/*
 * 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.bazel;

import com.google.common.collect.ImmutableList;
import com.google.idea.blaze.base.lang.buildfile.language.semantics.RuleDefinition;
import com.google.idea.blaze.base.model.primitives.WorkspaceRoot;
import com.google.idea.blaze.base.settings.Blaze.BuildSystem;
import com.intellij.openapi.components.ServiceManager;
import com.intellij.openapi.extensions.ExtensionPointName;
import javax.annotation.Nullable;

/**
 * Extension points specify the build systems supported by this plugin.<br>
 * The order of the extension points establishes a priority (highest priority first), for situations
 * where we don't have an existing project to use for context (e.g. the 'import project' action).
 */
public interface BuildSystemProvider {

  ExtensionPointName<BuildSystemProvider> EP_NAME =
      ExtensionPointName.create("com.google.idea.blaze.BuildSystemProvider");

  static BuildSystemProvider defaultBuildSystem() {
    return EP_NAME.getExtensions()[0];
  }

  @Nullable
  static BuildSystemProvider getBuildSystemProvider(BuildSystem buildSystem) {
    for (BuildSystemProvider provider : EP_NAME.getExtensions()) {
      if (provider.buildSystem() == buildSystem) {
        return provider;
      }
    }
    return null;
  }

  static boolean isBuildSystemAvailable(BuildSystem buildSystem) {
    return getBuildSystemProvider(buildSystem) != null;
  }

  static WorkspaceRootProvider getWorkspaceRootProvider(BuildSystem buildSystem) {
    BuildSystemProvider provider = getBuildSystemProvider(buildSystem);
    if (provider == null) {
      throw new RuntimeException(
          String.format("Build system '%s' not supported by this plugin", buildSystem));
    }
    return provider.getWorkspaceRootProvider();
  }

  static BuildSystemProvider getInstance() {
    return ServiceManager.getService(BuildSystemProvider.class);
  }

  /**
   * Returns the default build system for this application. This should only be called in situations
   * where it doesn't make sense to use the current project.<br>
   * Otherwise, use {@link com.google.idea.blaze.base.settings.Blaze#getBuildSystem}
   */
  BuildSystem buildSystem();

  WorkspaceRootProvider getWorkspaceRootProvider();

  /** Directories containing artifacts produced during the build process. */
  ImmutableList<String> buildArtifactDirectories(WorkspaceRoot root);

  /** The URL providing the built-in BUILD rule's documentation, if one can be found. */
  @Nullable
  String getRuleDocumentationUrl(RuleDefinition rule);
}