// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package core

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"math/big"
	"strings"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/common/math"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/state"
	"github.com/ethereum/go-ethereum/core/tracing"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/rlp"
	"github.com/ethereum/go-ethereum/trie"
	"github.com/ethereum/go-ethereum/triedb"
	"github.com/ethereum/go-ethereum/triedb/pathdb"
	"github.com/holiman/uint256"
)

//go:generate go run github.com/fjl/gencodec -type Genesis -field-override genesisSpecMarshaling -out gen_genesis.go

var errGenesisNoConfig = errors.New("genesis has no chain configuration")

// Deprecated: use types.Account instead.
type GenesisAccount = types.Account

// Deprecated: use types.GenesisAlloc instead.
type GenesisAlloc = types.GenesisAlloc

// Genesis specifies the header fields, state of a genesis block. It also defines hard
// fork switch-over blocks through the chain configuration.
type Genesis struct {
	Config     *params.ChainConfig `json:"config"`
	Nonce      uint64              `json:"nonce"`
	Timestamp  uint64              `json:"timestamp"`
	ExtraData  []byte              `json:"extraData"`
	GasLimit   uint64              `json:"gasLimit"   gencodec:"required"`
	Difficulty *big.Int            `json:"difficulty" gencodec:"required"`
	Mixhash    common.Hash         `json:"mixHash"`
	Coinbase   common.Address      `json:"coinbase"`
	Alloc      types.GenesisAlloc  `json:"alloc"      gencodec:"required"`

	// These fields are used for consensus tests. Please don't use them
	// in actual genesis blocks.
	Number        uint64      `json:"number"`
	GasUsed       uint64      `json:"gasUsed"`
	ParentHash    common.Hash `json:"parentHash"`
	BaseFee       *big.Int    `json:"baseFeePerGas"` // EIP-1559
	ExcessBlobGas *uint64     `json:"excessBlobGas"` // EIP-4844
	BlobGasUsed   *uint64     `json:"blobGasUsed"`   // EIP-4844
}

// copy copies the genesis.
func (g *Genesis) copy() *Genesis {
	if g != nil {
		cpy := *g
		if g.Config != nil {
			conf := *g.Config
			cpy.Config = &conf
		}
		return &cpy
	}
	return nil
}

func ReadGenesis(db ethdb.Database) (*Genesis, error) {
	var genesis Genesis
	stored := rawdb.ReadCanonicalHash(db, 0)
	if (stored == common.Hash{}) {
		return nil, fmt.Errorf("invalid genesis hash in database: %x", stored)
	}
	blob := rawdb.ReadGenesisStateSpec(db, stored)
	if blob == nil {
		return nil, errors.New("genesis state missing from db")
	}
	if len(blob) != 0 {
		if err := genesis.Alloc.UnmarshalJSON(blob); err != nil {
			return nil, fmt.Errorf("could not unmarshal genesis state json: %s", err)
		}
	}
	genesis.Config = rawdb.ReadChainConfig(db, stored)
	if genesis.Config == nil {
		return nil, errors.New("genesis config missing from db")
	}
	genesisBlock := rawdb.ReadBlock(db, stored, 0)
	if genesisBlock == nil {
		return nil, errors.New("genesis block missing from db")
	}
	genesisHeader := genesisBlock.Header()
	genesis.Nonce = genesisHeader.Nonce.Uint64()
	genesis.Timestamp = genesisHeader.Time
	genesis.ExtraData = genesisHeader.Extra
	genesis.GasLimit = genesisHeader.GasLimit
	genesis.Difficulty = genesisHeader.Difficulty
	genesis.Mixhash = genesisHeader.MixDigest
	genesis.Coinbase = genesisHeader.Coinbase
	genesis.BaseFee = genesisHeader.BaseFee
	genesis.ExcessBlobGas = genesisHeader.ExcessBlobGas
	genesis.BlobGasUsed = genesisHeader.BlobGasUsed

