/*
 * Copyright (C) 2017 The Dagger Authors.
 *
 * 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 dagger.internal.codegen;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.squareup.javapoet.MethodSpec.methodBuilder;
import static javax.lang.model.element.Modifier.PRIVATE;
import static javax.lang.model.element.Modifier.PROTECTED;

import com.squareup.javapoet.TypeName;
import dagger.internal.codegen.langmodel.DaggerTypes;
import java.util.Optional;

/**
 * A binding expression that wraps a modifiable binding expression in a public, no-arg method.
 *
 * <p>Dependents of this binding expression will just call the modifiable binding method.
 */
final class ModifiableConcreteMethodBindingExpression extends MethodBindingExpression {

  private final BindingRequest request;
  private final ModifiableBindingType modifiableBindingType;
  private final ComponentImplementation componentImplementation;
  private final boolean bindingCannotBeModified;
  private Optional<String> methodName = Optional.empty();

  ModifiableConcreteMethodBindingExpression(
      BindingRequest request,
      ResolvedBindings resolvedBindings,
      MethodImplementationStrategy methodImplementationStrategy,
      BindingExpression wrappedBindingExpression,
      ModifiableBindingType modifiableBindingType,
      ComponentImplementation componentImplementation,
      boolean bindingCannotBeModified,
      DaggerTypes types) {
    super(
        request,
        resolvedBindings,
        methodImplementationStrategy,
        wrappedBindingExpression,
        componentImplementation,
        types);
    this.request = checkNotNull(request);
    this.modifiableBindingType = checkNotNull(modifiableBindingType);
    this.componentImplementation = checkNotNull(componentImplementation);
    this.bindingCannotBeModified = bindingCannotBeModified;
  }

  @Override
  protected void addMethod() {
    if (methodName.isPresent()) {
      return;
    }

    if (supertypeModifiableBindingMethod().isPresent()) {
      methodName = supertypeModifiableBindingMethod().map(method -> method.methodSpec().name);
      return;
    }

    // Add the modifiable binding method to the component if we haven't already.
    methodName = Optional.of(componentImplementation.getUniqueMethodName(request));
    componentImplementation.addModifiableBindingMethod(
        modifiableBindingType,
        request,
        returnType(),
        methodBuilder(methodName.get())
            .addModifiers(bindingCannotBeModified ? PRIVATE : PROTECTED)
            .returns(TypeName.get(returnType()))
            .addCode(methodBody())
            .build(),
        bindingCannotBeModified);
  }

  @Override
  protected String methodName() {
    checkState(methodName.isPresent(), "addMethod() must be called before methodName().");
    return methodName.get();
  }

  @Override
  protected boolean isModifiableImplementationMethod() {
    return true;
  }
}