Escrow Smart Contract

1import "@contracts/common-messages"
2import "@contracts/errors"
3import "@contracts/contract_USDT/usdt-utils"
4import "fees-management"
5import "messages"
6import "storage"

8contract ContractUSDT {
9    author: "Alexandr_K"
10    version: "0.0.4"
11    description: "Escrow contract USDT"
12    storage: StorageUsdt
13    incomingMessages: AllowedMessage
14}

16type AllowedMessage =
17    | TransferNotificationForRecipient
18    | ChangePercent
19    | AcceptPercent
20    | RefundUsdt
21    | ErrRefund
22    | ErrMode
23    | BurnContract

28fun StorageUsdt.isActive(self, extra: ExtraFieldsUsdt): bool {
29    if (extra.completed) {
30        return false;
31    }
32    return self.clientAmount >= extra.clientAmountInit &&
33    self.providerDeposit >= extra.providerDepositInit;
34}

67fun sendExcessesTon(to: address, amount: coins) {
68    if (amount > MIN_MESSAGE_VALUE_BOUND) {
69        val excessesMsg = createMessage({
70            bounce: BounceMode.NoBounce,
71            dest: to,
72            value: amount,
73        });
74        excessesMsg.send(SEND_MODE_IGNORE_ERRORS);
75    }
76}

78fun contractUsdtWallet(): address {
79    return calcAddressOfJettonWallet(contract.getAddress());
80}

105fun onBouncedMessage(in: InMessageBounced) {
106    in.bouncedBody.skipBouncedPrefix();
107    val msg = lazy BounceOpToHandle.fromSlice(in.bouncedBody);
108    var storage = lazy StorageUsdt.load();
109    match (msg) {
110        TransferBounce => {
111            if (msg.queryId == QueryRole.Client as uint64) {
112                storage.clientAmount += msg.jettonAmount;
113            } else if (msg.queryId == QueryRole.Provider as uint64) {
114                storage.providerDeposit += msg.jettonAmount;
115            } else if (msg.queryId == QueryRole.Admin as uint64) {
116                var extra: ExtraFieldsUsdt = lazy storage.extra.load();
117                extra.royaltyInit += msg.jettonAmount;
118                storage.extra = extra.toCell();
119            } else {
120                // ErrRefund (QueryRole.None) и неизвестные id: учёт не уменьшали
121                return;
122            }
123        }
124    }
125    storage.save();
126}

131fun onInternalMessage(in: InMessage) {
132    if (in.body.isEmpty()) {
133        return;
134    }

137val msg = lazy AllowedMessage.fromSlice(in.body);
138var storage: StorageUsdt = lazy StorageUsdt.load();
139val tonBalanceBeforeMsg = contract.getOriginalBalance() - in.valueCoins;
140val storageFee = MIN_TONS_FOR_STORAGE_THIS_CONTRACT -
141min(tonBalanceBeforeMsg, MIN_TONS_FOR_STORAGE_THIS_CONTRACT);
142var msgValue = in.valueCoins - storageFee - CONTRACT_GAS_CONSUMPTION;

145TransferNotificationForRecipient => {
146    assert (in.senderAddress == contractUsdtWallet()) throw Errors.InvalidWallet;
147    assert (msg.transferInitiator != null) throw Errors.InvalidData;
148    if (msg.transferInitiator == storage.clientAddress) {
149        storage.clientAmount += msg.jettonAmount;
150        storage.save();
151    } else if (msg.transferInitiator == storage.providerAddress) {
152        storage.providerDeposit += msg.jettonAmount;
153        storage.save();
154    }
155    sendExcessesTon(msg.transferInitiator, msgValue);
156}

162ChangePercent => {
163    assert (msgValue > 0) throw Errors.NotEnoughGas;
164    assert (in.senderAddress == storage.clientAddress) throw Errors.UnauthorizedSender;
165    assert (msg.percent >= 0 && msg.percent <= 100) throw Errors.WrongPercent;
166    var extra: ExtraFieldsUsdt = lazy storage.extra.load();
167    assert (extra.completed == false) throw Errors.ContractIsCompleted;
168    assert (storage.isActive(extra)) throw Errors.ContractIsNotActive;
169    extra.percent = msg.percent;
170    if (msg.percent == 100) {
171        extra.completed = true;
172        storage.providerDeposit += extra.clientAmountInit - extra.royaltyInit;
173        storage.clientAmount -= extra.clientAmountInit;
174    }
175    storage.extra = extra.toCell();
176    storage.save();
177    sendExcessesTon(in.senderAddress, msgValue);
178}

