package rpcservices

import (
	"bytes"
	"context"
	"fmt"

	"github.com/ledgerwatch/erigon-lib/gointerfaces/engine"
	types2 "github.com/ledgerwatch/erigon-lib/gointerfaces/types"
	"github.com/ledgerwatch/erigon/core/types"
	"github.com/ledgerwatch/erigon/rlp"
	"google.golang.org/protobuf/types/known/emptypb"
)

type EngineBackend struct {
	server engine.EngineClient
}

func NewEngineBackend(server engine.EngineClient) *EngineBackend {
	return &EngineBackend{server: server}
}

func (back *EngineBackend) EngineNewPayload(ctx context.Context, payload *types2.ExecutionPayload) (res *engine.EnginePayloadStatus, err error) {
	return back.server.EngineNewPayload(ctx, payload)
}

func (back *EngineBackend) EngineForkchoiceUpdated(ctx context.Context, request *engine.EngineForkChoiceUpdatedRequest) (*engine.EngineForkChoiceUpdatedResponse, error) {
	return back.server.EngineForkChoiceUpdated(ctx, request)
}

func (back *EngineBackend) EngineGetPayload(ctx context.Context, payloadId uint64) (res *engine.EngineGetPayloadResponse, err error) {
	return back.server.EngineGetPayload(ctx, &engine.EngineGetPayloadRequest{
		PayloadId: payloadId,
	})
}

func (back *EngineBackend) EngineGetPayloadBodiesByHashV1(ctx context.Context, request *engine.EngineGetPayloadBodiesByHashV1Request) (*engine.EngineGetPayloadBodiesV1Response, error) {
	return back.server.EngineGetPayloadBodiesByHashV1(ctx, request)
}

func (back *EngineBackend) EngineGetPayloadBodiesByRangeV1(ctx context.Context, request *engine.EngineGetPayloadBodiesByRangeV1Request) (*engine.EngineGetPayloadBodiesV1Response, error) {
	return back.server.EngineGetPayloadBodiesByRangeV1(ctx, request)
}

func (back *EngineBackend) PendingBlock(ctx context.Context) (*types.Block, error) {
	blockRlp, err := back.server.PendingBlock(ctx, &emptypb.Empty{})
	if err != nil {
		return nil, fmt.Errorf("ETHBACKENDClient.PendingBlock() error: %w", err)
	}
	if blockRlp == nil {
		return nil, nil
	}

	var block types.Block
	err = rlp.Decode(bytes.NewReader(blockRlp.BlockRlp), &block)
	if err != nil {
		return nil, fmt.Errorf("decoding block from %x: %w", blockRlp.BlockRlp, err)
	}

	return &block, nil
}