platform/lang-impl/src/com/intellij/util/download/impl/FileSetVersionsFetcherBase.java

/*
 * Copyright 2000-2011 JetBrains s.r.o.
 *
 * 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.intellij.util.download.impl;

import com.intellij.facet.frameworks.LibrariesDownloadAssistant;
import com.intellij.facet.frameworks.beans.Artifact;
import com.intellij.facet.frameworks.beans.ArtifactItem;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.application.ex.ApplicationManagerEx;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.util.download.DownloadableFileDescription;
import com.intellij.util.download.DownloadableFileSetDescription;
import com.intellij.util.download.DownloadableFileSetVersions;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.net.URL;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 * @author nik
 */
public abstract class FileSetVersionsFetcherBase<FS extends DownloadableFileSetDescription, F extends DownloadableFileDescription> implements DownloadableFileSetVersions<FS> {
  private static final Comparator<DownloadableFileSetDescription> VERSIONS_COMPARATOR = new Comparator<DownloadableFileSetDescription>() {
    @Override
    public int compare(DownloadableFileSetDescription o1, DownloadableFileSetDescription o2) {
      return -StringUtil.compareVersionNumbers(o1.getVersionString(), o2.getVersionString());
    }
  };
  protected final String myGroupId;
  private final URL[] myLocalUrls;

  public FileSetVersionsFetcherBase(@Nullable String groupId, @NotNull URL[] localUrls) {
    myLocalUrls = localUrls;
    myGroupId = groupId;
  }

  @Override
  public void fetchVersions(@NotNull final FileSetVersionsCallback<FS> callback) {
    ApplicationManager.getApplication().executeOnPooledThread(new Runnable() {
      @Override
      public void run() {
        callback.onSuccess(fetchVersions());
      }
    });
  }

  @NotNull
  @Override
  public List<FS> fetchVersions() {
    ApplicationManagerEx.getApplicationEx().assertTimeConsuming();
    final Artifact[] versions;
    if (myGroupId != null) {
      versions = LibrariesDownloadAssistant.getVersions(myGroupId, myLocalUrls);
    }
    else {
      versions = LibrariesDownloadAssistant.getVersions(myLocalUrls);
    }
    final List<FS> result = new ArrayList<FS>();
    for (Artifact version : versions) {
      final ArtifactItem[] items = version.getItems();
      final List<F> files = new ArrayList<F>();
      for (ArtifactItem item : items) {
        String url = item.getUrl();
        final String prefix = version.getUrlPrefix();
        if (url == null) {
          if (prefix != null) {
            url = prefix + item.getName();
          }
        } else {
          url = prependPrefix(url, prefix);
        }
        assert url != null;

        files.add(createFileDescription(item, url, prefix));
      }
      result.add(createVersion(version, files));
    }
    Collections.sort(result, VERSIONS_COMPARATOR);
    return result;
  }

  @NotNull
  protected static String prependPrefix(@NotNull String url, @Nullable String prefix) {
    if (!url.startsWith("http://") && prefix != null) {
      url = prefix + url;
    }
    return url;
  }

  protected abstract F createFileDescription(ArtifactItem item, String url, @Nullable String prefix);

  protected abstract FS createVersion(Artifact version, List<F> files);
}