// Copyright (c) 2017, 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.shaking;

import com.android.tools.r8.graph.DexItemFactory;
import com.android.tools.r8.origin.Origin;
import com.android.tools.r8.shaking.ProguardConfigurationParser.IdentifierPatternWithWildcards;
import com.android.tools.r8.utils.AndroidApiLevel;
import com.android.tools.r8.utils.LongInterval;
import com.google.common.collect.ImmutableList;
import java.util.List;

public class ProguardConfigurationUtils {

  public static ProguardAssumeNoSideEffectRule buildAssumeNoSideEffectsRuleForApiLevel(
      DexItemFactory factory, AndroidApiLevel apiLevel) {
    Origin synthesizedFromApiLevel =
        new Origin(Origin.root()) {
          @Override
          public String part() {
            return "<SYNTHESIZED_FROM_API_LEVEL_" + apiLevel.getLevel() + ">";
          }
        };

    ProguardAccessFlags publicStaticFinalFlags = new ProguardAccessFlags();
    publicStaticFinalFlags.setPublic();
    publicStaticFinalFlags.setStatic();
    publicStaticFinalFlags.setFinal();

    return ProguardAssumeNoSideEffectRule.builder()
        .setOrigin(synthesizedFromApiLevel)
        .setClassType(ProguardClassType.CLASS)
        .setClassNames(
            ProguardClassNameList.singletonList(
                ProguardTypeMatcher.create(factory.androidOsBuildVersionType)))
        .setMemberRules(
            ImmutableList.of(
                ProguardMemberRule.builder()
                    .setAccessFlags(publicStaticFinalFlags)
                    .setRuleType(ProguardMemberType.FIELD)
                    .setTypeMatcher(ProguardTypeMatcher.create(factory.intType))
                    .setName(IdentifierPatternWithWildcards.withoutWildcards("SDK_INT"))
                    .setReturnValue(
                        new ProguardMemberRuleReturnValue(
                            new LongInterval(apiLevel.getLevel(), Integer.MAX_VALUE)))
                    .build()))
        .build();
  }

  /**
   * Check if an explicit rule matching the field public static final int
   * android.os.Build$VERSION.SDK_INT is present.
   */
  public static boolean hasExplicitAssumeValuesOrAssumeNoSideEffectsRuleForMinSdk(
      DexItemFactory factory, List<ProguardConfigurationRule> rules) {
    for (ProguardConfigurationRule rule : rules) {
      if (!(rule instanceof ProguardAssumeValuesRule
          || rule instanceof ProguardAssumeNoSideEffectRule)) {
        continue;
      }
      if (rule.getClassType() != ProguardClassType.CLASS) {
        continue;
      }
      if (!rule.getClassAnnotations().isEmpty() || !rule.getInheritanceAnnotations().isEmpty()) {
        continue;
      }
      if (rule.hasInheritanceClassName()
          && !rule.getInheritanceClassName().matches(factory.objectType)) {
        continue;
      }
      if (rule.getClassNames().hasWildcards()
          || !rule.getClassNames().matches(factory.androidOsBuildVersionType)) {
        continue;
      }
      for (ProguardMemberRule memberRule : rule.getMemberRules()) {
        if (memberRule.getRuleType() == ProguardMemberType.ALL
            || memberRule.getRuleType() == ProguardMemberType.ALL_FIELDS) {
          return true;
        }
        if (memberRule.getRuleType() != ProguardMemberType.FIELD) {
          continue;
        }
        if (!memberRule.getAnnotations().isEmpty()) {
          continue;
        }
        if (memberRule.getAccessFlags().isProtected()
            || memberRule.getAccessFlags().isPrivate()
            || memberRule.getAccessFlags().isAbstract()
            || memberRule.getAccessFlags().isTransient()
            || memberRule.getAccessFlags().isVolatile()) {
          continue;
        }
        if (memberRule.getNegatedAccessFlags().isPublic()
            || memberRule.getNegatedAccessFlags().isStatic()
            || memberRule.getNegatedAccessFlags().isFinal()) {
          continue;
        }
        if (!memberRule.getType().matches(factory.intType)) {
          continue;
        }
        if (!memberRule.getName().matches("SDK_INT")) {
          continue;
        }
        return true;
      }
    }
    return false;
  }
}