/*
 * Copyright 2011 Google Inc.
 *
 * 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.
 */

// Author: jmarantz@google.com (Joshua Marantz)

#ifndef NET_INSTAWEB_REWRITER_PUBLIC_REWRITE_GFLAGS_H_
#define NET_INSTAWEB_REWRITER_PUBLIC_REWRITE_GFLAGS_H_

#include "pagespeed/kernel/base/basictypes.h"

namespace net_instaweb {

class MessageHandler;
class RewriteDriverFactory;
class RewriteOptions;

// Implements rewriter options as command-line options, using the
// Google "gflags" package.
class RewriteGflags {
 public:
  // The constructor parses the options.
  RewriteGflags(const char* progname, int* argc, char*** argv);

  // Constructor that does no option parsing.
  RewriteGflags() {}

  // Apply the parsed options to the options and factory.  Note that some of
  // the command-line flags control how the factory is constructed, whereas
  // others affect the rewriting options, and should be considered global
  // defaults.
  bool SetOptions(RewriteDriverFactory* factory, RewriteOptions* options) const;

  // Like above, but doesn't expect a RewriteDriverFactory.
  bool SetupOptionsOnly(RewriteOptions* options, MessageHandler* handler) const;

  // Like above, but only modifies the RewriteDriverFactory.
  void SetupFactoryOnly(RewriteDriverFactory* factory) const;

  // LRU size is potentially needed at factory construction time so it
  // is exposed as a method.
  int64 lru_cache_size_bytes() const;

  // Determines whether a flag was explicitly set, as opposed to having its
  // default value.
  static bool WasExplicitlySet(const char* name);

  // Sets the rewrite level/list passed on the specified option names
  // & values.  The flag names are passed in to provide better error
  // messages.
  //
  // False is returned if the values cannot be parsed.
  bool SetRewriters(const char* rewriters_flag_name,
                    const char* rewriters_value,
                    const char* rewrite_level_flag_name,
                    const char* rewrite_level_value,
                    RewriteOptions* options,
                    MessageHandler* handler) const;

 private:
  // There is no data in this class because the underlying gflags
  // class holds the parsed options in globals.

  DISALLOW_COPY_AND_ASSIGN(RewriteGflags);
};

}  // namespace net_instaweb

#endif  // NET_INSTAWEB_REWRITER_PUBLIC_REWRITE_GFLAGS_H_