// CreateTransaction returns a fully signed transaction paying to the specified
// outputs while observing the desired fee rate. The passed fee rate should be
// expressed in satoshis-per-byte.
//
// This function is safe for concurrent access.
func (m *memWallet) CreateTransaction(outputs []*wire.TxOut, feeRate btcutil.Amount) (*wire.MsgTx, error) {
	m.Lock()
	defer m.Unlock()

	tx := wire.NewMsgTx()

	// Tally up the total amount to be sent in order to perform coin
	// selection shortly below.
	var outputAmt btcutil.Amount
	for _, output := range outputs {
		outputAmt += btcutil.Amount(output.Value)
		tx.AddTxOut(output)
	}

	// Attempt to fund the transaction with spendable utxos.
	if err := m.fundTx(tx, outputAmt, btcutil.Amount(feeRate)); err != nil {
		return nil, err
	}

	// Populate all the selected inputs with valid sigScript for spending.
	// Along the way record all outputs being spent in order to avoid a
	// potential double spend.
	spentOutputs := make([]*utxo, 0, len(tx.TxIn))
	for i, txIn := range tx.TxIn {
		outPoint := txIn.PreviousOutPoint
		utxo := m.utxos[outPoint]

		extendedKey, err := m.hdRoot.Child(utxo.keyIndex)
		if err != nil {
			return nil, err
		}

		privKey, err := extendedKey.ECPrivKey()
		if err != nil {
			return nil, err
		}

		sigScript, err := txscript.SignatureScript(tx, i, utxo.pkScript,
			txscript.SigHashAll, privKey, true)
		if err != nil {
			return nil, err
		}

		txIn.SignatureScript = sigScript

		spentOutputs = append(spentOutputs, utxo)
	}

	// As these outputs are now being spent by this newly created
	// transaction, mark the outputs are "locked". This action ensures
	// these outputs won't be double spent by any subsequent transactions.
	// These locked outputs can be freed via a call to UnlockOutputs.
	for _, utxo := range spentOutputs {
		utxo.isLocked = true
	}

	return tx, nil
}

func TestOutputSplittingOversizeTx(t *testing.T) {
	tearDown, pool, _ := TstCreatePoolAndTxStore(t)
	defer tearDown()

	requestAmount := btcutil.Amount(5)
	bigInput := int64(3)
	smallInput := int64(2)
	request := TstNewOutputRequest(
		t, 1, "34eVkREKgvvGASZW7hkgE2uNc1yycntMK6", requestAmount, pool.Manager().ChainParams())
	seriesID, eligible := TstCreateCreditsOnNewSeries(t, pool, []int64{smallInput, bigInput})
	changeStart := TstNewChangeAddress(t, pool, seriesID, 0)
	w := newWithdrawal(0, []OutputRequest{request}, eligible, *changeStart)
	w.txOptions = func(tx *withdrawalTx) {
		tx.calculateFee = TstConstantFee(0)
		tx.calculateSize = func() int {
			// Trigger an output split right after the second input is added.
			if len(tx.inputs) == 2 {
				return txMaxSize + 1
			}
			return txMaxSize - 1
		}
	}

	if err := w.fulfillRequests(); err != nil {
		t.Fatal(err)
	}

	if len(w.transactions) != 2 {
		t.Fatalf("Wrong number of finalized transactions; got %d, want 2", len(w.transactions))
	}

	tx1 := w.transactions[0]
	if len(tx1.outputs) != 1 {
		t.Fatalf("Wrong number of outputs on tx1; got %d, want 1", len(tx1.outputs))
	}
	if tx1.outputs[0].amount != btcutil.Amount(bigInput) {
		t.Fatalf("Wrong amount for output in tx1; got %d, want %d", tx1.outputs[0].amount,
			bigInput)
	}

