Move all transaction metadata logic in a single file

4 files changed, 73 insertions, 26 deletions

diff --git a/bank/src/main/kotlin/tech/libeufin/bank/Database.kt b/bank/src/main/kotlin/tech/libeufin/bank/Database.kt
index 14cc1666..2e73e065 100644
--- a/bank/src/main/kotlin/tech/libeufin/bank/Database.kt
+++ b/bank/src/main/kotlin/tech/libeufin/bank/Database.kt
@@ -768,49 +768,40 @@ class Database(dbConfig: String, private val bankCurrency: String): java.io.Clos
                         BankTransactionResult.CONFLICT
                     }
                     else -> {
+                        val metadata = TxMetadata.parse(tx.subject)
                         if (it.getBoolean("out_creditor_is_exchange")) {
-                            // Parse subject
-                            val reservePub = try {
-                                EddsaPublicKey(tx.subject)
-                            } catch (e: Exception) {
-                                null
-                            }
-                            if (reservePub != null) {
-                                val rowId = it.getLong("out_credit_row_id")
+                            val rowId = it.getLong("out_credit_row_id")
+                            if (metadata is IncomingTxMetadata) {
+                              
                                 val stmt = conn.prepareStatement("""
                                     INSERT INTO taler_exchange_incoming 
                                         (reserve_pub, bank_transaction) 
                                     VALUES (?, ?)
                                 """)
-                                stmt.setBytes(1, reservePub.raw)
+                                stmt.setBytes(1, metadata.reservePub.raw)
                                 stmt.setLong(2, rowId)
                                 stmt.executeUpdate()
                                 conn.execSQLUpdate("NOTIFY incoming_tx, '${"${tx.creditorAccountId} $rowId"}'")
                             } else {
                                 // TODO bounce
+                                logger.warn("exchange account ${tx.creditorAccountId} received a transaction $rowId with malformed metadata, will bounce in future version")
                             }
-                        } else if (it.getBoolean("out_debtor_is_exchange")) {
-                            // Parse subject
-                            val metadata = try {
-                                val split = tx.subject.split(" ", limit=2) ;
-                                Pair(ShortHashCode(split[0]), split[2])
-                            } catch (e: Exception) {
-                                null
-                            }
-                            if (metadata != null) {
-                                val rowId = it.getLong("out_debit_row_id")
+                        }
+                        if (it.getBoolean("out_debtor_is_exchange")) {
+                            val rowId = it.getLong("out_debit_row_id")
+                            if (metadata is OutgoingTxMetadata) {
                                 val stmt = conn.prepareStatement("""
                                     INSERT INTO taler_exchange_outgoing 
                                         (wtid, exchange_base_url, bank_transaction) 
                                     VALUES (?, ?, ?)
                                 """)
-                                stmt.setBytes(1, metadata.first.raw)
-                                stmt.setString(2, metadata.second)
+                                stmt.setBytes(1, metadata.wtid.raw)
+                                stmt.setString(2, metadata.exchangeBaseUrl)
                                 stmt.setLong(3, rowId)
                                 stmt.executeUpdate()
                                 conn.execSQLUpdate("NOTIFY outgoing_tx, '${"${tx.debtorAccountId} $rowId"}'")
                             } else {
-                                // TODO log ?
+                                logger.warn("exchange account ${tx.debtorAccountId} sent a transaction $rowId with malformed metadata")
                             }
                         }
                         BankTransactionResult.SUCCESS
@@ -1498,7 +1489,7 @@ class Database(dbConfig: String, private val bankCurrency: String): java.io.Clos
         pmtInfId: String = "not used",
         endToEndId: String = "not used",
         ): TalerTransferCreationResult = conn { conn ->
-        val subject = "${req.wtid.encoded()} ${req.exchange_base_url}"
+        val subject = OutgoingTxMetadata(req.wtid, req.exchange_base_url).toString()
         val stmt = conn.prepareStatement("""
             SELECT
               out_exchange_balance_insufficient
diff --git a/bank/src/main/kotlin/tech/libeufin/bank/Metadata.kt b/bank/src/main/kotlin/tech/libeufin/bank/Metadata.kt
new file mode 100644
index 00000000..119de048
--- /dev/null
+++ b/bank/src/main/kotlin/tech/libeufin/bank/Metadata.kt
@@ -0,0 +1,54 @@
+/*
+ * This file is part of LibEuFin.
+ * Copyright (C) 2019 Stanisci and Dold.
+
+ * 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.bank
+
+sealed interface TxMetadata {
+    // TODO versioning ?
+    companion object {
+        fun parse(subject: String): TxMetadata? {
+            // IncomingTxMetadata
+            try {
+                return IncomingTxMetadata(EddsaPublicKey(subject))
+            } catch (e: Exception) { }
+
+            // OutgoingTxMetadata
+            try {
+                val (wtid, exchangeBaseUrl) = subject.split(" ", limit=2) ; 
+                return OutgoingTxMetadata(ShortHashCode(wtid), exchangeBaseUrl)
+            } catch (e: Exception) { }
+
+            // No well formed metadata
+            return null
+        }
+
+        fun encode(metadata: TxMetadata): String {
+            return when (metadata) {
+                is IncomingTxMetadata -> "${metadata.reservePub}"
+                is OutgoingTxMetadata -> "${metadata.wtid} ${metadata.exchangeBaseUrl}"
+            }
+        }
+    }
+}
+
+data class IncomingTxMetadata(val reservePub: EddsaPublicKey): TxMetadata {
+    override fun toString(): String = TxMetadata.encode(this)
+}
+data class OutgoingTxMetadata(val wtid: ShortHashCode, val exchangeBaseUrl: String): TxMetadata {
+    override fun toString(): String = TxMetadata.encode(this)
+}
\ No newline at end of file
diff --git a/bank/src/main/kotlin/tech/libeufin/bank/WireGatewayApiHandlers.kt b/bank/src/main/kotlin/tech/libeufin/bank/WireGatewayApiHandlers.kt
index 7dfbe1c5..1971ba29 100644
--- a/bank/src/main/kotlin/tech/libeufin/bank/WireGatewayApiHandlers.kt
+++ b/bank/src/main/kotlin/tech/libeufin/bank/WireGatewayApiHandlers.kt
@@ -136,9 +136,11 @@ fun Routing.talerWireGatewayHandlers(db: Database, ctx: BankApplicationContext)
                 "Currency mismatch",
                 TalerErrorCode.TALER_EC_GENERIC_CURRENCY_MISMATCH
             )
+
+        val subject = IncomingTxMetadata(req.reserve_pub).toString()
         
