/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2012 - Hans-Kristian Arntzen
 *
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "SDL.h"
#include "../driver.h"
#include <stdlib.h>
#include <string.h>
#include "../general.h"
#include "scaler/scaler.h"
#include "gfx_common.h"
#include "gfx_context.h"

#ifdef HAVE_X11
#include "context/x11_common.h"
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_FREETYPE
#include "fonts/fonts.h"
#endif

#ifndef __APPLE__ // Broken on OSX.
#include "SDL/SDL_syswm.h"
#endif

static void convert_16bit_16bit_direct(uint16_t *out, unsigned outpitch, const uint16_t *input, unsigned width, unsigned height, unsigned pitch, const SDL_PixelFormat *fmt);
static void convert_32bit_32bit_direct(uint32_t *out, unsigned outpitch, const uint32_t *input, unsigned width, unsigned height, unsigned pitch, const SDL_PixelFormat *fmt);
static void convert_16bit_16bit_shift(uint16_t *out, unsigned outpitch, const uint16_t *input, unsigned width, unsigned height, unsigned pitch, const SDL_PixelFormat *fmt);
static void convert_32bit_32bit_shift(uint32_t *out, unsigned outpitch, const uint32_t *input, unsigned width, unsigned height, unsigned pitch, const SDL_PixelFormat *fmt);

typedef struct sdl_video
{
   SDL_Surface *screen, *buffer;
   bool quitting;
   bool rgb32;
   bool upsample;

   bool render32;

   void (*convert_16_func)(uint16_t*, unsigned, const uint16_t*, unsigned, unsigned, unsigned, const SDL_PixelFormat*);
   void (*convert_32_func)(uint32_t*, unsigned, const uint32_t*, unsigned, unsigned, unsigned, const SDL_PixelFormat*);

#ifdef HAVE_FREETYPE
   font_renderer_t *font;
   uint8_t font_r;
   uint8_t font_g;
   uint8_t font_b;
#endif

   struct scaler_ctx scaler;
   unsigned last_width;
   unsigned last_height;
} sdl_video_t;

static void sdl_gfx_free(void *data)
{
   sdl_video_t *vid = (sdl_video_t*)data;
   if (!vid)
      return;

   if (vid->buffer)
      SDL_FreeSurface(vid->buffer);

   SDL_QuitSubSystem(SDL_INIT_VIDEO);

#ifdef HAVE_FREETYPE
   if (vid->font)
      font_renderer_free(vid->font);
#endif

   scaler_ctx_gen_reset(&vid->scaler);

   free(vid);
}

static void sdl_init_font(sdl_video_t *vid, const char *font_path, unsigned font_size)
{
#ifdef HAVE_FREETYPE
   if (!g_settings.video.font_enable)
      return;

   const char *path = font_path;
   if (!*path)
      path = font_renderer_get_default_font();

   if (path)
   {
      vid->font = font_renderer_new(path, font_size);
      if (vid->font)
      {
         int r = g_settings.video.msg_color_r * 255;
         int g = g_settings.video.msg_color_g * 255;
         int b = g_settings.video.msg_color_b * 255;

         r = r < 0 ? 0 : (r > 255 ? 255 : r);
         g = g < 0 ? 0 : (g > 255 ? 255 : g);
         b = b < 0 ? 0 : (b > 255 ? 255 : b);

         // RGB888 -> RGB565
         if (!vid->render32)
         {
            r >>= 3;
            g >>= 2;
            b >>= 3;
         }

         vid->font_r = r;
         vid->font_g = g;
         vid->font_b = b;
      }
      else
         RARCH_WARN("Failed to init font.\n");
   }
   else
      RARCH_LOG("Did not find default font.\n");
#else
   (void)vid;
   (void)font_path;
   (void)font_size;
#endif
}

// Not very optimized, but hey :D
static void sdl_render_msg_16(sdl_video_t *vid, SDL_Surface *buffer, const char *msg, unsigned width, unsigned height, const SDL_PixelFormat *fmt)
{
#ifdef HAVE_FREETYPE
   if (!vid->font)
      return;

   struct font_output_list out;
   font_renderer_msg(vid->font, msg, &out);
   struct font_output *head = out.head;

   int msg_base_x = g_settings.video.msg_pos_x * width;
   int msg_base_y = (1.0 - g_settings.video.msg_pos_y) * height;

   unsigned rshift = fmt->Rshift;
   unsigned gshift = fmt->Gshift;
   unsigned bshift = fmt->Bshift;

