Serialize JSON document bodies

codegen/smithy-python-codegen/src/main/java/software/amazon/smithy/python/codegen/CodegenUtils.java

@@ -38,9 +38,11 @@
 import software.amazon.smithy.codegen.core.CodegenException;
 import software.amazon.smithy.codegen.core.Symbol;
 import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.knowledge.NullableIndex;
 import software.amazon.smithy.model.node.Node;
 import software.amazon.smithy.model.shapes.MemberShape;
 import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.traits.DefaultTrait;
 import software.amazon.smithy.model.traits.ErrorTrait;
 import software.amazon.smithy.model.traits.TimestampFormatTrait;
 import software.amazon.smithy.model.traits.TimestampFormatTrait.Format;
@@ -288,4 +290,44 @@ private static ZonedDateTime parseHttpDate(Node value) {
         Instant instant = Instant.from(DateTimeFormatter.RFC_1123_DATE_TIME.parse(value.expectStringNode().getValue()));
         return instant.atZone(ZoneId.of("UTC"));
     }
+
+    /**
+     * Writes an accessor for a structure member, handling defaultedness and nullability.
+     *
+     * @param context The generation context.
+     * @param writer The writer to write to.
+     * @param variableName The python variable name pointing to the structure to be accessed.
+     * @param member The member to access.
+     * @param runnable A runnable which uses the member.
+     */
+    public static void accessStructureMember(
+        GenerationContext context,
+        PythonWriter writer,
+        String variableName,
+        MemberShape member,
+        Runnable runnable
+    ) {
+        var shouldDedent = false;
+        var isNullable = NullableIndex.of(context.model()).isMemberNullable(member);
+        var memberName = context.symbolProvider().toMemberName(member);
+        if (member.getMemberTrait(context.model(), DefaultTrait.class).isPresent()) {
+            if (isNullable) {
+                writer.write("if $1L._hasattr($2S) and $1L.$2L is not None:", variableName, memberName);
+            } else {
+                writer.write("if $L._hasattr($S):", variableName, memberName);
+            }
+            writer.indent();
+            shouldDedent = true;
+        } else if (isNullable) {
+            writer.write("if $L.$L is not None:", variableName, memberName);
+            writer.indent();
+            shouldDedent = true;
+        }
+
+        runnable.run();
+
+        if (shouldDedent) {
+            writer.dedent();
+        }
+    }
 }

codegen/smithy-python-codegen/src/main/java/software/amazon/smithy/python/codegen/integration/DocumentMemberSerVisitor.java

