// Copyright (c) 2020, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package com.android.tools.r8.ir.analysis.value;

import static com.android.tools.r8.ir.analysis.type.Nullability.maybeNull;

import com.android.tools.r8.graph.AppInfoWithClassHierarchy;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DexClass;
import com.android.tools.r8.graph.DexEncodedField;
import com.android.tools.r8.graph.DexField;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.graph.FieldResolutionResult.SuccessfulFieldResolutionResult;
import com.android.tools.r8.graph.GraphLens;
import com.android.tools.r8.graph.ProgramMethod;
import com.android.tools.r8.ir.analysis.type.ClassTypeElement;
import com.android.tools.r8.ir.analysis.type.TypeElement;
import com.android.tools.r8.ir.code.IRCode;
import com.android.tools.r8.ir.code.Instruction;
import com.android.tools.r8.ir.code.StaticGet;
import com.android.tools.r8.ir.code.TypeAndLocalInfoSupplier;
import com.android.tools.r8.ir.code.Value;
import com.android.tools.r8.ir.optimize.enums.EnumDataMap;
import com.android.tools.r8.shaking.AppInfoWithLiveness;

public abstract class SingleFieldValue extends SingleValue {

  final DexField field;

  SingleFieldValue(DexField field) {
    this.field = field;
  }

  public DexField getField() {
    return field;
  }

  public abstract ObjectState getState();

  public boolean mayHaveFinalizeMethodDirectlyOrIndirectly(AppView<AppInfoWithLiveness> appView) {
    DexType fieldType = field.type;
    if (fieldType.isClassType()) {
      ClassTypeElement fieldClassType =
          TypeElement.fromDexType(fieldType, maybeNull(), appView).asClassType();
      return appView.appInfo().mayHaveFinalizeMethodDirectlyOrIndirectly(fieldClassType);
    }
    assert fieldType.isArrayType() || fieldType.isPrimitiveType();
    return false;
  }

  @Override
  public boolean isSingleFieldValue() {
    return true;
  }

  @Override
  public SingleFieldValue asSingleFieldValue() {
    return this;
  }

  @Override
  public abstract boolean equals(Object o);

  @Override
  public abstract int hashCode();

  @Override
  public Instruction createMaterializingInstruction(
      AppView<? extends AppInfoWithClassHierarchy> appView,
      IRCode code,
      TypeAndLocalInfoSupplier info) {
    TypeElement type = TypeElement.fromDexType(field.type, maybeNull(), appView);
    assert type.lessThanOrEqual(info.getOutType(), appView);
    Value outValue = code.createValue(type, info.getLocalInfo());
    return new StaticGet(outValue, field);
  }

  @Override
  public boolean isMaterializableInContext(
      AppView<AppInfoWithLiveness> appView, ProgramMethod context) {
    SuccessfulFieldResolutionResult resolutionResult =
        appView.appInfo().resolveField(field).asSuccessfulResolution();
    return resolutionResult != null && resolutionResult.isAccessibleFrom(context, appView).isTrue();
  }

  @Override
  public boolean isMaterializableInAllContexts(AppView<AppInfoWithLiveness> appView) {
    DexEncodedField encodedField = appView.appInfo().resolveField(field).getResolvedField();
    if (encodedField == null) {
      assert false;
      return false;
    }
    if (!encodedField.isPublic()) {
      return false;
    }
    DexClass holder = appView.definitionFor(encodedField.getHolderType());
    if (holder == null) {
      assert false;
      return false;
    }
    return holder.isPublic();
  }

  @Override
  public SingleValue rewrittenWithLens(AppView<AppInfoWithLiveness> appView, GraphLens lens) {
    AbstractValueFactory factory = appView.abstractValueFactory();
    if (field.holder == field.type) {
      EnumDataMap enumDataMap = appView.unboxedEnums();
      if (enumDataMap.hasUnboxedValueFor(field)) {
        return factory.createSingleNumberValue(enumDataMap.getUnboxedValue(field));
      }
    }
    return factory.createSingleFieldValue(
        lens.lookupField(field), getState().rewrittenWithLens(appView, lens));
  }
}