// This is free and unencumbered software released into the public domain.
//
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// software under copyright law.
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package verkle

import (
	"errors"
	"fmt"
)

type HashedNode struct{}

func (HashedNode) Insert([]byte, []byte, NodeResolverFn) error {
	return errInsertIntoHash
}

func (HashedNode) Delete([]byte, NodeResolverFn) (bool, error) {
	return false, errors.New("cant delete a hashed node in-place")
}

func (HashedNode) Get([]byte, NodeResolverFn) ([]byte, error) {
	return nil, errors.New("can not read from a hash node")
}

func (HashedNode) Commit() *Point {
	// TODO: we should reconsider what to do with the VerkleNode interface and how
	//       HashedNode fits into the picture, since Commit(), Commitment() and Hash()
	//	     now panics. Despite these calls must not happen at runtime, it is still
	//	     quite risky. The reason we end up in this place is because PBSS came quite
	//	     recently compared with the VerkleNode interface design. We should probably
	//	     reconsider splitting the interface or find some safer workaround.
	panic("can not commit a hash node")
}

func (HashedNode) Commitment() *Point {
	panic("can not get commitment of a hash node")
}

func (HashedNode) GetProofItems(keylist, NodeResolverFn) (*ProofElements, []byte, []Stem, error) {
	return nil, nil, nil, errors.New("can not get the full path, and there is no proof of absence")
}

func (HashedNode) Serialize() ([]byte, error) {
	return nil, errSerializeHashedNode
}

func (HashedNode) Copy() VerkleNode {
	return HashedNode{}
}

func (HashedNode) toDot(parent, path string) string {
	return fmt.Sprintf("hash%s [label=\"unresolved\"]\n%s -> hash%s\n", path, parent, path)
}

func (HashedNode) setDepth(_ byte) {
	// do nothing
}

func (HashedNode) Hash() *Fr {
	panic("can not hash a hashed node")
}