// 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 eth implements the Ethereum protocol.
package eth

import (
	"encoding/json"
	"errors"
	"fmt"
	"math/big"
	"runtime"
	"sync"

	"github.com/ethereum/go-ethereum/accounts"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/consensus"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/bloombits"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/state/pruner"
	"github.com/ethereum/go-ethereum/core/txpool"
	"github.com/ethereum/go-ethereum/core/txpool/blobpool"
	"github.com/ethereum/go-ethereum/core/txpool/legacypool"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/core/vm"
	"github.com/ethereum/go-ethereum/eth/downloader"
	"github.com/ethereum/go-ethereum/eth/ethconfig"
	"github.com/ethereum/go-ethereum/eth/gasprice"
	"github.com/ethereum/go-ethereum/eth/protocols/eth"
	"github.com/ethereum/go-ethereum/eth/protocols/snap"
	"github.com/ethereum/go-ethereum/eth/tracers"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/event"
	"github.com/ethereum/go-ethereum/internal/ethapi"
	"github.com/ethereum/go-ethereum/internal/shutdowncheck"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/miner"
	"github.com/ethereum/go-ethereum/node"
	"github.com/ethereum/go-ethereum/p2p"
	"github.com/ethereum/go-ethereum/p2p/dnsdisc"
	"github.com/ethereum/go-ethereum/p2p/enode"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/rlp"
	"github.com/ethereum/go-ethereum/rpc"
)

// Config contains the configuration options of the ETH protocol.
// Deprecated: use ethconfig.Config instead.
type Config = ethconfig.Config

// Ethereum implements the Ethereum full node service.
type Ethereum struct {
	config *ethconfig.Config

	// Handlers
	txPool *txpool.TxPool

	blockchain         *core.BlockChain
	handler            *handler
	ethDialCandidates  enode.Iterator
	snapDialCandidates enode.Iterator

	// DB interfaces
	chainDb ethdb.Database // Block chain database

	eventMux       *event.TypeMux
	engine         consensus.Engine
	accountManager *accounts.Manager

	bloomRequests     chan chan *bloombits.Retrieval // Channel receiving bloom data retrieval requests
	bloomIndexer      *core.ChainIndexer             // Bloom indexer operating during block imports
	closeBloomHandler chan struct{}

	APIBackend *EthAPIBackend

	miner    *miner.Miner
	gasPrice *big.Int

	networkID     uint64
	netRPCService *ethapi.NetAPI

	p2pServer *p2p.Server

	lock sync.RWMutex // Protects the variadic fields (e.g. gas price and etherbase)

	shutdownTracker *shutdowncheck.ShutdownTracker // Tracks if and when the node has shutdown ungracefully
}

// New creates a new Ethereum object (including the initialisation of the common Ethereum object),
// whose lifecycle will be managed by the provided node.
func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
	// Ensure configuration values are compatible and sane
	if config.SyncMode == downloader.LightSync {
		return nil, errors.New("can't run eth.Ethereum in light sync mode, light mode has been deprecated")
	}
	if !config.SyncMode.IsValid() {
		return nil, fmt.Errorf("invalid sync mode %d", config.SyncMode)
	}
	if config.Miner.GasPrice == nil || config.Miner.GasPrice.Sign() <= 0 {
		log.Warn("Sanitizing invalid miner gas price", "provided", config.Miner.GasPrice, "updated", ethconfig.Defaults.Miner.GasPrice)
		config.Miner.GasPrice = new(big.Int).Set(ethconfig.Defaults.Miner.GasPrice)
	}
	if config.NoPruning && config.TrieDirtyCache > 0 {
		if config.SnapshotCache > 0 {
			config.TrieCleanCache += config.TrieDirtyCache * 3 / 5
			config.SnapshotCache += config.TrieDirtyCache * 2 / 5
		} else {
			config.TrieCleanCache += config.TrieDirtyCache
		}
		config.TrieDirtyCache = 0
	}
	log.Info("Allocated trie memory caches", "clean", common.StorageSize(config.TrieCleanCache)*1024*1024, "dirty", common.StorageSize(config.TrieDirtyCache)*1024*1024)