@@ -0,0 +1,256 @@
+/*
+ * Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *   http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.smithy.python.codegen.integration;
+
+import java.util.Optional;
+import software.amazon.smithy.codegen.core.CodegenException;
+import software.amazon.smithy.model.shapes.BigDecimalShape;
+import software.amazon.smithy.model.shapes.BigIntegerShape;
+import software.amazon.smithy.model.shapes.BlobShape;
+import software.amazon.smithy.model.shapes.BooleanShape;
+import software.amazon.smithy.model.shapes.ByteShape;
+import software.amazon.smithy.model.shapes.DocumentShape;
+import software.amazon.smithy.model.shapes.DoubleShape;
+import software.amazon.smithy.model.shapes.FloatShape;
+import software.amazon.smithy.model.shapes.IntegerShape;
+import software.amazon.smithy.model.shapes.ListShape;
+import software.amazon.smithy.model.shapes.LongShape;
+import software.amazon.smithy.model.shapes.MapShape;
+import software.amazon.smithy.model.shapes.MemberShape;
+import software.amazon.smithy.model.shapes.OperationShape;
+import software.amazon.smithy.model.shapes.ResourceShape;
+import software.amazon.smithy.model.shapes.ServiceShape;
+import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.shapes.ShapeVisitor;
+import software.amazon.smithy.model.shapes.ShortShape;
+import software.amazon.smithy.model.shapes.StringShape;
+import software.amazon.smithy.model.shapes.StructureShape;
+import software.amazon.smithy.model.shapes.TimestampShape;
+import software.amazon.smithy.model.shapes.UnionShape;
+import software.amazon.smithy.model.traits.TimestampFormatTrait.Format;
+import software.amazon.smithy.python.codegen.GenerationContext;
+import software.amazon.smithy.python.codegen.PythonWriter;
+
+/**
+ * Visitor to serialize member values for aggregate types into document bodies.
+ *
+ * <p>The standard implementations are as follows; these implementations may be
+ * overridden unless otherwise specified.
+ *
+ * <ul>
+ *   <li>Blob: base64 encoded and encoded to a utf-8 string.</li>
+ *   <li>Timestamp: serialized to a string.</li>
+ *   <li>Service, Operation, Resource, Member: not deserializable from documents. <b>Not overridable.</b></li>
+ *   <li>List, Map, Set, Structure, Union: delegated to a serialization function.
+ *     <b>Not overridable.</b></li>
+ *   <li>All other types: unmodified.</li>
+ * </ul>
+ */
+public class DocumentMemberSerVisitor implements ShapeVisitor<String> {
+    private final GenerationContext context;
+    private final PythonWriter writer;
+    private final MemberShape member;
+    private final String dataSource;
+    private final Format defaultTimestampFormat;
+
+    /**
+     * @param context The generation context.
+     * @param writer The writer to write to.
+     * @param member The member shape being deserialized. Used for any extra traits
+     *               it might bear, such as the timestamp format.
+     * @param dataSource The in-code location of the data to provide an output of
+     *                   ({@code output.foo}, {@code entry}, etc.)
+     * @param defaultTimestampFormat The default timestamp format used in absence
+     *                               of a TimestampFormat trait.
+     */
+    public DocumentMemberSerVisitor(
+        GenerationContext context,
+        PythonWriter writer,
+        MemberShape member,
+        String dataSource,
+        Format defaultTimestampFormat
+    ) {
+        this.context = context;
+        this.writer = writer;
+        this.member = member;
+        this.dataSource = dataSource;
+        this.defaultTimestampFormat = defaultTimestampFormat;
+    }
+
+    /**
+     * @return the member this visitor is being run against. Used to discover member-applied
+     * traits, such as @timestampFormat.
+     */
+    protected Optional<MemberShape> memberShape() {
+        return Optional.ofNullable(member);
+    }
+
+    /**
+     * Gets the generation context.
+     *
+     * @return The generation context.
+     */
+    protected final GenerationContext context() {
+        return context;
+    }
+
+    /**
+     * Gets the PythonWriter being written to.
+     *
+     * <p>This should only be used to add imports.
+     *
+     * @return The writer to add imports to.
+     */
+    protected final PythonWriter writer() {
+        return writer;
+    }
+
+    /**
+     * Gets the in-code location of the data to provide an output of
+     * ({@code output.foo}, {@code entry}, etc.).
+     *
+     * @return The data source.
+     */
+    protected final String dataSource() {
+        return dataSource;
+    }
+
+    /**
+     * Gets the default timestamp format used in absence of a TimestampFormat trait.
+     *
+     * @return The default timestamp format.
+     */
+    protected final Format getDefaultTimestampFormat() {
+        return defaultTimestampFormat;
+    }
+
+    @Override
+    public String blobShape(BlobShape blobShape) {
+        writer.addStdlibImport("base64", "b64encode");
+        return String.format("b64encode(%s).decode('utf-8')", dataSource());
+    }
+
+    @Override
+    public String booleanShape(BooleanShape booleanShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String byteShape(ByteShape byteShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String shortShape(ShortShape shortShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String integerShape(IntegerShape integerShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String longShape(LongShape longShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String floatShape(FloatShape floatShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String documentShape(DocumentShape documentShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String doubleShape(DoubleShape doubleShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String bigIntegerShape(BigIntegerShape bigIntegerShape) {
+        return String.format("str(%s)", dataSource());
+    }
+
+    @Override
+    public String bigDecimalShape(BigDecimalShape bigDecimalShape) {
+        return String.format("str(%s.normalize())", dataSource());
+    }
+
+    @Override
+    public final String operationShape(OperationShape shape) {
+        throw new CodegenException("Operation shapes cannot be bound to documents.");
+    }
+
+    @Override
+    public final String resourceShape(ResourceShape shape) {
+        throw new CodegenException("Resource shapes cannot be bound to documents.");
+    }
+
+    @Override
+    public final String serviceShape(ServiceShape shape) {
+        throw new CodegenException("Service shapes cannot be bound to documents.");
+    }
+
+    @Override
+    public final String memberShape(MemberShape shape) {
+        throw new CodegenException("Member shapes cannot be bound to documents.");
+    }
+
+    @Override
+    public String stringShape(StringShape stringShape) {
+        return dataSource();
+    }
+
+    @Override
+    public String timestampShape(TimestampShape timestampShape) {
+        return HttpProtocolGeneratorUtils.getTimestampInputParam(
+            context(), writer(), dataSource(), timestampShape, getDefaultTimestampFormat());
+    }
+
+    @Override
+    public String listShape(ListShape listShape) {
+        return getDelegateSerializer(listShape);
+    }
+
+    @Override
+    public String mapShape(MapShape mapShape) {
+        return getDelegateSerializer(mapShape);
+    }
+
+    @Override
+    public String structureShape(StructureShape structureShape) {
+        return getDelegateSerializer(structureShape);
+    }
+
+    @Override
+    public String unionShape(UnionShape unionShape) {
+        return getDelegateSerializer(unionShape);
+    }
+
+    private String getDelegateSerializer(Shape shape) {
+        return getDelegateSerializer(shape, dataSource);
+    }
+
+    private String getDelegateSerializer(Shape shape, String customDataSource) {
+        var serSymbol = context.protocolGenerator().getSerializationFunction(context, shape.getId());
+        writer.addImport(serSymbol, serSymbol.getName());
+        return serSymbol.getName() + "(" + customDataSource + ", config)";
+    }
+}

