
//***************************************************************************
//* Copyright (c) 2023-2024 SPAdes team
//* All Rights Reserved
//* See file LICENSE for details.
//***************************************************************************

/*
This file is a part of KMC software distributed under GNU GPL 3 licence.
The homepage of the KMC project is http://sun.aei.polsl.pl/kmc

Authors: Sebastian Deorowicz and Agnieszka Debudaj-Grabysz

Version: 2.2.0
Date   : 2015-04-15
*/

#ifndef _KMER_API_H
#define _KMER_API_H


#include "kmer_defs.h"
#include <string>
#include <iostream>
#include "mmer.h"
class CKMCFile;

class CKmerAPI
{
protected:

	uint64 *kmer_data;				// An array to store kmer's data. On 64 bits 32 symbols can be stored
									// Data are shifted to let sufix's symbols to start with a border of a byte

	
	uint32 kmer_length;				// Kmer's length, in symbols
	uchar byte_alignment;			// A number of "empty" symbols placed before prefix to let sufix's symbols to start with a border of a byte

	uint32 no_of_rows;				// A number of 64-bits words allocated for kmer_data 	

	friend class CKMCFile;
	
	//----------------------------------------------------------------------------------
	inline void clear()
	{
		memset(kmer_data, 0, sizeof(*kmer_data) * no_of_rows);
	}

	//----------------------------------------------------------------------------------
	inline void insert2bits(uint32 pos, uchar val)
	{
		kmer_data[(pos + byte_alignment) >> 5] += (uint64)val << (62 - (((pos + byte_alignment) & 31) * 2));
	}

	inline uchar extract2bits(uint32 pos)
	{
		return (kmer_data[(pos + byte_alignment) >> 5] >> (62 - (((pos + byte_alignment) & 31) * 2))) & 3;
	}
	//----------------------------------------------------------------------------------
	inline void SHL_insert2bits(uchar val)
	{
		kmer_data[0] <<= 2;
		if (byte_alignment)
		{
			uint64 mask = ~(((1ull << 2 * byte_alignment) - 1) << (64 - 2 * byte_alignment));
			kmer_data[0] &= mask;
		}
		for (uint32 i = 1; i < no_of_rows; ++i)
		{
			kmer_data[i - 1] += kmer_data[i] >> 62;
			kmer_data[i] <<= 2;
		}
		kmer_data[no_of_rows - 1] += (uint64)val << (62 - (((kmer_length - 1 + byte_alignment) & 31) * 2));
	}
	// ----------------------------------------------------------------------------------
	inline void from_binary(const char* kmer)
	{
		clear();
		for (uint32 i = 0; i < kmer_length; ++i)
			insert2bits(i, kmer[i]);
	}

	// ----------------------------------------------------------------------------------
	template<typename RandomAccessIterator>
	inline void to_string_impl(RandomAccessIterator iter)
	{
		uchar *byte_ptr;
		uchar c;
		uchar temp_byte_alignment = byte_alignment;
		uint32 cur_string_size = 0;
		for (uint32 row_counter = 0; row_counter < no_of_rows; row_counter++)
		{
			byte_ptr = reinterpret_cast<uchar*>(&kmer_data[row_counter]);

			byte_ptr += 7;					// shift a pointer towards a MSB

			for (uint32 i = 0; (i < kmer_length) && (i < 32); i += 4)		// 32 symbols of any "row" in kmer_data
			{
				if ((i == 0) && temp_byte_alignment)				// check if a byte_alignment placed before a prefix is to be skipped
					temp_byte_alignment--;
				else
				{
					c = 0xc0 & *byte_ptr;			//11000000
					c = c >> 6;
					*(iter + cur_string_size++) = char_codes[c];
					if (cur_string_size == kmer_length) break;
				}

				if ((i == 0) && temp_byte_alignment)				// check if a  byte_alignment placed before a prefix is to be skipped
					temp_byte_alignment--;
				else
				{
					c = 0x30 & *byte_ptr;			//00110000
					c = c >> 4;
					*(iter + cur_string_size++) = char_codes[c];
					if (cur_string_size == kmer_length) break;
				}