	tx2 := w.transactions[1]
	if len(tx2.outputs) != 1 {
		t.Fatalf("Wrong number of outputs on tx2; got %d, want 1", len(tx2.outputs))
	}
	if tx2.outputs[0].amount != btcutil.Amount(smallInput) {
		t.Fatalf("Wrong amount for output in tx2; got %d, want %d", tx2.outputs[0].amount,
			smallInput)
	}

	if len(w.status.outputs) != 1 {
		t.Fatalf("Wrong number of output statuses; got %d, want 1", len(w.status.outputs))
	}
	status := w.status.outputs[request.outBailmentID()].status
	if status != statusSplit {
		t.Fatalf("Wrong output status; got '%s', want '%s'", status, statusSplit)
	}
}

func TestWithdrawalTxInputTotal(t *testing.T) {
	tearDown, pool, _ := TstCreatePoolAndTxStore(t)
	defer tearDown()

	tx := createWithdrawalTx(t, pool, []int64{5}, []int64{})

	if tx.inputTotal() != btcutil.Amount(5) {
		t.Fatalf("Wrong total output; got %v, want %v", tx.outputTotal(), btcutil.Amount(5))
	}
}

func TestWithdrawalTxOutputTotal(t *testing.T) {
	tearDown, pool, _ := TstCreatePoolAndTxStore(t)
	defer tearDown()

	tx := createWithdrawalTx(t, pool, []int64{}, []int64{4})
	tx.changeOutput = wire.NewTxOut(int64(1), []byte{})

	if tx.outputTotal() != btcutil.Amount(4) {
		t.Fatalf("Wrong total output; got %v, want %v", tx.outputTotal(), btcutil.Amount(4))
	}
}

func TestStoreTransactionsWithChangeOutput(t *testing.T) {
	tearDown, pool, store := TstCreatePoolAndTxStore(t)
	defer tearDown()

	wtx := createWithdrawalTxWithStoreCredits(t, store, pool, []int64{5e6}, []int64{1e6, 1e6})
	wtx.changeOutput = wire.NewTxOut(int64(3e6), []byte{})
	msgtx := wtx.toMsgTx()
	tx := &changeAwareTx{MsgTx: msgtx, changeIdx: int32(len(msgtx.TxOut) - 1)}

	if err := storeTransactions(store, []*changeAwareTx{tx}); err != nil {
		t.Fatal(err)
	}

	sha := msgtx.TxSha()
	txDetails, err := store.TxDetails(&sha)
	if err != nil {
		t.Fatal(err)
	}
	if txDetails == nil {
		t.Fatal("The new tx doesn't seem to have been stored")
	}

	storedTx := txDetails.TxRecord.MsgTx
	outputTotal := int64(0)
	for i, txOut := range storedTx.TxOut {
		if int32(i) != tx.changeIdx {
			outputTotal += txOut.Value
		}
	}
	if outputTotal != int64(2e6) {
		t.Fatalf("Unexpected output amount; got %v, want %v", outputTotal, int64(2e6))
	}

	inputTotal := btcutil.Amount(0)
	for _, debit := range txDetails.Debits {
		inputTotal += debit.Amount
	}
	if inputTotal != btcutil.Amount(5e6) {
		t.Fatalf("Unexpected input amount; got %v, want %v", inputTotal, btcutil.Amount(5e6))
	}

	credits, err := store.UnspentOutputs()
	if err != nil {
		t.Fatal(err)
	}
	if len(credits) != 1 {
		t.Fatalf("Unexpected number of credits in txstore; got %d, want 1", len(credits))
	}
	changeOutpoint := wire.OutPoint{Hash: sha, Index: uint32(tx.changeIdx)}
	if credits[0].OutPoint != changeOutpoint {
		t.Fatalf("Credit's outpoint (%v) doesn't match the one from change output (%v)",
			credits[0].OutPoint, changeOutpoint)
	}
}