   for (; head; head = head->next)
   {
      int base_x = msg_base_x + head->off_x;
      int base_y = msg_base_y - head->off_y - head->height;

      int glyph_width  = head->width;
      int glyph_height = head->height;

      const uint8_t *src = head->output;

      if (base_x < 0)
      {
         src -= base_x;
         glyph_width += base_x;
         base_x = 0;
      }

      if (base_y < 0)
      {
         src -= base_y * (int)head->pitch;
         glyph_height += base_y;
         base_y = 0;
      }

      int max_width  = width - base_x;
      int max_height = height - base_y;

      if (max_width <= 0 || max_height <= 0)
         continue;

      if (glyph_width > max_width)
         glyph_width = max_width;
      if (glyph_height > max_height)
         glyph_height = max_height;

      uint16_t *out = (uint16_t*)buffer->pixels + base_y * (buffer->pitch >> 1) + base_x;

      for (int y = 0; y < glyph_height; y++, src += head->pitch, out += buffer->pitch >> 1)
      {
         for (int x = 0; x < glyph_width; x++)
         {
            unsigned blend = src[x];
            unsigned out_pix = out[x];
            unsigned r = (out_pix >> rshift) & 0x1f;
            unsigned g = (out_pix >> gshift) & 0x3f;
            unsigned b = (out_pix >> bshift) & 0x1f;

            unsigned out_r = (r * (256 - blend) + vid->font_r * blend) >> 8;
            unsigned out_g = (g * (256 - blend) + vid->font_g * blend) >> 8;
            unsigned out_b = (b * (256 - blend) + vid->font_b * blend) >> 8;
            out[x] = (out_r << rshift) | (out_g << gshift) | (out_b << bshift);
         }
      }
   }

   font_renderer_free_output(&out);

#else
   (void)vid;
   (void)buffer;
   (void)msg;
   (void)width;
   (void)height;
#endif
}

static void sdl_render_msg_32(sdl_video_t *vid, SDL_Surface *buffer, const char *msg, unsigned width, unsigned height, const SDL_PixelFormat *fmt)
{
#ifdef HAVE_FREETYPE
   if (!vid->font)
      return;

   struct font_output_list out;
   font_renderer_msg(vid->font, msg, &out);
   struct font_output *head = out.head;

   int msg_base_x = g_settings.video.msg_pos_x * width;
   int msg_base_y = (1.0 - g_settings.video.msg_pos_y) * height;

   unsigned rshift = fmt->Rshift;
   unsigned gshift = fmt->Gshift;
   unsigned bshift = fmt->Bshift;

   for (; head; head = head->next)
   {
      int base_x = msg_base_x + head->off_x;
      int base_y = msg_base_y - head->off_y - head->height;

      int glyph_width  = head->width;
      int glyph_height = head->height;

      const uint8_t *src = head->output;

      if (base_x < 0)
      {
         src -= base_x;
         glyph_width += base_x;
         base_x = 0;
      }

      if (base_y < 0)
      {
         src -= base_y * (int)head->pitch;
         glyph_height += base_y;
         base_y = 0;
      }

      int max_width  = width - base_x;
      int max_height = height - base_y;

      if (max_width <= 0 || max_height <= 0)
         continue;

      if (glyph_width > max_width)
         glyph_width = max_width;
      if (glyph_height > max_height)
         glyph_height = max_height;

      uint32_t *out = (uint32_t*)buffer->pixels + base_y * (buffer->pitch >> 2) + base_x;

      for (int y = 0; y < glyph_height; y++, src += head->pitch, out += buffer->pitch >> 2)
      {
         for (int x = 0; x < glyph_width; x++)
         {
            unsigned blend = src[x];
            unsigned out_pix = out[x];
            unsigned r = (out_pix >> rshift) & 0xff;
            unsigned g = (out_pix >> gshift) & 0xff;
            unsigned b = (out_pix >> bshift) & 0xff;

            unsigned out_r = (r * (256 - blend) + vid->font_r * blend) >> 8;
            unsigned out_g = (g * (256 - blend) + vid->font_g * blend) >> 8;
            unsigned out_b = (b * (256 - blend) + vid->font_b * blend) >> 8;
            out[x] = (out_r << rshift) | (out_g << gshift) | (out_b << bshift);
         }
      }
   }

   font_renderer_free_output(&out);