				if ((i == 0) && temp_byte_alignment)				// check if a  byte_alignment placed before a prefix is to be skipped
					temp_byte_alignment--;
				else
				{
					c = 0x0c & *byte_ptr;			//00001100
					c = c >> 2;
					*(iter + cur_string_size++) = char_codes[c];
					if (cur_string_size == kmer_length) break;
				}
				// no need to check byte alignment as its length is at most 3 
				c = 0x03 & *byte_ptr;			//00000011
				*(iter + cur_string_size++) = char_codes[c];
				if (cur_string_size == kmer_length) break;

				byte_ptr--;
			}
		}
	}
	
	// ----------------------------------------------------------------------------------
	template<typename RandomAccessIterator>
	inline bool from_string_impl(const RandomAccessIterator iter, uint32 len)
	{
		unsigned char c_char;
		uchar c_binary;
		uchar temp_byte_alignment;
		if (kmer_length != len)
		{
			if (kmer_length && kmer_data)
				delete[] kmer_data;

			kmer_length = len;

			if (kmer_length % 4)
				byte_alignment = 4 - (kmer_length % 4);
			else
				byte_alignment = 0;


			if (kmer_length != 0)
			{
				no_of_rows = (((kmer_length + byte_alignment) % 32) ? (kmer_length + byte_alignment) / 32 + 1 : (kmer_length + byte_alignment) / 32);
				//no_of_rows = (int)ceil((double)(kmer_length + byte_alignment) / 32);
				kmer_data = new uint64[no_of_rows];
				//memset(kmer_data, 0, sizeof(*kmer_data) * no_of_rows);
			}
		}

		memset(kmer_data, 0, sizeof(*kmer_data) * no_of_rows);
		temp_byte_alignment = byte_alignment;
		uint32 i = 0;
		uint32 i_in_string = 0;
		uchar *byte_ptr;

		for (uint32 row_index = 0; row_index < no_of_rows; row_index++)
		{
			byte_ptr = reinterpret_cast<uchar*>(&kmer_data[row_index]);
			byte_ptr += 7;					// shift a pointer towards a MSB

			while (i < kmer_length)
			{
				if ((i_in_string == 0) && temp_byte_alignment)				// check if a byte_alignment placed before a prefix is to be skipped
				{
					temp_byte_alignment--;
					i++;
				}
				else
				{
					c_char = *(iter + i_in_string);
					c_binary = num_codes[c_char];
					c_binary = c_binary << 6;		//11000000
					*byte_ptr = *byte_ptr | c_binary;
					i++;
					i_in_string++;
					if (i_in_string == kmer_length) break;
				}

				if ((i_in_string == 0) && temp_byte_alignment)				// check if a byte_alignment placed before a prefix is to be skipped
				{
					temp_byte_alignment--;
					i++;
				}
				else
				{
					c_char = *(iter + i_in_string);
					c_binary = num_codes[c_char];
					c_binary = c_binary << 4;
					*byte_ptr = *byte_ptr | c_binary;
					i++;
					i_in_string++;
					if (i_in_string == kmer_length) break;
				}

				//!!!if ((i == 0) && temp_byte_alignment)	//poprawka zg3oszona przez Maaka D3ugosza			// check if a byte_alignment placed before a prefix is to be skipped
				if ((i_in_string == 0) && temp_byte_alignment)				// check if a byte_alignment placed before a prefix is to be skipped
				{
					temp_byte_alignment--;
					i++;
				}
				else
				{
					c_char = *(iter + i_in_string);
					c_binary = num_codes[c_char];
					c_binary = c_binary << 2;
					*byte_ptr = *byte_ptr | c_binary;
					i++;
					i_in_string++;
					if (i_in_string == kmer_length) break;
				}

