package com.google.inject.spi;

import com.google.inject.AbstractModule;
import com.google.inject.Binding;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Key;
import com.google.inject.Provider;
import com.google.inject.TypeLiteral;
import java.util.Map;
import junit.framework.TestCase;

/** @author sberlin@gmail.com (Sam Berlin) */
public class InjectorSpiTest extends TestCase {

  public void testExistingBinding() {
    Injector injector =
        Guice.createInjector(
            new AbstractModule() {
              @Override
              protected void configure() {
                bind(Foo.class);
                bind(Baz.class);
              }
            });
    // Sanity check -- ensure we return the proper binding for all existing bindings.
    for (Map.Entry<Key<?>, Binding<?>> entry : injector.getAllBindings().entrySet()) {
      assertSame(entry.getValue(), injector.getExistingBinding(entry.getKey()));
    }

    // Now run through specifics...
    Binding<?> binding;

    // 1) non-Provider Foo.class
    binding = injector.getExistingBinding(Key.get(Foo.class));
    assertNotNull(binding);
    assertEquals(Foo.class, binding.getKey().getTypeLiteral().getRawType());

    // 2) Provider<Foo> class (should already exist, because Baz @Injects it).
    // the assertTrue is a bit stricter than necessary, but makes sure this works for pre-existing Provider bindings
    assertTrue(injector.getAllBindings().containsKey(Key.get(new TypeLiteral<Provider<Foo>>() {})));
    binding = injector.getExistingBinding(Key.get(new TypeLiteral<Provider<Foo>>() {}));
    assertNotNull(binding);
    assertEquals(Provider.class, binding.getKey().getTypeLiteral().getRawType());
    assertEquals(Foo.class, ((Provider) binding.getProvider().get()).get().getClass());

    // 3) non-Provider Baz.class
    binding = injector.getExistingBinding(Key.get(Baz.class));
    assertNotNull(binding);
    assertEquals(Baz.class, binding.getKey().getTypeLiteral().getRawType());

    // 4) Provider<Baz> class (should not already exist, because nothing used it yet).
    // the assertFalse is a bit stricter than necessary, but makes sure this works for non-pre-existing Provider bindings
    assertFalse(
        injector.getAllBindings().containsKey(Key.get(new TypeLiteral<Provider<Baz>>() {})));
    binding = injector.getExistingBinding(Key.get(new TypeLiteral<Provider<Baz>>() {}));
    assertNotNull(binding);
    assertEquals(Provider.class, binding.getKey().getTypeLiteral().getRawType());
    assertEquals(Baz.class, ((Provider) binding.getProvider().get()).get().getClass());

    // 5) non-Provider Bar, doesn't exist.
    assertNull(injector.getExistingBinding(Key.get(Bar.class)));

    // 6) Provider Bar, doesn't exist.
    assertNull(injector.getExistingBinding(Key.get(new TypeLiteral<Provider<Bar>>() {})));
  }

  private static class Foo {}

  private static class Bar {}

  private static class Baz {
    @SuppressWarnings("unused")
    @Inject
    Provider<Foo> fooP;
  }
}