#include "pibytearray.h"


int PIHuffman::nodeCompare(const void * f, const void * s) {
	return (reinterpret_cast<node * >(const_cast<void * >(s))->freq -
			reinterpret_cast<node * >(const_cast<void * >(f))->freq);
}


PIVector<uchar> PIHuffman::compress(const PIVector<uchar> & src) {
	calcFrequencies(src);
	return src;
}


void PIHuffman::calcFrequencies(const PIVector<uchar> & src) {
	nodes.resize(256);
	for (uint i = 0; i < 256; ++i) {
		nodes[i].parent = nodes[i].right = nodes[i].left = 0;
		nodes[i].freq = 0;
		nodes[i].word.resize(1);
		nodes[i].word[0] = static_cast<uchar>(i);
	}
	for (uint i = 0; i < src.size(); ++i)
		nodes[src[i]].freq++;
	std::qsort(nodes.data(), 256, sizeof(node), nodeCompare);
	for (uint i = 255; i >= 0; --i)
		if (nodes[i].freq > 0 && i < 255)
			{nodes.remove(i + 1, 255 - i); break;}
	for (uint i = 0; i < nodes.size(); ++i)
		cout << string((char*)nodes[i].word.data(), 1) << ": " << nodes[i].freq << endl;
}


PIHuffman PIByteArray::huffman;

PIByteArray & PIByteArray::convertToBase64() {
	base64HelpStruct hs;
	PIByteArray t;
	if (size() == 0) return *this;
	uint sz = (size() / 3) * 3;
	for (uint i = 0; i < sz; ++i) {
		hs.byte0 = hs.byte1 = hs.byte2 = 0;
		hs.byte0 = at(i);
		hs.byte1 = at(++i);
		hs.byte2 = at(++i);
		t.push_back(base64Table[hs.ascii0]);
		t.push_back(base64Table[hs.ascii1]);
		t.push_back(base64Table[hs.ascii2]);
		t.push_back(base64Table[hs.ascii3]);
	}
	hs.byte0 = hs.byte1 = hs.byte2 = 0; sz = size() % 3;
	switch (sz) {
		case 1:
			hs.byte0 = back();
			t.push_back(base64Table[hs.ascii0]);
			t.push_back(base64Table[hs.ascii1]);
			t.push_back('=');
			t.push_back('=');
			break;
		case 2:
			hs.byte0 = at(size() - 2); hs.byte1 = back();
			t.push_back(base64Table[hs.ascii0]);
			t.push_back(base64Table[hs.ascii1]);
			t.push_back(base64Table[hs.ascii2]);
			t.push_back('=');
			break;
		default: break;
	}
	*this = t;
	return *this;
}


PIByteArray & PIByteArray::convertFromBase64() {
	base64HelpStruct hs;
	PIByteArray t;
	uint sz = size();
	if (sz == 0) return *this;
	for (uint i = 0; i < sz; ++i) {
		hs.byte0 = hs.byte1 = hs.byte2 = 0;
		hs.ascii0 = base64InvTable[at(i)];
		hs.ascii1 = base64InvTable[at(++i)];
		hs.ascii2 = base64InvTable[at(++i)];
		hs.ascii3 = base64InvTable[at(++i)];
		t.push_back(hs.byte0);
		t.push_back(hs.byte1);
		t.push_back(hs.byte2);
	}
	if (back() == '=') t.pop_back();
		if (sz > 1) if (at(sz - 2) == '=') t.pop_back();
	*this = t;
	return *this;
}


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;
}