Test reparent branch

cli/prune/prune.go

@@ -53,6 +53,12 @@ func (f *pruneCmd) run(cmd *cobra.Command, args []string) {
 			fmt.Println(err)
 			os.Exit(1)
 		}
+
+		_, err := git.ReparentBranches(repo, *status)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
 	}
 }
 

lib/git/delete.go

@@ -5,7 +5,8 @@ import (
 )
 
 type BranchesAvailableForRemovalStatus struct {
-	BranchesForRemoval []BranchNode
+	BranchesForRemoval    []BranchNode
+	FullGraphBeforeDelete *BranchNodeWrapper
 }
 
 func BranchesAvailableForRemoval(repo *gogit.Repository) (*BranchesAvailableForRemovalStatus, error) {
@@ -20,7 +21,8 @@ func BranchesAvailableForRemoval(repo *gogit.Repository) (*BranchesAvailableForR
 	}
 
 	return &BranchesAvailableForRemovalStatus{
-		BranchesForRemoval: toDelete,
+		BranchesForRemoval:    toDelete,
+		FullGraphBeforeDelete: bnw,
 	}, nil
 }
 

lib/git/parent.go

@@ -0,0 +1,65 @@
+package git
+
+import (
+	"fmt"
+
+	gogit "github.com/go-git/go-git/v5"
+)
+
+type ReparentBranchesStatus struct {
+}
+
+func ReparentBranches(repo *gogit.Repository,
+	preRemovedState BranchesAvailableForRemovalStatus) (*ReparentBranchesStatus, error) {
+
+	if len(preRemovedState.BranchesForRemoval) == 0 {
+		return nil, nil
+	}
+
+	ref, err := repo.Head()
+	if err != nil {
+		return nil, err
+	}
+
+	if !ref.Name().IsBranch() {
+		return nil, fmt.Errorf("You must be on a branch. Check if you are in a detatched state.")
+	}
+
+	if preRemovedState.FullGraphBeforeDelete == nil {
+		return nil, fmt.Errorf("No branch graph from pre delete")
+	}
+
+	localRepoPreDelete := preRemovedState.FullGraphBeforeDelete.BranchMap
+	for _, deletedBranch := range preRemovedState.BranchesForRemoval {
+		rmedNode := localRepoPreDelete[deletedBranch.Name]
+		newParent := getFirstLivingParent(rmedNode, preRemovedState.BranchesForRemoval)
+
+		fmt.Println(newParent)
+	}
+
+	return nil, nil
+}
+
+// Find the first upstream branch of a given node provided it doesn't exist in the deletedBranches list
+func getFirstLivingParent(node *BranchNode, deletedBranches []BranchNode) string {
+	// This branch has no parent :(
+	if node.Upstream == nil {
+		return ""
+	}
+
+	if isDeletedBranch(node.Name, deletedBranches) {
+		return getFirstLivingParent(node.Upstream, deletedBranches)
+	}
+
+	return node.Name
+}
+
+func isDeletedBranch(branch string, branches []BranchNode) bool {
+	for _, b := range branches {
+		if b.Name == branch {
+			return true
+		}
+	}
+
+	return false
+}