refactor endpoint bindings/middleware (#455)

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/GoDependency.java

@@ -22,6 +22,7 @@
 import java.util.Set;
 import java.util.TreeSet;
 import software.amazon.smithy.codegen.core.CodegenException;
+import software.amazon.smithy.codegen.core.Symbol;
 import software.amazon.smithy.codegen.core.SymbolDependency;
 import software.amazon.smithy.codegen.core.SymbolDependencyContainer;
 import software.amazon.smithy.utils.SetUtils;
@@ -146,6 +147,24 @@ public String getVersion() {
         return version;
     }
 
+    /**
+     * Creates a Symbol for a name exported by this package.
+     * @param name The name.
+     * @return The symbol.
+     */
+    public Symbol valueSymbol(String name) {
+        return SymbolUtils.createValueSymbolBuilder(name, this).build();
+    }
+
+    /**
+     * Creates a pointable Symbol for a name exported by this package.
+     * @param name The name.
+     * @return The symbol.
+     */
+    public Symbol pointableSymbol(String name) {
+        return SymbolUtils.createPointableSymbolBuilder(name, this).build();
+    }
+
     @Override
     public List<SymbolDependency> getDependencies() {
         Set<SymbolDependency> symbolDependencySet = new TreeSet<>(SetUtils.of(getSymbolDependency()));

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/GoStdlibTypes.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2020 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.go.codegen;
+
+import software.amazon.smithy.codegen.core.Symbol;
+
+/**
+ * Collection of Symbol constants for types in the go standard library.
+ */
+@SuppressWarnings({"checkstyle:ConstantName", "checkstyle:LineLength"})
+public final class GoStdlibTypes {
+    private GoStdlibTypes() { }
+
+    public static final class Context {
+        public static final Symbol Context = SmithyGoDependency.CONTEXT.valueSymbol("Context");
+    }
+
+    public static final class Fmt {
+        public static final Symbol Errorf = SmithyGoDependency.FMT.valueSymbol("Errorf");
+    }
+}

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/GoWriter.java

@@ -136,6 +136,17 @@ public static Writable goTemplate(String contents, Map<String, Object>... args)
         };
     }
 
+    /**
+     * Returns a Writable for the string and args to be composed inline to another writer's contents.
+     *
+     * @param content  string to write.
+     * @param args     Arguments to use when evaluating the contents string.
+     * @return Writable to be evaluated.
+     */
+    public static Writable goTemplate(Object content, Object... args) {
+        return writer -> writer.write(content, args);
+    }
+
     public static Writable goDocTemplate(String contents) {
         return goDocTemplate(contents, new HashMap<>());
     }

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/OperationGenerator.java

@@ -22,6 +22,7 @@
 import software.amazon.smithy.codegen.core.CodegenException;
 import software.amazon.smithy.codegen.core.Symbol;
 import software.amazon.smithy.codegen.core.SymbolProvider;
+import software.amazon.smithy.go.codegen.endpoints.EndpointParameterOperationBindingsGenerator;
 import software.amazon.smithy.go.codegen.integration.MiddlewareRegistrar;
 import software.amazon.smithy.go.codegen.integration.ProtocolGenerator;
 import software.amazon.smithy.go.codegen.integration.RuntimeClientPlugin;
@@ -134,9 +135,12 @@ public void run() {
                 func (*$T) operationName() string {
                     return $S
                 }
+
+                $W
                 """,
                 inputSymbol,
-                operationSymbol.getName()
+                operationSymbol.getName(),
+                new EndpointParameterOperationBindingsGenerator(operation, inputShape, inputSymbol).generate()
         );
 
         // The output structure gets a metadata member added.

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/SmithyGoTypes.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2020 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.go.codegen;
+
+import software.amazon.smithy.codegen.core.Symbol;
+
+/**
+ * Collection of Symbol constants for types in the smithy-go runtime.
+ */
+@SuppressWarnings({"checkstyle:ConstantName", "checkstyle:LineLength"})
+public final class SmithyGoTypes {
+    private SmithyGoTypes() { }
+
+    public static final class Ptr {
+        public static final Symbol String = SmithyGoDependency.SMITHY_PTR.valueSymbol("String");
+        public static final Symbol Bool = SmithyGoDependency.SMITHY_PTR.valueSymbol("Bool");
+    }
+
+    public static final class Middleware {
+        public static final Symbol Stack = SmithyGoDependency.SMITHY_MIDDLEWARE.pointableSymbol("Stack");
+        public static final Symbol SerializeInput = SmithyGoDependency.SMITHY_MIDDLEWARE.pointableSymbol("SerializeInput");
+        public static final Symbol SerializeOutput = SmithyGoDependency.SMITHY_MIDDLEWARE.pointableSymbol("SerializeOutput");
+        public static final Symbol SerializeHandler = SmithyGoDependency.SMITHY_MIDDLEWARE.pointableSymbol("SerializeHandler");
+        public static final Symbol Metadata = SmithyGoDependency.SMITHY_MIDDLEWARE.pointableSymbol("Metadata");
+    }
+
+    public static final class Transport {
+        public static final class Http {
+            public static final Symbol Request = SmithyGoDependency.SMITHY_HTTP_TRANSPORT.pointableSymbol("Request");
+        }
+    }
+}

codegen/smithy-go-codegen/src/main/java/software/amazon/smithy/go/codegen/endpoints/EndpointClientPluginsGenerator.java

@@ -19,8 +19,6 @@
 import java.util.List;
 import java.util.Optional;
 import software.amazon.smithy.codegen.core.Symbol;
-import software.amazon.smithy.codegen.core.SymbolProvider;
-import software.amazon.smithy.go.codegen.GoCodegenPlugin;
 import software.amazon.smithy.go.codegen.GoSettings;
 import software.amazon.smithy.go.codegen.SymbolUtils;
 import software.amazon.smithy.go.codegen.integration.ConfigField;
@@ -48,11 +46,6 @@ public class EndpointClientPluginsGenerator implements GoIntegration {
 
     private final List<RuntimeClientPlugin> runtimeClientPlugins = new ArrayList<>();
 
-
-    private static String getAddEndpointMiddlewareFuncName(String operationName) {
-        return String.format("add%sResolveEndpointMiddleware", operationName);
-    }
-
     private static String getExportedParameterName(Parameter parameter) {
         return StringUtils.capitalize(parameter.getName().getName().getValue());
     }
@@ -106,18 +99,13 @@ public void processFinalizedModel(GoSettings settings, Model model) {
         for (ToShapeId operationId : topDownIndex.getContainedOperations(service)) {
             OperationShape operationShape = model.expectShape(operationId.toShapeId(), OperationShape.class);
 
-            SymbolProvider symbolProvider = GoCodegenPlugin.createSymbolProvider(model, settings);
-
-            String inputHelperFuncName = getAddEndpointMiddlewareFuncName(
-                    symbolProvider.toSymbol(operationShape).getName()
-            );
+            Symbol addFunc = SymbolUtils.createValueSymbolBuilder(EndpointMiddlewareGenerator.ADD_FUNC_NAME).build();
             runtimeClientPlugins.add(RuntimeClientPlugin.builder()
                     .operationPredicate((m, s, o) -> {
                         return o.equals(operationShape);
                     })
                     .registerMiddleware(MiddlewareRegistrar.builder()
-                            .resolvedFunction(SymbolUtils.createValueSymbolBuilder(inputHelperFuncName)
-                                    .build())
+                            .resolvedFunction(addFunc)
                             .useClientOptions()
                             .build())
                     .build());