func (self *EthReg) Resolver(n *big.Int) *registrar.Registrar {
	xe := self.backend
	if n != nil {
		xe = self.backend.AtStateNum(n.Int64())
	}
	return registrar.New(xe)
}

func testInit(t *testing.T) (self *testFrontend) {
	// initialise and start minimal ethereum stack
	ethereum, err := testEth(t)
	if err != nil {
		t.Errorf("error creating ethereum: %v", err)
		return
	}
	err = ethereum.Start()
	if err != nil {
		t.Errorf("error starting ethereum: %v", err)
		return
	}

	// mock frontend
	self = &testFrontend{t: t, ethereum: ethereum}
	self.xeth = xe.New(ethereum, self)
	self.wait = self.xeth.UpdateState()
	addr, _ := self.ethereum.Etherbase()

	// initialise the registry contracts
	reg := registrar.New(self.xeth)
	var registrarTxhash, hashRegTxhash, urlHintTxhash string
	registrarTxhash, err = reg.SetGlobalRegistrar("", addr)
	if err != nil {
		t.Errorf("error creating GlobalRegistrar: %v", err)
	}

	hashRegTxhash, err = reg.SetHashReg("", addr)
	if err != nil {
		t.Errorf("error creating HashReg: %v", err)
	}
	urlHintTxhash, err = reg.SetUrlHint("", addr)
	if err != nil {
		t.Errorf("error creating UrlHint: %v", err)
	}
	if !processTxs(self, t, 3) {
		t.Errorf("error mining txs")
	}
	_ = registrarTxhash
	_ = hashRegTxhash
	_ = urlHintTxhash

	/* TODO:
	* lookup receipt and contract addresses by tx hash
	* name registration for HashReg and UrlHint addresses
	* mine those transactions
	* then set once more SetHashReg SetUrlHint
	 */

	return

}

// Register registers a new content hash in the registry.
func (api *PrivateRegistarAPI) Register(sender common.Address, addr common.Address, contentHashHex string) (bool, error) {
	block := api.be.bc.CurrentBlock()
	state, err := state.New(block.Root(), api.be.chainDb)
	if err != nil {
		return false, err
	}

	codeb := state.GetCode(addr)
	codeHash := common.BytesToHash(crypto.Keccak256(codeb))
	contentHash := common.HexToHash(contentHashHex)

	_, err = registrar.New(api.be).SetHashToHash(sender, codeHash, contentHash)
	return err == nil, err
}

func (self *adminApi) RegisterUrl(req *shared.Request) (interface{}, error) {
	args := new(RegisterUrlArgs)
	if err := self.coder.Decode(req.Params, &args); err != nil {
		return nil, shared.NewDecodeParamError(err.Error())
	}

	sender := common.HexToAddress(args.Sender)
	registry := registrar.New(self.xeth)
	_, err := registry.SetUrlToHash(sender, common.HexToHash(args.ContentHash), args.Url)
	if err != nil {
		return false, err
	}

	return true, nil
}

func (self *adminApi) SetHashReg(req *shared.Request) (interface{}, error) {
	args := new(SetHashRegArgs)
	if err := self.coder.Decode(req.Params, &args); err != nil {
		return nil, shared.NewDecodeParamError(err.Error())
	}

	reg := registrar.New(self.xeth)
	sender := common.HexToAddress(args.Sender)
	txhash, err := reg.SetHashReg(args.HashReg, sender)
	if err != nil {
		return false, err
	}

	return txhash, nil
}

func (self *adminApi) SetUrlHint(req *shared.Request) (interface{}, error) {
	args := new(SetUrlHintArgs)
	if err := self.coder.Decode(req.Params, &args); err != nil {
		return nil, shared.NewDecodeParamError(err.Error())
	}

	urlHint := args.UrlHint
	sender := common.HexToAddress(args.Sender)

	reg := registrar.New(self.xeth)
	txhash, err := reg.SetUrlHint(urlHint, sender)
	if err != nil {
		return nil, err
	}

