#include <fmt/core.h>
#include <SFML/Graphics.hpp>
#include <numbers>
#include <cmath>
#include "matrix.hpp"

using matrix::Matrix;
using namespace fmt;

const int SCREEN_HEIGHT=480;
const int SCREEN_WIDTH=SCREEN_HEIGHT * 2;
const int MAP_SIZE=8;
const int TILE_SIZE=(SCREEN_WIDTH/2) / MAP_SIZE;
const float FOV = std::numbers::pi / 3.0;
const float HALF_FOV = FOV / 2;
const int CASTED_RAYS=30;
const float STEP_ANGLE = FOV / CASTED_RAYS;
const int MAX_DEPTH = MAP_SIZE * TILE_SIZE;
const float SCALE = (SCREEN_WIDTH / 2) / CASTED_RAYS;

Matrix MAP{
  {1,1,1,1,1,1,1,1},
  {1,0,1,0,0,0,0,1},
  {1,0,1,0,0,1,1,1},
  {1,0,0,0,0,0,0,1},
  {1,1,0,0,0,0,0,1},
  {1,0,0,1,1,1,0,1},
  {1,0,0,0,1,0,0,1},
  {1,1,1,1,1,1,1,1}
};

float player_x = SCREEN_WIDTH / 4;
float player_y = SCREEN_WIDTH / 4;
float player_angle = std::numbers::pi;

void draw_map_rect(sf::RenderWindow &window, sf::Color color, int x, int y) {
  sf::RectangleShape rect({TILE_SIZE-1, TILE_SIZE-1});
  rect.setFillColor(color);
  rect.setPosition(x * TILE_SIZE, y * TILE_SIZE);
  window.draw(rect);
}

void draw_map(sf::RenderWindow &window, Matrix &map) {
  sf::Color light_grey{191, 191, 191};
  sf::Color dark_grey{65,65,65};

  for(size_t y = 0; y < matrix::height(map); y++) {
    for(size_t x = 0; x < matrix::width(map); x++) {
      draw_map_rect(window, map[y][x] == 1 ? light_grey : dark_grey, x, y);
    }
  }
}

void draw_line(sf::RenderWindow &window, sf::Vector2f start, sf::Vector2f end) {
  sf::Vertex line[] = {
      sf::Vertex(start),
      sf::Vertex(end)
  };

  window.draw(line, 2, sf::Lines);
}

void ray_casting(sf::RenderWindow &window, Matrix& map) {
  float start_angle = player_angle - HALF_FOV;

  for(int ray = 0; ray < CASTED_RAYS; ray++, start_angle += STEP_ANGLE)
  {
    for(int depth = 1; depth < MAX_DEPTH; depth++) {
      float target_x = player_x - std::sin(start_angle) * depth;
      float target_y = player_y + std::cos(start_angle) * depth;

      int col = int(target_x / TILE_SIZE);
      int row = int(target_y / TILE_SIZE);

      if(map[row][col] == 1) {
        draw_map_rect(window, {195, 137, 38}, col & TILE_SIZE, row * TILE_SIZE);
        draw_line(window, {player_x, player_y}, {target_x, target_y});
        break;
      }
    }
  }
}

int main() {
  sf::RenderWindow window(sf::VideoMode(SCREEN_WIDTH, SCREEN_HEIGHT), "Raycaster");

  while(window.isOpen()) {
    sf::Event event;

    draw_map(window, MAP);
    ray_casting(window, MAP);
    window.display();

    while(window.pollEvent(event)) {
      if(event.type == sf::Event::Closed) {
        window.close();
      }
    }
  }

  return 0;
}