	return &genesis, nil
}

// hashAlloc computes the state root according to the genesis specification.
func hashAlloc(ga *types.GenesisAlloc, isVerkle bool) (common.Hash, error) {
	// If a genesis-time verkle trie is requested, create a trie config
	// with the verkle trie enabled so that the tree can be initialized
	// as such.
	var config *triedb.Config
	if isVerkle {
		config = &triedb.Config{
			PathDB:   pathdb.Defaults,
			IsVerkle: true,
		}
	}
	// Create an ephemeral in-memory database for computing hash,
	// all the derived states will be discarded to not pollute disk.
	emptyRoot := types.EmptyRootHash
	if isVerkle {
		emptyRoot = types.EmptyVerkleHash
	}
	db := rawdb.NewMemoryDatabase()
	statedb, err := state.New(emptyRoot, state.NewDatabase(triedb.NewDatabase(db, config), nil))
	if err != nil {
		return common.Hash{}, err
	}
	for addr, account := range *ga {
		if account.Balance != nil {
			statedb.AddBalance(addr, uint256.MustFromBig(account.Balance), tracing.BalanceIncreaseGenesisBalance)
		}
		statedb.SetCode(addr, account.Code)
		statedb.SetNonce(addr, account.Nonce, tracing.NonceChangeGenesis)
		for key, value := range account.Storage {
			statedb.SetState(addr, key, value)
		}
	}
	root, err := statedb.Commit(0, false, false)
	return root, err
}

// flushAlloc is very similar with hash, but the main difference is all the
// generated states will be persisted into the given database.
func flushAlloc(ga *types.GenesisAlloc, triedb *triedb.Database) (common.Hash, error) {
	triedbConfig := triedb.Config()
	if triedbConfig != nil {
		origin := triedbConfig.NoTries
		triedbConfig.NoTries = false
		defer func() {
			triedbConfig.NoTries = origin
		}()
	}

	emptyRoot := types.EmptyRootHash
	if triedb.IsVerkle() {
		emptyRoot = types.EmptyVerkleHash
	}
	statedb, err := state.New(emptyRoot, state.NewDatabase(triedb, nil))
	if err != nil {
		return common.Hash{}, err
	}
	for addr, account := range *ga {
		if account.Balance != nil {
			// This is not actually logged via tracer because OnGenesisBlock
			// already captures the allocations.
			statedb.AddBalance(addr, uint256.MustFromBig(account.Balance), tracing.BalanceIncreaseGenesisBalance)
		}
		statedb.SetCode(addr, account.Code)
		statedb.SetNonce(addr, account.Nonce, tracing.NonceChangeGenesis)
		for key, value := range account.Storage {
			statedb.SetState(addr, key, value)
		}
	}
	root, err := statedb.Commit(0, false, false)
	if err != nil {
		return common.Hash{}, err
	}
	// Commit newly generated states into disk if it's not empty.
	if root != types.EmptyRootHash {
		if err := triedb.Commit(root, true); err != nil {
			return common.Hash{}, err
		}
	}
	return root, nil
}

func getGenesisState(db ethdb.Database, blockhash common.Hash) (alloc types.GenesisAlloc, err error) {
	blob := rawdb.ReadGenesisStateSpec(db, blockhash)
	if len(blob) != 0 {
		if err := alloc.UnmarshalJSON(blob); err != nil {
			return nil, err
		}

		return alloc, nil
	}

	// Genesis allocation is missing and there are several possibilities:
	// the node is legacy which doesn't persist the genesis allocation or
	// the persisted allocation is just lost.
	// - supported networks(mainnet, testnets), recover with defined allocations
	// - private network, can't recover
	var genesis *Genesis
	switch blockhash {
	case params.MainnetGenesisHash:
		genesis = DefaultGenesisBlock()
	case params.BSCGenesisHash:
		genesis = DefaultBSCGenesisBlock()
	case params.ChapelGenesisHash:
		genesis = DefaultChapelGenesisBlock()
	}
	if genesis != nil {
		return genesis.Alloc, nil
	}

	return nil, nil
}

// field type overrides for gencodec
type genesisSpecMarshaling struct {
	Nonce         math.HexOrDecimal64
	Timestamp     math.HexOrDecimal64
	ExtraData     hexutil.Bytes
	GasLimit      math.HexOrDecimal64
	GasUsed       math.HexOrDecimal64
	Number        math.HexOrDecimal64
	Difficulty    *math.HexOrDecimal256
	Alloc         map[common.UnprefixedAddress]types.Account
	BaseFee       *math.HexOrDecimal256
	ExcessBlobGas *math.HexOrDecimal64
	BlobGasUsed   *math.HexOrDecimal64
}

