// Copyright 2015 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.rules.java;

import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.analysis.skylark.SkylarkApiProvider;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
import java.util.Iterator;

/**
 * A class that exposes the java_toolchain providers to Skylark. It is intended to provide a simple
 * and stable interface for Skylark users.
 */
@SkylarkModule(
  name = "JavaToolchainSkylarkApiProvider",
  doc =
      "Provides access to information about the Java toolchain rule. "
          + "Accessible as a 'java_toolchain' field on a Target struct."
)
@AutoCodec
public final class JavaToolchainSkylarkApiProvider extends SkylarkApiProvider {
  /** The name of the field in Skylark used to access this class. */
  public static final String NAME = "java_toolchain";

  /** @return the input Java language level */
  // TODO(cushon): remove this API; it bakes a deprecated detail of the javac API into Bazel
  @SkylarkCallable(name = "source_version", doc = "The java source version.", structField = true)
  public String getSourceVersion() {
    JavaToolchainProvider javaToolchainProvider =
        JavaToolchainProvider.from(getInfo());
    Iterator<String> it = javaToolchainProvider.getJavacOptions().iterator();
    while (it.hasNext()) {
      if (it.next().equals("-source") && it.hasNext()) {
        return it.next();
      }
    }
    return System.getProperty("java.specification.version");
  }

  /** @return the target Java language level */
  // TODO(cushon): remove this API; it bakes a deprecated detail of the javac API into Bazel
  @SkylarkCallable(name = "target_version", doc = "The java target version.", structField = true)
  public String getTargetVersion() {
    JavaToolchainProvider javaToolchainProvider =
        JavaToolchainProvider.from(getInfo());
    Iterator<String> it = javaToolchainProvider.getJavacOptions().iterator();
    while (it.hasNext()) {
      if (it.next().equals("-target") && it.hasNext()) {
        return it.next();
      }
    }
    return System.getProperty("java.specification.version");
  }

  /** @return The {@link Artifact} of the javac jar */
  @SkylarkCallable(
      name = "javac_jar",
      doc = "The javac jar.",
      structField = true
  )
  public Artifact getJavacJar() {
    JavaToolchainProvider javaToolchainProvider =
        JavaToolchainProvider.from(getInfo());
    return javaToolchainProvider.getJavac();
  }

}
