/// @file
/// @brief Task2: member function definitions/implementations

#include "task2.hpp" // task2::select, task2::select_union

#include <array>         // std::array
#include <functional>    // std::function
#include <unordered_set> // std::unordered_set
#include <vector>        // std::vector
#include <algorithm>


namespace task2 {


/// @brief Selects the subset of vertices for which a boolean function evaluates to true
/// @param vertices Two-dimensional vertices to select from
/// @param region Boolean function to evaluate if a vertex is selected
/// @param invert Inverts the selection process if set to true
/// @return Indices of the selected vertices
std::unordered_set<size_t> select(const std::vector<Vec2d>& vertices, const Region& region, bool invert) {
  std::unordered_set<size_t> selected_indices;
  for (size_t i = 0; i < vertices.size(); ++i) {
    const bool isSelected = region(vertices[i]);
    if ((isSelected && !invert) || (!isSelected && invert)) {
      selected_indices.insert(i);
    }
  }
  return selected_indices;
}


/// @brief Selects the subset of vertices for which ANY of a sequence of boolean functions evaluates to true
/// @param vertices Two-dimensional vertices to select from
/// @param regions Sequence of boolean functions to evaluate
/// @param invert Inverts the selection process if set to 'true'
/// @return Indices of the selected vertices
std::unordered_set<size_t> select_union(const std::vector<Vec2d>& vertices, const std::vector<Region>& regions, bool invert) {
  std::unordered_set<size_t> selected_indices;
  for (size_t i = 0; i < vertices.size(); ++i) {
    bool isSelected = false;
    // Check if any region function evaluates to true
    for (const Region& region : regions) {
      isSelected = isSelected || region(vertices[i]);
      if (isSelected && !invert) {
        // Exit inner loop if selected and not inverting
        break;
      }
    }
    if (isSelected && invert) {
      // Add to selected set only if inverting and not already selected
    } else {
      // Add to selected set for normal selection or inverted with not yet selected
      selected_indices.insert(i);
    }
  }
  return selected_indices;
}

} // namespace task2