#include "FluidSim/Solver.hpp"

#include <algorithm>

namespace fluidsim::port {

Solver::Solver(std::vector<Pipe1D> &pipes, BoundarySystem &boundaries)
    : pipes_(pipes), boundaries_(boundaries) {}

void Solver::add_component(Component &component) { components_.push_back(&component); }

void Solver::step(float dt) {
    if (!std::isfinite(dt) || dt < 0)
        throw std::invalid_argument("invalid solver timestep");
    if (dt == 0)
        return;
    boundaries_.validate_topology();
    const float maximum_dt = dt / static_cast<float>(std::max(minimum_substeps, 1));
    double remaining = dt;
    int count = 0;
    while (remaining > double(dt) * 1e-7) {
        float sub_dt = std::min(maximum_dt, static_cast<float>(remaining));
        for (auto &pipe : pipes_)
            sub_dt = std::min(sub_dt, pipe.prepare_step());
        if (!(sub_dt > 0) || ++count > 1000000)
            throw std::runtime_error("solver timestep failed to progress");
        ++substep_count_;
        boundaries_.resolve(sub_dt);
        for (auto &pipe : pipes_)
            pipe.advance(sub_dt);
        for (Component *component : components_)
            component->update_state(sub_dt);
        remaining -= sub_dt;
    }
    ++step_count_;
}

} // namespace fluidsim::port