func testFundingTransactionLockedOutputs(lnwallet *LightningWallet, t *testing.T) {
	// Create two channels, both asking for 8 BTC each, totalling 16
	// BTC.
	// TODO(roasbeef): tests for concurrent funding.
	//  * also func for below
	fundingAmount := btcutil.Amount(8 * 1e8)
	chanReservation1, err := lnwallet.InitChannelReservation(fundingAmount,
		SIGHASH, testHdSeed, 4)
	if err != nil {
		t.Fatalf("unable to initialize funding reservation 1: %v", err)
	}
	chanReservation2, err := lnwallet.InitChannelReservation(fundingAmount,
		SIGHASH, testHdSeed, 4)
	if err != nil {
		t.Fatalf("unable to initialize funding reservation 2: %v", err)
	}

	// Neither should have any change, as all our output sizes are
	// identical (4BTC).
	ourContribution1 := chanReservation1.OurContribution()
	if len(ourContribution1.Inputs) != 2 {
		t.Fatalf("outputs for funding tx not properly selected, has %v "+
			"outputs should have 2", len(ourContribution1.Inputs))
	}
	if len(ourContribution1.ChangeOutputs) != 0 {
		t.Fatalf("funding transaction should have no change, instead has %v",
			len(ourContribution1.ChangeOutputs))
	}
	ourContribution2 := chanReservation2.OurContribution()
	if len(ourContribution2.Inputs) != 2 {
		t.Fatalf("outputs for funding tx not properly selected, have %v "+
			"outputs should have 2", len(ourContribution2.Inputs))
	}
	if len(ourContribution2.ChangeOutputs) != 0 {
		t.Fatalf("funding transaction should have no change, instead has %v",
			len(ourContribution2.ChangeOutputs))
	}

	// Now attempt to reserve funds for another channel, this time requesting
	// 5 BTC. We only have 4BTC worth of outpoints that aren't locked, so
	// this should fail.
	amt := btcutil.Amount(8 * 1e8)
	failedReservation, err := lnwallet.InitChannelReservation(amt,
		SIGHASH, testHdSeed, 4)
	if err == nil {
		t.Fatalf("not error returned, should fail on coin selection")
	}
	if err != coinset.ErrCoinsNoSelectionAvailable {
		t.Fatalf("error not coinselect error: %v", err)
	}
	if failedReservation != nil {
		t.Fatalf("reservation should be nil")
	}
}

// TestRollbackLastOutputWhenNewOutputAdded checks that we roll back the last
// output if a tx becomes too big right after we add a new output to it.
func TestRollbackLastOutputWhenNewOutputAdded(t *testing.T) {
	tearDown, pool, _ := TstCreatePoolAndTxStore(t)
	defer tearDown()

	net := pool.Manager().ChainParams()
	series, eligible := TstCreateCreditsOnNewSeries(t, pool, []int64{5, 5})
	requests := []OutputRequest{
		// This is ordered by bailment ID
		TstNewOutputRequest(t, 1, "34eVkREKgvvGASZW7hkgE2uNc1yycntMK6", 1, net),
		TstNewOutputRequest(t, 2, "3PbExiaztsSYgh6zeMswC49hLUwhTQ86XG", 2, net),
	}
	changeStart := TstNewChangeAddress(t, pool, series, 0)

	w := newWithdrawal(0, requests, eligible, *changeStart)
	w.txOptions = func(tx *withdrawalTx) {
		tx.calculateFee = TstConstantFee(0)
		tx.calculateSize = func() int {
			// Trigger an output split right after the second output is added.
			if len(tx.outputs) > 1 {
				return txMaxSize + 1
			}
			return txMaxSize - 1
		}
	}

	if err := w.fulfillRequests(); err != nil {
		t.Fatal("Unexpected error:", err)
	}

	// At this point we should have two finalized transactions.
	if len(w.transactions) != 2 {
		t.Fatalf("Wrong number of finalized transactions; got %d, want 2", len(w.transactions))
	}

