[DRAFT] Add account updater service

larky/src/main/java/com/verygood/security/larky/ModuleSupplier.java

@@ -20,6 +20,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 
+import com.verygood.security.larky.modules.AccountUpdaterModule;
 import com.verygood.security.larky.modules.BinasciiModule;
 import com.verygood.security.larky.modules.C99MathModule;
 import com.verygood.security.larky.modules.NetworkTokenModule;
@@ -98,6 +99,7 @@ public class ModuleSupplier {
   public static final ImmutableSet<StarlarkValue> VGS_MODULES = ImmutableSet.of(
       VaultModule.INSTANCE,
       NetworkTokenModule.INSTANCE,
+      AccountUpdaterModule.INSTANCE,
       CerebroModule.INSTANCE,
       ChaseModule.INSTANCE,
       JKSModule.INSTANCE

larky/src/main/java/com/verygood/security/larky/modules/AccountUpdaterModule.java

@@ -0,0 +1,108 @@
+package com.verygood.security.larky.modules;
+
+import com.google.common.collect.ImmutableList;
+import com.verygood.security.larky.modules.vgs.aus.LarkyAccountUpdater;
+import com.verygood.security.larky.modules.vgs.aus.MockAccountUpdaterService;
+import com.verygood.security.larky.modules.vgs.aus.NoopAccountUpdaterService;
+import com.verygood.security.larky.modules.vgs.aus.spi.AccountUpdaterService;
+import net.starlark.java.annot.Param;
+import net.starlark.java.annot.ParamType;
+import net.starlark.java.annot.StarlarkBuiltin;
+import net.starlark.java.annot.StarlarkMethod;
+import net.starlark.java.eval.*;
+
+import java.util.List;
+import java.util.ServiceLoader;
+
+@StarlarkBuiltin(
+    name = "native_au",
+    category = "BUILTIN",
+    doc = "Overridable Account Updater API in Larky")
+public class AccountUpdaterModule implements LarkyAccountUpdater {
+  public static final AccountUpdaterModule INSTANCE = new AccountUpdaterModule();
+
+  public static final String ENABLE_MOCK_PROPERTY = "larky.modules.vgs.nts.enableMockAccountUpdater";
+
+  private final AccountUpdaterService AccountUpdaterService;
+
+  public AccountUpdaterModule() {
+    ServiceLoader<AccountUpdaterService> loader = ServiceLoader.load(AccountUpdaterService.class);
+    List<AccountUpdaterService> AccountUpdaterProviders = ImmutableList.copyOf(loader.iterator());
+
+    if (Boolean.getBoolean(ENABLE_MOCK_PROPERTY)) {
+      AccountUpdaterService = new MockAccountUpdaterService();
+    } else if (AccountUpdaterProviders.isEmpty()) {
+      AccountUpdaterService = new NoopAccountUpdaterService();
+    } else {
+      if (AccountUpdaterProviders.size() != 1) {
+        throw new IllegalArgumentException(
+            String.format(
+                "AccountUpdaterModule expecting only 1 network token provider of type AccountUpdaterService, found %d",
+                AccountUpdaterProviders.size()));
+      }
+      AccountUpdaterService = AccountUpdaterProviders.get(0);
+    }
+  }
+
+  @StarlarkMethod(
+      name = "get_card",
+      doc = "Retrieves a newer information for the provided card.",
+      useStarlarkThread = true,
+      parameters = {
+        @Param(
+            name = "number",
+            named = true,
+            doc = "Card PAN. Used to look up the corresponding card information to be returned",
+            allowedTypes = {@ParamType(type = String.class)}),
+        @Param(
+            name = "exp_month",
+            named = true,
+            doc =
+                "Card expiration month. Used to pass to the network for retrieving the corresponding card information",
+            allowedTypes = {@ParamType(type = String.class)}),
+        @Param(
+            name = "exp_year",
+            named = true,
+            doc =
+                "Card expiration year. Used to pass to the network for retrieving the corresponding card information",
+            allowedTypes = {@ParamType(type = String.class)}),
+        @Param(
+            name = "name",
+            named = true,
+            doc =
+                "Card owner name. Used to pass to the network for retrieving the corresponding card information",
+            allowedTypes = {@ParamType(type = String.class)}),
+        @Param(
+            name = "vgs_merchant_id",
+            named = true,
+            doc = "VGS merchant id to get a network token for",
+            defaultValue = "''",
+            allowedTypes = {@ParamType(type = String.class)}),
+      })
+  @Override
+  public Dict<String, Object> getCard(
+      String number,
+      Integer expireMonth,
+      Integer expireYear,
+      String name,
+      String vgsMerchantId,
+      StarlarkThread thread)
+      throws EvalException {
+    if (number.trim().isEmpty()) {
+      throw Starlark.errorf("card number argument cannot be blank");
+    }
+    final AccountUpdaterService.Card card;
+    try {
+      card =
+          AccountUpdaterService.getCard(number, expireMonth, expireYear, name, vgsMerchantId);
+    } catch (UnsupportedOperationException exception) {
+      throw Starlark.errorf("au.get_card operation must be overridden");
+    }
+    return Dict.<String, Object>builder()
+        .put("number", card.getNumber())
+        .put("expireMonth", StarlarkInt.of(card.getExpireMonth()))
+        .put("expireYear", StarlarkInt.of(card.getExpireYear()))
+        .put("name", card.getName())
+        .build(thread.mutability());
+  }
+}

larky/src/main/java/com/verygood/security/larky/modules/vgs/aus/LarkyAccountUpdater.java

