#include "Waterline.h"
#include "../core/Aquarium.h"
#include "../utils/Random.h"
#include "../utils/defs.h"

Waterline::Waterline() : Entity(0, WATERLINE_Y) {
  shape[0] = "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
  shape[1] = "^^^^ ^^^  ^^^   ^^^    ^^^^      ";
  shape[2] = "^^^^      ^^^^     ^^^    ^^     ";
  shape[3] = "^^      ^^^^      ^^^    ^^^^^^  ";

  const size_t width = Aquarium::getInstance().getWidth();

  for (size_t i = 0; i < NUM_WAVE_LAYERS; ++i) {
    const std::string &original = shape[i];
    const size_t pattern_len = original.length();

    // Calculate how many full patterns + remainder we need
    const size_t full_patterns = width / pattern_len;
    const size_t remainder = width % pattern_len;

    shape[i].reserve(width);
    for (size_t p = 0; p < full_patterns; ++p) {
      shape[i] += original;
    }
    if (remainder > 0) {
      shape[i] += original.substr(0, remainder);
    }

    // Create color line
    colorLines[i].assign(shape[i].size(), WATERLINE_COLOR);
  }

  // Initialize cache vectors
  cached_image.assign(shape.begin(), shape.end());
  cached_mask.assign(colorLines.begin(), colorLines.end());
}

void Waterline::update() noexcept {
  // Use cached probability calculations
  static constexpr float thresholds[NUM_WAVE_LAYERS] = {
      0.0f, // Layer 0 never moves
      0.25f / WAVE_MOVE_CHANCE, 0.5f / WAVE_MOVE_CHANCE,
      0.75f / WAVE_MOVE_CHANCE};

  for (size_t i = 1; i < NUM_WAVE_LAYERS; ++i) {
    if (Random::floatInRange(0.0f, 1.0f) < thresholds[i]) {
      if (Random::intInRange(0, 1) == 0) {
        shiftStringLeft(shape[i]);
      } else {
        shiftStringRight(shape[i]);
      }
    }
  }

  // Update cached vectors
  std::copy(shape.begin(), shape.end(), cached_image.begin());
  std::copy(colorLines.begin(), colorLines.end(), cached_mask.begin());
}

void Waterline::shiftStringLeft(std::string &str) {
  if (!str.empty()) {
    char first = str.front();
    str.erase(0, 1);
    str.push_back(first);
  }
}

void Waterline::shiftStringRight(std::string &str) {
  if (!str.empty()) {
    char last = str.back();
    str.pop_back();
    str.insert(0, 1, last);
  }
}

const std::vector<std::string> &Waterline::getImage() const {
  return cached_image;
}

const std::vector<std::string> &Waterline::getMask() const {
  return cached_mask;
}