				c_char = *(iter + i_in_string);
				c_binary = num_codes[c_char];
				*byte_ptr = *byte_ptr | c_binary;
				i++;
				i_in_string++;
				if (i_in_string == kmer_length) break;

				if (i % 32 == 0)
					break; //check if a new "row" is to be started
				byte_ptr--;
			}
		};
		return true;
	}
public:
	static const char char_codes[];
	static char num_codes[256];
	static uchar rev_comp_bytes_LUT[];
	static uint64 alignment_mask[];
	struct _si  
	{
		_si()
		{
			for (int i = 0; i < 256; i++)
                num_codes[i] = -1;
			num_codes['A'] = num_codes['a'] = 0;
			num_codes['C'] = num_codes['c'] = 1;
			num_codes['G'] = num_codes['g'] = 2;
			num_codes['T'] = num_codes['t'] = 3;
        }
    } static _init;


// ----------------------------------------------------------------------------------
// The constructor creates kmer for the number of symbols equal to length. 
// The array kmer_data has the size of ceil((length + byte_alignment) / 32))
// IN	: length - a number of symbols of a kmer
// ----------------------------------------------------------------------------------
	inline CKmerAPI(uint32 length = 0)
	{
		if (length)
		{
			if (length % 4)
				byte_alignment = 4 - (length % 4);	
			else
				byte_alignment = 0;

			no_of_rows = (((length + byte_alignment) % 32) ? (length + byte_alignment) / 32 + 1 : (length + byte_alignment) / 32); 
			//no_of_rows = (int)ceil((double)(length + byte_alignment) / 32);
			kmer_data = new uint64[no_of_rows];

			memset(kmer_data, 0, sizeof(*kmer_data) * no_of_rows);
		}
		else
		{
			kmer_data = NULL;
			no_of_rows = 0;
			byte_alignment = 0;
		}
		kmer_length = length;
	};
//-----------------------------------------------------------------------
// The destructor
//-----------------------------------------------------------------------
	inline ~CKmerAPI()
	{
		if (kmer_data != NULL)
			delete [] kmer_data;
	};

//-----------------------------------------------------------------------
// The copy constructor
//-----------------------------------------------------------------------
	inline CKmerAPI(const CKmerAPI &kmer)
	{
		kmer_length = kmer.kmer_length;
		byte_alignment = kmer.byte_alignment;
		no_of_rows = kmer.no_of_rows;
		
		kmer_data = new uint64[no_of_rows];
			
		for(uint32 i = 0; i < no_of_rows; i++)
			kmer_data[i] = kmer.kmer_data[i];

	};

//-----------------------------------------------------------------------
// The operator =
//-----------------------------------------------------------------------	
	inline CKmerAPI& operator=(const CKmerAPI &kmer)
	{
		if (kmer.kmer_length != kmer_length)
		{
			if (kmer_length && kmer_data)
				delete [] kmer_data;
		
			kmer_length = kmer.kmer_length;
			byte_alignment = kmer.byte_alignment;
			no_of_rows = kmer.no_of_rows;
		
			kmer_data = new uint64[no_of_rows];
		}

		for(uint32 i = 0; i < no_of_rows; i++)
			kmer_data[i] = kmer.kmer_data[i];

		return *this;
	};

//-----------------------------------------------------------------------
// The operator ==
//-----------------------------------------------------------------------
	inline bool operator==(const CKmerAPI &kmer)
	{
			if (kmer.kmer_length != kmer_length)
				return false;

			for(uint32 i = 0; i < no_of_rows; i++)
				if (kmer.kmer_data[i] != kmer_data[i])
					return false;

			return true;

	};

//-----------------------------------------------------------------------
// Operator < . If arguments differ in length a result is undefined
//-----------------------------------------------------------------------
	inline bool operator<(const CKmerAPI &kmer)
	{
			if (kmer.kmer_length != kmer_length)
				return false;					

			for(uint32 i = 0; i < no_of_rows; i++)
				if (kmer.kmer_data[i] > kmer_data[i])
					return true;
				else
					if (kmer.kmer_data[i] < kmer_data[i])
						return false;
				
			return false;
	};

