/*
 * Copyright (c)2019 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2023-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#ifndef ZT_ADDRESS_HPP
#define ZT_ADDRESS_HPP

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

#include <string>

#include "Constants.hpp"
#include "Utils.hpp"
#include "Buffer.hpp"

namespace ZeroTier {

/**
 * A ZeroTier address
 */
class Address
{
public:
	Address() : _a(0) {}
	Address(const Address &a) : _a(a._a) {}
	Address(uint64_t a) : _a(a & 0xffffffffffULL) {}

	/**
	 * @param bits Raw address -- 5 bytes, big-endian byte order
	 * @param len Length of array
	 */
	Address(const void *bits,unsigned int len) { setTo(bits,len); }

	inline Address &operator=(const Address &a) { _a = a._a; return *this; }
	inline Address &operator=(const uint64_t a) { _a = (a & 0xffffffffffULL); return *this; }

	/**
	 * @param bits Raw address -- 5 bytes, big-endian byte order
	 * @param len Length of array
	 */
	inline void setTo(const void *bits,const unsigned int len)
	{
		if (len < ZT_ADDRESS_LENGTH) {
			_a = 0;
			return;
		}
		const unsigned char *b = (const unsigned char *)bits;
		uint64_t a = ((uint64_t)*b++) << 32;
		a |= ((uint64_t)*b++) << 24;
		a |= ((uint64_t)*b++) << 16;
		a |= ((uint64_t)*b++) << 8;
		a |= ((uint64_t)*b);
		_a = a;
	}

	/**
	 * @param bits Buffer to hold 5-byte address in big-endian byte order
	 * @param len Length of array
	 */
	inline void copyTo(void *const bits,const unsigned int len) const
	{
		if (len < ZT_ADDRESS_LENGTH)
			return;
		unsigned char *b = (unsigned char *)bits;
		*(b++) = (unsigned char)((_a >> 32) & 0xff);
		*(b++) = (unsigned char)((_a >> 24) & 0xff);
		*(b++) = (unsigned char)((_a >> 16) & 0xff);
		*(b++) = (unsigned char)((_a >> 8) & 0xff);
		*b = (unsigned char)(_a & 0xff);
	}

	/**
	 * Append to a buffer in big-endian byte order
	 *
	 * @param b Buffer to append to
	 */
	template<unsigned int C>
	inline void appendTo(Buffer<C> &b) const
	{
		unsigned char *p = (unsigned char *)b.appendField(ZT_ADDRESS_LENGTH);
		*(p++) = (unsigned char)((_a >> 32) & 0xff);
		*(p++) = (unsigned char)((_a >> 24) & 0xff);
		*(p++) = (unsigned char)((_a >> 16) & 0xff);
		*(p++) = (unsigned char)((_a >> 8) & 0xff);
		*p = (unsigned char)(_a & 0xff);
	}

	/**
	 * @return Integer containing address (0 to 2^40)
	 */
	inline uint64_t toInt() const { return _a; }

	/**
	 * @return Hash code for use with Hashtable
	 */
	inline unsigned long hashCode() const { return (unsigned long)_a; }

	/**
	 * @return Hexadecimal string
	 */
	inline char *toString(char buf[11]) const { return Utils::hex10(_a,buf); }

	/**
	 * @return True if this address is not zero
	 */
	inline operator bool() const { return (_a != 0); }

	/**
	 * Check if this address is reserved
	 *
	 * The all-zero null address and any address beginning with 0xff are
	 * reserved. (0xff is reserved for future use to designate possibly
	 * longer addresses, addresses based on IPv6 innards, etc.)
	 *
	 * @return True if address is reserved and may not be used
	 */
	inline bool isReserved() const { return ((!_a)||((_a >> 32) == ZT_ADDRESS_RESERVED_PREFIX)); }

	/**
	 * @param i Value from 0 to 4 (inclusive)
	 * @return Byte at said position (address interpreted in big-endian order)
	 */
	inline uint8_t operator[](unsigned int i) const { return (uint8_t)(_a >> (32 - (i * 8))); }

	inline void zero() { _a = 0; }

	inline bool operator==(const uint64_t &a) const { return (_a == (a & 0xffffffffffULL)); }
	inline bool operator!=(const uint64_t &a) const { return (_a != (a & 0xffffffffffULL)); }
	inline bool operator>(const uint64_t &a) const { return (_a > (a & 0xffffffffffULL)); }
	inline bool operator<(const uint64_t &a) const { return (_a < (a & 0xffffffffffULL)); }
	inline bool operator>=(const uint64_t &a) const { return (_a >= (a & 0xffffffffffULL)); }
	inline bool operator<=(const uint64_t &a) const { return (_a <= (a & 0xffffffffffULL)); }

	inline bool operator==(const Address &a) const { return (_a == a._a); }
	inline bool operator!=(const Address &a) const { return (_a != a._a); }
	inline bool operator>(const Address &a) const { return (_a > a._a); }
	inline bool operator<(const Address &a) const { return (_a < a._a); }
	inline bool operator>=(const Address &a) const { return (_a >= a._a); }
	inline bool operator<=(const Address &a) const { return (_a <= a._a); }

private:
	uint64_t _a;
};

} // namespace ZeroTier

#endif