// Copyright (c) 2011 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.

#ifndef CHROME_BROWSER_EXTENSIONS_EXTERNAL_EXTENSION_PROVIDER_INTERFACE_H_
#define CHROME_BROWSER_EXTENSIONS_EXTERNAL_EXTENSION_PROVIDER_INTERFACE_H_
#pragma once

#include <vector>

#include "base/memory/linked_ptr.h"
#include "chrome/common/extensions/extension.h"

class FilePath;
class Version;

// This class is an abstract class for implementing external extensions
// providers.
class ExternalExtensionProviderInterface {
 public:
  // ExternalExtensionProvider uses this interface to communicate back to the
  // caller what extensions are registered, and which |id|, |version| and |path|
  // they have. See also VisitRegisteredExtension below. Ownership of |version|
  // is not transferred to the visitor.  Callers of the methods below must
  // ensure that |id| is a valid extension id (use Extension::IdIsValid(id)).
  class VisitorInterface {
   public:
    virtual void OnExternalExtensionFileFound(
        const std::string& id,
        const Version* version,
        const FilePath& path,
        Extension::Location location) = 0;

    virtual void OnExternalExtensionUpdateUrlFound(
        const std::string& id,
        const GURL& update_url,
        Extension::Location location) = 0;

     // Called after all the external extensions have been reported through
     // the above two methods.
    virtual void OnExternalProviderReady() = 0;

   protected:
    virtual ~VisitorInterface() {}
  };

  virtual ~ExternalExtensionProviderInterface() {}

  // The visitor (ExtensionsService) calls this function before it goes away.
  virtual void ServiceShutdown() = 0;

  // Enumerate registered extensions, calling
  // OnExternalExtension(File|UpdateUrl)Found on the |visitor| object for each
  // registered extension found.
  virtual void VisitRegisteredExtension() const = 0;

  // Test if this provider has an extension with id |id| registered.
  virtual bool HasExtension(const std::string& id) const = 0;

  // Gets details of an extension by its id.  Output params will be set only
  // if they are not NULL.  If an output parameter is not specified by the
  // provider type, it will not be changed.
  // This function is no longer used outside unit tests.
  virtual bool GetExtensionDetails(const std::string& id,
                                   Extension::Location* location,
                                   scoped_ptr<Version>* version) const = 0;

  // Determines if this provider had loaded the list of external extensions
  // from its source.
  virtual bool IsReady() = 0;
};

typedef std::vector<linked_ptr<ExternalExtensionProviderInterface> >
    ProviderCollection;

#endif  // CHROME_BROWSER_EXTENSIONS_EXTERNAL_EXTENSION_PROVIDER_INTERFACE_H_