// Copyright (c) 2010 The Chromium Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

package org.chromium.debug.core;

import org.chromium.debug.core.model.VmResourceId;

import org.eclipse.core.resources.IContainer;

import org.eclipse.core.resources.IFile;

import org.eclipse.core.runtime.CoreException;

import org.eclipse.debug.core.sourcelookup.ISourceContainer;

import org.eclipse.debug.core.sourcelookup.ISourceLookupDirector;

import org.eclipse.debug.core.sourcelookup.containers.ContainerSourceContainer;

import org.eclipse.debug.core.sourcelookup.containers.DefaultSourceContainer;

/**

 * Eclipse has a standard facility for looking up source file for a debug artifact.

 * LiveEdit feature has an opposite problem: find script in remote VM for a particular js file.

 * This class implements some approach to this problem. An instance of this class corresponds

 * to a particular debug launch.

 */

public class ReverseSourceLookup {

  private final ISourceLookupDirector sourceDirector;

  public ReverseSourceLookup(ISourceLookupDirector sourceDirector) {

    this.sourceDirector = sourceDirector;

  }

  /**

   * Tries to find a corresponding script for a file from a user workspace. The method uses

   * the file name and current source lookup rules to retrieve a resource id, regardless of

   * whether the resource has actually been loaded into the VM (you may want to set a breakpoint

   * on resource before it is actually loaded).

   */

  public VmResourceId findVmResource(IFile sourceFile) throws CoreException {

    for (ISourceContainer container : sourceDirector.getSourceContainers()) {

      VmResourceId scriptName = tryForContainer(sourceFile, container);

      if (scriptName != null) {

        return scriptName;

      }

    }

    return null;

  }

  private VmResourceId tryForContainer(IFile sourceFile, ISourceContainer container)

      throws CoreException {

    if (container.isComposite() && isSupportedCompositeContainer(container)) {

      ISourceContainer[] subContainers = container.getSourceContainers();

      for (ISourceContainer subContainer : subContainers) {

        VmResourceId res = tryForContainer(sourceFile, subContainer);

        if (res != null) {

          return res;

        }

      }

      return null;

    } else if (container instanceof VProjectSourceContainer) {

      VProjectSourceContainer projectSourceContainer = (VProjectSourceContainer) container;

      return projectSourceContainer.findScriptId(sourceFile);

    } else {

      String name = tryForNonVirtualContainer(sourceFile, container);

      if (name == null) {

        return null;

      }

      return VmResourceId.forName(name);

    }

  }

  /**

   * We use {@link ISourceContainer#getSourceContainers()} method to unwrap internal containers.

   * However it doesn't make sense for all composite containers (some of them may return their

   * subdirectories as containers, which is not what we need).

   */

  private boolean isSupportedCompositeContainer(ISourceContainer container) {

    return container instanceof DefaultSourceContainer;

  }

  /**

   * @param container that may not wrap VProjectSourceContainer

   */

  private String tryForNonVirtualContainer(IFile resource, ISourceContainer container) {

    if (container instanceof ContainerSourceContainer) {

      ContainerSourceContainer containerSourceContainer = (ContainerSourceContainer) container;

      IContainer resourceContainer = containerSourceContainer.getContainer();

      if (resourceContainer.getFullPath().isPrefixOf(resource.getFullPath())) {

        String name = resource.getFullPath().makeRelativeTo(

            resourceContainer.getFullPath()).toPortableString();

        return name;

      }

    } else if (container instanceof SourceNameMapperContainer) {

      SourceNameMapperContainer mappingContainer =

          (SourceNameMapperContainer) container;

      String subResult = tryForNonVirtualContainer(resource, mappingContainer.getTargetContainer());

      if (subResult != null) {

        return mappingContainer.getPrefix() + subResult;

      }

    }

    return null;

  }

}