/*! \file picrc.h
 * \ingroup Math
 * \~\brief
 * \~english CRC checksum calculation
 * \~russian Вычисление CRC контрольной суммы
 */
/*
    PIP - Platform Independent Primitives
    CRC checksum calculator
    Ivan Pelipenko peri4ko@yandex.ru

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PICRC_H
#define PICRC_H

#include "pistring.h"

template<int L>
class PIP_EXPORT uint_cl {
public:
	uint_cl() {
		for (int i = 0; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(const uint_cl<L> & v) {
		for (int i = 0; i < L / 8; ++i)
			data_[i] = v.data_[i];
	}
	uint_cl(uchar v) {
		for (int i = 0; i < L / 8; ++i)
			data_[i] = (i == 0 ? v : 0);
	}
	uint_cl(char v) {
		for (int i = 0; i < L / 8; ++i)
			data_[i] = (i == 0 ? v : 0);
	}
	uint_cl(ushort v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(short v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(uint v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(int v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(ulong v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(long v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(ullong v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}
	uint_cl(llong v) {
		int l = piMin<uint>(L / 8, sizeof(v));
		memcpy(data_, &v, l);
		for (int i = l; i < L / 8; ++i)
			data_[i] = 0;
	}

	operator bool() {
		for (int i = 0; i < L / 8; ++i)
			if (data_[i] > 0) return true;
		return false;
	}
	operator char() { return (char)data_[0]; }
	operator short() {
		short t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator int() {
		int t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator long() {
		long t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator llong() {
		llong t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator uchar() { return data_[0]; }
	operator ushort() {
		ushort t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator uint() {
		uint t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator ulong() {
		ulong t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}
	operator ullong() {
		ullong t(0);
		int l = piMin<uint>(L / 8, sizeof(t));
		memcpy(&t, data_, l);
		return t;
	}

	uint_cl<L> operator+(const uint_cl<L> & v) {
		uint_cl<L> t;
		uint cv;
		bool ov = false;
		for (int i = 0; i < L / 8; ++i) {
			cv = v.data_[i] + data_[i];
			if (ov) ++cv;
			ov         = cv > 255;
			t.data_[i] = ov ? cv - 256 : cv;
		}
		return t;
	}

	uint_cl<L> operator&(const uint_cl<L> & v) const {
		uint_cl<L> t;
		for (int i = 0; i < L / 8; ++i)
			t.data_[i] = v.data_[i] & data_[i];
		return t;
	}
	uint_cl<L> operator&(const uchar & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const ushort & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const uint & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const ulong & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const ullong & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const char & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const short & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const int & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const long & v) const { return *this & uint_cl<L>(v); }
	uint_cl<L> operator&(const llong & v) const { return *this & uint_cl<L>(v); }

	uint_cl<L> operator|(const uint_cl<L> & v) const {
		uint_cl<L> t;
		for (int i = 0; i < L / 8; ++i)
			t.data_[i] = v.data_[i] | data_[i];
		return t;
	}
	uint_cl<L> operator|(const uchar & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const ushort & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const uint & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const ulong & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const ullong & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const char & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const short & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const int & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const long & v) const { return *this | uint_cl<L>(v); }
	uint_cl<L> operator|(const llong & v) const { return *this | uint_cl<L>(v); }

	uint_cl<L> operator^(const uint_cl<L> & v) const {
		uint_cl<L> t;
		for (int i = 0; i < L / 8; ++i)
			t.data_[i] = v.data_[i] ^ data_[i];
		return t;
	}
	uint_cl<L> operator^(const uchar & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const ushort & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const uint & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const ulong & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const ullong & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const char & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const short & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const int & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const long & v) const { return *this ^ uint_cl<L>(v); }
	uint_cl<L> operator^(const llong & v) const { return *this ^ uint_cl<L>(v); }

	bool operator<(const uint_cl<L> & v) const {
		for (int i = 0; i < L / 8; ++i) {
			if (v.data_[i] > data_[i]) return true;
			if (v.data_[i] < data_[i]) return false;
		}
		return false;
	}
	bool operator<=(const uint_cl<L> & v) const {
		for (int i = 0; i < L / 8; ++i) {
			if (v.data_[i] > data_[i]) return true;
			if (v.data_[i] < data_[i]) return false;
		}
		return true;
	}
	bool operator>(const uint_cl<L> & v) const {
		for (int i = 0; i < L / 8; ++i) {
			if (v.data_[i] < data_[i]) return true;
			if (v.data_[i] > data_[i]) return false;
		}
		return false;
	}
	bool operator>=(const uint_cl<L> & v) const {
		for (int i = 0; i < L / 8; ++i) {
			if (v.data_[i] < data_[i]) return true;
			if (v.data_[i] > data_[i]) return false;
		}
		return true;
	}
	bool operator==(const uint_cl<L> & v) const {
		for (int i = 0; i < L / 8; ++i)
			if (v.data_[i] != data_[i]) return false;
		return true;
	}
	bool operator!=(const uint_cl<L> & v) const {
		for (int i = 0; i < L / 8; ++i)
			if (v.data_[i] != data_[i]) return true;
		return false;
	}
	bool operator<=(const uint_cl<8> & v1) { return (*(uchar *)data()) <= (*(uchar *)v1.data()); }

