/***************************************************************************************[Solver.cc]
Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
Copyright (c) 2007-2009, Niklas Sorensson
Copyright (c) 2009-2012, Mate Soos

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
**************************************************************************************************/

#ifndef PACKEDROW_H
#define PACKEDROW_H

//#define DEBUG_ROW

#include <vector>
#include "cmsat/constants.h"
#include "cmsat/SolverTypes.h"
#include "cmsat/Vec.h"
#include <string.h>
#include <iostream>
#include <algorithm>
#include <limits>

namespace CMSat {

using std::vector;

class PackedMatrix;

class PackedRow
{
public:
    bool operator ==(const PackedRow& b) const;
    bool operator !=(const PackedRow& b) const;

    PackedRow& operator=(const PackedRow& b)
    {
        #ifdef DEBUG_ROW
        assert(size > 0);
        assert(b.size > 0);
        assert(size == b.size);
        #endif

        memcpy(mp-1, b.mp-1, size+1);
        return *this;
    }

    PackedRow& operator^=(const PackedRow& b)
    {
        #ifdef DEBUG_ROW
        assert(size > 0);
        assert(b.size > 0);
        assert(b.size == size);
        #endif

        for (uint32_t i = 0; i != size; i++) {
            *(mp + i) ^= *(b.mp + i);
        }

        is_true_internal ^= b.is_true_internal;
        return *this;
    }

    void xorBoth(const PackedRow& b)
    {
        #ifdef DEBUG_ROW
        assert(size > 0);
        assert(b.size > 0);
        assert(b.size == size);
        #endif

        for (uint32_t i = 0; i != 2*size+1; i++) {
            *(mp + i) ^= *(b.mp + i);
        }

        is_true_internal ^= b.is_true_internal;
    }


    uint32_t popcnt() const;
    uint32_t popcnt(uint32_t from) const;

    bool popcnt_is_one() const
    {
        #if __GNUC__ >= 4
        int ret = 0;
        for (uint32_t i = 0; i != size; i++) {
            ret += __builtin_popcount(mp[i]&0xffffffff);
            ret += __builtin_popcount(mp[i]>>32);
            if (ret > 1) return false;
        }
        return ret == 1;
        #else
        uint32_t popcount = 0;
        for (uint32_t i = 0; i != size; i++) {
            uint64_t tmp = mp[i];
            while(tmp) {
                popcount += tmp & 1;
                tmp >>= 1;
            }
        }
        return popcount == 1;
        #endif
    }

    bool popcnt_is_one(uint32_t from) const
    {
        from++;

        //it's the last bit, there are none after, so it only has 1 bit set
        if (from/64 == size) {
            return true;
        }

        uint64_t tmp = mp[from/64];
        tmp >>= (from%64);
        if (tmp) return false;

        for (uint32_t i = from/64+1; i != size; i++)
            if (mp[i]) return false;
        return true;
    }

    inline const uint64_t& is_true() const
    {
        return is_true_internal;
    }

    inline bool isZero() const
    {
        for (uint32_t i = 0; i != size; i++) {
            if (mp[i]) return false;
        }
        return true;
    }

    inline void setZero()
    {
        memset(mp, 0, sizeof(uint64_t)*size);
    }

    inline void clearBit(const uint32_t i)
    {
        mp[i/64] &= ~((uint64_t)1 << (i%64));
    }

    inline void invert_is_true(const bool b = true)
    {
        is_true_internal ^= (uint64_t)b;
    }

    inline void setBit(const uint32_t i)
    {
        mp[i/64] |= ((uint64_t)1 << (i%64));
    }

    void swapBoth(PackedRow b)
    {
        #ifdef DEBUG_ROW
        assert(size > 0);
        assert(b.size > 0);
        assert(b.size == size);
        #endif

        uint64_t * __restrict mp1 = mp-1;
        uint64_t * __restrict mp2 = b.mp-1;

        uint32_t i = 2*(size+1);

        while(i != 0) {
            std::swap(*mp1, *mp2);
            mp1++;
            mp2++;
            i--;
        }
    }

    inline bool operator[](const uint32_t& i) const
    {
        #ifdef DEBUG_ROW
        assert(size*64 > i);
        #endif

        return (mp[i/64] >> (i%64)) & 1;
    }

    template<class T>
    void set(const T& v, const vector<uint16_t>& var_to_col, const uint32_t matrix_size)
    {
        assert(size == (matrix_size/64) + ((bool)(matrix_size % 64)));
        //mp = new uint64_t[size];
        setZero();
        for (uint32_t i = 0; i != v.size(); i++) {
            const uint32_t toset_var = var_to_col[v[i].var()];
            assert(toset_var != std::numeric_limits<uint32_t>::max());

            setBit(toset_var);
        }

        is_true_internal = !v.xorEqualFalse();
    }

    bool fill(vec<Lit>& tmp_clause, const vec<lbool>& assigns, const vector<Var>& col_to_var_original) const;

    inline unsigned long int scan(const unsigned long int var) const
    {
        #ifdef DEBUG_ROW
        assert(size > 0);
        #endif

        for(uint32_t i = var; i != size*64; i++) {
            if (this->operator[](i)) return i;
        }

        return std::numeric_limits<unsigned long int>::max();
    }

private:
    friend class PackedMatrix;
    friend std::ostream& operator << (std::ostream& os, const PackedRow& m);

    PackedRow(const uint32_t _size, uint64_t*  const _mp) :
        mp(_mp+1)
        , is_true_internal(*_mp)
        , size(_size)
    {}

    uint64_t* __restrict const mp;
    uint64_t& is_true_internal;
    const uint32_t size;
};

inline std::ostream& operator << (std::ostream& os, const PackedRow& m)
{
    for(uint32_t i = 0; i < m.size*64; i++) {
        os << m[i];
    }
    os << " -- xor: " << m.is_true();
    return os;
}

}

#endif //PACKEDROW_H
