/*
 * Copyright 2000-2008 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 jetbrains.buildServer.buildTriggers.vcs.clearcase.structure;

import com.intellij.execution.ExecutionException;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.ParseException;
import java.util.Date;
import java.util.List;
import jetbrains.buildServer.buildTriggers.vcs.clearcase.CCParseUtil;
import jetbrains.buildServer.buildTriggers.vcs.clearcase.ClearCaseConnection;
import jetbrains.buildServer.buildTriggers.vcs.clearcase.ClearCaseSupport;
import jetbrains.buildServer.buildTriggers.vcs.clearcase.VersionProcessor;
import jetbrains.buildServer.log.Loggers;
import jetbrains.buildServer.util.FileUtil;
import jetbrains.buildServer.vcs.IncludeRule;
import jetbrains.buildServer.vcs.VcsException;
import jetbrains.buildServer.vcs.VcsRoot;

public class CacheElement {
  private final Date myVersion;
  private final String myVersionString;
  private final File myCacheFile;
  private final ClearCaseStructureCache myOwner;
  private final String myPath;
  public static final int FILE_TYPE = 0;
  public static final int DIR_OPEN_TYPE = 1;
  public static final int DIR_CLOSE_TYPE = 2;
  
  private final ClearCaseSupport myParentSupport;
  private final VcsRoot myRoot;
  private final IncludeRule myIncludeRule;

  public CacheElement(final Date version,
                      final File cacheFile,
                      ClearCaseStructureCache owner,
                      final String path,
                      String versionStr,
                      final IncludeRule includeRule, final ClearCaseSupport parentSupport, final VcsRoot root) {
    myVersion = version;
    myCacheFile = cacheFile;
    myOwner = owner;
    myPath = path;
    myVersionString = versionStr;
    myIncludeRule = includeRule;
    myParentSupport = parentSupport;
    myRoot = root;

    Loggers.VCS.debug("ClearCase cache " + cacheFile.getPath() + " created for " + path);
    
  }

  public void processAllVersions(
    final VersionProcessor versionProcessor,
    boolean processRoot,
    ClearCaseConnection connection)
    throws VcsException {
    try {
      if (!myCacheFile.exists()) {
        CacheElement nearestCache = myOwner.getNearestExistingCache(myVersion, myPath, myIncludeRule, myRoot);
        if (nearestCache == null) {
          Loggers.VCS.debug("ClearCase cache " + myCacheFile.getPath() + " loading all versions");
          loadAllRevisions(myVersionString, connection);
        } else {
          try {
            Loggers.VCS.debug("ClearCase cache " + myCacheFile.getPath() + " loading differences from " + nearestCache.getVersionString());            
            loadDifferences(nearestCache, connection);
          } catch (ExecutionException e) {
            throw new IOException(e.getLocalizedMessage());
          } catch (ParseException e) {
            throw new IOException(e.getLocalizedMessage());
          }
        }
      }

      processAllVersionsInternal(versionProcessor, processRoot, connection);
    } catch (IOException e) {
      connection.processAllVersions(myVersionString, versionProcessor, processRoot, false);
    }

  }

  private void loadAllRevisions(String version, ClearCaseConnection connection) throws VcsException, IOException {
    myCacheFile.getParentFile().mkdirs();
    final DataOutputStream outputStream = new DataOutputStream(new FileOutputStream(myCacheFile));
    try {
      connection.processAllVersions(version, new WriteVersionProcessor(outputStream), true, false);
      outputStream.close();
    } catch (Throwable e) {
      outputStream.close();
      FileUtil.delete(myCacheFile);
    }

  }

  private void loadDifferences(final CacheElement nearestCache, final ClearCaseConnection connection)
    throws IOException, VcsException, ExecutionException, ParseException {
    final List<ChangedElementInfo> changedElements = loadChanges(nearestCache);
    
    
    final DataOutputStream outputStream = new DataOutputStream(new FileOutputStream(myCacheFile));
    final WriteVersionProcessor writeProcessor = new WriteVersionProcessor(outputStream);
    try {
      new CacheProcessor(new WriteCorrectingVersionProcessor(changedElements, writeProcessor), connection, nearestCache.getCacheFile())
        .processAllRevisions(true);
    } finally {
      outputStream.close();
    }
  }

  public File getCacheFile() {
    return myCacheFile;
  }

  private  List<ChangedElementInfo> loadChanges(final CacheElement nearestCache)
    throws ParseException, ExecutionException, IOException, VcsException {
    
    ClearCaseConnection tempConnection = myParentSupport.createConnection(myRoot, myIncludeRule);

    try {
      tempConnection.prepare(myVersionString);
      CollectingChangedFilesProcessor processor = new CollectingChangedFilesProcessor(tempConnection);
      CCParseUtil.processChangedFiles(tempConnection, nearestCache.getVersionString(), myVersionString, processor);
      return processor.getChanges();
    } finally {
      tempConnection.dispose();
    }
  }

  private String getVersionString() {
    return myVersionString;
  }


  public Date getVersion() {
    return myVersion;
  }

  private void processAllVersionsInternal(final VersionProcessor versionProcessor,
                                          final boolean processRoot,
                                          final ClearCaseConnection connection) throws VcsException, IOException {
    new CacheProcessor(versionProcessor, connection, myCacheFile).processAllRevisions(processRoot);
  }

}