/*
 * Copyright 2016 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.idea.blaze.base.lang.buildfile.sync;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.idea.blaze.base.command.info.BlazeInfo;
import com.google.idea.blaze.base.ideinfo.RuleIdeInfo;
import com.google.idea.blaze.base.lang.buildfile.language.semantics.BuildLanguageSpec;
import com.google.idea.blaze.base.model.SyncState;
import com.google.idea.blaze.base.model.primitives.Label;
import com.google.idea.blaze.base.model.primitives.WorkspaceRoot;
import com.google.idea.blaze.base.projectview.ProjectViewSet;
import com.google.idea.blaze.base.scope.BlazeContext;
import com.google.idea.blaze.base.scope.Scope;
import com.google.idea.blaze.base.scope.scopes.TimingScope;
import com.google.idea.blaze.base.settings.Blaze;
import com.google.idea.blaze.base.sync.BlazeSyncPlugin;
import com.google.idea.blaze.base.sync.workspace.BlazeRoots;
import com.google.idea.blaze.base.sync.workspace.WorkingSet;
import com.google.idea.blaze.base.sync.workspace.WorkspacePathResolver;
import com.google.idea.blaze.base.sync.projectview.WorkspaceLanguageSettings;
import com.google.repackaged.devtools.build.lib.query2.proto.proto2api.Build;
import com.google.repackaged.protobuf.InvalidProtocolBufferException;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;

import javax.annotation.Nullable;
import java.io.File;
import java.util.concurrent.ExecutionException;

/**
 * Updates the language specification during the blaze sync process
 */
public class BuildLangSyncPlugin extends BlazeSyncPlugin.Adapter {

  private static final Logger LOG = Logger.getInstance(BuildLangSyncPlugin.class);

  @Override
  public void updateSyncState(Project project,
                              BlazeContext context,
                              WorkspaceRoot workspaceRoot,
                              ProjectViewSet projectViewSet,
                              WorkspaceLanguageSettings workspaceLanguageSettings,
                              BlazeRoots blazeRoots,
                              @Nullable WorkingSet workingSet,
                              WorkspacePathResolver workspacePathResolver,
                              ImmutableMap<Label, RuleIdeInfo> ruleMap,
                              @Deprecated @Nullable File androidPlatformDirectory,
                              SyncState.Builder syncStateBuilder,
                              @Nullable SyncState previousSyncState) {

    LanguageSpecResult spec = getBuildLanguageSpec(project, workspaceRoot, previousSyncState, context);
    if (spec != null) {
      syncStateBuilder.put(LanguageSpecResult.class, spec);
    }
  }

  @Nullable
  private static LanguageSpecResult getBuildLanguageSpec(
    Project project,
    WorkspaceRoot workspace,
    @Nullable SyncState previousSyncState,
    BlazeContext parentContext) {
    LanguageSpecResult oldResult = previousSyncState != null ? previousSyncState.get(LanguageSpecResult.class) : null;
    if (oldResult != null && !oldResult.shouldRecalculateSpec()) {
      return oldResult;
    }
    LanguageSpecResult result = Scope.push(parentContext, (context) -> {
      context.push(new TimingScope("BUILD language spec"));
      BuildLanguageSpec spec = parseLanguageSpec(project, workspace, context);
      if (spec != null) {
        return new LanguageSpecResult(spec, System.currentTimeMillis());
      }
      return null;
    });
    return result != null ? result : oldResult;
  }

  @Nullable
  private static BuildLanguageSpec parseLanguageSpec(Project project, WorkspaceRoot workspace, BlazeContext context) {
    try {
      // it's wasteful converting to a string and back, but uses existing code, and has a very minor cost
      // (this is only run once per workspace)
      ListenableFuture<byte[]> future = BlazeInfo.getInstance()
        .runBlazeInfoGetBytes(context, Blaze.getBuildSystem(project), workspace, ImmutableList.of(), BlazeInfo.BUILD_LANGUAGE);

      return BuildLanguageSpec.fromProto(Build.BuildLanguage.parseFrom(future.get()));

    } catch (InterruptedException e) {
      Thread.currentThread().interrupt();
      return null;
    } catch (ExecutionException | InvalidProtocolBufferException | NullPointerException e) {
      if (!ApplicationManager.getApplication().isUnitTestMode()) {
        LOG.error(e);
      }
      return null;
    }
  }
}