// 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.cf.code;

import com.android.tools.r8.graph.CfCompareHelper;
import com.android.tools.r8.graph.DexClassAndMethod;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.graph.UseRegistry;
import com.android.tools.r8.ir.code.BasicBlock;
import com.android.tools.r8.ir.code.CatchHandlers;
import com.android.tools.r8.ir.conversion.CfBuilder;
import com.android.tools.r8.utils.structural.CompareToVisitor;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.function.BiConsumer;
import java.util.function.Consumer;

public class CfTryCatch {
  public final CfLabel start;
  public final CfLabel end;
  public final List<DexType> guards;
  public final List<CfLabel> targets;

  public CfTryCatch(CfLabel start, CfLabel end, List<DexType> guards, List<CfLabel> targets) {
    this.start = start;
    this.end = end;
    this.guards = guards;
    this.targets = targets;
    assert verifyAllNonNull(guards);
  }

  public void forEach(BiConsumer<DexType, CfLabel> consumer) {
    Iterator<DexType> guardIterator = guards.iterator();
    Iterator<CfLabel> targetIterator = targets.iterator();
    while (guardIterator.hasNext()) {
      consumer.accept(guardIterator.next(), targetIterator.next());
    }
    assert !targetIterator.hasNext();
  }

  public void forEachTarget(Consumer<CfLabel> consumer) {
    targets.forEach(consumer);
  }

  public CfLabel getStart() {
    return start;
  }

  public CfLabel getEnd() {
    return end;
  }

  public List<CfLabel> getTargets() {
    return targets;
  }

  private static boolean verifyAllNonNull(List<DexType> types) {
    for (DexType type : types) {
      assert type != null;
    }
    return true;
  }

  public static CfTryCatch fromBuilder(
      CfLabel start,
      CfLabel end,
      CatchHandlers<BasicBlock> handlers,
      CfBuilder builder) {
    List<DexType> guards = handlers.getGuards();
    ArrayList<CfLabel> targets = new ArrayList<>(handlers.getAllTargets().size());
    for (BasicBlock block : handlers.getAllTargets()) {
      targets.add(builder.getLabel(block));
    }
    return new CfTryCatch(start, end, guards, targets);
  }

  public int acceptCompareTo(CfTryCatch other, CompareToVisitor visitor, CfCompareHelper helper) {
    return visitor.visit(
        this,
        other,
        spec ->
            spec.withCustomItem(c -> c.start, helper.labelAcceptor())
                .withCustomItem(c -> c.end, helper.labelAcceptor())
                .withItemCollection(c -> c.guards)
                .withCustomItemCollection(c -> c.targets, helper.labelAcceptor()));
  }

  public void internalRegisterUse(UseRegistry registry, DexClassAndMethod context) {
    guards.forEach(registry::registerExceptionGuard);
  }
}