/*
    libmaus2
    Copyright (C) 2015 German Tischler

    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/>.
*/
#if ! defined(LIBMAUS2_LCS_NPL_HPP)
#define LIBMAUS2_LCS_NPL_HPP

#include <libmaus2/lcs/Aligner.hpp>

namespace libmaus2
{
	namespace lcs
	{
		/**
		 * NP variant aligning until end of one string is reached (instead of both as for NP)
		 **/
		struct NPL : public libmaus2::lcs::Aligner, public libmaus2::lcs::AlignmentTraceContainer
		{
			typedef NPL this_type;
			typedef std::unique_ptr<this_type> unique_ptr_type;
			typedef std::shared_ptr<this_type> shared_ptr_type;

			typedef int64_t index_type;

			struct NPElement
			{
				index_type offset;
				index_type id;
			};

			enum trace_op {
				trace_op_none,
				trace_op_diag,
				trace_op_ins,
				trace_op_del
			};
			struct TraceElement
			{
				index_type prev;
				index_type slide;
				trace_op op;
			};

			libmaus2::autoarray::AutoArray<NPElement> DE;
			libmaus2::autoarray::AutoArray<NPElement> DO;
			libmaus2::autoarray::AutoArray<TraceElement,libmaus2::autoarray::alloc_type_c> trace;

			uint64_t byteSize() const
			{
				return DE.byteSize() + DO.byteSize() + trace.byteSize();
			}

			template<typename iter_a, typename iter_b, bool neg>
			static inline index_type slide(iter_a a, iter_a const ae, iter_b b, iter_b const be, index_type const offset)
			{
				a += offset;
				b += offset;

				iter_a ac = a;
				iter_b bc = b;

				if ( (ae-ac) < (be-bc) )
					while ( ac < ae && *ac == *bc )
						++ac, ++bc;
				else
					while ( bc < be && *ac == *bc )
						++ac, ++bc;

				if ( neg )
					return ac-a;
				else
					return bc-b;
			}

			void align(uint8_t const * a, size_t const l_a, uint8_t const * b, size_t const l_b)
			{
				np(a,a+l_a,b,b+l_b);
			}

			AlignmentTraceContainer const & getTraceContainer() const
			{
				return *this;
			}

			template<typename iter_a, typename iter_b>
			index_type np(iter_a const a, iter_a const ae, iter_b const b, iter_b const be, index_type const maxd = std::numeric_limits<index_type>::max())
			{
				if ( ae < a )
					throw libmaus2::exception::LibMausException("NPL::np: ae < a");
				if ( be < b )
					throw libmaus2::exception::LibMausException("NPL::np: be < b");


				assert ( ae-a >= 0 );
				assert ( be-b >= 0 );

				size_t const an = ae-a;
				size_t const bn = be-b;

				if ( ! an )
				{
					AlignmentTraceContainer::reset();
					return 0;
				}
				else if ( ! bn )
				{
					AlignmentTraceContainer::reset();
					return 0;
				}

				size_t const sn = std::max(an,bn);
				// number of diagonals
				index_type const numdiag = (sn<<1)+1;
				int64_t id = 0;

				if ( numdiag > static_cast<index_type>(DE.size()) )
				{
					DE.resize(numdiag);
					DO.resize(numdiag);
				}

				NPElement * DP = DE.begin() + sn;
				NPElement * DN = DO.begin() + sn;

				// diagonal containing bottom right of matrix
				int64_t fdiag = std::numeric_limits<int64_t>::max();

				// how far do we get without an error?
				{
					if ( static_cast<int64_t>(trace.size()) < id+1 )
						trace.resize(id+1);

					index_type const s = slide<iter_a,iter_b,false>(a,ae,b,be,0);
					DP[0].offset = s;
					index_type const nodeid = id++;
					assert ( nodeid < static_cast<int64_t>(trace.size()) );
					DP[0].id = nodeid;
					trace[nodeid].prev = 0;
					trace[nodeid].slide = s;
					trace[nodeid].op = trace_op_none;
				}

				index_type d = 1;
				if ( DP[0].offset >= static_cast<int64_t>(std::min(an,bn)) )
				{
					assert ( DP[0].offset == static_cast<int64_t>(std::min(an,bn)) );
					fdiag = 0;
				}
				else
				{
					assert ( DP[0].offset < static_cast<int64_t>(std::min(an,bn)) );

					if ( static_cast<int64_t>(trace.size()) < id+3 )
						trace.resize(id+3);

