/**
 * Copyright 2012 Google Inc. All Rights Reserved.
 */
package com.google.appengine;

import static com.google.common.collect.Iterables.find;

import com.google.common.io.ByteStreams;
import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.common.io.Files;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.project.MavenProject;
import org.eclipse.aether.RepositorySystem;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.artifact.DefaultArtifact;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.resolution.ArtifactRequest;
import org.eclipse.aether.resolution.ArtifactResolutionException;
import org.eclipse.aether.resolution.ArtifactResult;
import org.eclipse.aether.resolution.VersionRangeRequest;
import org.eclipse.aether.resolution.VersionRangeResolutionException;
import org.eclipse.aether.resolution.VersionRangeResult;
import org.eclipse.aether.version.Version;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

/**
 * Resolves the sdk in the .m2 repository, retrieving the appropriate version for this version of
 * the plugin if necessary.
 *
 * @author Matt Stephenson <mattstep@google.com>
 */
public class SdkResolver {
  private static final String SDK_GROUP_ID = "com.google.appengine";
  private static final String SDK_ARTIFACT_ID = "appengine-java-sdk";
  private static final String SDK_EXTENSION = "zip";

  public static File getSdk(MavenProject project, RepositorySystem repoSystem, RepositorySystemSession repoSession, List<RemoteRepository>... repos)
          throws MojoExecutionException {
    Artifact artifact = (Artifact) find(project.getPluginArtifacts(), new Predicate<Artifact>() {
      @Override
      public boolean apply(Artifact artifact1) {
        return (artifact1.getArtifactId().equals("appengine-maven-plugin")
                && artifact1.getGroupId().equals("com.google.appengine"));
      }
    });

    String version = artifact.getVersion();
    // Temporary: need to remove once 1.9.76 is pushed.
    version  = "1.9.75.1";
    
    if(version.endsWith("-SNAPSHOT")) {
      String newestVersion = determineNewestVersion(repoSystem, repoSession, repos);
      return getSdk(newestVersion, repoSystem, repoSession, repos);
    }

    return getSdk(version, repoSystem, repoSession, repos);
  }

  private static String determineNewestVersion(RepositorySystem repoSystem, RepositorySystemSession repoSession, List<RemoteRepository>[] repos) throws MojoExecutionException {
    String version;VersionRangeRequest rangeRequest = new VersionRangeRequest();
    rangeRequest.setArtifact(new DefaultArtifact(SDK_GROUP_ID + ":" + SDK_ARTIFACT_ID + ":[0,)"));
    for(List<RemoteRepository> repoList : repos) {
      for(RemoteRepository repo : repoList) {
        rangeRequest.addRepository(repo);
      }
    }

    VersionRangeResult rangeResult;
    try {
      rangeResult = repoSystem.resolveVersionRange(repoSession, rangeRequest);
    } catch (VersionRangeResolutionException e) {
      throw new MojoExecutionException("Could not resolve latest version of the App Engine Java SDK", e);
    }

    List<Version> versions = rangeResult.getVersions();

    Collections.sort(versions);

    Version newest = Iterables.getLast(versions);

    version = newest.toString();
    return version;
  }

  public static File getSdk(String version, RepositorySystem repoSystem, RepositorySystemSession repoSession, List<RemoteRepository>... repos)
          throws MojoExecutionException {

    List<RemoteRepository> allRepos = ImmutableList.copyOf(Iterables.concat(repos));

    ArtifactRequest request = new ArtifactRequest(new DefaultArtifact(SDK_GROUP_ID, SDK_ARTIFACT_ID, SDK_EXTENSION, version), allRepos, null);

    ArtifactResult result;
    try {
      result = repoSystem.resolveArtifact(repoSession, request);
    } catch (ArtifactResolutionException e) {
      throw new MojoExecutionException("Could not resolve SDK artifact in Maven.", e);
    }

    File sdkArchive = result.getArtifact().getFile();
    File sdkRepoDir = sdkArchive.getParentFile();
    File sdkBaseDir = new File(sdkRepoDir, SDK_ARTIFACT_ID);

    if (sdkBaseDir.exists() && !sdkBaseDir.isDirectory()) {
      throw new MojoExecutionException("Could not unpack the SDK because there is an unexpected file at "
              + sdkBaseDir + " which conflicts with where we plan to unpack the SDK.");
    }

    if (!sdkBaseDir.exists()) {
      sdkBaseDir.mkdirs();
    }

    // While processing the zip archive, if we find an initial entry that is a directory, and all entries are a child
    // of this directory, then we append this to the sdkBaseDir we return.
    String sdkBaseDirSuffix = null;

    try {
      ZipFile sdkZipArchive = new ZipFile(sdkArchive);
      Enumeration<? extends ZipEntry> zipEntries = sdkZipArchive.entries();

      if (!zipEntries.hasMoreElements()) {
        throw new MojoExecutionException("The SDK zip archive appears corrupted.  There are no entries in the zip index.");
      }

      ZipEntry firstEntry = zipEntries.nextElement();
      if (firstEntry.isDirectory()) {
        sdkBaseDirSuffix = firstEntry.getName();
      } else {
        //Reinitialize entries
        zipEntries = sdkZipArchive.entries();
      }

      while (zipEntries.hasMoreElements()) {
        ZipEntry zipEntry = zipEntries.nextElement();

        if (!zipEntry.isDirectory()) {
          File zipEntryDestination = new File(sdkBaseDir, zipEntry.getName());

          if (!zipEntry.getName().startsWith(sdkBaseDirSuffix)) {
            //We found an entry that doesn't use this initial base directory, oh well, just set it to null.
            sdkBaseDirSuffix = null;
          }

          if (!zipEntryDestination.exists()) {
            Files.createParentDirs(zipEntryDestination);
            Files.write(ByteStreams.toByteArray(sdkZipArchive.getInputStream(zipEntry)), zipEntryDestination);
          }
        }
      }

    } catch (IOException e) {
      throw new MojoExecutionException("Could not open SDK zip archive.", e);
    }

    if (sdkBaseDirSuffix == null) {
      return sdkBaseDir;
    }

    return new File(sdkBaseDir, sdkBaseDirSuffix);
  }
}

@@ -2267,91 +2267,8 @@
 ();%0A
-    // Temporary: need to remove once 1.9.76 is pushed.%0A    version  = %221.9.75.1%22;%0A
     

Revert temporary change for handling corrupted 1.9.75 sdk zip file.