// GenesisMismatchError is raised when trying to overwrite an existing
// genesis block with an incompatible one.
type GenesisMismatchError struct {
	Stored, New common.Hash
}

func (e *GenesisMismatchError) Error() string {
	return fmt.Sprintf("database contains incompatible genesis (have %x, new %x)", e.Stored, e.New)
}

// ChainOverrides contains the changes to chain config
// Typically, these modifications involve hardforks that are not enabled on the BSC mainnet, intended for testing purposes.
type ChainOverrides struct {
	OverridePassedForkTime *uint64
	OverrideLorentz        *uint64
	OverrideMaxwell        *uint64
	OverrideFermi          *uint64
	OverrideVerkle         *uint64
}

// apply applies the chain overrides on the supplied chain config.
func (o *ChainOverrides) apply(cfg *params.ChainConfig) error {
	if o == nil || cfg == nil {
		return nil
	}
	if o.OverridePassedForkTime != nil {
		cfg.ShanghaiTime = o.OverridePassedForkTime
		cfg.KeplerTime = o.OverridePassedForkTime
		cfg.FeynmanTime = o.OverridePassedForkTime
		cfg.FeynmanFixTime = o.OverridePassedForkTime
		cfg.CancunTime = o.OverridePassedForkTime
		cfg.HaberTime = o.OverridePassedForkTime
		cfg.HaberFixTime = o.OverridePassedForkTime
		cfg.BohrTime = o.OverridePassedForkTime
		cfg.PascalTime = o.OverridePassedForkTime
		cfg.PragueTime = o.OverridePassedForkTime
	}
	if o.OverrideLorentz != nil {
		cfg.LorentzTime = o.OverrideLorentz
	}
	if o.OverrideMaxwell != nil {
		cfg.MaxwellTime = o.OverrideMaxwell
	}
	if o.OverrideFermi != nil {
		cfg.FermiTime = o.OverrideFermi
	}
	if o.OverrideVerkle != nil {
		cfg.VerkleTime = o.OverrideVerkle
	}
	return cfg.CheckConfigForkOrder()
}

// SetupGenesisBlock writes or updates the genesis block in db.
// The block that will be used is:
//
//	                     genesis == nil       genesis != nil
//	                  +------------------------------------------
//	db has no genesis |  main-net default  |  genesis
//	db has genesis    |  from DB           |  genesis (if compatible)
//
// The stored chain configuration will be updated if it is compatible (i.e. does not
// specify a fork block below the local head block). In case of a conflict, the
// error is a *params.ConfigCompatError and the new, unwritten config is returned.
func SetupGenesisBlock(db ethdb.Database, triedb *triedb.Database, genesis *Genesis) (*params.ChainConfig, common.Hash, *params.ConfigCompatError, error) {
	return SetupGenesisBlockWithOverride(db, triedb, genesis, nil)
}

func SetupGenesisBlockWithOverride(db ethdb.Database, triedb *triedb.Database, genesis *Genesis, overrides *ChainOverrides) (*params.ChainConfig, common.Hash, *params.ConfigCompatError, error) {
	// Copy the genesis, so we can operate on a copy.
	genesis = genesis.copy()
	// Sanitize the supplied genesis, ensuring it has the associated chain
	// config attached.
	if genesis != nil && genesis.Config == nil {
		return nil, common.Hash{}, nil, errGenesisNoConfig
	}
	// Commit the genesis if the database is empty
	ghash := rawdb.ReadCanonicalHash(db, 0)
	if (ghash == common.Hash{}) {
		if genesis == nil {
			log.Info("Writing default BSC mainnet genesis block")
			genesis = DefaultBSCGenesisBlock()
		} else {
			log.Info("Writing custom genesis block")
		}
		if err := overrides.apply(genesis.Config); err != nil {
			return nil, common.Hash{}, nil, err
		}