	// Assemble the Ethereum object
	chainDb, err := stack.OpenDatabaseWithFreezer("chaindata", config.DatabaseCache, config.DatabaseHandles, config.DatabaseFreezer, "eth/db/chaindata/", false)
	if err != nil {
		return nil, err
	}
	scheme, err := rawdb.ParseStateScheme(config.StateScheme, chainDb)
	if err != nil {
		return nil, err
	}
	// Try to recover offline state pruning only in hash-based.
	if scheme == rawdb.HashScheme {
		if err := pruner.RecoverPruning(stack.ResolvePath(""), chainDb); err != nil {
			log.Error("Failed to recover state", "error", err)
		}
	}
	// Transfer mining-related config to the ethash config.
	chainConfig, err := core.LoadChainConfig(chainDb, config.Genesis)
	if err != nil {
		return nil, err
	}
	engine, err := ethconfig.CreateConsensusEngine(chainConfig, chainDb)
	if err != nil {
		return nil, err
	}
	networkID := config.NetworkId
	if networkID == 0 {
		networkID = chainConfig.ChainID.Uint64()
	}
	eth := &Ethereum{
		config:            config,
		chainDb:           chainDb,
		eventMux:          stack.EventMux(),
		accountManager:    stack.AccountManager(),
		engine:            engine,
		closeBloomHandler: make(chan struct{}),
		networkID:         networkID,
		gasPrice:          config.Miner.GasPrice,
		bloomRequests:     make(chan chan *bloombits.Retrieval),
		bloomIndexer:      core.NewBloomIndexer(chainDb, params.BloomBitsBlocks, params.BloomConfirms),
		p2pServer:         stack.Server(),
		shutdownTracker:   shutdowncheck.NewShutdownTracker(chainDb),
	}
	bcVersion := rawdb.ReadDatabaseVersion(chainDb)
	var dbVer = "<nil>"
	if bcVersion != nil {
		dbVer = fmt.Sprintf("%d", *bcVersion)
	}
	log.Info("Initialising Ethereum protocol", "network", networkID, "dbversion", dbVer)

	if !config.SkipBcVersionCheck {
		if bcVersion != nil && *bcVersion > core.BlockChainVersion {
			return nil, fmt.Errorf("database version is v%d, Geth %s only supports v%d", *bcVersion, params.VersionWithMeta, core.BlockChainVersion)
		} else if bcVersion == nil || *bcVersion < core.BlockChainVersion {
			if bcVersion != nil { // only print warning on upgrade, not on init
				log.Warn("Upgrade blockchain database version", "from", dbVer, "to", core.BlockChainVersion)
			}
			rawdb.WriteDatabaseVersion(chainDb, core.BlockChainVersion)
		}
	}
	var (
		vmConfig = vm.Config{
			EnablePreimageRecording: config.EnablePreimageRecording,
		}
		cacheConfig = &core.CacheConfig{
			TrieCleanLimit:      config.TrieCleanCache,
			TrieCleanNoPrefetch: config.NoPrefetch,
			TrieDirtyLimit:      config.TrieDirtyCache,
			TrieDirtyDisabled:   config.NoPruning,
			TrieTimeLimit:       config.TrieTimeout,
			SnapshotLimit:       config.SnapshotCache,
			Preimages:           config.Preimages,
			StateHistory:        config.StateHistory,
			StateScheme:         scheme,
		}
	)
	if config.VMTrace != "" {
		var traceConfig json.RawMessage
		if config.VMTraceJsonConfig != "" {
			traceConfig = json.RawMessage(config.VMTraceJsonConfig)
		}
		t, err := tracers.LiveDirectory.New(config.VMTrace, traceConfig)
		if err != nil {
			return nil, fmt.Errorf("Failed to create tracer %s: %v", config.VMTrace, err)
		}
		vmConfig.Tracer = t
	}
	// Override the chain config with provided settings.
	var overrides core.ChainOverrides
	if config.OverrideCancun != nil {
		overrides.OverrideCancun = config.OverrideCancun
	}
	if config.OverrideVerkle != nil {
		overrides.OverrideVerkle = config.OverrideVerkle
	}
	// TODO (MariusVanDerWijden) get rid of shouldPreserve in a follow-up PR
	shouldPreserve := func(header *types.Header) bool {
		return false
	}
	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, config.Genesis, &overrides, eth.engine, vmConfig, shouldPreserve, &config.TransactionHistory)
	if err != nil {
		return nil, err
	}
	eth.bloomIndexer.Start(eth.blockchain)