	uint_cl<L> operator>>(const int & c) const {
		uint_cl<L> t;
		int l = L - c;
		bool bit;
		if (l <= 0) return t;
		for (int i = 0; i < l; ++i) {
			bit = 1 & (data_[(i + c) / 8] >> ((i + c) % 8));
			if (bit)
				t.data_[i / 8] |= (1 << (i % 8));
			else
				t.data_[i / 8] &= ~(1 << (i % 8));
		}
		return t;
	}
	uint_cl<L> operator>>(const uint & c) const { return (*this << (int)c); }
	uint_cl<L> operator<<(const int & c) const {
		uint_cl<L> t;
		int l = L - c;
		bool bit;
		if (l <= 0) return t;
		for (int i = c; i < L; ++i) {
			bit = 1 & (data_[(i - c) / 8] >> ((i - c) % 8));
			if (bit)
				t.data_[i / 8] |= (1 << (i % 8));
			else
				t.data_[i / 8] &= ~(1 << (i % 8));
		}
		return t;
	}
	uint_cl<L> operator<<(const uint & c) const { return (*this >> (int)c); }

	uint_cl<L> & inverse() const {
		for (int i = 0; i < L / 8; ++i)
			data_[i] = ~data_[i];
		return *this;
	}
	uint_cl<L> inversed() const {
		uint_cl<L> t(*this);
		for (int i = 0; i < L / 8; ++i)
			t.data_[i] = ~t.data_[i];
		return t;
	}
	uint_cl<L> reversed() const {
		uint_cl<L> t;
		bool bit;
		for (int i = 0; i < L; ++i) {
			bit = 1 & (data_[(L - i - 1) / 8] >> ((L - i - 1) % 8));
			if (bit)
				t.data_[i / 8] |= (1 << (i % 8));
			else
				t.data_[i / 8] &= ~(1 << (i % 8));
		}
		return t;
	}

	const uchar * data() const { return data_; }
	uchar * data() { return data_; }
	uint length() const { return L / 8; }

private:
	uchar data_[L / 8];
};


inline uchar reverseByte(uchar b) {
	uchar ret = 0;
	bool bit;
	for (int i = 0; i < 8; ++i) {
		bit = 1 & (b >> (7 - i));
		if (bit) ret |= (1 << i);
	}
	return ret;
}

template<uint L, typename N = uint_cl<L>>
class PIP_EXPORT PICRC {
public:
	PICRC(const N & poly = N()) {
		poly_              = poly;
		reverse_poly       = true;
		init_              = inversed(N(0));
		out_               = inversed(N(0));
		reverse_before_xor = reverse_data = false;
		initTable();
	}
	PICRC(const N & poly, bool reverse_poly_, const N & initial, const N & out_xor) {
		poly_              = poly;
		reverse_poly       = reverse_poly_;
		init_              = initial;
		out_               = out_xor;
		reverse_before_xor = reverse_data = false;
		initTable();
	}

	void setInitial(const N & v) { init_ = v; }
	void setOutXor(const N & v) { out_ = v; }
	void setReversePolynome(bool yes) {
		reverse_poly = yes;
		initTable();
	}
	void setReverseOutBeforeXOR(bool yes) { reverse_before_xor = yes; }
	void setReverseDataBytes(bool yes) { reverse_data = yes; }

	void initTable() {
		N tmp, pol = reverse_poly ? reversed(poly_) : poly_;
		// cout << std::hex << "poly " << (uint)N(poly_) << " -> " << (uint)N(pol) << endl;
		for (int i = 0; i < 256; ++i) {
			tmp = uchar(i);
			for (int j = 0; j < 8; ++j)
				tmp = ((tmp & 1) ? ((tmp >> 1) ^ pol) : (tmp >> 1));
			table[i] = tmp;
		}
	}

	N calculate(const void * data, int size) {
		N crc        = init_;
		uchar *data_ = (uchar *)data, cb;
		// cout << "process " << size << endl;
		uchar nTemp;
		for (int i = 0; i < size; ++i) {
			cb = data_[i];
			if (reverse_data) cb = reverseByte(cb);
			nTemp = cb ^ uchar(crc);
			crc   = crc >> 8;
			crc   = crc ^ table[nTemp];
		}
		if (reverse_before_xor) crc = reversed(crc);
		return crc ^ out_;
	}
	N calculate(const PIByteArray & d) { return calculate(d.data(), d.size()); }
	N calculate(const char * str) {
		PIByteArray s(PIString(str).toByteArray());
		return calculate(s.data(), s.size_s());
	}

private:
	inline N reversed(const N & v) { return v.reversed(); }
	inline N inversed(const N & v) { return v.inversed(); }

	N table[256];
	N poly_, init_, out_;
	bool reverse_poly, reverse_before_xor, reverse_data;
};

template<>
inline uchar PICRC<8, uchar>::reversed(const uchar & v) {
	return reverseByte(v);
}
template<>
inline ushort PICRC<16, ushort>::reversed(const ushort & v) {
	return uint_cl<16>(v).reversed();
}
template<>
inline uint PICRC<32, uint>::reversed(const uint & v) {
	return uint_cl<32>(v).reversed();
}
template<>
inline uchar PICRC<8, uchar>::inversed(const uchar & v) {
	return ~v;
}
template<>
inline ushort PICRC<16, ushort>::inversed(const ushort & v) {
	return ~v;
}
template<>
inline uint PICRC<32, uint>::inversed(const uint & v) {
	return ~v;
}

typedef PICRC<32, uint> CRC_32;
typedef PICRC<24> CRC_24;
typedef PICRC<16, ushort> CRC_16;
typedef PICRC<8, uchar> CRC_8;

inline CRC_32 standardCRC_32() {
	return CRC_32(0x04C11DB7, true, 0xFFFFFFFF, 0xFFFFFFFF);
}
inline CRC_16 standardCRC_16() {
	return CRC_16(0x8005, true, 0x0, 0x0);
}
inline CRC_16 standardCRC_16_Modbus() {
	return CRC_16(0x8005, 0xFFFF, 0xFFFF, false);
}
inline CRC_8 standardCRC_8() {
	return CRC_8(0xD5, true, 0x0, 0x0);
}

#endif // CRC_H