		block, err := genesis.Commit(db, triedb)
		if err != nil {
			return nil, common.Hash{}, nil, err
		}
		log.Info("genesis block hash", "hash", block.Hash())
		return genesis.Config, block.Hash(), nil, nil
	}
	// Commit the genesis if the genesis block exists in the ancient database
	// but the key-value database is empty without initializing the genesis
	// fields. This scenario can occur when the node is created from scratch
	// with an existing ancient store.
	storedCfg := rawdb.ReadChainConfig(db, ghash)
	if storedCfg == nil {
		// Ensure the stored genesis block matches with the given genesis. Private
		// networks must explicitly specify the genesis in the config file, mainnet
		// genesis will be used as default and the initialization will always fail.
		if genesis == nil {
			log.Info("Writing default main-net genesis block")
			genesis = DefaultGenesisBlock()
		} else {
			log.Info("Writing custom genesis block")
		}
		if err := overrides.apply(genesis.Config); err != nil {
			return nil, common.Hash{}, nil, err
		}

		if hash := genesis.ToBlock().Hash(); hash != ghash {
			return nil, common.Hash{}, nil, &GenesisMismatchError{ghash, hash}
		}
		block, err := genesis.Commit(db, triedb)
		if err != nil {
			return nil, common.Hash{}, nil, err
		}
		return genesis.Config, block.Hash(), nil, nil
	}
	// The genesis block has already been committed previously. Verify that the
	// provided genesis with chain overrides matches the existing one, and update
	// the stored chain config if necessary.
	if genesis != nil {
		if err := overrides.apply(genesis.Config); err != nil {
			return nil, common.Hash{}, nil, err
		}

		if hash := genesis.ToBlock().Hash(); hash != ghash {
			return nil, common.Hash{}, nil, &GenesisMismatchError{ghash, hash}
		}
	}
	// Check config compatibility and write the config. Compatibility errors
	// are returned to the caller unless we're already at block zero.
	head := rawdb.ReadHeadHeader(db)
	if head == nil {
		return nil, common.Hash{}, nil, errors.New("missing head header")
	}
	newCfg := genesis.chainConfigOrDefault(ghash, storedCfg)
	if err := overrides.apply(newCfg); err != nil {
		return nil, common.Hash{}, nil, err
	}

	// Sanity-check the new configuration.
	if err := newCfg.CheckConfigForkOrder(); err != nil {
		return nil, common.Hash{}, nil, err
	}

	// TODO(rjl493456442) better to define the comparator of chain config
	// and short circuit if the chain config is not changed.
	compatErr := storedCfg.CheckCompatible(newCfg, head.Number.Uint64(), head.Time)
	if compatErr != nil && ((head.Number.Uint64() != 0 && compatErr.RewindToBlock != 0) || (head.Time != 0 && compatErr.RewindToTime != 0)) {
		return newCfg, ghash, compatErr, nil
	}
	// Don't overwrite if the old is identical to the new. It's useful
	// for the scenarios that database is opened in the read-only mode.
	storedData, _ := json.Marshal(storedCfg)
	if newData, _ := json.Marshal(newCfg); !bytes.Equal(storedData, newData) {
		rawdb.WriteChainConfig(db, ghash, newCfg)
	}
	return newCfg, ghash, nil, nil
}