	// First tx should have one output with 1 and one change output with 4
	// satoshis.
	firstTx := w.transactions[0]
	req1 := requests[0]
	checkTxOutputs(t, firstTx,
		[]*withdrawalTxOut{&withdrawalTxOut{request: req1, amount: req1.Amount}})
	checkTxChangeAmount(t, firstTx, btcutil.Amount(4))

	// Second tx should have one output with 2 and one changeoutput with 3 satoshis.
	secondTx := w.transactions[1]
	req2 := requests[1]
	checkTxOutputs(t, secondTx,
		[]*withdrawalTxOut{&withdrawalTxOut{request: req2, amount: req2.Amount}})
	checkTxChangeAmount(t, secondTx, btcutil.Amount(3))
}

func ExampleAmount() {

	a := btcutil.Amount(0)
	fmt.Println("Zero Satoshi:", a)

	a = btcutil.Amount(1e8)
	fmt.Println("100,000,000 Satoshis:", a)

	a = btcutil.Amount(1e5)
	fmt.Println("100,000 Satoshis:", a)
	// Output:
	// Zero Satoshi: 0 BTC
	// 100,000,000 Satoshis: 1 BTC
	// 100,000 Satoshis: 0.001 BTC
}

// Check that some requested outputs are not fulfilled when we don't have credits for all
// of them.
func TestFulfillRequestsNotEnoughCreditsForAllRequests(t *testing.T) {
	tearDown, pool, _ := TstCreatePoolAndTxStore(t)
	defer tearDown()
	net := pool.Manager().ChainParams()

	// Create eligible inputs and the list of outputs we need to fulfil.
	seriesID, eligible := TstCreateCreditsOnNewSeries(t, pool, []int64{2e6, 4e6})
	out1 := TstNewOutputRequest(
		t, 1, "34eVkREKgvvGASZW7hkgE2uNc1yycntMK6", btcutil.Amount(3e6), net)
	out2 := TstNewOutputRequest(
		t, 2, "3PbExiaztsSYgh6zeMswC49hLUwhTQ86XG", btcutil.Amount(2e6), net)
	out3 := TstNewOutputRequest(
		t, 3, "3Qt1EaKRD9g9FeL2DGkLLswhK1AKmmXFSe", btcutil.Amount(5e6), net)
	outputs := []OutputRequest{out1, out2, out3}
	changeStart := TstNewChangeAddress(t, pool, seriesID, 0)

	w := newWithdrawal(0, outputs, eligible, *changeStart)
	if err := w.fulfillRequests(); err != nil {
		t.Fatal(err)
	}

	tx := w.transactions[0]
	// The created tx should spend both eligible credits, so we expect it to have
	// an input amount of 2e6+4e6 satoshis.
	inputAmount := eligible[0].Amount + eligible[1].Amount
	// We expect it to include outputs for requests 1 and 2, plus a change output, but
	// output request #3 should not be there because we don't have enough credits.
	change := inputAmount - (out1.Amount + out2.Amount + tx.calculateFee())
	expectedOutputs := []OutputRequest{out1, out2}
	sort.Sort(byOutBailmentID(expectedOutputs))
	expectedOutputs = append(
		expectedOutputs, TstNewOutputRequest(t, 4, changeStart.addr.String(), change, net))
	msgtx := tx.toMsgTx()
	checkMsgTxOutputs(t, msgtx, expectedOutputs)

	// withdrawal.status should state that outputs 1 and 2 were successfully fulfilled,
	// and that output 3 was not.
	expectedStatuses := map[OutBailmentID]outputStatus{
		out1.outBailmentID(): statusSuccess,
		out2.outBailmentID(): statusSuccess,
		out3.outBailmentID(): statusPartial}
	for _, wOutput := range w.status.outputs {
		if wOutput.status != expectedStatuses[wOutput.request.outBailmentID()] {
			t.Fatalf("Unexpected status for %v; got '%s', want '%s'", wOutput.request,
				wOutput.status, expectedStatuses[wOutput.request.outBailmentID()])
		}
	}
}

func TestHarness(t *testing.T) {
	// We should have (numMatureOutputs * 50 BTC) of mature unspendable
	// outputs.
	expectedBalance := btcutil.Amount(numMatureOutputs * 50 * btcutil.SatoshiPerBitcoin)
	harnessBalance := mainHarness.ConfirmedBalance()
	if harnessBalance != expectedBalance {
		t.Fatalf("expected wallet balance of %v instead have %v",
			expectedBalance, harnessBalance)
	}

