#include "board.hpp"
#include "forces.hpp"
#include "math.h"
#include "pedestrian.hpp"
#include "vector2d.hpp"

double g(double v_max_alpha, double w_alpha_norm) {
  if (w_alpha_norm <= v_max_alpha) {
    return 1;
  }
  return v_max_alpha / w_alpha_norm;
}

using namespace std;

// Numer of pedestrians
// $n_p$
// const int n_p = 100;

// Number of iterations
// $n_{iter}$
// const int n_iter = 100;

Pedestrian *init_pedestrians(int n_p) {
  Pedestrian *P = new Pedestrian[n_p];
  for (int i = 0; i < n_p; i++) {
    P[i] = Pedestrian();
  }
  return P;
}

Board init_board(int width, int length) {
  Vector2d obs[] = {Vector2d(2.0, 1.0), Vector2d(4.0, 1.0), Vector2d(6.0, 2.0), Vector2d(6.0, 4.0)};
  return Board(width, length, 4, obs);
}

int main(int argc, const char* argv[]) {

  Board B = init_board(10, 15);

  int n_p = atoi(argv[1]);
  int n_iter = atoi(argv[2]);

  Pedestrian *pedestrians = init_pedestrians(n_p);

  for (int t = 0; t < n_iter; t++) {

    for (int i = 0; i < n_p; i++) {

      Pedestrian &p = pedestrians[i];

      p.F_i.reset();

      //
      // $\vec{F}_\alpha(\vec{v}_\alpha, v^0_\alpha \vec{e}_\alpha) \vec{e}_\alpha(t) = \frac{1}{\tau_\alpha}(v^0_\alpha \vec{e}_\alpha - \vec{v}_\alpha)$
      //
      compute_acceleration_term(&p);

      //
      // $\sum_{\beta} \vec{F}_{\alpha\beta}(\vec{e}_{\alpha}, \vec{r}_{\alpha} - \vec{r}_{\beta})$
      //
      compute_repulsive_effects_from_pedestrians(pedestrians, &p, n_p);

      //
      // $\sum_{B} \vec{F}_{\alpha B}(\vec{e}_{\alpha}, \vec{r}_{\alpha} - \vec{r}_{B})$
      //
      compute_repulsive_effects_from_borders(B, &p);

      //
      // $\vec{w}_i = \vec{v}_i + \vec{F}_idt$
      //
      p.w_alpha = p.curr_vel + p.F_i * delta_t;

      //
      // $\vec{v}_i^{t+1} = \vec{w}_ig(\frac{v^{max}_i}{\Arrowvert \vec{w}_i \Arrowvert}) $
      //
      p.next_vel = p.w_alpha * g(p.v_max, p.w_alpha.norm());

      //
      // $\vec{r}_i^{t+1} += \vec{r}^t_i + v^t_idt$
      //
      p.curr_pos = p.curr_pos + p.curr_vel * delta_t;
    }

    for (int i = 0; i < n_p; i++) {
      pedestrians[i].update();
    }
  }

  return 0;
}