/*
 * 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.settings;

import com.google.common.collect.Lists;
import com.intellij.openapi.components.PersistentStateComponent;
import com.intellij.openapi.components.ServiceManager;
import com.intellij.openapi.components.State;
import com.intellij.openapi.components.Storage;
import com.intellij.openapi.components.StoragePathMacros;
import com.intellij.openapi.components.StorageScheme;
import com.intellij.openapi.project.Project;
import com.intellij.util.xmlb.annotations.AbstractCollection;
import java.util.Collection;
import java.util.List;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * Legacy storage for BlazeImportSettings. Introduced in 1.8, can be removed around ~2.2. Removal of
 * this class will cause old projects to stop loading.
 */
@State(
  name = "BlazeSettings",
  storages = {
    @Storage(file = StoragePathMacros.PROJECT_FILE),
    @Storage(
      file = StoragePathMacros.PROJECT_CONFIG_DIR + "/blaze.xml",
      scheme = StorageScheme.DIRECTORY_BASED
    )
  }
)
public class BlazeImportSettingsManagerLegacy
    implements PersistentStateComponent<BlazeImportSettingsManagerLegacy.State> {

  @Nullable private BlazeImportSettings importSettings;

  @NotNull private Project project;

  public BlazeImportSettingsManagerLegacy(@NotNull Project project) {
    this.project = project;
  }

  @NotNull
  public static BlazeImportSettingsManagerLegacy getInstance(@NotNull Project project) {
    return ServiceManager.getService(project, BlazeImportSettingsManagerLegacy.class);
  }

  @SuppressWarnings("unchecked")
  @Nullable
  @Override
  public State getState() {
    if (importSettings == null) {
      return null;
    }
    State state = new State();
    List<BlazeImportSettings> value = Lists.newArrayList();
    value.add(importSettings);
    state.setLinkedExternalProjectsSettings(value);
    return state;
  }

  @Override
  public void loadState(State state) {
    if (state == null) {
      importSettings = null;
      return;
    }

    Collection<BlazeImportSettings> settings = state.getLinkedExternalProjectsSettings();
    if (settings != null && !settings.isEmpty()) {
      importSettings = settings.iterator().next();
    } else {
      importSettings = null;
    }
  }

  @Nullable
  BlazeImportSettings migrateImportSettings() {
    BlazeImportSettings importSettings = this.importSettings;
    this.importSettings = null;
    return importSettings;
  }

  /** State class for the Blaze settings. */
  static class State {

    private List<BlazeImportSettings> importSettings = Lists.newArrayList();

    @AbstractCollection(
      surroundWithTag = false,
      elementTypes = {BlazeImportSettings.class}
    )
    public List<BlazeImportSettings> getLinkedExternalProjectsSettings() {
      return importSettings;
    }

    public void setLinkedExternalProjectsSettings(List<BlazeImportSettings> settings) {
      importSettings = settings;
    }
  }
}