// Copyright (C) 2026 Kiyotsugu Arai
// SPDX-License-Identifier: LGPL-3.0-or-later

// linear_programming_impl.hpp — simplex, simplexMaximize の実装

#ifndef SANGI_LINEAR_PROGRAMMING_IMPL_HPP
#define SANGI_LINEAR_PROGRAMMING_IMPL_HPP

#include <math/optimization/linear_programming.hpp>

namespace sangi {

template<typename T>
LPResult<T> simplex(
    const LinearProgram<T>& lp,
    T eps,
    size_t maxIterations)
{
    if (lp.numVariables() == 0 || lp.numConstraints() == 0) {
        return LPResult<T>::infeasible(0);
    }

    detail::SimplexSolver<T> solver(lp, eps, maxIterations);
    return solver.solve();
}

template<typename T>
LPResult<T> simplexMaximize(
    const LinearProgram<T>& lp,
    T eps,
    size_t maxIterations)
{
    // 目的関数の符号を反転してコピー
    LinearProgram<T> minLP = lp;
    for (auto& c : minLP.objective) {
        c = -c;
    }
    minLP.objectiveConstant = -lp.objectiveConstant;

    auto result = simplex(minLP, eps, maxIterations);

    // 目的関数値の符号を戻す
    result.objectiveValue = -result.objectiveValue;
    return result;
}

} // namespace sangi

#endif // SANGI_LINEAR_PROGRAMMING_IMPL_HPP