183AcceptPercent => {
184    assert (msgValue > 0) throw Errors.NotEnoughGas;
185    assert (in.senderAddress == storage.providerAddress) throw Errors.UnauthorizedSender;
186    var extra: ExtraFieldsUsdt = lazy storage.extra.load();
187    assert (extra.completed == false) throw Errors.ContractIsCompleted;
188    assert (extra.percent != 100) throw Errors.WrongPercent;
189    assert (msg.percent == extra.percent) throw Errors.WrongPercent;
190    extra.completed = true;
191    val percentValue = extra.clientAmountInit / 100 * msg.percent;
192    if (msg.percent == 0) {
193        extra.royaltyInit = 0;
194    }
195    storage.providerDeposit += percentValue - extra.royaltyInit;
196    storage.clientAmount -= percentValue;
197    storage.extra = extra.toCell();
198    storage.save();
199    sendExcessesTon(in.senderAddress, msgValue);
200}

208RefundUsdt => {
209    msgValue -= (MIN_MESSAGE_VALUE_BOUND + MIN_FORWARD_TON_AMOUNT);
210    assert (msgValue > 0) throw Errors.NotEnoughGas;
211    assert (msg.jettonAmount > 0) throw Errors.InvalidData;
212    var extra: ExtraFieldsUsdt = lazy storage.extra.load();
213    val transferRecipient: address = msg.addressRefund != null
214        ? msg.addressRefund
215        : in.senderAddress;
216    val isActive = storage.isActive(extra);
217    var queryId: uint64;
218    var jettonAmount: coins;
219    if (in.senderAddress == storage.clientAddress) {
220        queryId = QueryRole.Client;
221        if (isActive) {
222            val deposit: uint72 = (extra.clientAmountInit / 100) * 30;
223            val locked = extra.clientAmountInit + deposit;
224            assert (storage.clientAmount > locked) throw Errors.NotEnoughJettons;
225            jettonAmount = min(storage.clientAmount - locked, msg.jettonAmount);
226        } else {
227            jettonAmount = min(storage.clientAmount, msg.jettonAmount);
228        }
229        storage.clientAmount -= jettonAmount;
230    } else if (in.senderAddress == storage.providerAddress) {
231        queryId = QueryRole.Provider;
232        if (isActive) {
233            assert (
234                storage.providerDeposit > extra.providerDepositInit
235            ) throw Errors.NotEnoughJettons;
236            jettonAmount = min(
237                storage.providerDeposit - extra.providerDepositInit,
238                msg.jettonAmount,
239            );
240        } else {
241            jettonAmount = min(storage.providerDeposit, msg.jettonAmount);
242        }
243        storage.providerDeposit -= jettonAmount;
244    } else if (in.senderAddress == extra.adminAddress) {
245        queryId = QueryRole.Admin;
246        val maxRefundUsdt: uint72 = extra.completed ? extra.royaltyInit : 0;
247        jettonAmount = min(maxRefundUsdt, msg.jettonAmount);
248        extra.royaltyInit -= jettonAmount;
249        storage.extra = extra.toCell();
250    } else {
251        throw Errors.UnauthorizedSender;
252    }
253    assert (jettonAmount > 0) throw Errors.NotEnoughJettons;
254    storage.save();
255    sendAskToTransferUsdt(
256        queryId,
257        jettonAmount,
258        transferRecipient,
259        msgValue + MIN_MESSAGE_VALUE_BOUND + MIN_FORWARD_TON_AMOUNT,
260    );
261}

271ErrMode => {
272    assert (msgValue > 0) throw Errors.NotEnoughGas;
273    var extra: ExtraFieldsUsdt = lazy storage.extra.load();
274    var noticeTo: address? = null;
275    var noticeAboutClient: bool = false;
276    if (in.senderAddress == storage.clientAddress) {
277        if (msg.value == ErrModeVal.ProviderFullRights as int8) {
278            extra.errMode = ErrModeVal.ProviderFullRights;
279        } else if (msg.value == ErrModeVal.BlockErrorMode as int8) {
280            extra.errMode = ErrModeVal.BlockErrorMode;
281        } else if (
282            msg.value == ErrModeVal.ClientFullRightsAfterHalfYear as int8 &&
283            extra.errMode != ErrModeVal.BlockErrorMode as int8
284        ) {
285            extra.errMode = ErrModeVal.ClientFullRightsAfterHalfYear;
286            extra.errModeAt = blockchain.now() as uint64;
287            noticeTo = storage.providerAddress;
288            noticeAboutClient = true;
289        }
290    } else if (in.senderAddress == storage.providerAddress) {
291        if (msg.value == ErrModeVal.ClientFullRights as int8) {
292            extra.errMode = ErrModeVal.ClientFullRights;
293        } else if (msg.value == ErrModeVal.BlockErrorMode as int8) {
294            extra.errMode = ErrModeVal.BlockErrorMode;
295        } else if (
296            msg.value == ErrModeVal.ProviderFullRightsAfterHalfYear as int8 &&
297            extra.errMode != ErrModeVal.BlockErrorMode as int8
298        ) {
299            extra.errMode = ErrModeVal.ProviderFullRightsAfterHalfYear;
300            extra.errModeAt = blockchain.now() as uint64;
301            noticeTo = storage.clientAddress;
302            noticeAboutClient = false;
303        }
304    } else {
305        throw Errors.UnauthorizedSender;
306    }
307    if (noticeTo != null) {
308        assert (msgValue > HALF_YEAR_NOTICE_VALUE) throw Errors.NotEnoughGas;
309        msgValue -= HALF_YEAR_NOTICE_VALUE;
310    }
311    storage.extra = extra.toCell();
312    storage.save();
313    if (noticeTo != null) {
314        sendHalfYearControlNotice(noticeTo, noticeAboutClient);
315    }
316    sendExcessesTon(in.senderAddress, msgValue);
317}