// LoadChainConfig retrieves the predefined chain configuration for the built-in network.
// For non-built-in networks, it first attempts to load the stored chain configuration from the database.
// If the configuration is not present, it returns the configuration specified in the provided genesis specification.
func LoadChainConfig(db ethdb.Database, genesis *Genesis) (cfg *params.ChainConfig, ghash common.Hash, err error) {
	// Load the stored chain config from the database. It can be nil
	// in case the database is empty. Notably, we only care about the
	// chain config corresponds to the canonical chain.
	stored := rawdb.ReadCanonicalHash(db, 0)
	if stored != (common.Hash{}) {
		builtInConf := params.GetBuiltInChainConfig(stored)
		if builtInConf != nil {
			return builtInConf, stored, nil
		}
		storedcfg := rawdb.ReadChainConfig(db, stored)
		if storedcfg != nil {
			return storedcfg, stored, nil
		}
	}
	// Load the config from the provided genesis specification
	if genesis != nil {
		// Reject invalid genesis spec without valid chain config
		if genesis.Config == nil {
			return nil, common.Hash{}, errGenesisNoConfig
		}
		// If the canonical genesis header is present, but the chain
		// config is missing(initialize the empty leveldb with an
		// external ancient chain segment), ensure the provided genesis
		// is matched.
		ghash := genesis.ToBlock().Hash()
		if stored != (common.Hash{}) && ghash != stored {
			return nil, ghash, &GenesisMismatchError{stored, ghash}
		}
		return genesis.Config, ghash, nil
	}
	// There is no stored chain config and no new config provided,
	// In this case the default chain config(mainnet) will be used
	return params.BSCChainConfig, params.BSCGenesisHash, nil
}

// chainConfigOrDefault retrieves the attached chain configuration. If the genesis
// object is null, it returns the default chain configuration based on the given
// genesis hash, or the locally stored config if it's not a pre-defined network.
func (g *Genesis) chainConfigOrDefault(ghash common.Hash, stored *params.ChainConfig) *params.ChainConfig {
	conf := params.GetBuiltInChainConfig(ghash)
	if conf != nil {
		return conf
	}
	if g != nil {
		return g.Config // it could be a custom config for QA test, just return
	}
	return stored
}

// IsVerkle indicates whether the state is already stored in a verkle
// tree at genesis time.
func (g *Genesis) IsVerkle() bool {
	return g.Config.IsVerkleGenesis()
}

// ToBlock returns the genesis block according to genesis specification.
func (g *Genesis) ToBlock() *types.Block {
	root, err := hashAlloc(&g.Alloc, g.IsVerkle())
	if err != nil {
		panic(err)
	}
	return g.toBlockWithRoot(root)
}

// toBlockWithRoot constructs the genesis block with the given genesis state root.
func (g *Genesis) toBlockWithRoot(root common.Hash) *types.Block {
	head := &types.Header{
		Number:     new(big.Int).SetUint64(g.Number),
		Nonce:      types.EncodeNonce(g.Nonce),
		Time:       g.Timestamp,
		ParentHash: g.ParentHash,
		Extra:      g.ExtraData,
		GasLimit:   g.GasLimit,
		GasUsed:    g.GasUsed,
		BaseFee:    g.BaseFee,
		Difficulty: g.Difficulty,
		MixDigest:  g.Mixhash,
		Coinbase:   g.Coinbase,
		Root:       root,
	}
	if g.GasLimit == 0 {
		head.GasLimit = params.GenesisGasLimit
	}
	if g.Difficulty == nil {
		if g.Config != nil && g.Config.Ethash == nil {
			head.Difficulty = big.NewInt(0)
		} else if g.Mixhash == (common.Hash{}) {
			head.Difficulty = params.GenesisDifficulty
		}
	}
	if g.Config != nil && g.Config.IsLondon(common.Big0) {
		if g.BaseFee != nil {
			head.BaseFee = g.BaseFee
		} else {
			if g.Config.Parlia != nil {
				head.BaseFee = new(big.Int).SetUint64(params.InitialBaseFeeForBSC)
			} else {
				head.BaseFee = new(big.Int).SetUint64(params.InitialBaseFee)
			}
		}
	}
	var (
		withdrawals []*types.Withdrawal
	)
	if conf := g.Config; conf != nil {
		num := big.NewInt(int64(g.Number))
		if conf.Parlia == nil && conf.IsShanghai(num, g.Timestamp) {
			head.WithdrawalsHash = &types.EmptyWithdrawalsHash
			withdrawals = make([]*types.Withdrawal, 0)
		}
		if conf.IsCancun(num, g.Timestamp) {
			if conf.Parlia != nil {
				head.WithdrawalsHash = &types.EmptyWithdrawalsHash
				withdrawals = make([]*types.Withdrawal, 0)
			}