	return txhash, nil
}

func (self *adminApi) Register(req *shared.Request) (interface{}, error) {
	args := new(RegisterArgs)
	if err := self.coder.Decode(req.Params, &args); err != nil {
		return nil, shared.NewDecodeParamError(err.Error())
	}

	sender := common.HexToAddress(args.Sender)
	// sender and contract address are passed as hex strings
	codeb := self.xeth.CodeAtBytes(args.Address)
	codeHash := common.BytesToHash(crypto.Sha3(codeb))
	contentHash := common.HexToHash(args.ContentHashHex)
	registry := registrar.New(self.xeth)

	_, err := registry.SetHashToHash(sender, codeHash, contentHash)
	if err != nil {
		return false, err
	}

	return true, nil
}

// also called by admin.contractInfo.get
func FetchDocsForContract(contractAddress string, xeth *xeth.XEth, ds *docserver.DocServer) (content []byte, err error) {
	// retrieve contract hash from state
	codehex := xeth.CodeAt(contractAddress)
	codeb := xeth.CodeAtBytes(contractAddress)

	if codehex == "0x" {
		err = fmt.Errorf("contract (%v) not found", contractAddress)
		return
	}
	codehash := common.BytesToHash(crypto.Sha3(codeb))
	// set up nameresolver with natspecreg + urlhint contract addresses
	reg := registrar.New(xeth)

	// resolve host via HashReg/UrlHint Resolver
	hash, err := reg.HashToHash(codehash)
	if err != nil {
		return
	}
	if ds.HasScheme("bzz") {
		content, err = ds.Get("bzz://"+hash.Hex()[2:], "")
		if err == nil { // non-fatal
			return
		}
		err = nil
		//falling back to urlhint
	}

	uri, err := reg.HashToUrl(hash)
	if err != nil {
		return
	}

	// get content via http client and authenticate content using hash
	content, err = ds.GetAuthContent(uri, hash)
	if err != nil {
		return
	}
	return
}

// RegisterUrl registers a new url in the registry.
func (api *PrivateRegistarAPI) RegisterUrl(sender common.Address, contentHashHex string, url string) (bool, error) {
	_, err := registrar.New(api.be).SetUrlToHash(sender, common.HexToHash(contentHashHex), url)
	return err == nil, err
}

// SetUrlHint queries the registry for an url.
func (api *PrivateRegistarAPI) SetUrlHint(hashreg string, from common.Address) (string, error) {
	return registrar.New(api.be).SetUrlHint(hashreg, from)
}

// SetGlobalRegistrar allows clients to set the global registry for the node.
// This method can be used to deploy a new registry. First zero out the current
// address by calling the method with namereg = '0x0' and then call this method
// again with '' as namereg. This will submit a transaction to the network which
// will deploy a new registry on execution. The TX hash is returned. When called
// with namereg '' and the current address is not zero the current global is
// address is returned..
func (api *PrivateRegistarAPI) SetGlobalRegistrar(namereg string, from common.Address) (string, error) {
	return registrar.New(api.be).SetGlobalRegistrar(namereg, from)
}

// end to end test
func TestNatspecE2E(t *testing.T) {
	t.Skip()

	tf := testInit(t)
	defer tf.ethereum.Stop()
	addr, _ := tf.ethereum.Etherbase()

	// create a contractInfo file (mock cloud-deployed contract metadocs)
	// incidentally this is the info for the HashReg contract itself
	ioutil.WriteFile("/tmp/"+testFileName, []byte(testContractInfo), os.ModePerm)
	dochash := crypto.Keccak256Hash([]byte(testContractInfo))

	// take the codehash for the contract we wanna test
	codeb := tf.xeth.CodeAtBytes(registrar.HashRegAddr)
	codehash := crypto.Keccak256Hash(codeb)

	reg := registrar.New(tf.xeth)
	_, err := reg.SetHashToHash(addr, codehash, dochash)
	if err != nil {
		t.Errorf("error registering: %v", err)
	}
	_, err = reg.SetUrlToHash(addr, dochash, "file:///"+testFileName)
	if err != nil {
		t.Errorf("error registering: %v", err)
	}
	if !processTxs(tf, t, 5) {
		return
	}

