// SPDX-License-Identifier: BUSL-1.1
//
// Copyright (C) 2025, Berachain Foundation. All rights reserved.
// Use of this software is governed by the Business Source License included
// in the LICENSE file of this repository and at www.mariadb.com/bsl11.
//
// ANY USE OF THE LICENSED WORK IN VIOLATION OF THIS LICENSE WILL AUTOMATICALLY
// TERMINATE YOUR RIGHTS UNDER THIS LICENSE FOR THE CURRENT AND ALL OTHER
// VERSIONS OF THE LICENSED WORK.
//
// THIS LICENSE DOES NOT GRANT YOU ANY RIGHT IN ANY TRADEMARK OR LOGO OF
// LICENSOR OR ITS AFFILIATES (PROVIDED THAT YOU MAY USE A TRADEMARK OR LOGO OF
// LICENSOR AS EXPRESSLY REQUIRED BY THIS LICENSE).
//
// TO THE EXTENT PERMITTED BY APPLICABLE LAW, THE LICENSED WORK IS PROVIDED ON
// AN “AS IS” BASIS. LICENSOR HEREBY DISCLAIMS ALL WARRANTIES AND CONDITIONS,
// EXPRESS OR IMPLIED, INCLUDING (WITHOUT LIMITATION) WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, AND
// TITLE.

package core

import (
	ctypes "github.com/berachain/beacon-kit/consensus-types/types"
	"github.com/berachain/beacon-kit/primitives/crypto"
	statedb "github.com/berachain/beacon-kit/state-transition/core/state"
)

func (sp *StateProcessor) GetSignatureVerifierFn(st *statedb.StateDB) (
	func(blk *ctypes.BeaconBlock, signature crypto.BLSSignature) error,
	error,
) {
	genesisValidatorsRoot, err := st.GetGenesisValidatorsRoot()
	if err != nil {
		return nil, err
	}

	return func(blk *ctypes.BeaconBlock, signature crypto.BLSSignature) error {
		fd := ctypes.NewForkData(
			sp.cs.ActiveForkVersionForTimestamp(blk.GetTimestamp()),
			genesisValidatorsRoot,
		)
		domain := fd.ComputeDomain(sp.cs.DomainTypeProposer())

		//nolint:govet // shadow
		proposer, err := st.ValidatorByIndex(blk.GetProposerIndex())
		if err != nil {
			return err
		}
		signingRoot := ctypes.ComputeSigningRoot(blk, domain)
		return sp.signer.VerifySignature(proposer.GetPubkey(), signingRoot[:], signature)
	}, nil
}