			// EIP-4788: The parentBeaconBlockRoot of the genesis block is always
			// the zero hash. This is because the genesis block does not have a parent
			// by definition.
			if conf.Parlia == nil || conf.IsBohr(num, g.Timestamp) {
				head.ParentBeaconRoot = new(common.Hash)
			}

			// EIP-4844 fields
			head.ExcessBlobGas = g.ExcessBlobGas
			head.BlobGasUsed = g.BlobGasUsed
			if head.ExcessBlobGas == nil {
				head.ExcessBlobGas = new(uint64)
			}
			if head.BlobGasUsed == nil {
				head.BlobGasUsed = new(uint64)
			}
		}
		if conf.IsPrague(num, g.Timestamp) {
			head.RequestsHash = &types.EmptyRequestsHash
		}
	}
	return types.NewBlock(head, &types.Body{Withdrawals: withdrawals}, nil, trie.NewStackTrie(nil))
}

// Commit writes the block and state of a genesis specification to the database.
// The block is committed as the canonical head block.
func (g *Genesis) Commit(db ethdb.Database, triedb *triedb.Database) (*types.Block, error) {
	if g.Number != 0 {
		return nil, errors.New("can't commit genesis block with number > 0")
	}
	config := g.Config
	if config == nil {
		return nil, errors.New("invalid genesis without chain config")
	}
	if err := config.CheckConfigForkOrder(); err != nil {
		return nil, err
	}
	if config.Clique != nil && len(g.ExtraData) < 32+crypto.SignatureLength {
		return nil, errors.New("can't start clique chain without signers")
	}
	// flush the data to disk and compute the state root
	root, err := flushAlloc(&g.Alloc, triedb)
	if err != nil {
		return nil, err
	}
	block := g.toBlockWithRoot(root)

	// Marshal the genesis state specification and persist.
	blob, err := json.Marshal(g.Alloc)
	if err != nil {
		return nil, err
	}
	rawdb.WriteGenesisStateSpec(db, block.Hash(), blob)
	rawdb.WriteTd(db, block.Hash(), block.NumberU64(), block.Difficulty())
	rawdb.WriteBlock(db, block)
	rawdb.WriteReceipts(db, block.Hash(), block.NumberU64(), nil)
	rawdb.WriteCanonicalHash(db, block.Hash(), block.NumberU64())
	rawdb.WriteHeadBlockHash(db, block.Hash())
	rawdb.WriteHeadFastBlockHash(db, block.Hash())
	rawdb.WriteHeadHeaderHash(db, block.Hash())
	rawdb.WriteChainConfig(db, block.Hash(), config)
	return block, nil
}

// MustCommit writes the genesis block and state to db, panicking on error.
// The block is committed as the canonical head block.
func (g *Genesis) MustCommit(db ethdb.Database, triedb *triedb.Database) *types.Block {
	block, err := g.Commit(db, triedb)
	if err != nil {
		panic(err)
	}
	return block
}

// EnableVerkleAtGenesis indicates whether the verkle fork should be activated
// at genesis. This is a temporary solution only for verkle devnet testing, where
// verkle fork is activated at genesis, and the configured activation date has
// already passed.
//
// In production networks (mainnet and public testnets), verkle activation always
// occurs after the genesis block, making this function irrelevant in those cases.
func EnableVerkleAtGenesis(db ethdb.Database, genesis *Genesis) (bool, error) {
	if genesis != nil {
		if genesis.Config == nil {
			return false, errGenesisNoConfig
		}
		return genesis.Config.EnableVerkleAtGenesis, nil
	}
	if ghash := rawdb.ReadCanonicalHash(db, 0); ghash != (common.Hash{}) {
		chainCfg := rawdb.ReadChainConfig(db, ghash)
		if chainCfg != nil {
			return chainCfg.EnableVerkleAtGenesis, nil
		}
	}
	return false, nil
}

