fix(watchtower): fix watchtower taker-side restart bug

[caglaryucekaya]

This PR fixes #1887, which causes the swaps to appear failed on the taker side if the watcher already completed it and the taker is restarted. The issue is fixed by checking if the watcher has spent the maker payment or refunded the taker payment before kick-starting an unfinished saved swap. If the watcher has not completed the swap, taker continues the swap itself. If the watcher has completed the swap, the saved swap is also completed by using new events MakerPaymentSpentByWatcher or TakerPaymentRefundedByWatcher.

[smk762]

@kivqa @endrilickollari to test this one, set up a UTXO (e.g. doc/marty) swap to yourself or each other with legacy desktop and/or CLI. After taker has sent payment, but before maker has validated / confirmed it, kill the maker and taker. Leave them dead for a few hours / overnight; long enough for the refund process to initiate - the watchtower should complete the refund / trade.

Once done, review your swap json files for the swap uuid. Confirm they contain the new events listed in #1908 (comment)

[cipig]

started swap, killed taker after takerpayment sent and waited for watcher to send makerpayment to taker in this tx https://kmdexplorer.io/tx/a2513faf3d479b8e14096be9b0ba8977d669a7a9ca722be0e2bbe3833fa51a4e, then restarted taker

swap is shown as successful but also as "recoverable":

when i click "recover funds" i get this error:

{
    "error": "rpc:211] dispatcher_legacy:141] lp_swap:1290] saved_swap:115] taker_swap:2054] Maker payment is spent, swap is not recoverable",
    "is_valid": false
}

@smk762 do you know where ADEX Desktop gets the "is_recoverable" info from?
this is the swap json on taker:

{
   "error_events" : [
      "StartFailed",
      "NegotiateFailed",
      "TakerFeeSendFailed",
      "MakerPaymentValidateFailed",
      "MakerPaymentWaitConfirmFailed",
      "TakerPaymentTransactionFailed",
      "TakerPaymentWaitConfirmFailed",
      "TakerPaymentDataSendFailed",
      "TakerPaymentWaitForSpendFailed",
      "MakerPaymentSpendFailed",
      "TakerPaymentWaitRefundStarted",
      "TakerPaymentRefundStarted",
      "TakerPaymentRefunded",
      "TakerPaymentRefundedByWatcher",
      "TakerPaymentRefundFailed",
      "TakerPaymentRefundFinished"
   ],
   "events" : [
      {
         "event" : {
            "data" : {
               "fee_to_send_taker_fee" : {
                  "amount" : "0.01",
                  "coin" : "BKC",
                  "paid_from_trading_vol" : false
               },
               "lock_duration" : 7800,
               "maker" : "1bb83b58ec130e28e0a6d5d2acf2eb01b0d3f1670e021d47d31db8a858219da8",
               "maker_amount" : "0.0002242635176757669346718091484148480034385278502795202464610220754081201372130419989391613335048222965",
               "maker_coin" : "KMD",
               "maker_coin_htlc_pubkey" : "023c5ba1d7ef6fa015eb33defb3aba2a961898a51bbb7ff30344d07ba75ad3f289",
               "maker_coin_start_block" : 3565984,
               "maker_payment_confirmations" : 4,
               "maker_payment_requires_nota" : false,
               "maker_payment_spend_trade_fee" : {
                  "amount" : "0.00001",
                  "coin" : "KMD",
                  "paid_from_trading_vol" : true
               },
               "maker_payment_wait" : 1693238935,
               "my_persistent_pub" : "023c5ba1d7ef6fa015eb33defb3aba2a961898a51bbb7ff30344d07ba75ad3f289",
               "p2p_privkey" : null,
               "started_at" : 1693235815,
               "taker_amount" : "1744.271629717673521850899742930591259640102827763496143958868894601542416452442159383033419023136247",
               "taker_coin" : "BKC",
               "taker_coin_htlc_pubkey" : "023c5ba1d7ef6fa015eb33defb3aba2a961898a51bbb7ff30344d07ba75ad3f289",
               "taker_coin_start_block" : 803049,
               "taker_payment_confirmations" : 10,
               "taker_payment_lock" : 1693243615,
               "taker_payment_requires_nota" : false,
               "taker_payment_trade_fee" : {
                  "amount" : "0.01",
                  "coin" : "BKC",
                  "paid_from_trading_vol" : false
               },
               "uuid" : "959ffdd6-e44a-4bd0-a3bd-63638b2633fb"
            },
            "type" : "Started"
         },
         "timestamp" : 1693235815735
      },
      {
         "event" : {
            "data" : {
               "maker_coin_htlc_pubkey" : "031bb83b58ec130e28e0a6d5d2acf2eb01b0d3f1670e021d47d31db8a858219da8",
               "maker_coin_swap_contract_addr" : null,
               "maker_payment_locktime" : 1693251415,
               "maker_pubkey" : "000000000000000000000000000000000000000000000000000000000000000000",
               "secret_hash" : "c1eae4df923e04a343030902472e70664a525e6d",
               "taker_coin_htlc_pubkey" : "031bb83b58ec130e28e0a6d5d2acf2eb01b0d3f1670e021d47d31db8a858219da8",
               "taker_coin_swap_contract_addr" : null
            },
            "type" : "Negotiated"
         },
         "timestamp" : 1693235817736
      },
      {
         "event" : {
            "data" : {
               "tx_hash" : "41786ada882ae6a4813d652b61891b1edc8811092e2f84f72f88e8260fda84fa",
               "tx_hex" : "010000000111392e35fad1a0e0b455384b646b9bb0eb27e956ab80c5399ec843c9a0c38659020000006b483045022100d29d609751f023bf722049e4b7f19a46a44cf7e8f6dcb9f1a3c7a06867ece9f6022013624858e7edbc95e7547af1fe27970433c73078b30cdced601e870b4abca6c10121023c5ba1d7ef6fa015eb33defb3aba2a961898a51bbb7ff30344d07ba75ad3f289ffffffff0290df0a0c000000001976a914ca1e04745e8ca0c60d8c5881531d51bec470743f88ac3b16119e280000001976a91484c74592ed8ac05340906784d277ca4d4e0af08e88ac69baec64"
            },
            "type" : "TakerFeeSent"
         },
         "timestamp" : 1693235817945
      },
      {
         "event" : {
            "data" : null,
            "type" : "TakerPaymentInstructionsReceived"
         },
         "timestamp" : 1693235818946
      },
      {
         "event" : {
            "data" : {
               "tx_hash" : "fde016f09eb34cbeb80eace3fa5e8d8598ecbdb798434836edc895ec8ab931d3",
               "tx_hex" : "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"
            },
            "type" : "MakerPaymentReceived"
         },
         "timestamp" : 1693235818947
      },
      {
         "event" : {
            "type" : "MakerPaymentWaitConfirmStarted"
         },
         "timestamp" : 1693235818947
      },
      {
         "event" : {
            "type" : "MakerPaymentValidatedAndConfirmed"
         },
         "timestamp" : 1693236044367
      },
      {
         "event" : {
            "data" : {
               "tx_hash" : "78f952ba2fee441a0b7bb7480c928ed76b85ba48c2b094280e6ab5e55ef27377",
               "tx_hex" : "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"
            },
            "type" : "TakerPaymentSent"
         },
         "timestamp" : 1693236044762
      },
      {
         "event" : {
...
            ],
            "type" : "WatcherMessageSent"
         },
         "timestamp" : 1693236044764
      },
      {
         "event" : {
            "data" : {
               "secret" : "17456a9b1b3817b612737c929a731e241a28147fc0530e876f9f79e34abd86f7",
               "transaction" : {
                  "tx_hash" : "f51443a662c9335d09af53d29d4ff763704dcbc6eb5224cbd4b836d1d33e675f",
                  "tx_hex" : "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"
               }
            },
            "type" : "TakerPaymentSpent"
         },
         "timestamp" : 1693245236842
      },
      {
         "event" : {
            "data" : {
               "tx_hash" : "a2513faf3d479b8e14096be9b0ba8977d669a7a9ca722be0e2bbe3833fa51a4e",
               "tx_hex" : "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"
            },
            "type" : "MakerPaymentSpentByWatcher"
         },
         "timestamp" : 1693245236928
      },
      {
         "event" : {
            "type" : "Finished"
         },
         "timestamp" : 1693245236928
      }
   ],
   "gui" : "Komodo Wallet 0.6.0-beta",
   "maker_amount" : "0.0002242635176757669346718091484148480034385278502795202464610220754081201372130419989391613335048222965",
   "maker_coin" : "KMD",
   "maker_coin_usd_price" : null,
   "mm_version" : "1.0.7-beta_d1d09b4",
   "my_order_uuid" : "959ffdd6-e44a-4bd0-a3bd-63638b2633fb",
   "success_events" : [
      "Started",
      "Negotiated",
      "TakerFeeSent",
      "TakerPaymentInstructionsReceived",
      "MakerPaymentReceived",
      "MakerPaymentWaitConfirmStarted",
      "MakerPaymentValidatedAndConfirmed",
      "TakerPaymentSent",
      "WatcherMessageSent",
      "TakerPaymentSpent",
      "MakerPaymentSpent",
      "MakerPaymentSpentByWatcher",
      "Finished"
   ],
   "taker_amount" : "1744.271629717673521850899742930591259640102827763496143958868894601542416452442159383033419023136247",
   "taker_coin" : "BKC",
   "taker_coin_usd_price" : null,
   "type" : "Taker",
   "uuid" : "959ffdd6-e44a-4bd0-a3bd-63638b2633fb"
}