					{
						index_type const p = DP[0].offset;
						index_type const s = slide<iter_a,iter_b,true>(a,ae,b+1,be,p);
						DN[-1].offset = p + s;
						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[-1].id = nodeid;
						trace[nodeid].prev = DP[0].id;
						trace[nodeid].slide = s;
						trace[nodeid].op = trace_op_ins;
					}
					{
						index_type const p = DP[0].offset+1;
						index_type const s = slide<iter_a,iter_b,false>(a,ae,b,be,p);
						DN[ 0].offset = p + s;
						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[ 0].id = nodeid;
						trace[nodeid].prev = DP[0].id;
						trace[nodeid].slide = s;
						trace[nodeid].op = trace_op_diag;
					}
					{
						index_type const p = DP[0].offset;
						index_type const s = slide<iter_a,iter_b,false>(a+1,ae,b,be,p);
						DN[ 1].offset = p + s;
						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[ 1].id = nodeid;
						trace[nodeid].prev = DP[0].id;
						trace[nodeid].slide = s;
						trace[nodeid].op = trace_op_del;
					}
					d += 1;
					std::swap(DP,DN);
				}
				for ( ; d < maxd ; ++d )
				{
					bool done = false;

					for ( int64_t di = -d+1; di <= d-1; ++di )
					{
						int64_t const apos = std::max( di,static_cast<int64_t>(0))+DP[di].offset;
						int64_t const bpos = std::max(-di,static_cast<int64_t>(0))+DP[di].offset;
						assert ( apos >= 0 );
						assert ( bpos >= 0 );

						assert ( static_cast< uint64_t >(apos) <= an );
						assert ( static_cast< uint64_t >(bpos) <= bn );

						if (
							static_cast< uint64_t >(apos) == an
							||
							static_cast< uint64_t >(bpos) == bn
						)
						{
							fdiag = di;
							done = true;
						}
					}
					if ( done )
						break;

					if ( static_cast<int64_t>(trace.size()) < id + (2*d+1) )
					{
						static uint64_t const cnt = 11;
						static uint64_t const div = 10;
						uint64_t const mult = (trace.size() * cnt) / div;
						uint64_t const reqsize = id + (2*d+1);
						uint64_t const newsize = std::max(mult,reqsize);
						trace.resize(newsize);
					}

					iter_a aa = a;
					iter_b bb = b + d;

					{
						// extend below
						index_type const p = DP[-d+1].offset;
						index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
						DN[-d].offset   = p + s;

						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[-d].id = nodeid;
						trace[nodeid].prev = DP[-d+1].id;
						trace[nodeid].slide = s;
						trace[nodeid].op = trace_op_ins;

						bb -= 1;
					}

					{
						index_type const top  = DP[-d+2].offset;
						index_type const diag = DP[-d+1].offset;

						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[-d+1].id = nodeid;

						if ( diag+1 >= top )
						{
							index_type const p = diag+1;
							index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
							DN[-d+1].offset = p + s;
							trace[nodeid].prev = DP[-d+1].id;
							trace[nodeid].slide = s;
							trace[nodeid].op = trace_op_diag;
						}
						else
						{
							index_type const p = top;
							index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
							DN[-d+1].offset = p + s;
							trace[nodeid].prev = DP[-d+2].id;
							trace[nodeid].slide = s;
							trace[nodeid].op = trace_op_ins;
						}

						bb -= 1;
					}

					for ( index_type di = -d+2; di < 0; ++di )
					{
						index_type const left = DP[di-1].offset;
						index_type const diag = DP[di].offset;
						index_type const top  = DP[di+1].offset;

						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[di].id = nodeid;

						if ( diag >= left )
						{
							if ( diag+1 >= top )
							{
								index_type const p = diag+1;
								index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_diag;
							}
							else
							{
								index_type const p = top;
								index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di+1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_ins;
							}
						}
						else
						{
							if ( left+1 >= top )
							{
								index_type const p = left+1;
								index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di-1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_del;
							}
							else
							{
								index_type const p = top;
								index_type const s = slide<iter_a,iter_b,true>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di+1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_ins;
							}
						}

						bb -= 1;
					}

					{
						index_type const left = DP[-1].offset;
						index_type const diag = DP[0].offset;
						index_type const top = DP[1].offset;