#else
   (void)vid;
   (void)buffer;
   (void)msg;
   (void)width;
   (void)height;
#endif
}

static void sdl_gfx_set_handles(void)
{
   // SysWMinfo headers are broken on OSX. :(
#if defined(_WIN32)
   SDL_SysWMinfo info;
   SDL_VERSION(&info.version);

   if (SDL_GetWMInfo(&info) == 1)
   {
      driver.display_type  = RARCH_DISPLAY_WIN32;
      driver.video_display = 0;
      driver.video_window  = (uintptr_t)info.window;
   }
#elif defined(HAVE_X11)
   SDL_SysWMinfo info;
   SDL_VERSION(&info.version);

   if (SDL_GetWMInfo(&info) == 1)
   {
      driver.display_type  = RARCH_DISPLAY_X11;
      driver.video_display = (uintptr_t)info.info.x11.display;
      driver.video_window  = (uintptr_t)info.info.x11.window;
   }
#endif
}

static void *sdl_gfx_init(const video_info_t *video, const input_driver_t **input, void **input_data)
{
#ifdef _WIN32
   gfx_set_dwm();
#endif

   SDL_InitSubSystem(SDL_INIT_VIDEO);

   sdl_video_t *vid = (sdl_video_t*)calloc(1, sizeof(*vid));
   if (!vid)
      return NULL;

   const SDL_VideoInfo *video_info = SDL_GetVideoInfo();
   rarch_assert(video_info);
   unsigned full_x = video_info->current_w;
   unsigned full_y = video_info->current_h;
   RARCH_LOG("Detecting desktop resolution %ux%u.\n", full_x, full_y);

   void *sdl_input = NULL;
   const SDL_PixelFormat *fmt = NULL;

   if (!video->fullscreen)
      RARCH_LOG("Creating window @ %ux%u\n", video->width, video->height);

   vid->render32 = !g_settings.video.force_16bit;
   vid->screen = SDL_SetVideoMode(video->width, video->height, vid->render32 ? 32 : 16, SDL_HWSURFACE | SDL_HWACCEL | SDL_DOUBLEBUF | (video->fullscreen ? SDL_FULLSCREEN : 0));

   if (!vid->screen)
   {
      RARCH_ERR("Failed to init SDL surface: %s\n", SDL_GetError());
      goto error;
   }

   if (!video->rgb32 && vid->render32)
      vid->upsample = true;

   SDL_ShowCursor(SDL_DISABLE);

   fmt = vid->screen->format;
   if (vid->render32)
   {
      RARCH_LOG("SDL: Creating 32-bit buffer.\n");
      vid->buffer = SDL_CreateRGBSurface(SDL_SWSURFACE, RARCH_SCALE_BASE * video->input_scale,
            RARCH_SCALE_BASE * video->input_scale, 32,
            fmt->Rmask, fmt->Bmask, fmt->Gmask, fmt->Amask);
   }
   else
   {
      RARCH_LOG("SDL: Creating 16-bit buffer.\n");
      vid->buffer = SDL_CreateRGBSurface(SDL_SWSURFACE, RARCH_SCALE_BASE * video->input_scale,
            RARCH_SCALE_BASE * video->input_scale, 16,
            fmt->Rmask, fmt->Gmask, fmt->Bmask, fmt->Amask);
   }
   RARCH_LOG("[Debug]: SDL Pixel format: Rshift = %u, Gshift = %u, Bshift = %u\n",
         (unsigned)fmt->Rshift, (unsigned)fmt->Gshift, (unsigned)fmt->Bshift);

   if (!vid->buffer)
   {
      RARCH_ERR("SDL_CreateRGBSurface failed: %s\n", SDL_GetError());
      goto error;
   }

   sdl_gfx_set_handles();

   sdl_input = input_sdl.init();
   if (sdl_input)
   {
      *input = &input_sdl;
      *input_data = sdl_input;
   }
   else
   {
      *input = NULL;
      *input_data = NULL;
   }

   vid->rgb32 = video->rgb32;

   sdl_init_font(vid, g_settings.video.font_path, g_settings.video.font_size);

   if (fmt->Rshift == 11 && fmt->Gshift ==  5 && fmt->Bshift == 0) // RGB565
   {
      RARCH_LOG("SDL: 16-bit format matches. Fast blit.\n");
      vid->convert_16_func = convert_16bit_16bit_direct;
   }
   else
   {
      RARCH_LOG("SDL: 16-bit format does not match. Needs conversion.\n");
      vid->convert_16_func = convert_16bit_16bit_shift;
   }

