#ifndef ALGOIM_POLYSET_HPP
#define ALGOIM_POLYSET_HPP

// algoim::PolySet

#include <cassert>
#include <vector>
#include "booluarray.hpp"
#include "real.hpp"
#include "xarray.hpp"

namespace algoim
{
inline namespace v1
{
// PolySet implements a simple container to hold one or more Bernstein polynomials
// and their associated masks
template <int N, int E>
struct PolySet {
    struct Poly {
        uvector<int, N>  ext;    // Degree/extent of polynomial
        size_t           offset; // Offset into buffer, storing the xarray<Real,N> polynomial data
        booluarray<N, E> mask;   // Mask
    };

    std::vector<real> buff;      // Memory buffer containing polynomial data
    std::vector<Poly> items;     // Record of contained polynomials

    // Access polynomial by index
    xarray<real, N> poly(size_t ind)
    {
        assert(0 <= ind && ind < items.size());
        return xarray<real, N>(&buff[items[ind].offset], items[ind].ext);
    }

    // Access mask by index
    booluarray<N, E>& mask(size_t ind)
    {
        assert(0 <= ind && ind < items.size());
        return items[ind].mask;
    }

    // Add a polynomial/mask pair to the container
    void push_back(const xarray<real, N>& p, const booluarray<N, E>& m)
    {
        items.push_back({p.ext(), buff.size(), m});
        buff.resize(buff.size() + p.size());
        poly(items.size() - 1) = p; // 这里做了一个数据深拷贝，这是为什么xarray在调用push_back后可以被释放
    }

    size_t count() const { return items.size(); }
};
} // namespace v1

} // namespace algoim

#endif