#include "draw-text.h"
#include "util.h"

static SDL_Rect
text_get_rect(
  SDL_Renderer * const renderer,
  TTF_Font * const font,
  const text_style_t * const style,
  const char * const buf
) {
  // get renderer size
  int renderer_w, renderer_h;
  if (SDL_GetRendererOutputSize(renderer, &renderer_w, &renderer_h)) {
    die("SDL_GetRendererOutputSize(): %s", SDL_GetError());
  }

  // get text size
  int text_w, text_h;
  if (TTF_SizeText(font, buf, &text_w, &text_h)) {
    die("TTF_SizeText(): %s", TTF_GetError());
  }

  // build rect
  switch (style->align) {
  case TEXT_ALIGN_TOP_LEFT:
    return (SDL_Rect) { 
      .x = style->pad.x,
      .y = style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_TOP_CENTER:
    return (SDL_Rect) {
      .x = (renderer_w - text_w) / 2 + style->pad.x,
      .y = style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_TOP_RIGHT:
    return (SDL_Rect) {
      .x = renderer_w - text_w - style->pad.x,
      .y = style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_CENTER_LEFT:
    return (SDL_Rect) {
      .x = style->pad.x,
      .y = (renderer_h - text_h) / 2 + style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_CENTER_CENTER:
    return (SDL_Rect) {
      .x = (renderer_w - text_w) / 2 + style->pad.x,
      .y = (renderer_h - text_h) / 2 + style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_CENTER_RIGHT:
    return (SDL_Rect) {
      .x = renderer_w - text_w - style->pad.x,
      .y = (renderer_h - text_h) / 2 + style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_BOTTOM_LEFT:
    return (SDL_Rect) {
      .x = style->pad.x,
      .y = renderer_h - text_h - style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_BOTTOM_CENTER:
    return (SDL_Rect) {
      .x = (renderer_w - text_w) / 2 + style->pad.x,
      .y = renderer_h - text_h - style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  case TEXT_ALIGN_BOTTOM_RIGHT:
    return (SDL_Rect) {
      .x = renderer_w - text_w - style->pad.x,
      .y = renderer_h - text_h - style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  default:
    return (SDL_Rect) {
      .x = style->pad.x,
      .y = style->pad.y,
      .w = text_w,
      .h = text_h,
    };
  }
}

void
draw_text(
  SDL_Renderer * const renderer,
  TTF_Font * const font,
  const text_style_t * const style,
  const char * const buf
) {
  // get rect
  const SDL_Rect rect = text_get_rect(renderer, font, style, buf);

  // create surface, check for error
  SDL_Surface *surface = TTF_RenderText_Shaded(font, buf, style->colors[0], style->colors[1]);
  if (!surface) {
    die("TTF_RenderText_Blended(): %s", TTF_GetError());
  }

  // create texture, check for error
  SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, surface);
  if (!texture) {
    die("SDL_CreateTextureFromSurface(): %s", SDL_GetError());
  }

  // free surface
  SDL_FreeSurface(surface);

  // render text
  if (SDL_RenderCopy(renderer, texture, NULL, &rect)) {
    die("SDL_RenderCopy(): %s", SDL_GetError());
  }

  // free texture
  SDL_DestroyTexture(texture);
}