nexus: wire gateway /transfer

4 files changed, 103 insertions, 28 deletions

diff --git a/nexus/src/main/kotlin/tech/libeufin/nexus/api/WireGatewayApi.kt b/nexus/src/main/kotlin/tech/libeufin/nexus/api/WireGatewayApi.kt
index f7374204..877101b2 100644
--- a/nexus/src/main/kotlin/tech/libeufin/nexus/api/WireGatewayApi.kt
+++ b/nexus/src/main/kotlin/tech/libeufin/nexus/api/WireGatewayApi.kt
@@ -29,6 +29,8 @@ import tech.libeufin.common.*
 import tech.libeufin.nexus.*
 import tech.libeufin.nexus.db.*
 import tech.libeufin.nexus.db.PaymentDAO.*
+import tech.libeufin.nexus.db.InitiatedDAO.*
+import tech.libeufin.nexus.db.ExchangeDAO.*
 import java.time.Instant
 
 
@@ -41,38 +43,28 @@ fun Routing.wireGatewayApi(db: Database, cfg: NexusConfig) {
     post("/taler-wire-gateway/transfer") {
         val req = call.receive<TransferRequest>()
         cfg.checkCurrency(req.amount)
-        // TODO
-        /*val res = db.exchange.transfer(
-            req = req,
-            login = username,
-            now = Instant.now()
+        val bankId = run {
+            val bytes = ByteArray(16)
+            kotlin.random.Random.nextBytes(bytes)
+            Base32Crockford.encode(bytes)
+        }
+        val res = db.exchange.transfer(
+            req,
+            bankId,
+            Instant.now()
         )
         when (res) {
-            is TransferResult.UnknownExchange -> throw unknownAccount(username)
-            is TransferResult.NotAnExchange -> throw conflict(
-                "$username is not an exchange account.",
-                TalerErrorCode.BANK_ACCOUNT_IS_NOT_EXCHANGE
-            )
-            is TransferResult.UnknownCreditor -> throw unknownCreditorAccount(req.credit_account.canonical)
-            is TransferResult.BothPartyAreExchange -> throw conflict(
-                "Wire transfer attempted with credit and debit party being both exchange account",
-                TalerErrorCode.BANK_ACCOUNT_IS_EXCHANGE
-            )
-            is TransferResult.ReserveUidReuse -> throw conflict(
+            TransferResult.RequestUidReuse -> throw conflict(
                 "request_uid used already",
                 TalerErrorCode.BANK_TRANSFER_REQUEST_UID_REUSED
             )
-            is TransferResult.BalanceInsufficient -> throw conflict(
-                "Insufficient balance for exchange",
-                TalerErrorCode.BANK_UNALLOWED_DEBIT
-            )
             is TransferResult.Success -> call.respond(
                 TransferResponse(
                     timestamp = res.timestamp,
                     row_id = res.id
                 )
             )
-        }*/
+        }
     }
     /*suspend fun <T> PipelineContext<Unit, ApplicationCall>.historyEndpoint(
         reduce: (List<T>, String) -> Any, 
@@ -122,7 +114,6 @@ fun Routing.wireGatewayApi(db: Database, cfg: NexusConfig) {
                 "reserve_pub used already",
                 TalerErrorCode.BANK_DUPLICATE_RESERVE_PUB_SUBJECT
             )
-            // TODO timestamp when idempotent
             is IncomingRegistrationResult.Success -> call.respond(
                 AddIncomingResponse(
                     timestamp = TalerProtocolTimestamp(timestamp),
diff --git a/nexus/src/main/kotlin/tech/libeufin/nexus/db/Database.kt b/nexus/src/main/kotlin/tech/libeufin/nexus/db/Database.kt
index b6422612..4cc70452 100644
--- a/nexus/src/main/kotlin/tech/libeufin/nexus/db/Database.kt
+++ b/nexus/src/main/kotlin/tech/libeufin/nexus/db/Database.kt
@@ -42,4 +42,5 @@ data class InitiatedPayment(
 class Database(dbConfig: DatabaseConfig): DbPool(dbConfig, "libeufin_nexus") {
     val payment = PaymentDAO(this)
     val initiated = InitiatedDAO(this)
+    val exchange = ExchangeDAO(this)
 }
\ No newline at end of file
diff --git a/nexus/src/main/kotlin/tech/libeufin/nexus/db/ExchangeDAO.kt b/nexus/src/main/kotlin/tech/libeufin/nexus/db/ExchangeDAO.kt
new file mode 100644
index 00000000..d3844167
--- /dev/null
+++ b/nexus/src/main/kotlin/tech/libeufin/nexus/db/ExchangeDAO.kt
@@ -0,0 +1,80 @@
+/*
+ * This file is part of LibEuFin.
+ * Copyright (C) 2024 Taler Systems S.A.
+
+ * LibEuFin is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation; either version 3, or
+ * (at your option) any later version.
+
+ * LibEuFin 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 Affero General
+ * Public License for more details.
+
+ * You should have received a copy of the GNU Affero General Public
+ * License along with LibEuFin; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>
+ */
+
+package tech.libeufin.nexus.db
+
+import tech.libeufin.common.db.one
+import tech.libeufin.common.db.getTalerTimestamp
+import tech.libeufin.common.micros
+import tech.libeufin.common.TalerProtocolTimestamp
+import tech.libeufin.common.TransferRequest
+import java.sql.ResultSet
+import java.time.Instant
+
+/** Data access logic for exchange specific logic */
+class ExchangeDAO(private val db: Database) {
+
+    /** Result of taler transfer transaction creation */
+    sealed interface TransferResult {
+        /** Transaction [id] and wire transfer [timestamp] */
+        data class Success(val id: Long, val timestamp: TalerProtocolTimestamp): TransferResult
+        data object RequestUidReuse: TransferResult
+    }
+
+    /** Perform a Taler transfer */
+    suspend fun transfer(
+        req: TransferRequest,
+        bankId: String,
+        now: Instant
+    ): TransferResult = db.serializable { conn ->
+        val subject = "${req.wtid} ${req.exchange_base_url.url}"
+        val stmt = conn.prepareStatement("""
+            SELECT
+                out_request_uid_reuse
+                ,out_tx_row_id
+                ,out_timestamp
+            FROM
+            taler_transfer (
+                ?, ?, ?,
+                (?,?)::taler_amount,
+                ?, ?, ?, ?
+            );
+        """)
+
+        stmt.setBytes(1, req.request_uid.raw)
+        stmt.setBytes(2, req.wtid.raw)
+        stmt.setString(3, subject)
+        stmt.setLong(4, req.amount.value)
+        stmt.setInt(5, req.amount.frac)
+        stmt.setString(6, req.exchange_base_url.url)
+        stmt.setString(7, req.credit_account.canonical)
+        stmt.setString(8, bankId)
+        stmt.setLong(9, now.micros())
+
+        stmt.one {
+            when {
+                it.getBoolean("out_request_uid_reuse") -> TransferResult.RequestUidReuse
+                else -> TransferResult.Success(
+                    id = it.getLong("out_tx_row_id"),
+                    timestamp = it.getTalerTimestamp("out_timestamp")
+                )
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/nexus/src/main/kotlin/tech/libeufin/nexus/db/InitiatedDAO.kt b/nexus/src/main/kotlin/tech/libeufin/nexus/db/InitiatedDAO.kt
index 04fd3965..052b75f9 100644
--- a/nexus/src/main/kotlin/tech/libeufin/nexus/db/InitiatedDAO.kt
+++ b/nexus/src/main/kotlin/tech/libeufin/nexus/db/InitiatedDAO.kt
@@ -22,6 +22,7 @@ package tech.libeufin.nexus.db
 import tech.libeufin.common.asInstant
 import tech.libeufin.common.db.all
 import tech.libeufin.common.db.executeUpdateViolation
+import tech.libeufin.common.db.oneUniqueViolation
 import tech.libeufin.common.db.getAmount
 import tech.libeufin.common.db.oneOrNull
 import tech.libeufin.common.micros
@@ -32,9 +33,9 @@ import java.time.Instant
 class InitiatedDAO(private val db: Database) {
 