@@ -0,0 +1,28 @@
+package com.verygood.security.larky.modules.vgs.aus;
+
+import net.starlark.java.eval.Dict;
+import net.starlark.java.eval.EvalException;
+import net.starlark.java.eval.StarlarkThread;
+import net.starlark.java.eval.StarlarkValue;
+
+public interface LarkyAccountUpdater extends StarlarkValue {
+  /**
+   * Get updated info for the provided card
+   *
+   * @param number card's number
+   * @param expireMonth card's expiration month
+   * @param expireYear card's expiration year
+   * @param name the name on the card
+   * @param vgsMerchantId vgs merchant public identifier
+   * @param thread Starlark thread object
+   * @return a dict contains the network token values
+   */
+  Dict<String, Object> getCard(
+      String number,
+      Integer expireMonth,
+      Integer expireYear,
+      String name,
+      String vgsMerchantId,
+      StarlarkThread thread)
+      throws EvalException;
+}

larky/src/main/java/com/verygood/security/larky/modules/vgs/aus/MockAccountUpdaterService.java

@@ -0,0 +1,51 @@
+package com.verygood.security.larky.modules.vgs.aus;
+
+import com.google.common.collect.ImmutableMap;
+import com.verygood.security.larky.modules.vgs.aus.spi.AccountUpdaterService;
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.Map;
+
+public class MockAccountUpdaterService implements AccountUpdaterService {
+
+  private static final String DEFAULT_MERCHANT_ID = "MC8SWErAVLuooPFYz9WTx5W1";
+
+  private static final Map<String, Card.CardBuilder> CARDS = ImmutableMap.of(
+      "CRD7TPQLA4BXpN3LAYpu3mDSy", Card.builder()
+          .number("4111111111111111")
+          .expireMonth(10)
+          .expireYear(27)
+          .name("John Doe"),
+      DEFAULT_MERCHANT_ID, Card.builder()
+          .number("4242424242424242")
+          .expireMonth(12)
+          .expireYear(27)
+          .name("John Doe")
+  );
+
+  @Override
+  public Card getCard(
+          String number, Integer expireMonth, Integer expireYear, String name, String vgsMerchantId) {
+    if (StringUtils.isBlank(vgsMerchantId)) {
+      return getForDefaultMerchant();
+    }
+    final Card card =
+       CARDS.get(vgsMerchantId)
+             .number("5204731600014784")
+             .expireMonth(12)
+             .expireYear(24)
+             .name("John Doe")
+             .build();
+
+    return card;
+  }
+
+  private Card getForDefaultMerchant() {
+    return CARDS.get(DEFAULT_MERCHANT_ID)
+        .number("5204731600014784")
+        .expireMonth(12)
+        .expireYear(24)
+        .name("John Doe")
+        .build();
+  } 
+}

larky/src/main/java/com/verygood/security/larky/modules/vgs/aus/NoopAccountUpdaterService.java

@@ -0,0 +1,11 @@
+package com.verygood.security.larky.modules.vgs.aus;
+
+import com.verygood.security.larky.modules.vgs.aus.spi.AccountUpdaterService;
+
+public class NoopAccountUpdaterService implements AccountUpdaterService {
+  @Override
+  public Card getCard(
+      String number, Integer expireMonth, Integer expireYear, String name, String vgsMerchantId) {
+    throw new UnsupportedOperationException("Not implemented");
+  }
+}

larky/src/main/java/com/verygood/security/larky/modules/vgs/aus/spi/AccountUpdaterService.java

@@ -0,0 +1,29 @@
+package com.verygood.security.larky.modules.vgs.aus.spi;
+
+import lombok.Builder;
+import lombok.Data;
+
+
+public interface AccountUpdaterService {
+  /**
+   * Get updated info for the provided card
+   *
+   * @param number card's number
+   * @param expireMonth card's expiration month
+   * @param expireYear card's expiration year
+   * @param name the name on the card
+   * @param merchantId vgs merchant public identifier
+   * @return the updated card
+   */
+  Card getCard(
+      String number, Integer expireMonth, Integer expireYear, String name, String vgsMerchantId);
+
+  @Data
+  @Builder
+  class Card {
+    private final String number;
+    private final Integer expireMonth;
+    private final Integer expireYear;
+    private final String name;
+  }
+}