	// NatSpec info for register method of HashReg contract installed
	// now using the same transactions to check confirm messages

	tf.wantNatSpec = true // this is set so now the backend uses natspec confirmation
	_, err = reg.SetHashToHash(addr, codehash, dochash)
	if err != nil {
		t.Errorf("error calling contract registry: %v", err)
	}

	fmt.Printf("GlobalRegistrar: %v, HashReg: %v, UrlHint: %v\n", registrar.GlobalRegistrarAddr, registrar.HashRegAddr, registrar.UrlHintAddr)
	if tf.lastConfirm != testExpNotice {
		t.Errorf("Wrong confirm message. expected\n'%v', got\n'%v'", testExpNotice, tf.lastConfirm)
	}

	// test unknown method
	exp := fmt.Sprintf(testExpNotice2, registrar.HashRegAddr)
	_, err = reg.SetOwner(addr)
	if err != nil {
		t.Errorf("error setting owner: %v", err)
	}

	if tf.lastConfirm != exp {
		t.Errorf("Wrong confirm message, expected\n'%v', got\n'%v'", exp, tf.lastConfirm)
	}

	// test unknown contract
	exp = fmt.Sprintf(testExpNotice3, registrar.UrlHintAddr)

	_, err = reg.SetUrlToHash(addr, dochash, "file:///test.content")
	if err != nil {
		t.Errorf("error registering: %v", err)
	}

	if tf.lastConfirm != exp {
		t.Errorf("Wrong confirm message, expected '%v', got '%v'", exp, tf.lastConfirm)
	}

}

func testInit(t *testing.T) (self *testFrontend) {
	// initialise and start minimal ethereum stack
	ethereum, err := testEth(t)
	if err != nil {
		t.Errorf("error creating ethereum: %v", err)
		return
	}
	err = ethereum.Start(nil)
	if err != nil {
		t.Errorf("error starting ethereum: %v", err)
		return
	}

	// mock frontend
	self = &testFrontend{t: t, ethereum: ethereum}
	self.xeth = xe.New(nil, self)
	self.wait = self.xeth.UpdateState()
	addr, _ := self.ethereum.Etherbase()

	// initialise the registry contracts
	reg := registrar.New(self.xeth)
	registrar.GlobalRegistrarAddr = "0x0"

	var txG, txH, txU string
	txG, err = reg.SetGlobalRegistrar("", addr)
	if err != nil {
		t.Fatalf("error creating GlobalRegistrar: %v", err)
	}
	if !processTxs(self, t, 1) {
		t.Fatalf("error mining txs")
	}
	recG := self.xeth.GetTxReceipt(common.HexToHash(txG))
	if recG == nil {
		t.Fatalf("blockchain error creating GlobalRegistrar")
	}
	registrar.GlobalRegistrarAddr = recG.ContractAddress.Hex()

	txH, err = reg.SetHashReg("", addr)
	if err != nil {
		t.Errorf("error creating HashReg: %v", err)
	}
	if !processTxs(self, t, 1) {
		t.Errorf("error mining txs")
	}
	recH := self.xeth.GetTxReceipt(common.HexToHash(txH))
	if recH == nil {
		t.Fatalf("blockchain error creating HashReg")
	}
	registrar.HashRegAddr = recH.ContractAddress.Hex()

	txU, err = reg.SetUrlHint("", addr)
	if err != nil {
		t.Errorf("error creating UrlHint: %v", err)
	}
	if !processTxs(self, t, 1) {
		t.Errorf("error mining txs")
	}
	recU := self.xeth.GetTxReceipt(common.HexToHash(txU))
	if recU == nil {
		t.Fatalf("blockchain error creating UrlHint")
	}
	registrar.UrlHintAddr = recU.ContractAddress.Hex()

