Add endpoints2.0 middleware and param binding generation.

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

@@ -0,0 +1,150 @@
+/*
+ * 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.go.codegen.endpoints;
+
+import java.util.ArrayList;
+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;
+import software.amazon.smithy.go.codegen.integration.GoIntegration;
+import software.amazon.smithy.go.codegen.integration.MiddlewareRegistrar;
+import software.amazon.smithy.go.codegen.integration.RuntimeClientPlugin;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.knowledge.TopDownIndex;
+import software.amazon.smithy.model.shapes.OperationShape;
+import software.amazon.smithy.model.shapes.ServiceShape;
+import software.amazon.smithy.model.shapes.ToShapeId;
+import software.amazon.smithy.rulesengine.language.EndpointRuleSet;
+import software.amazon.smithy.rulesengine.language.syntax.parameters.Parameter;
+import software.amazon.smithy.rulesengine.traits.ClientContextParamsTrait;
+import software.amazon.smithy.rulesengine.traits.EndpointRuleSetTrait;
+import software.amazon.smithy.utils.ListUtils;
+import software.amazon.smithy.utils.StringUtils;
+
+
+/**
+ * Class responsible for registering client config fields that
+ * are modeled in endpoint rulesets.
+ */
+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().asString());
+    }
+
+    private static Symbol parameterAsSymbol(Parameter parameter) {
+        return switch (parameter.getType()) {
+            case STRING -> SymbolUtils.createPointableSymbolBuilder("string")
+                    .putProperty(SymbolUtils.GO_UNIVERSE_TYPE, true).build();
+
+            case BOOLEAN -> SymbolUtils.createPointableSymbolBuilder("bool")
+                    .putProperty(SymbolUtils.GO_UNIVERSE_TYPE, true).build();
+        };
+    }
+
+    @Override
+    public List<RuntimeClientPlugin> getClientPlugins() {
+        runtimeClientPlugins.add(RuntimeClientPlugin.builder()
+        .configFields(ListUtils.of(
+            ConfigField.builder()
+                    .name("BaseEndpoint")
+                    .type(SymbolUtils.createPointableSymbolBuilder("string")
+                        .putProperty(SymbolUtils.GO_UNIVERSE_TYPE, true).build())
+                    .documentation(
+                        """
+                        This endpoint will be given as input to an EndpointResolverV2.
+                        It is used for providing a custom base endpoint that is subject
+                        to modifications by the processing EndpointResolverV2.
+                        """
+                    )
+                    .build()
+        ))
+        .build());
+        return runtimeClientPlugins;
+    }
+
+    @Override
+    public void processFinalizedModel(GoSettings settings, Model model) {
+        ServiceShape service = settings.getService(model);
+        var rulesetTrait = service.getTrait(EndpointRuleSetTrait.class);
+        Optional<EndpointRuleSet> rulesetOpt = (rulesetTrait.isPresent())
+        ? Optional.of(EndpointRuleSet.fromNode(rulesetTrait.get().getRuleSet()))
+        : Optional.empty();
+        var clientContextParamsTrait = service.getTrait(ClientContextParamsTrait.class);
+
+        var topDownIndex = TopDownIndex.of(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()
+            );
+            runtimeClientPlugins.add(RuntimeClientPlugin.builder()
+                    .operationPredicate((m, s, o) -> {
+                        return o.equals(operationShape);
+                    })
+                    .registerMiddleware(MiddlewareRegistrar.builder()
+                            .resolvedFunction(SymbolUtils.createValueSymbolBuilder(inputHelperFuncName)
+                                    .build())
+                            .useClientOptions()
+                            .build())
+                    .build());
+
+            if (clientContextParamsTrait.isPresent()) {
+                if (rulesetOpt.isPresent()) {
+                    var clientContextParams = clientContextParamsTrait.get();
+                    var parameters = rulesetOpt.get().getParameters();
+                    parameters.toList().stream().forEach(param -> {
+                        if (
+                            clientContextParams.getParameters().containsKey(param.getName().asString())
+                            && !param.getBuiltIn().isPresent()
+                        ) {
+                            var documentation = param.getDocumentation().isPresent()
+                                ? param.getDocumentation().get()
+                                : "";
+
+                            runtimeClientPlugins.add(RuntimeClientPlugin.builder()
+                            .configFields(ListUtils.of(
+                                ConfigField.builder()
+                                        .name(getExportedParameterName(param))
+                                        .type(parameterAsSymbol(param))
+                                        .documentation(documentation)
+                                        .build()
+                            ))
+                            .build());
+                        }
+                    });
+                }
+            }
+        }
+    }
+}
+