codegen/smithy-python-codegen/src/main/java/software/amazon/smithy/python/codegen/integration/HttpBindingProtocolGenerator.java

@@ -71,6 +71,7 @@
 @SmithyUnstableApi
 public abstract class HttpBindingProtocolGenerator implements ProtocolGenerator {
 
+    private final Set<Shape> serializingDocumentShapes = new TreeSet<>();
     private final Set<Shape> deserializingDocumentShapes = new TreeSet<>();
 
     @Override
@@ -118,6 +119,7 @@ public void generateRequestSerializers(GenerationContext context) {
                 writer.popState();
             });
         }
+        generateDocumentBodyShapeSerializers(context, serializingDocumentShapes);
     }
 
     /**
@@ -343,11 +345,18 @@ private void serializeBody(
         var documentBindings = bindingIndex.getRequestBindings(operation, DOCUMENT);
         if (!documentBindings.isEmpty() || shouldWriteDefaultBody(context, operation)) {
             serializeDocumentBody(context, writer, operation, documentBindings);
+            for (HttpBinding binding : documentBindings) {
+                var target = context.model().expectShape(binding.getMember().getTarget());
+                serializingDocumentShapes.add(target);
+            }
         }
 
         var payloadBindings = bindingIndex.getRequestBindings(operation, PAYLOAD);
         if (!payloadBindings.isEmpty()) {
-            serializePayloadBody(context, writer, operation, payloadBindings.get(0));
+            var binding = payloadBindings.get(0);
+            serializePayloadBody(context, writer, operation, binding);
+            var target = context.model().expectShape(binding.getMember().getTarget());
+            serializingDocumentShapes.add(target);
         }
         writer.popState();
     }
@@ -395,6 +404,18 @@ protected abstract void serializeDocumentBody(
         List<HttpBinding> documentBindings
     );
 
+    /**
+     * Generates serialization functions for shapes in the given set.
+     *
+     * <p>These are the functions that serializeDocumentBody will call out to.
+     *
+     * @param context The generation context.
+     * @param shapes The shapes to generate deserialization for.
+     */
+    protected abstract void generateDocumentBodyShapeSerializers(
+        GenerationContext context,
+        Set<Shape> shapes
+    );
 
     /**
      * Writes the code needed to serialize the input payload of a request.