package utils

import (
	"fmt"
	"math/big"

	"github.com/scroll-tech/go-ethereum/accounts/abi"
	"github.com/scroll-tech/go-ethereum/common"
	"github.com/scroll-tech/go-ethereum/core/types"
	"github.com/scroll-tech/go-ethereum/crypto"

	"scroll-tech/common/types/encoding"
	"scroll-tech/common/types/encoding/codecv0"
	"scroll-tech/common/types/encoding/codecv1"

	bridgeAbi "scroll-tech/rollup/abi"
)

// Keccak2 compute the keccack256 of two concatenations of bytes32
func Keccak2(a common.Hash, b common.Hash) common.Hash {
	return common.BytesToHash(crypto.Keccak256(append(a.Bytes()[:], b.Bytes()[:]...)))
}

// ComputeMessageHash compute the message hash
func ComputeMessageHash(
	sender common.Address,
	target common.Address,
	value *big.Int,
	messageNonce *big.Int,
	message []byte,
) common.Hash {
	data, _ := bridgeAbi.L2ScrollMessengerABI.Pack("relayMessage", sender, target, value, messageNonce, message)
	return common.BytesToHash(crypto.Keccak256(data))
}

// BufferToUint256Le convert bytes array to uint256 array assuming little-endian
func BufferToUint256Le(buffer []byte) []*big.Int {
	buffer256 := make([]*big.Int, len(buffer)/32)
	for i := 0; i < len(buffer)/32; i++ {
		v := big.NewInt(0)
		shft := big.NewInt(1)
		for j := 0; j < 32; j++ {
			v = new(big.Int).Add(v, new(big.Int).Mul(shft, big.NewInt(int64(buffer[i*32+j]))))
			shft = new(big.Int).Mul(shft, big.NewInt(256))
		}
		buffer256[i] = v
	}
	return buffer256
}

// UnpackLog unpacks a retrieved log into the provided output structure.
// @todo: add unit test.
func UnpackLog(c *abi.ABI, out interface{}, event string, log types.Log) error {
	if log.Topics[0] != c.Events[event].ID {
		return fmt.Errorf("event signature mismatch")
	}
	if len(log.Data) > 0 {
		if err := c.UnpackIntoInterface(out, event, log.Data); err != nil {
			return err
		}
	}
	var indexed abi.Arguments
	for _, arg := range c.Events[event].Inputs {
		if arg.Indexed {
			indexed = append(indexed, arg)
		}
	}
	return abi.ParseTopics(out, indexed, log.Topics[1:])
}

// ChunkMetrics indicates the metrics for proposing a chunk.
type ChunkMetrics struct {
	// common metrics
	NumBlocks           uint64
	TxNum               uint64
	CrcMax              uint64
	FirstBlockTimestamp uint64

	// codecv0 metrics, default 0 for codecv1
	L1CommitCalldataSize uint64
	L1CommitGas          uint64

	// codecv1 metrics, default 0 for codecv0
	L1CommitBlobSize uint64
}

// CalculateChunkMetrics calculates chunk metrics.
func CalculateChunkMetrics(chunk *encoding.Chunk, codecVersion encoding.CodecVersion) (*ChunkMetrics, error) {
	var err error
	metrics := &ChunkMetrics{
		TxNum:               chunk.NumTransactions(),
		NumBlocks:           uint64(len(chunk.Blocks)),
		FirstBlockTimestamp: chunk.Blocks[0].Header.Time,
	}
	metrics.CrcMax, err = chunk.CrcMax()
	if err != nil {
		return nil, fmt.Errorf("failed to get crc max: %w", err)
	}
	switch codecVersion {
	case encoding.CodecV0:
		metrics.L1CommitCalldataSize, err = codecv0.EstimateChunkL1CommitCalldataSize(chunk)
		if err != nil {
			return nil, fmt.Errorf("failed to estimate chunk L1 commit calldata size: %w", err)
		}
		metrics.L1CommitGas, err = codecv0.EstimateChunkL1CommitGas(chunk)
		if err != nil {
			return nil, fmt.Errorf("failed to estimate chunk L1 commit gas: %w", err)
		}
		return metrics, nil
	case encoding.CodecV1:
		metrics.L1CommitBlobSize, err = codecv1.EstimateChunkL1CommitBlobSize(chunk)
		if err != nil {
			return nil, fmt.Errorf("failed to estimate chunk L1 commit blob size: %w", err)
		}
		return metrics, nil
	default:
		return nil, fmt.Errorf("unsupported codec version: %v", codecVersion)
	}
}

