// Copyright 2023 The XDC Network Authors
// XDPoS-specific blockchain extensions

package core

import (
	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/consensus"
	"github.com/ethereum/go-ethereum/core/state"
	"github.com/ethereum/go-ethereum/core/types"
)

// HookReward is called at the end of each epoch to distribute rewards
func (bc *BlockChain) HookReward(
	chain consensus.ChainHeaderReader,
	statedb *state.StateDB,
	parentState *state.StateDB,
	header *types.Header,
	masternodes []common.Address,
) error {
	if len(masternodes) == 0 {
		return nil
	}

	// Reward distribution is handled by XDCStateProcessor
	return nil
}

// HookPenalty is called to penalize misbehaving masternodes
func (bc *BlockChain) HookPenalty(
	chain consensus.ChainHeaderReader,
	blockNumberEpochSwitch uint64,
	currentBlockNumber uint64,
	masternodes []common.Address,
	candidates []common.Address,
	statedb *state.StateDB,
) ([]common.Address, error) {
	var penalized []common.Address
	return penalized, nil
}

// GetSigners returns the signers for a given block
func (bc *BlockChain) GetSigners(header *types.Header) ([]common.Address, error) {
	return nil, nil
}

// GetMasternodes returns the current masternode list
func (bc *BlockChain) GetMasternodes() []common.Address {
	return nil
}

// GetCurrentEpoch returns the current epoch number
func (bc *BlockChain) GetCurrentEpoch() uint64 {
	current := bc.CurrentBlock()
	if current == nil {
		return 0
	}
	epochLength := uint64(900)
	return current.Number.Uint64() / epochLength
}

// IsEpochSwitch returns true if the given block is an epoch switch block
func (bc *BlockChain) IsEpochSwitch(header *types.Header) bool {
	if header == nil || header.Number == nil {
		return false
	}
	epochLength := uint64(900)
	return header.Number.Uint64()%epochLength == 0
}

// GetValidators returns validators for a given block
func (bc *BlockChain) GetValidators(header *types.Header) ([]common.Address, error) {
	// Extract validators from block extra data or contract
	return nil, nil
}

// GetBlockFinality returns the finality percentage for a block
func (bc *BlockChain) GetBlockFinality(blockNumber *big.Int) (int, error) {
	// Calculate based on subsequent block signatures
	return 100, nil // Assume finalized for now
}