///////////////////////////////////////////////////////////////////////////////
//                                                                             
//  Copyright (C) 2008-2012  Artyom Beilis (Tonkikh) <artyomtnk@yahoo.com>     
//                                                                             
//  See accompanying file COPYING.TXT file for licensing details.
//
///////////////////////////////////////////////////////////////////////////////
#ifndef CPPCMS_BASE64_H
#define CPPCMS_BASE64_H

#include <cppcms/defs.h>
#include <string>
#include <iosfwd>


namespace cppcms {
	/// 
	/// \brief this namespace provides functions useful for modified Base64 encoding for URL.
	/// This encoding does not insert newline characters, do not pad the text with = character and
	/// use "_" and "-" instead of "+" and "/" characters reserved by URL format for special purposes.
	///
namespace b64url {
	
	///
	/// Calculate required buffer size of base64-url compatible encoding for source of size \a s
	///
	int CPPCMS_API encoded_size(size_t s);
	///
	/// Calculate required buffer size of base64-url compatible decoding for source of size \a s
	///
	/// Note, if original size is invalid, negative value is returned
	///
	int CPPCMS_API decoded_size(size_t s);

	///
	/// Perform base64 URL encoding of the binary data in range [\a begin,\a end), and store it to output buffer
	/// \a target. The size of target storage should have a capacity calculated with encoded_size(end-begin).
	///
	/// Pointer to the first character directly after text string ends is returned.
	///
	unsigned char CPPCMS_API *encode(unsigned char const *begin,unsigned char const *end,unsigned char *target);
	///
	/// Perform base64 URL encoding of the binary data in range [\a begin,\a end), and write it to output stream
	///
	void encode(unsigned char const *begin,unsigned char const *end,std::ostream &output);

	///
	/// Perform base64 URL decoding of the binary data in range [\a begin,\a end), and store it to output buffer
	/// \a target. The size of target storage should have a capacity calculated with encoded_size(end-begin).
	///
	/// Pointer to the first character directly after text string ends is returned. Invalid codes are substituted
	/// by 0 values.
	///
	///
	unsigned char CPPCMS_API *decode(unsigned char const *begin,unsigned char const *end,unsigned char *target);

	///
	/// Perform base64 URL decoding of the textual data \a input, and store it to \a output.
	///
	/// If the source is invalid returns false
	///
	///
	bool CPPCMS_API decode(std::string const &input,std::string &output);
	///
	/// Perform base64 URL encoding of the binary data \a input, and return it
	///
	///
	std::string CPPCMS_API encode(std::string const &input);
}
}


#endif