/*
 * Copyright (c) 2013, the Dart project authors.
 * 
 * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
 * 
 * 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.dart.engine.internal.task;

import com.google.dart.engine.ast.CompilationUnit;
import com.google.dart.engine.context.AnalysisException;
import com.google.dart.engine.element.HtmlElement;
import com.google.dart.engine.error.AnalysisError;
import com.google.dart.engine.html.ast.HtmlScriptTagNode;
import com.google.dart.engine.html.ast.HtmlUnit;
import com.google.dart.engine.html.ast.visitor.RecursiveXmlVisitor;
import com.google.dart.engine.internal.builder.HtmlUnitBuilder;
import com.google.dart.engine.internal.context.InternalAnalysisContext;
import com.google.dart.engine.internal.context.RecordingErrorListener;
import com.google.dart.engine.source.Source;

/**
 * Instances of the class {@code ResolveHtmlTask} resolve a specific source as an HTML file.
 */
public class ResolveHtmlTask extends AnalysisTask {
  /**
   * The source to be resolved.
   */
  private Source source;

  /**
   * The time at which the contents of the source were last modified.
   */
  private long modificationTime;

  /**
   * The HTML unit to be resolved.
   */
  private HtmlUnit unit;

  /**
   * The {@link HtmlUnit} that was resolved by this task.
   */
  private HtmlUnit resolvedUnit;

  /**
   * The element produced by resolving the source.
   */
  private HtmlElement element = null;

  /**
   * The resolution errors that were discovered while resolving the source.
   */
  private AnalysisError[] resolutionErrors = AnalysisError.NO_ERRORS;

  /**
   * Initialize a newly created task to perform analysis within the given context.
   * 
   * @param context the context in which the task is to be performed
   * @param source the source to be resolved
   * @param modificationTime the time at which the contents of the source were last modified
   * @param unit the HTML unit to be resolved
   */
  public ResolveHtmlTask(InternalAnalysisContext context, Source source, long modificationTime,
      HtmlUnit unit) {
    super(context);
    this.source = source;
    this.modificationTime = modificationTime;
    this.unit = unit;
  }

  @Override
  public <E> E accept(AnalysisTaskVisitor<E> visitor) throws AnalysisException {
    return visitor.visitResolveHtmlTask(this);
  }

  public HtmlElement getElement() {
    return element;
  }

  /**
   * Return the time at which the contents of the source that was parsed were last modified, or a
   * negative value if the task has not yet been performed or if an exception occurred.
   * 
   * @return the time at which the contents of the source that was parsed were last modified
   */
  public long getModificationTime() {
    return modificationTime;
  }

  public AnalysisError[] getResolutionErrors() {
    return resolutionErrors;
  }

  /**
   * Return the {@link HtmlUnit} that was resolved by this task.
   * 
   * @return the {@link HtmlUnit} that was resolved by this task
   */
  public HtmlUnit getResolvedUnit() {
    return resolvedUnit;
  }

  /**
   * Return the source that was or is to be resolved.
   * 
   * @return the source was or is to be resolved
   */
  public Source getSource() {
    return source;
  }

  @Override
  protected String getTaskDescription() {
    if (source == null) {
      return "resolve as html null source";
    }
    return "resolve as html " + source.getFullName();
  }

  @Override
  protected void internalPerform() throws AnalysisException {
    //
    // Build the standard HTML element.
    //
    HtmlUnitBuilder builder = new HtmlUnitBuilder(getContext());
    element = builder.buildHtmlElement(source, modificationTime, unit);
    final RecordingErrorListener errorListener = builder.getErrorListener();
    //
    // Validate the directives
    //
    unit.accept(new RecursiveXmlVisitor<Void>() {
      @Override
      public Void visitHtmlScriptTagNode(HtmlScriptTagNode node) {
        CompilationUnit script = node.getScript();
        if (script != null) {
          GenerateDartErrorsTask.validateDirectives(getContext(), source, script, errorListener);
        }
        return null;
      }
    });
    //
    // Record all resolution errors.
    //
    resolutionErrors = errorListener.getErrorsForSource(source);
    //
    // Remember the resolved unit.
    //
    resolvedUnit = unit;
  }
}