#include <SDL2/SDL.h>
#include <stdio.h>

void drawPaddle(SDL_Renderer *renderer, int paddleX, int paddleWidth);

int main(void) {

  /*
   * RETURN CODES
   *  0: Success
   *  1: SDL init fail
   *  2: Error creating Window
   *  3: Error creating renderer
   *
   */
  
  /* ----------------
   *  SDL Init
   * ----------------
   */
  if (SDL_Init(SDL_INIT_EVERYTHING)!=0) {
    perror("[FAILED] Initialising SLD");
    return 1;
  }

  int go; //Var for loop control
  
  /* ----------------
   *  Main Window
   * ----------------
   * Create the main output Window for SDL
   */

  // Window vars
  int winPosX = 100; int winPosY = 100;
  int winWidth = 640; int winHeight = 480;

  SDL_Window *window1 = SDL_CreateWindow(
    "Main Window",
    winPosX, winPosY,
    winWidth, winHeight,
    SDL_WINDOW_SHOWN
  );
  if (window1==NULL) {
    perror("[FAILED] Creating Window window1");
    return 2; //Error creating Window
  }

  /*
   * ----------------
   *  Renderer
   * ----------------
   * Creates the main renderer (tied to main window)
   */

  SDL_Renderer * renderer1 = SDL_CreateRenderer(window1, -1, 0);
  if (renderer1==NULL) {
    perror("[FAILED] Creating renderer renderer1 for window1");
    return 3;
  }

  /*
   * ----------------
   *  Game variables
   * ----------------
   */
   
  char moveX=0;

  int paddleWidth=100;
  int paddleX=(winWidth/2)-(paddleWidth/2);

  SDL_SetRenderDrawColor(renderer1, 0x22, 0x22, 0x22, 0xFF); //RGBA
  SDL_RenderClear(renderer1);

  go=1;
  while(go) {

    /*
     * ----------------
     *  Event handling
     * ----------------
     */
    SDL_Event incomingEvent;
    while (SDL_PollEvent(&incomingEvent)) {
      switch (incomingEvent.type) {
        case SDL_QUIT:
          // User requested program quit - e.g. window close
          go=0;
          break;
        case SDL_KEYDOWN:
          switch(incomingEvent.key.keysym.sym) {
            case SDLK_ESCAPE:
              go=0;
              break;
            case SDLK_LEFT:
              moveX=-1;
              break;
            case SDLK_RIGHT:
              moveX=1;
              break;
          }
          break;
        case SDL_KEYUP:
          switch(incomingEvent.key.keysym.sym) {
            case SDLK_LEFT:
              moveX=0;
              break;
            case SDLK_RIGHT:
              moveX=0;
              break;
          }
          break;
      }
    }
    
    paddleX+=moveX*1;

    /*
     * ----------------
     *  Draw to buffer
     * ----------------
     */
    SDL_SetRenderDrawColor(renderer1, 0x22, 0x22, 0x22, 0xFF); //RGBA
    SDL_RenderClear(renderer1);

    drawPaddle(renderer1, paddleX, paddleWidth);
    
    /*
     * --------------------------------
     *  Output to Window
     * --------------------------------
     */
     SDL_RenderPresent(renderer1);
     SDL_Delay(6);
  }
 
  /*
   * --------------------------------
   *  Clean up after ourselves
   * --------------------------------
   */
   SDL_DestroyWindow(window1);
   SDL_Quit();

  return 0;
}

void drawPaddle(SDL_Renderer *renderer, int paddleX, int paddleWidth) {
  SDL_SetRenderDrawColor(renderer, 0x66, 0x66, 0x66, 0xFF);
  for (int i=paddleX; i<(paddleX+paddleWidth); i++) {
    for (int j=0; j<10; j++) {
      SDL_RenderDrawPoint(renderer,i,j+480-20);
   }
  }
}