#include "rain.h"
#include "constants.h"
#include "overlay.h"

typedef struct {
    bool reached_bottom = false;
    int y;
    int length;
    int speed;
    unsigned long last_moved;
} Raindrop;

Raindrop raindrops[PANEL_WIDTH];
bool rain_initialized = false;

void setup_rain() {
  for (int i = 0; i<PANEL_WIDTH; i++) {
      raindrops[i].y = 0 - random(24);
      raindrops[i].length = random(20, 28);
      raindrops[i].speed = random(25, 100);
      raindrops[i].last_moved = millis();
  }
}

void draw_rain(MatrixPanel_I2S_DMA *matrix, Mode mode) {
  //matrix ->drawBitmap(0, 0, overlay, 64, 32, matrix->color565(64, 0, 0));
  if (!rain_initialized) {
    setup_rain();
    rain_initialized = true;
  }
  unsigned long timestamp = millis();
  for (int x = 0; x < PANEL_WIDTH; x++) {
    if ((timestamp - raindrops[x].last_moved) > raindrops[x].speed) {
      // step down a pixel
      raindrops[x].y++;
      raindrops[x].last_moved = timestamp;
    }
    if (raindrops[x].y > PANEL_HEIGHT) {
      raindrops[x].y = 0;
      raindrops[x].reached_bottom = true;
    }
    if (raindrops[x].y >= 0) {
      //draw our pixel
      matrix->drawPixel(x, raindrops[x].y, matrix->color565(128, 255, 128));
      // draw our trail
      for (int trail_offset = 1; trail_offset < raindrops[x].length; trail_offset++) {
        int trail_y = raindrops[x].y - trail_offset;
        if (trail_y >= 0) {
          int pixel_num = (trail_y * PANEL_WIDTH) + x;
          if (overlay[ pixel_num / 8 ] & (1 << (7 - (pixel_num % 8)) ) and mode != Stealth) {
            if (mode == HighVis) {
              matrix->drawPixel(x, trail_y, matrix->color565(128, 255, 128));
            } else {
              matrix->drawPixel(x, trail_y, matrix->color565(
                      (128 / raindrops[x].length) * (raindrops[x].length - trail_offset), 
                      (255 / raindrops[x].length) * (raindrops[x].length - trail_offset),
                      (128 / raindrops[x].length) * (raindrops[x].length - trail_offset))
              );
            }
          } else {
            matrix->drawPixel(x, trail_y, matrix->color565(0, (255 / raindrops[x].length) * (raindrops[x].length - trail_offset), 0));
          }
        } else if (raindrops[x].reached_bottom) {
          int pixel_num = ((PANEL_HEIGHT + trail_y) * PANEL_WIDTH) + x;
          if (raindrops[x].y >= 0) {

            if (overlay[ pixel_num / 8 ] & (1 << (7 - (pixel_num % 8)) ) and mode != Stealth) {
              if (mode == HighVis) {
                matrix->drawPixel(x, PANEL_HEIGHT + trail_y, matrix->color565(128, 255, 128));
              } else {
                matrix->drawPixel(x, PANEL_HEIGHT + trail_y, matrix->color565(
                      (128 / raindrops[x].length) * (raindrops[x].length - trail_offset), 
                      (255 / raindrops[x].length) * (raindrops[x].length - trail_offset),
                      (128 / raindrops[x].length) * (raindrops[x].length - trail_offset))
                );
              }
            } else {
              matrix->drawPixel(x, PANEL_HEIGHT + trail_y, matrix->color565(0,(255 / raindrops[x].length) * (raindrops[x].length - trail_offset), 0));
            }
          } else {
            break;
          }
        }
      }
    }
  }
}