// Copyright 2014 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.objc;

import static com.google.devtools.build.lib.rules.objc.XcodeProductType.LIBRARY_STATIC;

import com.google.common.collect.ImmutableSet;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
import com.google.devtools.build.lib.analysis.RuleContext;
import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
import com.google.devtools.build.lib.rules.cpp.ArtifactCategory;
import com.google.devtools.build.lib.rules.cpp.CcLinkParams;
import com.google.devtools.build.lib.rules.cpp.CcLinkParamsProvider;
import com.google.devtools.build.lib.rules.cpp.CcLinkParamsStore;
import com.google.devtools.build.lib.rules.cpp.LinkerInputs;
import com.google.devtools.build.lib.rules.cpp.LinkerInputs.LibraryToLink;
import com.google.devtools.build.lib.rules.objc.ObjcCommon.ResourceAttributes;
import com.google.devtools.build.lib.rules.test.InstrumentedFilesProvider;
import com.google.devtools.build.lib.syntax.Type;
import com.google.devtools.build.lib.vfs.FileSystemUtils;

/**
 * Implementation for {@code objc_library}.
 */
public class ObjcLibrary implements RuleConfiguredTargetFactory {

  /**
   * A {@link CcLinkParamsStore} to be propagated to dependent cc_{library, binary} targets.
   */
  private static class ObjcLibraryCcLinkParamsStore extends CcLinkParamsStore {

    private final ObjcCommon common;

    public ObjcLibraryCcLinkParamsStore(ObjcCommon common) {
      this.common = common;
    }

    @Override
    protected void collect(
        CcLinkParams.Builder builder, boolean linkingStatically, boolean linkShared) {
      ObjcProvider objcProvider = common.getObjcProvider();

      ImmutableSet.Builder<LibraryToLink> libraries = new ImmutableSet.Builder<>();
      for (Artifact library : objcProvider.get(ObjcProvider.LIBRARY)) {
        libraries.add(LinkerInputs.opaqueLibraryToLink(
            library, ArtifactCategory.STATIC_LIBRARY,
            FileSystemUtils.removeExtension(library.getRootRelativePathString())));
      }

      libraries.addAll(objcProvider.get(ObjcProvider.CC_LIBRARY));

      builder.addLibraries(libraries.build());
    }
  }

  /**
   * Constructs an {@link ObjcCommon} instance based on the attributes of the given rule context.
   */
  private ObjcCommon common(RuleContext ruleContext) {
    return new ObjcCommon.Builder(ruleContext)
        .setCompilationAttributes(
            CompilationAttributes.Builder.fromRuleContext(ruleContext).build())
        .setResourceAttributes(new ResourceAttributes(ruleContext))
        .addDefines(ruleContext.getTokenizedStringListAttr("defines"))
        .setCompilationArtifacts(CompilationSupport.compilationArtifacts(ruleContext))
        .addDeps(ruleContext.getPrerequisites("deps", Mode.TARGET))
        .addRuntimeDeps(ruleContext.getPrerequisites("runtime_deps", Mode.TARGET))
        .addDepObjcProviders(
            ruleContext.getPrerequisites("bundles", Mode.TARGET, ObjcProvider.class))
        .addNonPropagatedDepObjcProviders(
            ruleContext.getPrerequisites("non_propagated_deps", Mode.TARGET, ObjcProvider.class))
        .setIntermediateArtifacts(ObjcRuleClasses.intermediateArtifacts(ruleContext))
        .setAlwayslink(ruleContext.attributes().get("alwayslink", Type.BOOLEAN))
        .setHasModuleMap()
        .build();
  }

  @Override
  public ConfiguredTarget create(RuleContext ruleContext)
      throws InterruptedException, RuleErrorException {
    // Support treating objc_library as experimental_objc_library
    if (ruleContext.getFragment(ObjcConfiguration.class).useExperimentalObjcLibrary()) {
      return ExperimentalObjcLibrary.configureExperimentalObjcLibrary(ruleContext);
    }
    
    ObjcCommon common = common(ruleContext);

    XcodeProvider.Builder xcodeProviderBuilder = new XcodeProvider.Builder();
    NestedSetBuilder<Artifact> filesToBuild = NestedSetBuilder.<Artifact>stableOrder()
        .addAll(common.getCompiledArchive().asSet());

    CompilationSupport compilationSupport =
        new CompilationSupport(ruleContext)
            .registerCompileAndArchiveActions(common)
            .registerFullyLinkAction(common.getObjcProvider())
            .addXcodeSettings(xcodeProviderBuilder, common)
            .validateAttributes();

    new ResourceSupport(ruleContext)
        .validateAttributes()
        .addXcodeSettings(xcodeProviderBuilder);

    new XcodeSupport(ruleContext)
        .addFilesToBuild(filesToBuild)
        .addXcodeSettings(xcodeProviderBuilder, common.getObjcProvider(), LIBRARY_STATIC)
        .addDependencies(xcodeProviderBuilder, new Attribute("bundles", Mode.TARGET))
        .addDependencies(xcodeProviderBuilder, new Attribute("deps", Mode.TARGET))
        .addNonPropagatedDependencies(
            xcodeProviderBuilder, new Attribute("non_propagated_deps", Mode.TARGET))
        .registerActions(xcodeProviderBuilder.build());

    J2ObjcMappingFileProvider j2ObjcMappingFileProvider = J2ObjcMappingFileProvider.union(
        ruleContext.getPrerequisites("deps", Mode.TARGET, J2ObjcMappingFileProvider.class));
    J2ObjcEntryClassProvider j2ObjcEntryClassProvider = new J2ObjcEntryClassProvider.Builder()
        .addTransitive(ruleContext.getPrerequisites("deps", Mode.TARGET,
            J2ObjcEntryClassProvider.class)).build();

    return ObjcRuleClasses.ruleConfiguredTarget(ruleContext, filesToBuild.build())
        .addProvider(XcodeProvider.class, xcodeProviderBuilder.build())
        .addProvider(ObjcProvider.class, common.getObjcProvider())
        .addProvider(J2ObjcEntryClassProvider.class, j2ObjcEntryClassProvider)
        .addProvider(J2ObjcMappingFileProvider.class, j2ObjcMappingFileProvider)
        .addProvider(
            InstrumentedFilesProvider.class,
            compilationSupport.getInstrumentedFilesProvider(common))
        .addProvider(
            CcLinkParamsProvider.class,
            new CcLinkParamsProvider(new ObjcLibraryCcLinkParamsStore(common)))
        .build();
  }
}