						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[0].id = nodeid;

						if ( diag >= left )
						{
							if ( diag >= top )
							{
								index_type const p = diag+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[0].offset = p + s;
								trace[nodeid].prev = DP[0].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_diag;
							}
							else
							{
								index_type const p = top+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[0].offset = p + s;
								trace[nodeid].prev = DP[1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_ins;
							}
						}
						else
						{
							if ( left >= top )
							{
								index_type const p = left+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[0].offset = p + s;
								trace[nodeid].prev = DP[-1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_del;
							}
							else
							{
								index_type const p = top+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[0].offset = p + s;
								trace[nodeid].prev = DP[1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_ins;
							}
						}

						aa += 1;
					}

					for ( index_type di = 1; di <= d-2 ; ++di )
					{
						index_type const left = DP[di-1].offset;
						index_type const diag = DP[di].offset;
						index_type const top  = DP[di+1].offset;

						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[di].id = nodeid;

						if ( diag+1 >= left )
						{
							if ( diag >= top )
							{
								index_type const p = diag+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_diag;
							}
							else
							{
								index_type const p = top+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di+1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_ins;
							}
						}
						else
						{
							if ( left >= top+1 )
							{
								index_type const p = left;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di-1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_del;
							}
							else
							{
								index_type const p = top+1;
								index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
								DN[di].offset = p + s;
								trace[nodeid].prev = DP[di+1].id;
								trace[nodeid].slide = s;
								trace[nodeid].op = trace_op_ins;
							}
						}

						aa += 1;
					}

					{
						index_type const left = DP[d-2].offset;
						index_type const diag = DP[d-1].offset;

						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[d-1].id = nodeid;

						if ( diag+1 >= left )
						{
							index_type const p = diag+1;
							index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
							DN[ d-1].offset = p + s;
							trace[nodeid].prev = DP[d-1].id;
							trace[nodeid].slide = s;
							trace[nodeid].op = trace_op_diag;
						}
						else
						{
							index_type const p = left;
							index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
							DN[ d-1].offset = p + s;
							trace[nodeid].prev = DP[d-2].id;
							trace[nodeid].slide = s;
							trace[nodeid].op = trace_op_del;
						}

						aa += 1;
					}

					{
						// extend above
						index_type const p = DP[ d-1].offset;
						index_type const s = slide<iter_a,iter_b,false>(aa,ae,bb,be,p);
						DN[d  ].offset = p + s;
						index_type const nodeid = id++;
						assert ( nodeid < static_cast<int64_t>(trace.size()) );
						DN[d].id = nodeid;
						trace[nodeid].prev = DP[ d-1].id;
						trace[nodeid].slide = s;
						trace[nodeid].op = trace_op_del;
					}

					std::swap(DP,DN);
				}

				if ( d == maxd )
				{
					libmaus2::exception::LibMausException lme;
					lme.getStream() << "[E] NPL: exceeded maximum amount of diagonals." << std::endl;
					lme.finish();
					throw lme;
				}

				index_type const ed = d-1;

				if ( AlignmentTraceContainer::capacity() <= std::min(an,bn)+ed )
					AlignmentTraceContainer::resize(std::min(an,bn)+ed);
				AlignmentTraceContainer::reset();

				index_type tid = DP[fdiag].id;
				while ( trace[tid].op != trace_op_none )
				{
					for ( index_type i = 0; i < trace[tid].slide; ++i )
						*(--AlignmentTraceContainer::ta) = STEP_MATCH;
					// std::cerr << "(" << trace[tid].slide << ")";

					switch ( trace[tid].op )
					{
						case trace_op_diag:
							*(--AlignmentTraceContainer::ta) = STEP_MISMATCH;
							//std::cerr << "diag";
							break;
						case trace_op_ins:
							*(--AlignmentTraceContainer::ta) = STEP_INS;
							//std::cerr << "ins";
							break;
						case trace_op_del:
							*(--AlignmentTraceContainer::ta) = STEP_DEL;
							//std::cerr << "del";
							break;
						case trace_op_none:
							break;
					}
					tid = trace[tid].prev;
				}

				for ( index_type i = 0; i < trace[tid].slide; ++i )
					*(--AlignmentTraceContainer::ta) = STEP_MATCH;
				//std::cerr << "(" << trace[tid].slide << ")";
				//std::cerr << std::endl;

				// std::cerr << "d=" << d << std::endl;
				return ed;
			}

			void cutTrace(int64_t const ed, int64_t const faccnt = 2, int64_t facden = 1)
			{
				assert ( ed >= 0 );
				int64_t const s = (ed+1)*(ed+1);
				if ( static_cast<int64_t>(trace.size()) > (faccnt*s)/facden )
					trace.resize(s);
			}
		};
	}
}
#endif
