// Copyright 2017 The Bazel Authors. All rights reserved.
//
// 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 com.google.devtools.build.lib.analysis.platform;

import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.events.Location;
import com.google.devtools.build.lib.packages.NativeInfo;
import com.google.devtools.build.lib.packages.NativeProvider;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
import com.google.devtools.build.lib.skylarkbuildapi.platform.ConstraintValueInfoApi;
import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
import com.google.devtools.build.lib.util.Fingerprint;
import java.util.Objects;

/** Provider for a platform constraint value that fulfills a {@link ConstraintSettingInfo}. */
@Immutable
@AutoCodec
public class ConstraintValueInfo extends NativeInfo implements ConstraintValueInfoApi {
  /** Name used in Skylark for accessing this provider. */
  public static final String SKYLARK_NAME = "ConstraintValueInfo";

  /** Skylark constructor and identifier for this provider. */
  public static final NativeProvider<ConstraintValueInfo> PROVIDER =
      new NativeProvider<ConstraintValueInfo>(ConstraintValueInfo.class, SKYLARK_NAME) {};

  private final ConstraintSettingInfo constraint;
  private final Label label;

  @VisibleForSerialization
  ConstraintValueInfo(ConstraintSettingInfo constraint, Label label, Location location) {
    super(PROVIDER, location);

    this.constraint = constraint;
    this.label = label;
  }

  @Override
  public ConstraintSettingInfo constraint() {
    return constraint;
  }

  @Override
  public Label label() {
    return label;
  }

  @Override
  public void repr(SkylarkPrinter printer) {
    printer.format(
        "ConstraintValueInfo(setting=%s, %s)", constraint.label().toString(), label.toString());
  }

  /** Returns a new {@link ConstraintValueInfo} with the given data. */
  public static ConstraintValueInfo create(ConstraintSettingInfo constraint, Label value) {
    return create(constraint, value, Location.BUILTIN);
  }

  /** Returns a new {@link ConstraintValueInfo} with the given data. */
  public static ConstraintValueInfo create(
      ConstraintSettingInfo constraint, Label value, Location location) {
    return new ConstraintValueInfo(constraint, value, location);
  }

  /** Add this constraint value to the given fingerprint. */
  public void addTo(Fingerprint fp) {
    this.constraint.addTo(fp);
    fp.addString(label.getCanonicalForm());
  }

  @Override
  public boolean equals(Object o) {
    if (!(o instanceof ConstraintValueInfo)) {
      return false;
    }
    ConstraintValueInfo that = (ConstraintValueInfo) o;
    return Objects.equals(constraint, that.constraint)
        && Objects.equals(label, that.label);
  }

  @Override
  public int hashCode() {
    return Objects.hash(constraint, label);
  }
}