         // TODO check conflict in transaction
-        if (db.bankTransactionCheckExists(req.reserve_pub.encoded()) != null)
+        if (db.bankTransactionCheckExists(subject) != null)
             throw conflict(
                 "Reserve pub. already used",
                 TalerErrorCode.TALER_EC_BANK_DUPLICATE_RESERVE_PUB_SUBJECT
@@ -158,7 +160,7 @@ fun Routing.talerWireGatewayHandlers(db: Database, ctx: BankApplicationContext)
             amount = req.amount,
             creditorAccountId = exchangeAccount.id,
             transactionDate = txTimestamp,
-            subject = req.reserve_pub.encoded()
+            subject = subject
         )
         val res = db.bankTransactionCreate(op)
         /**
diff --git a/bank/src/test/kotlin/TalerApiTest.kt b/bank/src/test/kotlin/TalerApiTest.kt
index 0cdd450a..ebe74fde 100644
--- a/bank/src/test/kotlin/TalerApiTest.kt
+++ b/bank/src/test/kotlin/TalerApiTest.kt
@@ -74,7 +74,7 @@ class TalerApiTest {
             BankInternalTransaction(
                 creditorAccountId = from,
                 debtorAccountId = to,
-                subject = randShortHashCode().encoded(),
+                subject = IncomingTxMetadata(randShortHashCode()).toString(),
                 amount = TalerAmount( 10, 0, "KUDOS"),
                 accountServicerReference = "acct-svcr-ref",
                 endToEndId = "end-to-end-id",