	// Current tip should be at a height of numMatureOutputs plus the
	// required number of blocks for coinbase maturity.
	nodeInfo, err := mainHarness.Node.GetInfo()
	if err != nil {
		t.Fatalf("unable to execute getinfo on node: %v", err)
	}
	expectedChainHeight := numMatureOutputs + uint32(mainHarness.ActiveNet.CoinbaseMaturity)
	if uint32(nodeInfo.Blocks) != expectedChainHeight {
		t.Errorf("Chain height is %v, should be %v",
			nodeInfo.Blocks, expectedChainHeight)
	}

	for _, testCase := range harnessTestCases {
		testCase(mainHarness, t)
	}

	testTearDownAll(t)
}

// getFundingParams pulls the relevant transaction information from the json returned by blockchain.info
// To generate a new valid transaction all of the parameters of the TxOut we are
// spending from must be used.
func getFundingParams(rawtx *blockChainInfoTx, vout uint32) (*wire.TxOut, *wire.OutPoint) {
	blkChnTxOut := rawtx.Outputs[vout]

	hash, err := wire.NewShaHashFromStr(rawtx.Hash)
	if err != nil {
		log.Fatal(err)
	}

	// Then convert it to a btcutil amount
	amnt := btcutil.Amount(int64(blkChnTxOut.Value))

	if err != nil {
		log.Fatal(err)
	}

	outpoint := wire.NewOutPoint(hash, vout)

	subscript, err := hex.DecodeString(blkChnTxOut.ScriptHex)
	if err != nil {
		log.Fatal(err)
	}

	oldTxOut := wire.NewTxOut(int64(amnt), subscript)

	return oldTxOut, outpoint
}

// TstCreateCreditsOnStore inserts a new credit in the given store for
// every item in the amounts slice.
func TstCreateCreditsOnStore(t *testing.T, s *wtxmgr.Store, pkScript []byte,
	amounts []int64) []wtxmgr.Credit {
	msgTx := createMsgTx(pkScript, amounts)
	meta := &wtxmgr.BlockMeta{
		Block: wtxmgr.Block{Height: TstInputsBlock},
	}

	rec, err := wtxmgr.NewTxRecordFromMsgTx(msgTx, time.Now())
	if err != nil {
		t.Fatal(err)
	}

	if err := s.InsertTx(rec, meta); err != nil {
		t.Fatal("Failed to create inputs: ", err)
	}

	credits := make([]wtxmgr.Credit, len(msgTx.TxOut))
	for i := range msgTx.TxOut {
		if err := s.AddCredit(rec, meta, uint32(i), false); err != nil {
			t.Fatal("Failed to create inputs: ", err)
		}
		credits[i] = wtxmgr.Credit{
			OutPoint: wire.OutPoint{
				Hash:  rec.Hash,
				Index: uint32(i),
			},
			BlockMeta: *meta,
			Amount:    btcutil.Amount(msgTx.TxOut[i].Value),
			PkScript:  msgTx.TxOut[i].PkScript,
		}
	}
	return credits
}

