/mycila-testing/tags/2.0-rc1/mycila-testing-plugins/mycila-testing-guice/src/main/java/com/mycila/testing/plugin/guice/Guice1TestPlugin.java

/**

 * Copyright (C) 2008 Mathieu Carbou <mathieu.carbou@gmail.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *         http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License 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 com.mycila.testing.plugin.guice;



import com.google.inject.AbstractModule;

import com.google.inject.Binder;

import com.google.inject.Guice;

import com.google.inject.Inject;

import com.google.inject.Injector;

import com.google.inject.Module;

import com.google.inject.Provider;

import com.google.inject.Stage;

import com.google.inject.TypeLiteral;

import com.google.inject.binder.AnnotatedBindingBuilder;

import com.google.inject.binder.LinkedBindingBuilder;

import com.google.inject.binder.ScopedBindingBuilder;

import com.mycila.testing.core.api.TestContext;

import static com.mycila.testing.core.introspect.Filters.*;

import com.mycila.testing.core.plugin.DefaultTestPlugin;



import java.lang.reflect.Field;

import java.lang.reflect.Method;

import java.lang.reflect.Type;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;



/**

 * @author Mathieu Carbou (mathieu.carbou@gmail.com)

 */

public final class Guice1TestPlugin extends DefaultTestPlugin {



    public static final String INJECTOR = "com.google.inject.Injector";



    @Override

    public void prepareTestInstance(final TestContext context) {

        context.attributes().set("guice.providers", new ArrayList<Provider<?>>());

        GuiceContext ctx = context.introspector().testClass().getAnnotation(GuiceContext.class);



        // create modules

        List<Module> modules = new ArrayList<Module>();

        modules.add(new AbstractModule() {

            @Override

            protected void configure() {

                bind(ProviderSetup.class).toInstance(new ProviderSetup() {

                    @Inject

                    void inject(Injector injector) {

                        for (Provider<?> provider : context.attributes().<List<Provider<?>>>remove("guice.providers")) {

                            injector.injectMembers(provider);

                        }

                    }

                });

            }

        });

        modules.addAll(contextualModules(ctx));

        modules.addAll(providedModules(context));

        modules.add(bindings(context));

        modules.add(providedBindings(context));

        if (context.introspector().instance() instanceof Module) {

            modules.add((Module) context.introspector().instance());

        }



        // create injector

        Injector injector = Guice.createInjector(findStage(ctx), modules);

        context.attributes().set(INJECTOR, injector);



        injector.injectMembers(context.introspector().instance());

    }



    private Module bindings(final TestContext context) {

        return new Module() {

            public void configure(Binder binder) {

                for (final Field field : context.introspector().selectFields(fieldsAnnotatedBy(Bind.class))) {

                    Guice1TestPlugin.this.configure(context, binder, field.getGenericType(), field.getAnnotation(Bind.class), new InjectedProvider<Object>() {

                        public Object getInternal() {

                            return context.introspector().get(field);

                        }

                    });



                }

            }

        };

    }



    private Module providedBindings(final TestContext context) {

        return new Module() {

            public void configure(Binder binder) {

                for (final Method method : context.introspector().selectMethods(excludeOverridenMethods(methodsAnnotatedBy(Bind.class)))) {

                    Guice1TestPlugin.this.configure(context, binder, method.getGenericReturnType(), method.getAnnotation(Bind.class), new InjectedProvider<Object>() {

                        public Object getInternal() {

                            return context.introspector().invoke(method);

                        }

                    });



                }

            }

        };

    }



    @SuppressWarnings({"unchecked"})

    private <T> void configure(TestContext context, Binder binder, Type type, Bind annotation, InjectedProvider<T> provider) {

        AnnotatedBindingBuilder<T> builder1 = (AnnotatedBindingBuilder<T>) binder.bind(TypeLiteral.get(type));

        LinkedBindingBuilder<T> builder2 = annotation.annotatedBy().equals(NoAnnotation.class) ? builder1 : builder1.annotatedWith(annotation.annotatedBy());

        ScopedBindingBuilder builder3 = builder2.toProvider(provider);

        if (!annotation.scope().equals(NoAnnotation.class)) {

            builder3.in(annotation.scope());

        }

        context.attributes().<List<InjectedProvider<T>>>get("guice.providers").add(provider);

    }



    @SuppressWarnings({"unchecked"})

    private List<Module> providedModules(TestContext ctx) {

        List<Module> modules = new ArrayList<Module>();

        for (Method method : ctx.introspector().selectMethods(excludeOverridenMethods(and(methodsReturning(Module.class), methodsAnnotatedBy(ModuleProvider.class))))) {

            modules.add((Module) ctx.introspector().invoke(method));

        }

        for (Method method : ctx.introspector().selectMethods(excludeOverridenMethods(and(methodsReturning(Module[].class), methodsAnnotatedBy(ModuleProvider.class))))) {

            modules.addAll(Arrays.asList((Module[]) ctx.introspector().invoke(method)));

        }

        for (Method method : ctx.introspector().selectMethods(excludeOverridenMethods(and(methodsReturning(Iterable.class), methodsAnnotatedBy(ModuleProvider.class))))) {

            for (Module module : (Iterable<Module>) ctx.introspector().invoke(method)) {

                modules.add(module);

            }

        }

        return modules;

    }



    private Stage findStage(GuiceContext ctx) {

        return ctx == null ? Stage.DEVELOPMENT : ctx.stage();

    }



    private List<Module> contextualModules(GuiceContext context) {

        List<Module> modules = new ArrayList<Module>();

        if (context != null) {

            for (Class<? extends Module> moduleClass : context.value()) {

                try {

                    modules.add(moduleClass.newInstance());

                } catch (Exception e) {

                    throw new IllegalStateException(String.format("Error instanciating module class '%s': %s", moduleClass.getName(), e.getMessage()), e);

                }

            }

        }

        return modules;

    }



    private static interface ProviderSetup {

    }



    private static abstract class InjectedProvider<T> implements Provider<T> {



        @Inject

        Injector injector;



        public final T get() {

            T t = getInternal();

            injector.injectMembers(t);

            return t;

        }



        protected abstract T getInternal();

    }



}