	return
}

func TestContract(t *testing.T) {
	t.Skip("contract testing is implemented with mining in ethash test mode. This takes about 7seconds to run. Unskip and run on demand")
	coinbase := common.HexToAddress(testAddress)
	tmp, repl, ethereum := testREPL(t, func(conf *eth.Config) {
		conf.Etherbase = coinbase
		conf.PowTest = true
	})
	if err := ethereum.Start(); err != nil {
		t.Errorf("error starting ethereum: %v", err)
		return
	}
	defer ethereum.Stop()
	defer os.RemoveAll(tmp)

	reg := registrar.New(repl.xeth)
	_, err := reg.SetGlobalRegistrar("", coinbase)
	if err != nil {
		t.Errorf("error setting HashReg: %v", err)
	}
	_, err = reg.SetHashReg("", coinbase)
	if err != nil {
		t.Errorf("error setting HashReg: %v", err)
	}
	_, err = reg.SetUrlHint("", coinbase)
	if err != nil {
		t.Errorf("error setting HashReg: %v", err)
	}
	/* TODO:
	* lookup receipt and contract addresses by tx hash
	* name registration for HashReg and UrlHint addresses
	* mine those transactions
	* then set once more SetHashReg SetUrlHint
	 */

	source := `contract test {\n` +
		"   /// @notice Will multiply `a` by 7." + `\n` +
		`   function multiply(uint a) returns(uint d) {\n` +
		`       return a * 7;\n` +
		`   }\n` +
		`}\n`

	if checkEvalJSON(t, repl, `admin.stopNatSpec()`, `true`) != nil {
		return
	}

	contractInfo, err := ioutil.ReadFile("info_test.json")
	if err != nil {
		t.Fatalf("%v", err)
	}
	if checkEvalJSON(t, repl, `primary = eth.accounts[0]`, `"`+testAddress+`"`) != nil {
		return
	}
	if checkEvalJSON(t, repl, `source = "`+source+`"`, `"`+source+`"`) != nil {
		return
	}

	// if solc is found with right version, test it, otherwise read from file
	sol, err := compiler.New("")
	if err != nil {
		t.Logf("solc not found: mocking contract compilation step")
	} else if sol.Version() != solcVersion {
		t.Logf("WARNING: solc different version found (%v, test written for %v, may need to update)", sol.Version(), solcVersion)
	}

	if err != nil {
		info, err := ioutil.ReadFile("info_test.json")
		if err != nil {
			t.Fatalf("%v", err)
		}
		_, err = repl.re.Run(`contract = JSON.parse(` + strconv.Quote(string(info)) + `)`)
		if err != nil {
			t.Errorf("%v", err)
		}
	} else {
		if checkEvalJSON(t, repl, `contract = eth.compile.solidity(source).test`, string(contractInfo)) != nil {
			return
		}
	}

	if checkEvalJSON(t, repl, `contract.code`, `"0x605880600c6000396000f3006000357c010000000000000000000000000000000000000000000000000000000090048063c6888fa114602e57005b603d6004803590602001506047565b8060005260206000f35b60006007820290506053565b91905056"`) != nil {
		return
	}

	if checkEvalJSON(
		t, repl,
		`contractaddress = eth.sendTransaction({from: primary, data: contract.code})`,
		`"0x46d69d55c3c4b86a924a92c9fc4720bb7bce1d74"`,
	) != nil {
		return
	}

	if !processTxs(repl, t, 8) {
		return
	}

	callSetup := `abiDef = JSON.parse('[{"constant":false,"inputs":[{"name":"a","type":"uint256"}],"name":"multiply","outputs":[{"name":"d","type":"uint256"}],"type":"function"}]');
Multiply7 = eth.contract(abiDef);
multiply7 = Multiply7.at(contractaddress);
`
	_, err = repl.re.Run(callSetup)
//.........这里部分代码省略.........

func New(xe *xeth.XEth) (self *EthReg) {
	self = &EthReg{backend: xe}
	self.registry = registrar.New(xe)
	return
}