/*
	PIP - Platform Independent Primitives
	Byte array
	Copyright (C) 2020  Ivan Pelipenko peri4ko@yandex.ru

	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 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 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/>.
*/

#include "pibytearray.h"
#include "pistring.h"
#include <iostream>

/*! \class PIByteArray
 * \brief Byte array
 * \details This class based on PIDeque<uchar> and provide some handle function
 * to manipulate it.
 *
 * \section PIByteArray_sec0 Usage
 * %PIByteArray can be used to store custom data and manipulate it. There are many
 * stream operators to store/restore common types to byte array. Store operators
 * places data at the end of array, restore operators takes data from the beginning
 * of array.
 * In addition there are Base 64 convertions and checksums:
 * * plain 8-bit
 * * plain 32-bit
 *
 * One of the major usage of %PIByteArray is stream functions. You can form binary
 * packet from many types (also dynamic types, e.g. PIVector) with one line:
 * \snippet pibytearray.cpp 0
 *
 * Or you can descibe stream operator of your own type and store/restore vectors of
 * your type:
 * \snippet pibytearray.cpp 1
 *
 * For store/restore custom data blocks there is PIByteArray::RawData class. Stream
 * operators of this class simply store/restore data block to/from byte array.
 * \snippet pibytearray.cpp 2
 *
 * \section PIByteArray_sec1 Attention
 * Stream operator of %PIByteArray store byte array as vector, not simply append
 * content of byte array. This operators useful to transmit custom data as %PIByteArray
 * packed into parent byte array, e.g. to form packet from %PIByteArray.
 * To append one byte array to another use funtion \a append().
 * \snippet pibytearray.cpp 3
 *
 *
 */


static const uchar base64Table[64] = {
0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5a, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e,
0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
0x77, 0x78, 0x79, 0x7a, 0x30, 0x31, 0x32, 0x33,
0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2b, 0x2f};

static const uchar base64InvTable[256] = {
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x3E, 0x0, 0x0, 0x0, 0x3F,
0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
0x3C, 0x3D, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6,
0x7, 0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE,
0xF, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
0x17, 0x18, 0x19, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
0x31, 0x32, 0x33, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0};


struct base64HelpStruct {
	base64HelpStruct() {v = 0;}
	inline void setBytes(const uchar * r, int size = 3) {
		v = 0;
		switch (size) {
		case 3: v |= r[2];
		case 2: v |= r[1] << 8;
		case 1: v |= r[0] << 16;
		}
	}
	inline void getBytes(uchar * r) {
		r[0] = (v >> 16) & 0xFF;
		r[1] = (v >> 8)  & 0xFF;
		r[2] =  v        & 0xFF;
	}
	inline void setAscii(const uchar * r, int size = 4) {
		v = 0;
		switch (size) {
		case 4: v |= (base64InvTable[r[3]] & 0x3F);
		case 3: v |= (base64InvTable[r[2]] & 0x3F) << 6;
		case 2: v |= (base64InvTable[r[1]] & 0x3F) << 12;
		case 1: v |= (base64InvTable[r[0]] & 0x3F) << 18;
		}
	}
	inline void getAscii(uchar * r) {
		r[0] = base64Table[(v >> 18) & 0x3F];
		r[1] = base64Table[(v >> 12) & 0x3F];
		r[2] = base64Table[(v >> 6)  & 0x3F];
		r[3] = base64Table[ v        & 0x3F];
	}
	uint v;
};


PIByteArray &PIByteArray::convertToBase64() {
	return *this = toBase64();
}


PIByteArray &PIByteArray::convertFromBase64() {
	return *this = fromBase64(*this);
}


PIByteArray PIByteArray::toBase64() const {
	if (isEmpty()) return PIByteArray();
	base64HelpStruct hs;
	PIByteArray ret;
	int sz = (size_s() / 3) * 3, ri = -1;
	uchar t[4];
	ret.resize(((size_s() - 1) / 3 + 1) * 4);
	for (int i = 0; i < sz; i += 3) {
		hs.setBytes(data(i));
		hs.getAscii(t);
		ret[++ri] = (t[0]);
		ret[++ri] = (t[1]);
		ret[++ri] = (t[2]);
		ret[++ri] = (t[3]);
	}
	int der = size_s() % 3;
	switch (der) {
		case 1:
			hs.setBytes(data(sz), 1);
			hs.getAscii(t);
			ret[++ri] = (t[0]);
			ret[++ri] = (t[1]);
			ret[++ri] = ('=');
			ret[++ri] = ('=');
			break;
		case 2:
			hs.setBytes(data(sz), 2);
			hs.getAscii(t);
			ret[++ri] = (t[0]);
			ret[++ri] = (t[1]);
			ret[++ri] = (t[2]);
			ret[++ri] = ('=');
			break;
		default: break;
	}
	return ret;
}


PIByteArray PIByteArray::fromBase64(const PIByteArray & base64) {
	if (base64.isEmpty()) return PIByteArray();
	base64HelpStruct hs;
	PIByteArray ret;
	int sz = base64.size_s(), ind = -1;
	uchar t[4];
	ret.resize(sz / 4 * 3);
	for (int i = 0; i < sz; i += 4) {
		hs.setAscii(base64.data(i));
		hs.getBytes(t);
		ret[++ind] = (t[0]);
		ret[++ind] = (t[1]);
		ret[++ind] = (t[2]);
	}
	if (base64.back() == '=') ret.pop_back();
		if (sz > 1) if (base64[sz - 2] == '=') ret.pop_back();
	return ret;
}