// TstCreateSeriesCredits creates a new credit for every item in the amounts
// slice, locked to the given series' address with branch==1 and index==0.
func TstCreateSeriesCredits(t *testing.T, pool *Pool, seriesID uint32, amounts []int64) []credit {
	addr := TstNewWithdrawalAddress(t, pool, seriesID, Branch(1), Index(0))
	pkScript, err := txscript.PayToAddrScript(addr.addr)
	if err != nil {
		t.Fatal(err)
	}
	msgTx := createMsgTx(pkScript, amounts)
	txHash := msgTx.TxHash()
	credits := make([]credit, len(amounts))
	for i := range msgTx.TxOut {
		c := wtxmgr.Credit{
			OutPoint: wire.OutPoint{
				Hash:  txHash,
				Index: uint32(i),
			},
			BlockMeta: wtxmgr.BlockMeta{
				Block: wtxmgr.Block{Height: TstInputsBlock},
			},
			Amount:   btcutil.Amount(msgTx.TxOut[i].Value),
			PkScript: msgTx.TxOut[i].PkScript,
		}
		credits[i] = newCredit(c, *addr)
	}
	return credits
}

func createAndFulfillWithdrawalRequests(t *testing.T, pool *Pool, roundID uint32) withdrawalInfo {

	params := pool.Manager().ChainParams()
	seriesID, eligible := TstCreateCreditsOnNewSeries(t, pool, []int64{2e6, 4e6})
	requests := []OutputRequest{
		TstNewOutputRequest(t, 1, "34eVkREKgvvGASZW7hkgE2uNc1yycntMK6", 3e6, params),
		TstNewOutputRequest(t, 2, "3PbExiaztsSYgh6zeMswC49hLUwhTQ86XG", 2e6, params),
	}
	changeStart := TstNewChangeAddress(t, pool, seriesID, 0)
	dustThreshold := btcutil.Amount(1e4)
	startAddr := TstNewWithdrawalAddress(t, pool, seriesID, 1, 0)
	lastSeriesID := seriesID
	w := newWithdrawal(roundID, requests, eligible, *changeStart)
	if err := w.fulfillRequests(); err != nil {
		t.Fatal(err)
	}
	return withdrawalInfo{
		requests:      requests,
		startAddress:  *startAddr,
		changeStart:   *changeStart,
		lastSeriesID:  lastSeriesID,
		dustThreshold: dustThreshold,
		status:        *w.status,
	}
}

// evalOutputs evaluates each of the passed outputs, creating a new matching
// utxo within the wallet if we're able to spend the output.
func (m *memWallet) evalOutputs(outputs []*wire.TxOut, txHash *chainhash.Hash,
	isCoinbase bool, undo *undoEntry) {

	for i, output := range outputs {
		pkScript := output.PkScript

		// Scan all the addresses we currently control to see if the
		// output is paying to us.
		for keyIndex, addr := range m.addrs {
			pkHash := addr.ScriptAddress()
			if !bytes.Contains(pkScript, pkHash) {
				continue
			}

			// If this is a coinbase output, then we mark the
			// maturity height at the proper block height in the
			// future.
			var maturityHeight int32
			if isCoinbase {
				maturityHeight = m.currentHeight + int32(m.net.CoinbaseMaturity)
			}

			op := wire.OutPoint{Hash: *txHash, Index: uint32(i)}
			m.utxos[op] = &utxo{
				value:          btcutil.Amount(output.Value),
				keyIndex:       keyIndex,
				maturityHeight: maturityHeight,
				pkScript:       pkScript,
			}
			undo.utxosCreated = append(undo.utxosCreated, op)
		}
	}
}

// parseAccountBalanceNtfnParams parses out the account name, total balance,
// and whether or not the balance is confirmed or unconfirmed from the
// parameters of an accountbalance notification.
func parseAccountBalanceNtfnParams(params []json.RawMessage) (account string,
	balance btcutil.Amount, confirmed bool, err error) {

	if len(params) != 3 {
		return "", 0, false, wrongNumParams(len(params))
	}

	// Unmarshal first parameter as a string.
	err = json.Unmarshal(params[0], &account)
	if err != nil {
		return "", 0, false, err
	}

	// Unmarshal second parameter as a floating point number.
	var fbal float64
	err = json.Unmarshal(params[1], &fbal)
	if err != nil {
		return "", 0, false, err
	}