// BatchMetrics indicates the metrics for proposing a batch.
type BatchMetrics struct {
	// common metrics
	NumChunks           uint64
	FirstBlockTimestamp uint64

	// codecv0 metrics, default 0 for codecv1
	L1CommitCalldataSize uint64
	L1CommitGas          uint64

	// codecv1 metrics, default 0 for codecv0
	L1CommitBlobSize uint64
}

// CalculateBatchMetrics calculates batch metrics.
func CalculateBatchMetrics(batch *encoding.Batch, codecVersion encoding.CodecVersion) (*BatchMetrics, error) {
	var err error
	metrics := &BatchMetrics{
		NumChunks:           uint64(len(batch.Chunks)),
		FirstBlockTimestamp: batch.Chunks[0].Blocks[0].Header.Time,
	}
	switch codecVersion {
	case encoding.CodecV0:
		metrics.L1CommitGas, err = codecv0.EstimateBatchL1CommitGas(batch)
		if err != nil {
			return nil, fmt.Errorf("failed to estimate batch L1 commit gas: %w", err)
		}
		metrics.L1CommitCalldataSize, err = codecv0.EstimateBatchL1CommitCalldataSize(batch)
		if err != nil {
			return nil, fmt.Errorf("failed to estimate batch L1 commit calldata size: %w", err)
		}
		return metrics, nil
	case encoding.CodecV1:
		metrics.L1CommitBlobSize, err = codecv1.EstimateBatchL1CommitBlobSize(batch)
		if err != nil {
			return nil, fmt.Errorf("failed to estimate chunk L1 commit blob size: %w", err)
		}
		return metrics, nil
	default:
		return nil, fmt.Errorf("unsupported codec version: %v", codecVersion)
	}
}

// GetChunkHash retrieves the hash of a chunk.
func GetChunkHash(chunk *encoding.Chunk, totalL1MessagePoppedBefore uint64, codecVersion encoding.CodecVersion) (common.Hash, error) {
	switch codecVersion {
	case encoding.CodecV0:
		daChunk, err := codecv0.NewDAChunk(chunk, totalL1MessagePoppedBefore)
		if err != nil {
			return common.Hash{}, fmt.Errorf("failed to create codecv0 DA chunk: %w", err)
		}
		chunkHash, err := daChunk.Hash()
		if err != nil {
			return common.Hash{}, fmt.Errorf("failed to get codecv0 DA chunk hash: %w", err)
		}
		return chunkHash, nil
	case encoding.CodecV1:
		daChunk, err := codecv1.NewDAChunk(chunk, totalL1MessagePoppedBefore)
		if err != nil {
			return common.Hash{}, fmt.Errorf("failed to create codecv1 DA chunk: %w", err)
		}
		chunkHash, err := daChunk.Hash()
		if err != nil {
			return common.Hash{}, fmt.Errorf("failed to get codecv1 DA chunk hash: %w", err)
		}
		return chunkHash, nil
	default:
		return common.Hash{}, fmt.Errorf("unsupported codec version: %v", codecVersion)
	}
}

// BatchMetadata represents the metadata of a batch.
type BatchMetadata struct {
	BatchHash      common.Hash
	BatchBytes     []byte
	StartChunkHash common.Hash
	EndChunkHash   common.Hash
}

