.Files
+			break
+		}
+	}
+}
+
+func (op *EditCommentOperation) GetFiles() []repository.Hash {
+	return op.Files
+}
+
+func (op *EditCommentOperation) Validate() error {
+	if err := op.OpBase.Validate(op, EditCommentOp); err != nil {
+		return err
+	}
+
+	if err := op.Target.Validate(); err != nil {
+		return errors.Wrap(err, "target hash is invalid")
+	}
+
+	if !text.Safe(op.Message) {
+		return fmt.Errorf("message is not fully printable")
+	}
+
+	return nil
+}
+
+func NewEditCommentOp(author identity.Interface, unixTime int64, target entity.Id, message string, files []repository.Hash) *EditCommentOperation {
+	return &EditCommentOperation{
+		OpBase:  dag.NewOpBase(EditCommentOp, author, unixTime),
+		Target:  target,
+		Message: message,
+		Files:   files,
+	}
+}
+
+// EditComment is a convenience function to apply the operation
+func EditComment(b Interface, author identity.Interface, unixTime int64, target entity.Id, message string, files []repository.Hash, metadata map[string]string) (*EditCommentOperation, error) {
+	op := NewEditCommentOp(author, unixTime, target, message, files)
+	for key, val := range metadata {
+		op.SetMetadata(key, val)
+	}
+	if err := op.Validate(); err != nil {
+		return nil, err
+	}
+	b.Append(op)
+	return op, nil
+}
+
+// EditCreateComment is a convenience function to edit the body of a bug (the first comment)
+func EditCreateComment(b Interface, author identity.Interface, unixTime int64, message string, files []repository.Hash, metadata map[string]string) (*EditCommentOperation, error) {
+	createOp := b.FirstOp().(*CreateOperation)
+	return EditComment(b, author, unixTime, createOp.Id(), message, files, metadata)
+}