PIByteArray PIByteArray::fromBase64(const PIString & base64) {
	return fromBase64(base64.toByteArray());
}


PIByteArray & PIByteArray::compressRLE(uchar threshold) {
	PIByteArray t;
	uchar fb, clen, mlen = 255 - threshold;
	for (uint i = 0; i < size();) {
		fb = at(i);
		clen = 1;
		while (at(++i) == fb) {
			++clen;
			if (clen == mlen)
				break;
		}
		if (clen > 1) {
			t.push_back(threshold + clen);
			t.push_back(fb);
			continue;
		}
		if (fb >= threshold) {
			t.push_back(threshold + 1);
			t.push_back(fb);
		} else
			t.push_back(fb);
	}
	*this = t;
	return *this;
}


PIByteArray & PIByteArray::decompressRLE(uchar threshold) {
	PIByteArray t;
	uchar fb, clen;
	for (uint i = 0; i < size(); ++i) {
		fb = at(i);
		if (fb >= threshold) {
			clen = fb - threshold;
			fb = at(++i);
			for (uint j = 0; j < clen; ++j)
				t.push_back(fb);
			continue;
		} else
			t.push_back(fb);
	}
	*this = t;
	return *this;
}


uchar PIByteArray::checksumPlain8() const {
	uchar c = 0;
	int sz = size_s();
	for (int i = 0; i < sz; ++i)
		c += at(i);
	c = ~(c + 1);
	return c;
}


uint PIByteArray::checksumPlain32() const {
	uint c = 0;
	int sz = size_s();
	for (int i = 0; i < sz; ++i)
		c += at(i) * (i + 1);
	c = ~(c + 1);
	return c;
}


uint PIByteArray::hash() const {
	return piHashData(data(), size_s());
}


PIString PIByteArray::toString(int base) const {
	PIString ret;
	int sz = size_s();
	for (int i = 0; i < sz; ++i) {
		if (i > 0) ret += " ";
		if (base == 2) ret += "b";
		if (base == 8) ret += "0";
		if (base == 16) ret += "0x";
		ret += PIString::fromNumber(at(i), base);
	}
	return ret;
}


PIString PIByteArray::toHex() const {
	PIByteArray hex(size() * 2);
	uchar *hexData = hex.data();
	const uchar *d = data();
	for (int i = 0; i < size_s(); ++i) {
		int j = (d[i] >> 4) & 0xf;
		if (j <= 9) hexData[i*2] = (j + '0');
		else hexData[i*2] = (j + 'a' - 10);
		j = d[i] & 0xf;
		if (j <= 9) hexData[i*2+1] = (j + '0');
		else hexData[i*2+1] = (j + 'a' - 10);
	}
	return PIString(hex);
}


PIByteArray PIByteArray::fromUserInput(PIString str) {
	PIByteArray ret;
	if (str.trim().isEmpty()) return ret;
	str.replaceAll("\n", " ").replaceAll("\t", " ").replaceAll("  ", " ");
	PIStringList bl(str.split(" "));
	bool ok(false);
	piForeachC (PIString & b, bl) {
		int bv = b.toInt(-1, &ok);
		if (ok) ret << uchar(bv);
	}
	return ret;
}


PIByteArray PIByteArray::fromHex(PIString str) {
	PIByteArray hexEncoded = str.toByteArray();
	PIByteArray res((hexEncoded.size() + 1)/ 2);
	uchar *result = res.data() + res.size();
	bool odd_digit = true;
	for (int i = hexEncoded.size() - 1; i >= 0; --i) {
		int ch = hexEncoded.at(i);
		int tmp;
		if (ch >= '0' && ch <= '9') tmp = ch - '0';
		else if (ch >= 'a' && ch <= 'f') tmp = ch - 'a' + 10;
		else if (ch >= 'A' && ch <= 'F') tmp = ch - 'A' + 10;
		else continue;
		if (odd_digit) {
			--result;
			*result = tmp;
			odd_digit = false;
		} else {
			*result |= tmp << 4;
			odd_digit = true;
		}
	}
	res.remove(0, result - res.data());
	return res;
}


PICout operator <<(PICout s, const PIByteArray & ba) {
	s.space();
	s.setControl(0, true);
	s << "{";
	for (uint i = 0; i < ba.size(); ++i) {
		s << ba[i];
		if (i < ba.size() - 1) s << ", ";
	}
	s << "}";
	s.restoreControl();
	return s;
}


#ifdef PIP_STD_IOSTREAM
std::ostream &operator <<(std::ostream & s, const PIByteArray & ba) {
	s << "{";
	for (uint i = 0; i < ba.size(); ++i) {
		s << ba[i];
		if (i < ba.size() - 1) s << ", ";
	}
	s << "}";
	return s;
}
#endif


PIByteArray & operator >>(PIByteArray & s, PIByteArray & v) {
	if (s.size_s() < 4) {
		s.clear();
		v.clear();
		return s;
	}
	assert(s.size_s() >= 4);
	int sz = 0;
	s >> sz;
	if (sz > (s.size_s() - 4)) {
		piCout << "[PIByteArray] Warning: operator >> wants too much data, discard!" << sz << s.size_s();
		s.clear();
		v.clear();
		return s;
	}
	v.resize(sz);
	if (sz > 0) {
		memcpy(v.data(), s.data(), v.size());
		s.remove(0, v.size());
	}
	return s;
}