	if config.BlobPool.Datadir != "" {
		config.BlobPool.Datadir = stack.ResolvePath(config.BlobPool.Datadir)
	}
	blobPool := blobpool.New(config.BlobPool, eth.blockchain)

	if config.TxPool.Journal != "" {
		config.TxPool.Journal = stack.ResolvePath(config.TxPool.Journal)
	}
	legacyPool := legacypool.New(config.TxPool, eth.blockchain)

	eth.txPool, err = txpool.New(config.TxPool.PriceLimit, eth.blockchain, []txpool.SubPool{legacyPool, blobPool})
	if err != nil {
		return nil, err
	}
	// Permit the downloader to use the trie cache allowance during fast sync
	cacheLimit := cacheConfig.TrieCleanLimit + cacheConfig.TrieDirtyLimit + cacheConfig.SnapshotLimit
	if eth.handler, err = newHandler(&handlerConfig{
		NodeID:         eth.p2pServer.Self().ID(),
		Database:       chainDb,
		Chain:          eth.blockchain,
		TxPool:         eth.txPool,
		Network:        networkID,
		Sync:           config.SyncMode,
		BloomCache:     uint64(cacheLimit),
		EventMux:       eth.eventMux,
		RequiredBlocks: config.RequiredBlocks,
	}); err != nil {
		return nil, err
	}

	eth.miner = miner.New(eth, config.Miner, eth.engine)
	eth.miner.SetExtra(makeExtraData(config.Miner.ExtraData))

	eth.APIBackend = &EthAPIBackend{stack.Config().ExtRPCEnabled(), stack.Config().AllowUnprotectedTxs, eth, nil}
	if eth.APIBackend.allowUnprotectedTxs {
		log.Info("Unprotected transactions allowed")
	}
	gpoParams := config.GPO
	if gpoParams.Default == nil {
		gpoParams.Default = config.Miner.GasPrice
	}
	eth.APIBackend.gpo = gasprice.NewOracle(eth.APIBackend, gpoParams)

	// Setup DNS discovery iterators.
	dnsclient := dnsdisc.NewClient(dnsdisc.Config{})
	eth.ethDialCandidates, err = dnsclient.NewIterator(eth.config.EthDiscoveryURLs...)
	if err != nil {
		return nil, err
	}
	eth.snapDialCandidates, err = dnsclient.NewIterator(eth.config.SnapDiscoveryURLs...)
	if err != nil {
		return nil, err
	}

	// Start the RPC service
	eth.netRPCService = ethapi.NewNetAPI(eth.p2pServer, networkID)

	// Register the backend on the node
	stack.RegisterAPIs(eth.APIs())
	stack.RegisterProtocols(eth.Protocols())
	stack.RegisterLifecycle(eth)

	// Successful startup; push a marker and check previous unclean shutdowns.
	eth.shutdownTracker.MarkStartup()

	return eth, nil
}

func makeExtraData(extra []byte) []byte {
	if len(extra) == 0 {
		// create default extradata
		extra, _ = rlp.EncodeToBytes([]interface{}{
			uint(params.VersionMajor<<16 | params.VersionMinor<<8 | params.VersionPatch),
			"geth",
			runtime.Version(),
			runtime.GOOS,
		})
	}
	if uint64(len(extra)) > params.MaximumExtraDataSize {
		log.Warn("Miner extra data exceed limit", "extra", hexutil.Bytes(extra), "limit", params.MaximumExtraDataSize)
		extra = nil
	}
	return extra
}

// APIs return the collection of RPC services the ethereum package offers.
// NOTE, some of these services probably need to be moved to somewhere else.
func (s *Ethereum) APIs() []rpc.API {
	apis := ethapi.GetAPIs(s.APIBackend)

	// Append any APIs exposed explicitly by the consensus engine
	apis = append(apis, s.engine.APIs(s.BlockChain())...)