//-----------------------------------------------------------------------
// Return a symbol of a kmer from an indicated position (numbered form 0).
// The symbol is returned as an ASCI character A/C/G/T
// IN	: pos - a position of a symbol
// RET	: symbol - a symbol placed on a position pos
//-----------------------------------------------------------------------
	inline char get_asci_symbol(unsigned int pos)
	{
		if (pos >= kmer_length)
			return 0;
		
		uint32 current_row = (pos + byte_alignment) / 32;
		uint32 current_pos = ((pos + byte_alignment) % 32) * 2;
		uint64 mask = 0xc000000000000000 >> current_pos;
		uint64 symbol = kmer_data[current_row] & mask;
		symbol = symbol >> (64 - current_pos - 2);
		return char_codes[symbol];
	
	};

	//-----------------------------------------------------------------------
	// Return a symbol of a kmer from an indicated position (numbered form 0)
	// The symbol is returned as a numerical value 0/1/2/3
	// IN	: pos - a position of a symbol
	// RET	: symbol - a symbol placed on a position pos
	//-----------------------------------------------------------------------
	inline uchar get_num_symbol(unsigned int pos)
	{
		if (pos >= kmer_length)
			return 0;

		uint32 current_row = (pos + byte_alignment) / 32;
		uint32 current_pos = ((pos + byte_alignment) % 32) * 2;
		uint64 mask = 0xc000000000000000 >> current_pos;
		uint64 symbol = kmer_data[current_row] & mask;
		symbol = symbol >> (64 - current_pos - 2);
		uchar* byte_ptr = reinterpret_cast<uchar*>(&symbol);
		return *byte_ptr;

	};

	//-----------------------------------------------------------------------
	// Convert kmer into string (an alphabet ACGT)
	// RET	: string kmer
	//-----------------------------------------------------------------------
	inline std::string to_string()
	{
		std::string string_kmer;		
		string_kmer.resize(kmer_length);
		to_string_impl(string_kmer.begin());	
		return string_kmer;
	};
	//-----------------------------------------------------------------------
	// Convert kmer into string (an alphabet ACGT). The function assumes enough memory was allocated
	// OUT	: str - string kmer. 
	//-----------------------------------------------------------------------
	inline void to_string(char *str)
	{
		to_string_impl(str);
		str[kmer_length] = '\0';
	};

	//-----------------------------------------------------------------------
	// Convert kmer into string (an alphabet ACGT)
	// OUT 	: str - string kmer
	//-----------------------------------------------------------------------
	inline void to_string(std::string &str)
	{	
		str.resize(kmer_length);
		to_string_impl(str.begin());
	};

	//-----------------------------------------------------------------------
	// Convert a string of an alphabet ACGT into a kmer of a CKmerAPI
	// IN	: kmer_string	- a string of an alphabet ACGT
	// RET	: true			- if succesfull
	//-----------------------------------------------------------------------
	inline bool from_string(const char* kmer_string)
	{
		uint32 len = 0;
		for (;  kmer_string[len] != '\0' ; ++len)
		{
			if (num_codes[(uchar)kmer_string[len]] == -1)
				return false;
		}
		return from_string_impl(kmer_string, len);
	}

	//-----------------------------------------------------------------------
	// Convert a string of an alphabet ACGT into a kmer of a CKmerAPI
	// IN	: kmer_string	- a string of an alphabet ACGT
	// RET	: true			- if succesfull
	//-----------------------------------------------------------------------
	inline bool from_string(const std::string& kmer_string)
	{					
		for (uint32 ii = 0; ii < kmer_string.size(); ++ii)
		{
			if (num_codes[(uchar)kmer_string[ii]] == -1)
				return false;
		}
		return from_string_impl(kmer_string.begin(), static_cast<uint32>(kmer_string.length()));		
	}