   if (fmt->Rshift == 16 && fmt->Gshift == 8 && fmt->Bshift == 0) // ARGB8888
   {
      RARCH_LOG("SDL: 32-bit format matches. Fast blit.\n");
      vid->convert_32_func = convert_32bit_32bit_direct;
   }
   else
   {
      RARCH_LOG("SDL: 32-bit format does not match. Needs conversion.\n");
      vid->convert_32_func = convert_32bit_32bit_shift;
   }

   vid->scaler.scaler_type = video->smooth ? SCALER_TYPE_BILINEAR : SCALER_TYPE_POINT;
   vid->scaler.in_fmt  = vid->render32 ? SCALER_FMT_ARGB8888 : SCALER_FMT_RGB565;
   vid->scaler.out_fmt = vid->scaler.in_fmt;

   return vid;

error:
   sdl_gfx_free(vid);
   return NULL;
}

static inline uint16_t conv_pixel_32_16(uint32_t pix, const SDL_PixelFormat *fmt)
{
   uint16_t r = ((pix & 0x00f80000) >> 18) << fmt->Rshift;
   uint16_t g = ((pix & 0x0000fc00) >> 10) << fmt->Gshift;
   uint16_t b = ((pix & 0x000000f8) >>  3) << fmt->Bshift;
   return r | g | b;
}

static inline uint32_t conv_pixel_16_32(uint16_t pix, const SDL_PixelFormat *fmt)
{
   uint32_t r = (pix >> 11) & 0x1f;
   uint32_t g = (pix >>  5) & 0x3f;
   uint32_t b = (pix >>  0) & 0x1f;

   r = (r << 3) | (r >> 2);
   g = (g << 2) | (g >> 4);
   b = (b << 3) | (b >> 2);

   return (r << fmt->Rshift) | (g << fmt->Gshift) | (b << fmt->Bshift);
}

static void convert_32bit_16bit(uint16_t *out, unsigned outpitch,
      const uint32_t *input, unsigned width, unsigned height,
      unsigned pitch, const SDL_PixelFormat *fmt)
{
   for (unsigned y = 0; y < height; y++)
   {
      for (unsigned x = 0; x < width; x++)
         out[x] = conv_pixel_32_16(input[x], fmt);

      out += outpitch >> 1;
      input += pitch >> 2;
   }
}

static void convert_16bit_32bit(uint32_t *out, unsigned outpitch,
      const uint16_t *input, unsigned width, unsigned height,
      unsigned pitch, const SDL_PixelFormat *fmt)
{
   for (unsigned y = 0; y < height; y++)
   {
      for (unsigned x = 0; x < width; x++)
         out[x] = conv_pixel_16_32(input[x], fmt);

      out += outpitch >> 2;
      input += pitch >> 1;
   }
}

static void convert_16bit_16bit_direct(uint16_t *out, unsigned outpitch,
      const uint16_t *input, unsigned width, unsigned height,
      unsigned pitch, const SDL_PixelFormat *fmt)
{
   for (unsigned y = 0; y < height; y++)
   {
      uint16_t *dest = out + ((y * outpitch) >> 1);
      const uint16_t *src = input + ((y * pitch) >> 1);
      memcpy(dest, src, width * sizeof(uint16_t));
   }
   (void)fmt;
}

static void convert_32bit_32bit_direct(uint32_t *out, unsigned outpitch,
      const uint32_t *input, unsigned width, unsigned height,
      unsigned pitch, const SDL_PixelFormat *fmt)
{
   for (unsigned y = 0; y < height; y++)
   {
      uint32_t *dest = out + ((y * outpitch) >> 2);
      const uint32_t *src = input + ((y * pitch) >> 2);
      memcpy(dest, src, width * sizeof(uint32_t));
   }
   (void)fmt;
}

static void convert_16bit_16bit_shift(uint16_t *out, unsigned outpitch,
      const uint16_t *input, unsigned width, unsigned height,
      unsigned pitch, const SDL_PixelFormat *fmt)
{
   for (unsigned y = 0; y < height; y++)
   {
      uint16_t *dest      = out + ((y * outpitch) >> 1);
      const uint16_t *src = input + ((y * pitch) >> 1);

      for (unsigned x = 0; x < width; x++)
      {
         uint16_t color = src[x];
         uint16_t r = ((color >> 11) & 0x1f) << fmt->Rshift;
         uint16_t g = ((color >>  5) & 0x3f) << fmt->Gshift;
         uint16_t b = ((color >>  0) & 0x1f) << fmt->Bshift;
         dest[x] = r | g | b;
      }
   }
}