	// Append all the local APIs and return
	return append(apis, []rpc.API{
		{
			Namespace: "miner",
			Service:   NewMinerAPI(s),
		}, {
			Namespace: "eth",
			Service:   downloader.NewDownloaderAPI(s.handler.downloader, s.blockchain, s.eventMux),
		}, {
			Namespace: "admin",
			Service:   NewAdminAPI(s),
		}, {
			Namespace: "debug",
			Service:   NewDebugAPI(s),
		}, {
			Namespace: "net",
			Service:   s.netRPCService,
		},
	}...)
}

func (s *Ethereum) ResetWithGenesisBlock(gb *types.Block) {
	s.blockchain.ResetWithGenesisBlock(gb)
}

func (s *Ethereum) Miner() *miner.Miner { return s.miner }

func (s *Ethereum) AccountManager() *accounts.Manager  { return s.accountManager }
func (s *Ethereum) BlockChain() *core.BlockChain       { return s.blockchain }
func (s *Ethereum) TxPool() *txpool.TxPool             { return s.txPool }
func (s *Ethereum) EventMux() *event.TypeMux           { return s.eventMux }
func (s *Ethereum) Engine() consensus.Engine           { return s.engine }
func (s *Ethereum) ChainDb() ethdb.Database            { return s.chainDb }
func (s *Ethereum) IsListening() bool                  { return true } // Always listening
func (s *Ethereum) Downloader() *downloader.Downloader { return s.handler.downloader }
func (s *Ethereum) Synced() bool                       { return s.handler.synced.Load() }
func (s *Ethereum) SetSynced()                         { s.handler.enableSyncedFeatures() }
func (s *Ethereum) ArchiveMode() bool                  { return s.config.NoPruning }
func (s *Ethereum) BloomIndexer() *core.ChainIndexer   { return s.bloomIndexer }

// Protocols returns all the currently configured
// network protocols to start.
func (s *Ethereum) Protocols() []p2p.Protocol {
	protos := eth.MakeProtocols((*ethHandler)(s.handler), s.networkID, s.ethDialCandidates)
	if s.config.SnapshotCache > 0 {
		protos = append(protos, snap.MakeProtocols((*snapHandler)(s.handler), s.snapDialCandidates)...)
	}
	return protos
}

// Start implements node.Lifecycle, starting all internal goroutines needed by the
// Ethereum protocol implementation.
func (s *Ethereum) Start() error {
	eth.StartENRUpdater(s.blockchain, s.p2pServer.LocalNode())

	// Start the bloom bits servicing goroutines
	s.startBloomHandlers(params.BloomBitsBlocks)

	// Regularly update shutdown marker
	s.shutdownTracker.Start()

	// Figure out a max peers count based on the server limits
	maxPeers := s.p2pServer.MaxPeers
	if s.config.LightServ > 0 {
		if s.config.LightPeers >= s.p2pServer.MaxPeers {
			return fmt.Errorf("invalid peer config: light peer count (%d) >= total peer count (%d)", s.config.LightPeers, s.p2pServer.MaxPeers)
		}
		maxPeers -= s.config.LightPeers
	}
	// Start the networking layer and the light server if requested
	s.handler.Start(maxPeers)
	return nil
}

// Stop implements node.Lifecycle, terminating all internal goroutines used by the
// Ethereum protocol.
func (s *Ethereum) Stop() error {
	// Stop all the peer-related stuff first.
	s.ethDialCandidates.Close()
	s.snapDialCandidates.Close()
	s.handler.Stop()

	// Then stop everything else.
	s.bloomIndexer.Close()
	close(s.closeBloomHandler)
	s.txPool.Close()
	s.blockchain.Stop()
	s.engine.Close()

	// Clean shutdown marker as the last thing before closing db
	s.shutdownTracker.Stop()

	s.chainDb.Close()
	s.eventMux.Stop()

	return nil
}

// SyncMode retrieves the current sync mode, either explicitly set, or derived
// from the chain status.
func (s *Ethereum) SyncMode() downloader.SyncMode {
	// If we're in snap sync mode, return that directly
	if s.handler.snapSync.Load() {
		return downloader.SnapSync
	}
	// We are probably in full sync, but we might have rewound to before the
	// snap sync pivot, check if we should re-enable snap sync.
	head := s.blockchain.CurrentBlock()
	if pivot := rawdb.ReadLastPivotNumber(s.chainDb); pivot != nil {
		if head.Number.Uint64() < *pivot {
			return downloader.SnapSync
		}
	}
	// We are in a full sync, but the associated head state is missing. To complete
	// the head state, forcefully rerun the snap sync. Note it doesn't mean the
	// persistent state is corrupted, just mismatch with the head block.
	if !s.blockchain.HasState(head.Root) {
		log.Info("Reenabled snap sync as chain is stateless")
		return downloader.SnapSync
	}
	// Nope, we're really full syncing
	return downloader.FullSync
}