10enum ErrModeVal {
11    ClientFullRights = 1
12    ProviderFullRights = 2
13    ClientFullRightsAfterHalfYear = 16   // клиент получает полные права через полгода
14    ProviderFullRightsAfterHalfYear = 26 // исполнитель — через полгода
15    BlockErrorMode = 99
16}

321ErrRefund => {
322    msgValue -= (MIN_MESSAGE_VALUE_BOUND + MIN_FORWARD_TON_AMOUNT);
323    assert (msgValue > 0) throw Errors.NotEnoughGas;
324    assert (msg.jettonAmount > 0) throw Errors.InvalidData;
325    val extra: ExtraFieldsUsdt = lazy storage.extra.load();
326    if (
327        !extra.allowsErrRefund(
328            in.senderAddress,
329            storage.clientAddress,
330            storage.providerAddress,
331        )
332    ) {
333        throw Errors.UnauthorizedSender;
334    }
335    val transferRecipient: address = msg.addressRefund != null
336        ? msg.addressRefund
337        : in.senderAddress;
338    sendAskToTransferUsdt(
339        QueryRole.None,
340        msg.jettonAmount as coins,
341        transferRecipient,
342        msgValue + MIN_MESSAGE_VALUE_BOUND + MIN_FORWARD_TON_AMOUNT,
343    );
344}

36fun ExtraFieldsUsdt.allowsErrRefund(
37    self,
38    sender: address,
39    client: address,
40    provider: address,
41): bool {
42    if (sender == client) {
43        if (self.errMode == ErrModeVal.ClientFullRights as int8) {
44            return true;
45        }
46        return self.errMode == ErrModeVal.ClientFullRightsAfterHalfYear as int8 &&
47            (blockchain.now() as uint64) >= self.errModeAt + HALF_YEAR;
48    }
49    if (sender == provider) {
50        if (self.errMode == ErrModeVal.ProviderFullRights as int8) {
51            return true;
52        }
53        return self.errMode == ErrModeVal.ProviderFullRightsAfterHalfYear as int8 &&
54            (blockchain.now() as uint64) >= self.errModeAt + HALF_YEAR;
55    }
56    return false;
57}

351BurnContract => {
352    assert (msgValue > 0) throw Errors.NotEnoughGas;
353    val extra: ExtraFieldsUsdt = lazy storage.extra.load();
354    val deployer = extra.deployerAddress(storage.clientAddress, storage.providerAddress);
355    assert (
356        in.senderAddress == deployer || in.senderAddress == extra.adminAddress
357    ) throw Errors.UnauthorizedSender;
358    assert (
359        storage.clientAmount == 0 && storage.providerDeposit == 0
360    ) throw Errors.BalancesNotEmpty;
361    if (extra.completed && extra.royaltyInit > 0) {
362        val jettonTon = MIN_MESSAGE_VALUE_BOUND + MIN_FORWARD_TON_AMOUNT;
363        msgValue -= jettonTon;
364        assert (msgValue > 0) throw Errors.NotEnoughGas;
365        sendAskToTransferUsdt(
366            QueryRole.Admin,
367            extra.royaltyInit as coins,
368            extra.adminAddress,
369            msgValue + jettonTon,
370        );
371    }
372    val burn = createMessage({
373        bounce: BounceMode.NoBounce,
374        dest: in.senderAddress,
375        value: 0,
376    });
377    burn.send(SEND_MODE_CARRY_ALL_BALANCE | SEND_MODE_DESTROY);
378}

59fun ExtraFieldsUsdt.deployerAddress(self, client: address, provider: address): address {
60    if (self.mode == QueryRole.Client as int8) {
61        return client;
62    }
63    assert (self.mode == QueryRole.Provider as int8) throw Errors.UnauthorizedSender;
64    return provider;
65}