#include "HGBase64.h"
#include "HGInc.h"

HGResult HGAPI HGBase_Base64Encode(const HGByte* originalData, HGSize originalSize,
	HGByte* base64Data, HGSize* base64Size)
{
	if (NULL == originalData || 0 == originalSize)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	if (NULL != base64Data)
	{
		static const HGByte base64Table[] =
		{
			'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
			'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
			'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
			'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
			'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
			'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
			'w', 'x', 'y', 'z', '0', '1', '2', '3',
			'4', '5', '6', '7', '8', '9', '+', '/'
		};

		HGSize numberOfCycles = originalSize / 3;

		//#pragma omp parallel for
		for (HGSize i = 0; i < numberOfCycles; ++i)
		{
			const HGByte* originalDataEx = originalData + i * 3;
			HGByte* base64DataEx = base64Data + i * 4;

			HGUInt temp = (((HGUInt)originalDataEx[0] << 16) | ((HGUInt)originalDataEx[1] << 8)
				| ((HGUInt)originalDataEx[2])) & 0x00FFFFFF;
			base64DataEx[0] = base64Table[(temp >> 18) & 0x3F];
			base64DataEx[1] = base64Table[(temp >> 12) & 0x3F];
			base64DataEx[2] = base64Table[(temp >> 6) & 0x3F];
			base64DataEx[3] = base64Table[temp & 0x3F];
		}

		const HGByte* originalDataEx = originalData + numberOfCycles * 3;
		HGByte* base64DataEx = base64Data + numberOfCycles * 4;

		HGSize sizeOfRemaining = originalSize - numberOfCycles * 3;
		if (1 == sizeOfRemaining)
		{
			HGUInt temp = ((HGUInt)originalDataEx[0] << 16) & 0x00FF0000;
			base64DataEx[0] = base64Table[(temp >> 18) & 0x3F];
			base64DataEx[1] = base64Table[(temp >> 12) & 0x3F];
			base64DataEx[2] = '=';
			base64DataEx[3] = '=';
		}
		else if (2 == sizeOfRemaining)
		{
			HGUInt temp = (((HGUInt)originalDataEx[0] << 16) | ((HGUInt)originalDataEx[1] << 8)) & 0x00FFFF00;
			base64DataEx[0] = base64Table[(temp >> 18) & 0x3F];
			base64DataEx[1] = base64Table[(temp >> 12) & 0x3F];
			base64DataEx[2] = base64Table[(temp >> 6) & 0x3F];
			base64DataEx[3] = '=';
		}
	}

	if (NULL != base64Size)
	{
		HGSize newSize = (originalSize / 3) * 4;
		if (0 != originalSize % 3)
		{
			newSize += 4;
		}

		*base64Size = newSize;
	}

	return HGBASE_ERR_OK;
}

HGResult HGAPI HGBase_Base64Decode(const HGByte* base64Data, HGSize base64Size,
	HGByte* originalData, HGSize* originalSize)
{
	if (NULL == base64Data || 0 == base64Size)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	if (NULL != originalData)
	{
		static const HGByte base64Table_1[] =
		{
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 62, 64, 64, 64, 63,
			52, 53, 54, 55, 56, 57, 58, 59,
			60, 61, 64, 64, 64, 64, 64, 64,
			64, 0, 1, 2, 3, 4, 5, 6,
			7, 8, 9, 10, 11, 12, 13, 14,
			15, 16, 17, 18, 19, 20, 21, 22,
			23, 24, 25, 64, 64, 64, 64, 64,
			64, 26, 27, 28, 29, 30, 31, 32,
			33, 34, 35, 36, 37, 38, 39, 40,
			41, 42, 43, 44, 45, 46, 47, 48,
			49, 50, 51, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64,
			64, 64, 64, 64, 64, 64, 64, 64
		};

		HGSize numberOfCycles = (base64Size - 1) / 4;

		//#pragma omp parallel for
		for (HGSize i = 0; i < numberOfCycles; ++i)
		{
			const HGByte* base64DataEx = base64Data + i * 4;
			HGByte* originalDataEx = originalData + i * 3;