	//-----------------------------------------------------------------------
	// Convert k-mer to its reverse complement
	//-----------------------------------------------------------------------
	inline bool reverse()
	{
		if (kmer_data == NULL)
		{
			return false;
		}

		// number of bytes used to store the k-mer in the 0-th row
		const uint32 size_in_byte = ((kmer_length + byte_alignment) / 4) / no_of_rows;
		uchar* byte1;
		uchar* byte2;

		if (no_of_rows == 1)
		{
			*kmer_data <<= 2 * byte_alignment;
			byte1 = reinterpret_cast<uchar*>(kmer_data)+8 - size_in_byte;
			byte2 = reinterpret_cast<uchar*>(kmer_data)+7;

			for (uint32 i_bytes = 0; i_bytes < size_in_byte / 2; ++i_bytes)
			{
				unsigned char temp = rev_comp_bytes_LUT[*byte1];
				*byte1 = rev_comp_bytes_LUT[*byte2];
				*byte2 = temp;

				++byte1;
				--byte2;
			}

			if (size_in_byte % 2)
			{
				*byte1 = rev_comp_bytes_LUT[*byte1];
			}
		}
		else
		{
			for (uint32 i_rows = no_of_rows - 1; i_rows > 0; --i_rows)
			{
				kmer_data[i_rows] >>= 64 - 8 * size_in_byte - 2 * byte_alignment;

				// more significant row
				uint64 previous = kmer_data[i_rows - 1];
				previous <<= 8 * size_in_byte + 2 * byte_alignment;
				kmer_data[i_rows] |= previous;

				byte1 = reinterpret_cast<uchar*>(kmer_data + i_rows);
				byte2 = reinterpret_cast<uchar*>(kmer_data + i_rows) + 7;

				for (int i_bytes = 0; i_bytes < 4; ++i_bytes)
				{
					unsigned char temp = rev_comp_bytes_LUT[*byte1];
					*byte1 = rev_comp_bytes_LUT[*byte2];
					*byte2 = temp;

					++byte1;
					--byte2;
				}
			}

			// clear less significant bits
			kmer_data[0] >>= 64 - 8 * size_in_byte - 2 * byte_alignment;
			kmer_data[0] <<= 64 - 8 * size_in_byte;

			byte1 = reinterpret_cast<uchar*>(kmer_data)+8 - size_in_byte;
			byte2 = reinterpret_cast<uchar*>(kmer_data)+7;

			for (uint32 i_bytes = 0; i_bytes < size_in_byte / 2; ++i_bytes)
			{
				unsigned char temp = rev_comp_bytes_LUT[*byte1];
				*byte1 = rev_comp_bytes_LUT[*byte2];
				*byte2 = temp;

				++byte1;
				--byte2;
			}

			if (size_in_byte % 2)
			{
				*byte1 = rev_comp_bytes_LUT[*byte1];
			}

			for (uint32 i_rows = 0; i_rows < no_of_rows / 2; ++i_rows)
			{
				std::swap(kmer_data[i_rows], kmer_data[no_of_rows - i_rows - 1]);
			}
		}

		// clear alignment
		*kmer_data &= alignment_mask[byte_alignment];

		return true;
	}

//-----------------------------------------------------------------------
// Counts a signature of an existing kmer
// IN	: sig_len	- the length of a signature
// RET	: signature value
//-----------------------------------------------------------------------
	 uint32 get_signature(uint32 sig_len)
	 {
		 uchar symb;
		 CMmer cur_mmr(sig_len);
		 
		 for(uint32 i = 0; i < sig_len; ++i)
		 {
			 symb = get_num_symbol(i);
			 cur_mmr.insert(symb);
		 }
		 CMmer min_mmr(cur_mmr);
		 for (uint32 i = sig_len; i < kmer_length; ++i)
		 {
			 symb = get_num_symbol(i);
			 cur_mmr.insert(symb);
			 
			 if (cur_mmr < min_mmr)
				 min_mmr = cur_mmr;
		 }
		 return min_mmr.get();
	 }
	
	 
};


#endif

// ***** EOF
