content: /*
   * Copyright (C) 2016 The Android Open Source Project
   *
   * 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 androidx.test.espresso.remote;
  
  import static androidx.test.internal.util.Checks.checkNotNull;
  import static androidx.test.internal.util.Checks.checkState;
  import static androidx.test.internal.util.LogUtil.lazyArg;
  import static androidx.test.internal.util.LogUtil.logDebug;
  
  import android.util.LruCache;
  import androidx.annotation.NonNull;
  import androidx.annotation.Nullable;
  import androidx.annotation.VisibleForTesting;
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
  import java.util.Arrays;
  import java.util.Locale;
  
  /** Reflectively invokes the constructor of a declared class. */
  public final class ConstructorInvocation {
    private static final String TAG = "ConstructorInvocation";
    private static final LruCache<ConstructorKey, Constructor<?>> constructorCache =
        new LruCache<>(256 /* LRU eviction after max size exceeded */);
  
    private final Class<?> clazz;
    @Nullable private final Class<? extends Annotation> annotationClass;
    @Nullable private final Class<?>[] parameterTypes;
  
    /**
     * Creates a new {@link ConstructorInvocation}.
     *
     * <p>Constructor lookup is either done using an annotation by passing the {@code annotationClass}
     * as a parameter or through {@code parameterTypes} lookup. This class will attempt to lookup a
     * constructor by first looking for a constructor annotated with {@code annotationClass}. If no
     * constructors are found it will fallback and try to use {@code parameterTypes}.
     *
     * @param clazz the declared class to create the instance off
     * @param annotationClass the annotation class to lookup the constructor
     * @param parameterTypes array of parameter types to lookup a constructor on the declared class.
     *     The declared order of parameter types must match the order of the constructor parameters
     *     passed into {@link #invokeConstructor(Object...)}.
     */
    public ConstructorInvocation(
        @NonNull Class<?> clazz,
        @Nullable Class<? extends Annotation> annotationClass,
        @Nullable Class<?>... parameterTypes) {
      this.clazz = checkNotNull(clazz, "clazz cannot be null!");
      this.annotationClass = annotationClass;
      this.parameterTypes = parameterTypes;
    }
  
    @VisibleForTesting
    static void invalidateCache() {
      constructorCache.evictAll();
    }
  
    /**
     * Invokes the target constructor with the provided constructor parameters
     *
     * @param constructorParams array of objects to be passed as arguments to the constructor
     * @return a new instance of the declared class
     */
    public Object invokeConstructor(Object... constructorParams) {
      return invokeConstructorExplosively(constructorParams);
    }
  
    private Object invokeConstructorExplosively(Object... constructorParams) {
      Object returnValue = null;
      Constructor<?> constructor = null;
      ConstructorKey constructorKey = new ConstructorKey(clazz, parameterTypes);
      try {
        // Lookup constructor in cache
        constructor = constructorCache.get(constructorKey);
        if (null == constructor) {
          logDebug(
              TAG,
              "Cache miss for constructor: %s(%s). Loading into cache.",
              clazz.getSimpleName(),
              lazyArg(() -> Arrays.toString(constructorParams)));
          // Lookup constructor using annotation class
          if (annotationClass != null) {
            for (Constructor<?> candidate : clazz.getDeclaredConstructors()) {
              if (candidate.isAnnotationPresent(annotationClass)) {
                constructor = candidate;
                break;
              }
            }
          }
          // No annotated constructor found. Try constructor lookup by parameter types
          if (null == constructor) {
            constructor = clazz.getConstructor(parameterTypes);
          }
  
          checkState(
              constructor != null,
              "No constructor found for annotation: %s, or parameter types: %s",
              annotationClass,
              Arrays.asList(parameterTypes));
          constructorCache.put(constructorKey, constructor);
        } else {
          logDebug(
              TAG,
              "Cache hit for constructor: %s(%s).",
              clazz.getSimpleName(),
              lazyArg(() -> Arrays.toString(constructorParams)));
        }
  
        constructor.setAccessible(true);
        returnValue = constructor.newInstance(constructorParams);
      } catch (InvocationTargetException ite) {
        throw new RemoteProtocolException(
            String.format(
                Locale.ROOT,
                "Cannot invoke constructor %s with constructorParams [%s] on clazz %s",
                constructor,
                Arrays.toString(constructorParams),
                clazz.getName()),
            ite);
      } catch (IllegalAccessException iae) {
        throw new RemoteProtocolException(
            String.format(Locale.ROOT, "Cannot create instance of %s", clazz.getName()), iae);
      } catch (InstantiationException ia) {
        throw new RemoteProtocolException(
            String.format(Locale.ROOT, "Cannot create instance of %s", clazz.getName()), ia);
      } catch (NoSuchMethodException nsme) {
        throw new RemoteProtocolException(
            String.format(
                Locale.ROOT,
                "No constructor found for clazz: %s. Available constructors: %s",
                clazz.getName(),
                Arrays.asList(clazz.getConstructors())),
            nsme);
      } catch (SecurityException se) {
        throw new RemoteProtocolException(
            String.format(Locale.ROOT, "Constructor not accessible: %s", constructor.getName()), se);
      } finally {
        logDebug(
            TAG, "%s(%s)", clazz.getSimpleName(), lazyArg(() -> Arrays.toString(constructorParams)));
      }
      return returnValue;
    }
  
    private static final class ConstructorKey {
      private final Class<?> type;
      private final Class<?>[] parameterTypes;
  
      public ConstructorKey(Class<?> type, Class<?>[] parameterTypes) {
        this.type = type;
        this.parameterTypes = parameterTypes;
      }
  
      @Override
      public boolean equals(Object o) {
        if (this == o) {
          return true;
        }
        if (o == null || getClass() != o.getClass()) {
          return false;
        }
  
        ConstructorKey that = (ConstructorKey) o;
  
        if (!type.equals(that.type)) {
          return false;
        }
        return Arrays.equals(parameterTypes, that.parameterTypes);
      }
  
      @Override
      public int hashCode() {
        int result = type.hashCode();
        result = 31 * result + Arrays.hashCode(parameterTypes);
        return result;
      }
    }
  }
  