// DefaultGenesisBlock returns the Ethereum main net genesis block.
func DefaultGenesisBlock() *Genesis {
	return &Genesis{
		Config:     params.MainnetChainConfig,
		Nonce:      66,
		ExtraData:  hexutil.MustDecode("0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa"),
		GasLimit:   5000,
		Difficulty: big.NewInt(17179869184),
		Alloc:      decodePrealloc(mainnetAllocData),
	}
}

// DefaultBSCGenesisBlock returns the BSC mainnet genesis block.
func DefaultBSCGenesisBlock() *Genesis {
	alloc := decodePrealloc(bscMainnetAllocData)
	return &Genesis{
		Config:     params.BSCChainConfig,
		Nonce:      0,
		ExtraData:  hexutil.MustDecode("0x00000000000000000000000000000000000000000000000000000000000000002a7cdd959bfe8d9487b2a43b33565295a698f7e26488aa4d1955ee33403f8ccb1d4de5fb97c7ade29ef9f4360c606c7ab4db26b016007d3ad0ab86a0ee01c3b1283aa067c58eab4709f85e99d46de5fe685b1ded8013785d6623cc18d214320b6bb6475978f3adfc719c99674c072166708589033e2d9afec2be4ec20253b8642161bc3f444f53679c1f3d472f7be8361c80a4c1e7e9aaf001d0877f1cfde218ce2fd7544e0b2cc94692d4a704debef7bcb61328b8f7166496996a7da21cf1f1b04d9b3e26a3d0772d4c407bbe49438ed859fe965b140dcf1aab71a96bbad7cf34b5fa511d8e963dbba288b1960e75d64430b3230294d12c6ab2aac5c2cd68e80b16b581ea0a6e3c511bbd10f4519ece37dc24887e11b55d7ae2f5b9e386cd1b50a4550696d957cb4900f03a82012708dafc9e1b880fd083b32182b869be8e0922b81f8e175ffde54d797fe11eb03f9e3bf75f1d68bf0b8b6fb4e317a0f9d6f03eaf8ce6675bc60d8c4d90829ce8f72d0163c1d5cf348a862d55063035e7a025f4da968de7e4d7e4004197917f4070f1d6caa02bbebaebb5d7e581e4b66559e635f805ff0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
		GasLimit:   40000000,
		Difficulty: big.NewInt(1),
		Mixhash:    common.Hash(hexutil.MustDecode("0x0000000000000000000000000000000000000000000000000000000000000000")),
		Coinbase:   common.HexToAddress("0xffffFFFfFFffffffffffffffFfFFFfffFFFfFFfE"),
		Timestamp:  0x5e9da7ce,
		Alloc:      alloc,
	}
}

// DefaultChapelGenesisBlock returns the BSC mainnet genesis block.
func DefaultChapelGenesisBlock() *Genesis {
	alloc := decodePrealloc(bscChapelAllocData)
	return &Genesis{
		Config:     params.ChapelChainConfig,
		Nonce:      0,
		ExtraData:  hexutil.MustDecode("0x00000000000000000000000000000000000000000000000000000000000000001284214b9b9c85549ab3d2b972df0deef66ac2c9b71b214cb885500844365e95cd9942c7276e7fd8a2959d3f95eae5dc7d70144ce1b73b403b7eb6e0980a75ecd1309ea12fa2ed87a8744fbfc9b863d535552c16704d214347f29fa77f77da6d75d7c752f474cf03cceff28abc65c9cbae594f725c80e12d0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
		GasLimit:   40000000,
		Difficulty: big.NewInt(1),
		Mixhash:    common.Hash(hexutil.MustDecode("0x0000000000000000000000000000000000000000000000000000000000000000")),
		Coinbase:   common.HexToAddress("0xffffFFFfFFffffffffffffffFfFFFfffFFFfFFfE"),
		Timestamp:  0x5e9da7ce,
		Alloc:      alloc,
	}
}

