package commands

import (
	"context"
	"fmt"
	"github.com/ledgerwatch/turbo-geth/common"
	"github.com/ledgerwatch/turbo-geth/common/hexutil"
	"github.com/ledgerwatch/turbo-geth/core"
	"github.com/ledgerwatch/turbo-geth/core/rawdb"
	"github.com/ledgerwatch/turbo-geth/core/state"
	"github.com/ledgerwatch/turbo-geth/core/types"
	"github.com/ledgerwatch/turbo-geth/eth"
	"github.com/ledgerwatch/turbo-geth/eth/stagedsync/stages"
	"github.com/ledgerwatch/turbo-geth/ethdb"
	"github.com/ledgerwatch/turbo-geth/params"
	"github.com/ledgerwatch/turbo-geth/rpc"
)

// PrivateDebugAPI
type PrivateDebugAPI interface {
	StorageRangeAt(ctx context.Context, blockHash common.Hash, txIndex uint64, contractAddress common.Address, keyStart hexutil.Bytes, maxResult int) (StorageRangeResult, error)
	TraceTransaction(ctx context.Context, hash common.Hash, config *eth.TraceConfig) (interface{}, error)
	AccountRange(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash, start []byte, maxResults int, nocode, nostorage, incompletes bool) (state.IteratorDump, error)
	GetModifiedAccountsByNumber(ctx context.Context, startNum rpc.BlockNumber, endNum *rpc.BlockNumber) ([]common.Address, error)
	GetModifiedAccountsByHash(_ context.Context, startHash common.Hash, endHash *common.Hash) ([]common.Address, error)
}

// APIImpl is implementation of the PrivateDebugAPI interface based on remote Db access
type PrivateDebugAPIImpl struct {
	db           ethdb.KV
	dbReader     ethdb.Getter
	chainContext core.ChainContext
}

// NewPrivateDebugAPI returns PrivateDebugAPIImpl instance
func NewPrivateDebugAPI(db ethdb.KV, dbReader ethdb.Getter, chainContext core.ChainContext) *PrivateDebugAPIImpl {
	return &PrivateDebugAPIImpl{
		db:           db,
		dbReader:     dbReader,
		chainContext: chainContext,
	}
}

// StorageRangeAt re-implementation of eth/api.go:StorageRangeAt
func (api *PrivateDebugAPIImpl) StorageRangeAt(ctx context.Context, blockHash common.Hash, txIndex uint64, contractAddress common.Address, keyStart hexutil.Bytes, maxResult int) (StorageRangeResult, error) {
	_, _, _, stateReader, err := ComputeTxEnv(ctx, &blockGetter{api.dbReader}, params.MainnetChainConfig, &chainContext{db: api.dbReader}, api.db, blockHash, txIndex, nil)
	if err != nil {
		return StorageRangeResult{}, err
	}
	return StorageRangeAt(stateReader, contractAddress, keyStart, maxResult)
}

// AccountRange re-implementation of eth/api.go:AccountRange
func (api *PrivateDebugAPIImpl) AccountRange(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash, start []byte, maxResults int, nocode, nostorage, incompletes bool) (state.IteratorDump, error) {
	var blockNumber uint64

	if number, ok := blockNrOrHash.Number(); ok {
		if number == rpc.PendingBlockNumber {
			return state.IteratorDump{}, fmt.Errorf("accountRange for pending block not supported")
		}
		if number == rpc.LatestBlockNumber {
			var err error

			blockNumber, _, err = stages.GetStageProgress(api.dbReader, stages.Execution)
			if err != nil {
				return state.IteratorDump{}, fmt.Errorf("las block has not found: %w", err)
			}
		} else {
			blockNumber = uint64(number)
		}

	} else if hash, ok := blockNrOrHash.Hash(); ok {
		block := rawdb.ReadBlockByHash(api.dbReader, hash)
		if block == nil {
			return state.IteratorDump{}, fmt.Errorf("block %s not found", hash.Hex())
		}
		blockNumber = block.NumberU64()
	}

	if maxResults > eth.AccountRangeMaxResults || maxResults <= 0 {
		maxResults = eth.AccountRangeMaxResults
	}

	dumper := state.NewDumper(api.db, blockNumber)
	res, err := dumper.IteratorDump(nocode, nostorage, incompletes, start, maxResults)
	if err != nil {
		return state.IteratorDump{}, err
	}
	hash := rawdb.ReadCanonicalHash(api.dbReader, blockNumber)
	if hash != (common.Hash{}) {
		header := rawdb.ReadHeader(api.dbReader, hash, blockNumber)
		if header != nil {
			res.Root = header.Root.String()
		}
	}

	return res, err
}

func (api *PrivateDebugAPIImpl) GetModifiedAccountsByNumber(_ context.Context, startNum rpc.BlockNumber, endNum *rpc.BlockNumber) ([]common.Address, error) {
	if endNum != nil && startNum.Int64() >= endNum.Int64() {
		return nil, fmt.Errorf("start block height (%d) must be less than end block height (%d)", startNum.Int64(), endNum.Int64())
	}

	execution, _, err := stages.GetStageProgress(api.dbReader, stages.Execution)
	if err != nil {
		return nil, err
	}

	lastBlockNumber := execution

	if startNum.Int64() < 1 || uint64(startNum.Int64()) > lastBlockNumber {
		return nil, fmt.Errorf("start block %x not found", uint64(startNum.Int64()))
	}

	if endNum == nil {
		*endNum = startNum
	} else {
		if endNum.Int64() < 1 || uint64(endNum.Int64()) > lastBlockNumber {
			return nil, fmt.Errorf("end block %x not found", uint64(endNum.Int64()))
		}
	}

	return api.getModifiedAccounts(uint64(startNum.Int64()), uint64(endNum.Int64()))
}

func (api *PrivateDebugAPIImpl) GetModifiedAccountsByHash(_ context.Context, startHash common.Hash, endHash *common.Hash) ([]common.Address, error) {
	startBlock := rawdb.ReadBlockByHash(api.dbReader, startHash)
	if startBlock == nil {
		return nil, fmt.Errorf("start block %x not found", startHash)
	}

	var endBlock *types.Block
	if endHash == nil {
		endBlock = startBlock
	} else {
		endBlock = rawdb.ReadBlockByHash(api.dbReader, *endHash)
		if endBlock == nil {
			return nil, fmt.Errorf("end block %x not found", *endHash)
		}
	}
	return api.getModifiedAccounts(startBlock.NumberU64(), endBlock.NumberU64())
}

func (api *PrivateDebugAPIImpl) getModifiedAccounts(startNum, endNum uint64) ([]common.Address, error) {
	if startNum >= endNum {
		return nil, fmt.Errorf("start block height (%d) must be less than end block height (%d)", startNum, endNum)
	}

	return ethdb.GetModifiedAccounts(api.dbReader, startNum, endNum)
}