	// Unmarshal third parameter as a boolean.
	err = json.Unmarshal(params[2], &confirmed)
	if err != nil {
		return "", 0, false, err
	}

	// Bounds check amount.
	bal, err := btcutil.NewAmount(fbal)
	if err != nil {
		return "", 0, false, err
	}

	return account, btcutil.Amount(bal), confirmed, nil
}

// parseTxAcceptedNtfnParams parses out the transaction hash and total amount
// from the parameters of a txaccepted notification.
func parseTxAcceptedNtfnParams(params []json.RawMessage) (*wire.ShaHash,
	btcutil.Amount, error) {

	if len(params) != 2 {
		return nil, 0, wrongNumParams(len(params))
	}

	// Unmarshal first parameter as a string.
	var txShaStr string
	err := json.Unmarshal(params[0], &txShaStr)
	if err != nil {
		return nil, 0, err
	}

	// Unmarshal second parameter as a floating point number.
	var famt float64
	err = json.Unmarshal(params[1], &famt)
	if err != nil {
		return nil, 0, err
	}

	// Bounds check amount.
	amt, err := btcutil.NewAmount(famt)
	if err != nil {
		return nil, 0, err
	}

	// Decode string encoding of transaction sha.
	txSha, err := wire.NewShaHashFromStr(txShaStr)
	if err != nil {
		return nil, 0, err
	}

	return txSha, btcutil.Amount(amt), nil
}

func fetchRawUnminedCreditAmount(v []byte) (btcutil.Amount, error) {
	if len(v) < 9 {
		str := "short unmined credit value"
		return 0, storeError(ErrData, str, nil)
	}
	return btcutil.Amount(byteOrder.Uint64(v)), nil
}

func makeInputSource(unspents []*wire.TxOut) InputSource {
	// Return outputs in order.
	currentTotal := btcutil.Amount(0)
	currentInputs := make([]*wire.TxIn, 0, len(unspents))
	f := func(target btcutil.Amount) (btcutil.Amount, []*wire.TxIn, [][]byte, error) {
		for currentTotal < target && len(unspents) != 0 {
			u := unspents[0]
			unspents = unspents[1:]
			nextInput := wire.NewTxIn(&wire.OutPoint{}, nil)
			currentTotal += btcutil.Amount(u.Value)
			currentInputs = append(currentInputs, nextInput)
		}
		return currentTotal, currentInputs, make([][]byte, len(currentInputs)), nil
	}
	return InputSource(f)
}

// Check that withdrawal.status correctly states that no outputs were fulfilled when we
// don't have enough eligible credits for any of them.
func TestFulfillRequestsNoSatisfiableOutputs(t *testing.T) {
	tearDown, pool, _ := TstCreatePoolAndTxStore(t)
	defer tearDown()

	seriesID, eligible := TstCreateCreditsOnNewSeries(t, pool, []int64{1e6})
	request := TstNewOutputRequest(
		t, 1, "3Qt1EaKRD9g9FeL2DGkLLswhK1AKmmXFSe", btcutil.Amount(3e6), pool.Manager().ChainParams())
	changeStart := TstNewChangeAddress(t, pool, seriesID, 0)

	w := newWithdrawal(0, []OutputRequest{request}, eligible, *changeStart)
	if err := w.fulfillRequests(); err != nil {
		t.Fatal(err)
	}

	if len(w.transactions) != 0 {
		t.Fatalf("Unexpected number of transactions; got %d, want 0", len(w.transactions))
	}

	if len(w.status.outputs) != 1 {
		t.Fatalf("Unexpected number of outputs in WithdrawalStatus; got %d, want 1",
			len(w.status.outputs))
	}

	status := w.status.outputs[request.outBailmentID()].status
	if status != statusPartial {
		t.Fatalf("Unexpected status for requested outputs; got '%s', want '%s'",
			status, statusPartial)
	}
}