// Copyright (c) 2019, 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.utils.codeinspector;

import com.android.tools.r8.graph.DexField;
import com.android.tools.r8.graph.DexMethod;
import java.util.function.Predicate;
import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

public class CodeMatchers {

  public static Matcher<MethodSubject> accessesField(FieldSubject targetSubject) {
    if (!targetSubject.isPresent()) {
      throw new IllegalArgumentException();
    }
    DexField target = targetSubject.getField().field;
    return new TypeSafeMatcher<MethodSubject>() {
      @Override
      protected boolean matchesSafely(MethodSubject subject) {
        if (!subject.isPresent()) {
          return false;
        }
        if (!subject.getMethod().hasCode()) {
          return false;
        }
        return subject.streamInstructions().anyMatch(isFieldAccessWithTarget(target));
      }

      @Override
      public void describeTo(Description description) {
        description.appendText("accesses field `" + target.toSourceString() + "`");
      }

      @Override
      public void describeMismatchSafely(final MethodSubject subject, Description description) {
        description.appendText("method did not");
      }
    };
  }

  public static Matcher<MethodSubject> invokesMethod(MethodSubject targetSubject) {
    if (!targetSubject.isPresent()) {
      throw new IllegalArgumentException();
    }
    DexMethod target = targetSubject.getMethod().method;
    return new TypeSafeMatcher<MethodSubject>() {
      @Override
      protected boolean matchesSafely(MethodSubject subject) {
        if (!subject.isPresent()) {
          return false;
        }
        if (!subject.getMethod().hasCode()) {
          return false;
        }
        return subject.streamInstructions().anyMatch(isInvokeWithTarget(target));
      }

      @Override
      public void describeTo(Description description) {
        description.appendText("invokes method `" + target.toSourceString() + "`");
      }

      @Override
      public void describeMismatchSafely(final MethodSubject subject, Description description) {
        description.appendText("method did not");
      }
    };
  }

  public static Predicate<InstructionSubject> isInvokeWithTarget(DexMethod target) {
    return instruction -> instruction.isInvoke() && instruction.getMethod() == target;
  }

  public static Predicate<InstructionSubject> isFieldAccessWithTarget(DexField target) {
    return instruction -> instruction.isFieldAccess() && instruction.getField() == target;
  }
}