[shamardy]

swap is shown as successful but also as "recoverable":
do you know where ADEX Desktop gets the "is_recoverable" info from?

I guess my_swap_status is used for this, so this is probably a bug in the PR. I will look into it.

[shamardy]

I guess my_swap_status is used for this, so this is probably a bug in the PR. I will look into it.

Should be fixed after the latest commit :)

[cipig]

Should be fixed after the latest commit :)

tested and it is fixed, recover button is gone in Desktop

other question: does watcher cover maker refunds too (eg when maker needs to refund makerpayment because takerpayment was not sent), or only taker?

[shamardy]

does watcher cover maker refunds too (eg when maker needs to refund makerpayment because takerpayment was not sent), or only taker?

Currently, watchers only covers takers, this was the priority due to security considerations but it's planned to cover maker refund in the future.

[kivqa]

I checked last commit 1eb1d48 on Komodo web wallet and macos native. Following was observed for Taker:
Status becomes 'Started' after step 'Taker Payment Sent'

dex_taker_issue.mov

App logs attached:
komodo_wallet_log_30.08.2023_13-08-53.log.zip

[shamardy]

I checked last commit 1eb1d48 on Komodo web wallet and macos native. Following was observed for Taker:
Status becomes 'Started' after step 'Taker Payment Sent'

I think this related to swaps events handling in web wallet, please note that WatcherMessageSent is a new event introduced by this PR (It was introduced before but it's activated in this PR) and it looks like that it's not handled correctly by web wallet.

[kivqa]

So we need enhancements for web app and potentially mobile client right? Or this fix should be applicable only to legacy Desktop and CLI?

[smk762]

yeah apps will need to tweak how they parse the swap json - https://github.com/KomodoPlatform/komodo-wallet/pull/1298#issuecomment-1698919691

[cipig]

https://sdk.devbuilds.komodo.earth/bugfix-watchtower/mm2_1eb1d48-linux-x86-64.zip is no more
can we please merge dev branch into this, so that a new build is compiled?

[shamardy]

can we please merge dev branch into this, so that a new build is compiled?

Merged with dev, new build should be compiled soon.

[smk762]

Working in CLI, though apps will need to update json parsing prior to using any release containing these changes.
cc:@CharlVS @naezith