/**
 * @file aihttpheaders.h
 * @brief Keep a list of HTTP headers.
 *
 * Copyright (c) 2012, Aleric Inglewood.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution.
 *
 * CHANGELOG
 *   and additional copyright holders.
 *
 *   15/08/2012
 *   Initial version, written by Aleric Inglewood @ SL
 */

#ifndef AIHTTPHEADERS_H
#define AIHTTPHEADERS_H

#include <string>
#include <map>
#include <iosfwd>
#include "llpointer.h"
#include "llthread.h"			// LLThreadSafeRefCount

extern "C" struct curl_slist;

class AIHTTPHeaders {
  public:
	enum op_type
	{
	  new_header,				// The inserted header must be the first one.
	  replace_if_exists,		// If a header of this type already exists, replace it. Otherwise add the header.
	  keep_existing_header		// If a header of this type already exists, do nothing.
	};

	// Construct an empty container.
	AIHTTPHeaders(void);

	// Construct a container with a single header.
	AIHTTPHeaders(std::string const& key, std::string const& value);

	// Clear all headers.
	void clear(void) { if (mContainer) mContainer->mKeyValuePairs.clear(); }

	// Add a header. Returns true if the header already existed.
	bool addHeader(std::string const& key, std::string const& value, op_type op = new_header);

	// Return true if there are no headers associated with this object.
	bool empty(void) const { return !mContainer || mContainer->mKeyValuePairs.empty(); }

	// Return true if the header already exists.
	bool hasHeader(std::string const& key) const;

	// Return true if key exists and fill value_out with the value. Return false otherwise.
	bool getValue(std::string const& key, std::string& value_out) const;

	// Append the headers to slist.
	void append_to(curl_slist*& slist) const;

	// For debug purposes.
	friend std::ostream& operator<<(std::ostream& os, AIHTTPHeaders const& headers);

  private:
	typedef std::map<std::string, std::string> container_t;
	typedef std::pair<container_t::iterator, bool> insert_t;

	struct Container : public LLThreadSafeRefCount {
	  container_t mKeyValuePairs;
	};

	LLPointer<Container> mContainer;
};

#endif // AIHTTPHEADERS_H