// GetBatchMetadata retrieves the metadata of a batch.
func GetBatchMetadata(batch *encoding.Batch, codecVersion encoding.CodecVersion) (*BatchMetadata, error) {
	numChunks := len(batch.Chunks)
	totalL1MessagePoppedBeforeEndDAChunk := batch.TotalL1MessagePoppedBefore
	for i := 0; i < numChunks-1; i++ {
		totalL1MessagePoppedBeforeEndDAChunk += batch.Chunks[i].NumL1Messages(totalL1MessagePoppedBeforeEndDAChunk)
	}

	switch codecVersion {
	case encoding.CodecV0:
		daBatch, err := codecv0.NewDABatch(batch)
		if err != nil {
			return nil, fmt.Errorf("failed to create codecv0 DA batch: %w", err)
		}

		batchMeta := &BatchMetadata{
			BatchHash:  daBatch.Hash(),
			BatchBytes: daBatch.Encode(),
		}

		startDAChunk, err := codecv0.NewDAChunk(batch.Chunks[0], batch.TotalL1MessagePoppedBefore)
		if err != nil {
			return nil, fmt.Errorf("failed to create codecv0 start DA chunk: %w", err)
		}

		batchMeta.StartChunkHash, err = startDAChunk.Hash()
		if err != nil {
			return nil, fmt.Errorf("failed to get codecv0 start DA chunk hash: %w", err)
		}

		endDAChunk, err := codecv0.NewDAChunk(batch.Chunks[numChunks-1], totalL1MessagePoppedBeforeEndDAChunk)
		if err != nil {
			return nil, fmt.Errorf("failed to create codecv0 end DA chunk: %w", err)
		}

		batchMeta.EndChunkHash, err = endDAChunk.Hash()
		if err != nil {
			return nil, fmt.Errorf("failed to get codecv0 end DA chunk hash: %w", err)
		}
		return batchMeta, nil
	case encoding.CodecV1:
		daBatch, err := codecv1.NewDABatch(batch)
		if err != nil {
			return nil, fmt.Errorf("failed to create codecv1 DA batch: %w", err)
		}

		batchMeta := &BatchMetadata{
			BatchHash:  daBatch.Hash(),
			BatchBytes: daBatch.Encode(),
		}

		startDAChunk, err := codecv1.NewDAChunk(batch.Chunks[0], batch.TotalL1MessagePoppedBefore)
		if err != nil {
			return nil, fmt.Errorf("failed to create codecv1 start DA chunk: %w", err)
		}

		batchMeta.StartChunkHash, err = startDAChunk.Hash()
		if err != nil {
			return nil, fmt.Errorf("failed to get codecv1 start DA chunk hash: %w", err)
		}

		endDAChunk, err := codecv1.NewDAChunk(batch.Chunks[numChunks-1], totalL1MessagePoppedBeforeEndDAChunk)
		if err != nil {
			return nil, fmt.Errorf("failed to create codecv1 end DA chunk: %w", err)
		}

		batchMeta.EndChunkHash, err = endDAChunk.Hash()
		if err != nil {
			return nil, fmt.Errorf("failed to get codecv1 end DA chunk hash: %w", err)
		}
		return batchMeta, nil
	default:
		return nil, fmt.Errorf("unsupported codec version: %v", codecVersion)
	}
}

// GetTotalL1MessagePoppedBeforeBatch retrieves the total L1 messages popped before the batch.
func GetTotalL1MessagePoppedBeforeBatch(parentBatchBytes []byte, codecVersion encoding.CodecVersion) (uint64, error) {
	switch codecVersion {
	case encoding.CodecV0:
		parentDABatch, err := codecv0.NewDABatchFromBytes(parentBatchBytes)
		if err != nil {
			return 0, fmt.Errorf("failed to create parent DA batch from bytes using codecv0, err: %w", err)
		}
		return parentDABatch.TotalL1MessagePopped, nil
	case encoding.CodecV1:
		parentDABatch, err := codecv1.NewDABatchFromBytes(parentBatchBytes)
		if err != nil {
			return 0, fmt.Errorf("failed to create parent DA batch from bytes using codecv1, err: %w", err)
		}
		return parentDABatch.TotalL1MessagePopped, nil
	default:
		return 0, fmt.Errorf("unsupported codec version: %v", codecVersion)
	}
}