			HGUInt t0 = base64Table_1[base64DataEx[0]];
			HGUInt t1 = base64Table_1[base64DataEx[1]];
			HGUInt t2 = base64Table_1[base64DataEx[2]];
			HGUInt t3 = base64Table_1[base64DataEx[3]];

			originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
			originalDataEx[1] = ((t1 << 4) | (t2 >> 2)) & 0xFF;
			originalDataEx[2] = ((t2 << 6) | t3) & 0xFF;
		}

		const HGByte* base64DataEx = base64Data + numberOfCycles * 4;
		HGByte* originalDataEx = originalData + numberOfCycles * 3;

		HGSize sizeOfRemaining = base64Size - numberOfCycles * 4;
		if (2 == sizeOfRemaining)
		{
			if ('=' != base64DataEx[0] && '=' != base64DataEx[1])
			{
				HGUInt t0 = base64Table_1[base64DataEx[0]];
				HGUInt t1 = base64Table_1[base64DataEx[1]];

				originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
			}
		}
		else if (3 == sizeOfRemaining)
		{
			if ('=' != base64DataEx[0] && '=' != base64DataEx[1])
			{
				HGUInt t0 = base64Table_1[base64DataEx[0]];
				HGUInt t1 = base64Table_1[base64DataEx[1]];
				HGUInt t2 = base64Table_1[base64DataEx[2]];

				if ('=' == base64DataEx[2])
				{
					originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
				}
				else
				{
					originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
					originalDataEx[1] = ((t1 << 4) | (t2 >> 2)) & 0xFF;
				}
			}
		}
		else if (4 == sizeOfRemaining)
		{
			if ('=' != base64DataEx[0] && '=' != base64DataEx[1])
			{
				HGUInt t0 = base64Table_1[base64DataEx[0]];
				HGUInt t1 = base64Table_1[base64DataEx[1]];
				HGUInt t2 = base64Table_1[base64DataEx[2]];
				HGUInt t3 = base64Table_1[base64DataEx[3]];

				if ('=' == base64DataEx[2] && '=' == base64DataEx[3])
				{
					originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
				}
				else if ('=' != base64DataEx[2] && '=' == base64DataEx[3])
				{
					originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
					originalDataEx[1] = ((t1 << 4) | (t2 >> 2)) & 0xFF;
				}
				else if ('=' != base64DataEx[2] && '=' != base64DataEx[3])
				{
					originalDataEx[0] = ((t0 << 2) | (t1 >> 4)) & 0xFF;
					originalDataEx[1] = ((t1 << 4) | (t2 >> 2)) & 0xFF;
					originalDataEx[2] = ((t2 << 6) | t3) & 0xFF;
				}
			}
		}
	}

	if (NULL != originalSize)
	{
		HGSize numberOfCycles = (base64Size - 1) / 4;
		const HGByte* base64DataEx = base64Data + numberOfCycles * 4;

		HGSize newSize = numberOfCycles * 3;

		HGSize sizeOfRemaining = base64Size - numberOfCycles * 4;
		if (2 == sizeOfRemaining)
		{
			if ('=' != base64DataEx[0] && '=' != base64DataEx[1])
			{
				newSize += 1;
			}
		}
		else if (3 == sizeOfRemaining)
		{
			if ('=' != base64DataEx[0] && '=' != base64DataEx[1])
			{
				if ('=' == base64DataEx[2])
				{
					newSize += 1;
				}
				else
				{
					newSize += 2;
				}
			}
		}
		else if (4 == sizeOfRemaining)
		{
			if ('=' != base64DataEx[0] && '=' != base64DataEx[1])
			{
				if ('=' == base64DataEx[2] && '=' == base64DataEx[3])
				{
					newSize += 1;
				}
				else if ('=' != base64DataEx[2] && '=' == base64DataEx[3])
				{
					newSize += 2;
				}
				else if ('=' != base64DataEx[2] && '=' != base64DataEx[3])
				{
					newSize += 3;
				}
			}
		}

		*originalSize = newSize;
	}

	return HGBASE_ERR_OK;
}