// DeveloperGenesisBlock returns the 'geth --dev' genesis block.
func DeveloperGenesisBlock(gasLimit uint64, faucet *common.Address) *Genesis {
	// Override the default period to the user requested one
	config := *params.AllDevChainProtocolChanges

	// Assemble and return the genesis with the precompiles and faucet pre-funded
	genesis := &Genesis{
		Config:     &config,
		GasLimit:   gasLimit,
		BaseFee:    big.NewInt(params.InitialBaseFee),
		Difficulty: big.NewInt(0),
		Alloc: map[common.Address]types.Account{
			common.BytesToAddress([]byte{0x01}): {Balance: big.NewInt(1)}, // ECRecover
			common.BytesToAddress([]byte{0x02}): {Balance: big.NewInt(1)}, // SHA256
			common.BytesToAddress([]byte{0x03}): {Balance: big.NewInt(1)}, // RIPEMD
			common.BytesToAddress([]byte{0x04}): {Balance: big.NewInt(1)}, // Identity
			common.BytesToAddress([]byte{0x05}): {Balance: big.NewInt(1)}, // ModExp
			common.BytesToAddress([]byte{0x06}): {Balance: big.NewInt(1)}, // ECAdd
			common.BytesToAddress([]byte{0x07}): {Balance: big.NewInt(1)}, // ECScalarMul
			common.BytesToAddress([]byte{0x08}): {Balance: big.NewInt(1)}, // ECPairing
			common.BytesToAddress([]byte{0x09}): {Balance: big.NewInt(1)}, // BLAKE2b
			common.BytesToAddress([]byte{0x0a}): {Balance: big.NewInt(1)}, // KZGPointEval
			common.BytesToAddress([]byte{0x0b}): {Balance: big.NewInt(1)}, // BLSG1Add
			common.BytesToAddress([]byte{0x0c}): {Balance: big.NewInt(1)}, // BLSG1MultiExp
			common.BytesToAddress([]byte{0x0d}): {Balance: big.NewInt(1)}, // BLSG2Add
			common.BytesToAddress([]byte{0x0e}): {Balance: big.NewInt(1)}, // BLSG2MultiExp
			common.BytesToAddress([]byte{0x0f}): {Balance: big.NewInt(1)}, // BLSG1Pairing
			common.BytesToAddress([]byte{0x10}): {Balance: big.NewInt(1)}, // BLSG1MapG1
			common.BytesToAddress([]byte{0x11}): {Balance: big.NewInt(1)}, // BLSG2MapG2
			// Pre-deploy system contracts
			params.BeaconRootsAddress:        {Nonce: 1, Code: params.BeaconRootsCode, Balance: common.Big0},
			params.HistoryStorageAddress:     {Nonce: 1, Code: params.HistoryStorageCode, Balance: common.Big0},
			params.WithdrawalQueueAddress:    {Nonce: 1, Code: params.WithdrawalQueueCode, Balance: common.Big0},
			params.ConsolidationQueueAddress: {Nonce: 1, Code: params.ConsolidationQueueCode, Balance: common.Big0},
		},
	}
	if faucet != nil {
		genesis.Alloc[*faucet] = types.Account{Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))}
	}
	return genesis
}

func decodePrealloc(data string) types.GenesisAlloc {
	var p []struct {
		Addr    *big.Int
		Balance *big.Int
		Misc    *struct {
			Nonce uint64
			Code  []byte
			Slots []struct {
				Key common.Hash
				Val common.Hash
			}
		} `rlp:"optional"`
	}
	if err := rlp.NewStream(strings.NewReader(data), 0).Decode(&p); err != nil {
		panic(err)
	}
	ga := make(types.GenesisAlloc, len(p))
	for _, account := range p {
		acc := types.Account{Balance: account.Balance}
		if account.Misc != nil {
			acc.Nonce = account.Misc.Nonce
			acc.Code = account.Misc.Code

			acc.Storage = make(map[common.Hash]common.Hash)
			for _, slot := range account.Misc.Slots {
				acc.Storage[slot.Key] = slot.Val
			}
		}
		ga[common.BigToAddress(account.Addr)] = acc
	}
	return ga
}