     /** Outgoing payments initiation result */
-    enum class PaymentInitiationResult {
-        REQUEST_UID_REUSE,
-        SUCCESS
+    sealed interface PaymentInitiationResult {
+        data class Success(val id: Long): PaymentInitiationResult
+        data object RequestUidReuse: PaymentInitiationResult
     }
 
     /** Register a new pending payment in the database */
@@ -47,16 +48,18 @@ class InitiatedDAO(private val db: Database) {
              ,initiation_time
              ,request_uid
            ) VALUES ((?,?)::taler_amount,?,?,?,?)
+           RETURNING initiated_outgoing_transaction_id
         """)
+        // TODO check payto uri
         stmt.setLong(1, paymentData.amount.value)
         stmt.setInt(2, paymentData.amount.frac)
         stmt.setString(3, paymentData.wireTransferSubject)
         stmt.setString(4, paymentData.creditPaytoUri.toString())
         stmt.setLong(5, paymentData.initiationTime.micros())
         stmt.setString(6, paymentData.requestUid)
-        if (stmt.executeUpdateViolation())
-            return@conn PaymentInitiationResult.SUCCESS
-        return@conn PaymentInitiationResult.REQUEST_UID_REUSE
+        stmt.oneUniqueViolation(PaymentInitiationResult.RequestUidReuse) {
+            PaymentInitiationResult.Success(it.getLong("initiated_outgoing_transaction_id"))
+        }
     }
 
     /** Register EBICS submission success */