static void convert_32bit_32bit_shift(uint32_t *out, unsigned outpitch,
      const uint32_t *input, unsigned width, unsigned height,
      unsigned pitch, const SDL_PixelFormat *fmt)
{
   for (unsigned y = 0; y < height; y++)
   {
      uint32_t *dest      = out + ((y * outpitch) >> 2);
      const uint32_t *src = input + ((y * pitch) >> 2);

      for (unsigned x = 0; x < width; x++)
      {
         uint32_t color = src[x];
         uint32_t r = ((color >> 16) & 0xff) << fmt->Rshift;
         uint32_t g = ((color >>  8) & 0xff) << fmt->Gshift;
         uint32_t b = ((color >>  0) & 0xff) << fmt->Bshift;
         dest[x] = r | g | b;
      }
   }
}

static void check_window(sdl_video_t *vid)
{
   SDL_Event event;
   while (SDL_PollEvent(&event))
   {
      switch (event.type)
      {
         case SDL_QUIT:
            vid->quitting = true;
            break;

         default:
            break;
      }
   }
}

static bool sdl_gfx_frame(void *data, const void *frame, unsigned width, unsigned height, unsigned pitch, const char *msg)
{
   if (!frame)
      return true;

   sdl_video_t *vid = (sdl_video_t*)data;

   if (SDL_MUSTLOCK(vid->buffer))
      SDL_LockSurface(vid->buffer);

   // 15-bit -> 32-bit.
   if (vid->upsample)
      convert_16bit_32bit((uint32_t*)vid->buffer->pixels, vid->buffer->pitch, (const uint16_t*)frame, width, height, pitch, vid->screen->format);
   // 15-bit -> 15-bit
   else if (!vid->rgb32)
      vid->convert_16_func((uint16_t*)vid->buffer->pixels, vid->buffer->pitch, (const uint16_t*)frame, width, height, pitch, vid->screen->format);
   // 32-bit -> 15-bit
   else if (vid->rgb32 && !vid->render32)
      convert_32bit_16bit((uint16_t*)vid->buffer->pixels, vid->buffer->pitch, (const uint32_t*)frame, width, height, pitch, vid->screen->format);
   // 32-bit -> 32-bit
   else
      vid->convert_32_func((uint32_t*)vid->buffer->pixels, vid->buffer->pitch, (const uint32_t*)frame, width, height, pitch, vid->screen->format);

   if (width != vid->last_width || height != vid->last_height)
   {
      vid->scaler.in_width  = width;
      vid->scaler.in_height = height;
      vid->scaler.in_stride = vid->buffer->pitch;

      vid->scaler.out_width  = vid->screen->w;
      vid->scaler.out_height = vid->screen->h;
      vid->scaler.out_stride = vid->screen->pitch;

      scaler_ctx_gen_filter(&vid->scaler);

      vid->last_width  = width;
      vid->last_height = height;
   }

   if (SDL_MUSTLOCK(vid->screen))
      SDL_LockSurface(vid->screen);

   scaler_ctx_scale(&vid->scaler, vid->screen->pixels, vid->buffer->pixels);

   if (SDL_MUSTLOCK(vid->buffer))
      SDL_UnlockSurface(vid->buffer);
   if (SDL_MUSTLOCK(vid->screen))
      SDL_UnlockSurface(vid->screen);

   if (msg)
   {
      if (vid->render32)
         sdl_render_msg_32(vid, vid->screen, msg, vid->screen->w, vid->screen->h, vid->screen->format);
      else
         sdl_render_msg_16(vid, vid->screen, msg, vid->screen->w, vid->screen->h, vid->screen->format);
   }

   char buf[128];
   if (gfx_window_title(buf, sizeof(buf)))
      SDL_WM_SetCaption(buf, NULL);

   SDL_Flip(vid->screen);

   return true;
}

static void sdl_gfx_set_nonblock_state(void *data, bool state)
{
   (void)data; // Can SDL even do this?
   (void)state;
}

static bool sdl_gfx_alive(void *data)
{
   sdl_video_t *vid = (sdl_video_t*)data;
   check_window(vid);
   return !vid->quitting;
}

static bool sdl_gfx_focus(void *data)
{
   (void)data;
   return (SDL_GetAppState() & (SDL_APPINPUTFOCUS | SDL_APPACTIVE)) == (SDL_APPINPUTFOCUS | SDL_APPACTIVE);
}

const video_driver_t video_sdl = {
   sdl_gfx_init,
   sdl_gfx_frame,
   sdl_gfx_set_nonblock_state,
   sdl_gfx_alive,
   sdl_gfx_focus,
   NULL,
   sdl_gfx_free,
   "sdl"
};