/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *  Copyright (C) 2011-2017 - Higor Euripedes
 *
 *  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 <stdlib.h>
#include <string.h>

#include <retro_inline.h>
#include <gfx/scaler/scaler.h>

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

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

#ifdef HAVE_MENU
#include "../../menu/menu_driver.h"
#endif

#include "SDL.h"
#include "SDL_syswm.h"
#include "../common/sdl2_common.h"

#include "../font_driver.h"

#include "../../configuration.h"
#include "../../retroarch.h"
#include "../../verbosity.h"

/*
 * FORWARD DECLARATIONS
 */

static void sdl2_gfx_free(void *data);

static INLINE void sdl_tex_zero(sdl2_tex_t *t)
{
   if (t->tex)
      SDL_DestroyTexture(t->tex);

   t->tex = NULL;
   t->w = t->h = t->pitch = 0;
}

static void sdl2_init_font(sdl2_video_t *vid, const char *font_path,
      unsigned font_size)
{
   int i, r, g, b;
   SDL_Color colors[256];
   SDL_Surface               *tmp = NULL;
   SDL_Palette               *pal = NULL;
   const struct font_atlas *atlas = NULL;
   settings_t           *settings = config_get_ptr();
   bool video_font_enable         = settings->bools.video_font_enable;
   float msg_color_r              = settings->floats.video_msg_color_r;
   float msg_color_g              = settings->floats.video_msg_color_g;
   float msg_color_b              = settings->floats.video_msg_color_b;

   if (!video_font_enable)
      return;

   if (!font_renderer_create_default(
            &vid->font_driver, &vid->font_data,
            *font_path ? font_path : NULL, font_size))
   {
      RARCH_WARN("[SDL]: Could not initialize fonts.\n");
      return;
   }

   r           = msg_color_r * 255;
   g           = msg_color_g * 255;
   b           = 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);

   vid->font_r = r;
   vid->font_g = g;
   vid->font_b = b;

   atlas       = vid->font_driver->get_atlas(vid->font_data);

   tmp         = SDL_CreateRGBSurfaceFrom(
         atlas->buffer, atlas->width,
         atlas->height, 8, atlas->width,
         0, 0, 0, 0);

   for (i = 0; i < 256; ++i)
   {
      colors[i].r = colors[i].g = colors[i].b = i;
      colors[i].a = 255;
   }

   pal = SDL_AllocPalette(256);
   SDL_SetPaletteColors(pal, colors, 0, 256);
   SDL_SetSurfacePalette(tmp, pal);
   SDL_SetColorKey(tmp, SDL_TRUE, 0);

   vid->font.tex  = SDL_CreateTextureFromSurface(vid->renderer, tmp);

   if (vid->font.tex)
   {
      vid->font.w      = atlas->width;
      vid->font.h      = atlas->height;
      vid->font.active = true;

      SDL_SetTextureBlendMode(vid->font.tex, SDL_BLENDMODE_ADD);
   }
   else
      RARCH_WARN("[SDL]: Failed to initialize font texture: %s\n", SDL_GetError());

   SDL_FreePalette(pal);
   SDL_FreeSurface(tmp);
}

static void sdl2_render_msg(sdl2_video_t *vid, const char *msg)
{
   int delta_x          = 0;
   int delta_y          = 0;
   unsigned      width  = vid->vp.width;
   unsigned      height = vid->vp.height;
   settings_t *settings = config_get_ptr();
   float msg_pos_x      = settings->floats.video_msg_pos_x;
   float msg_pos_y      = settings->floats.video_msg_pos_y;
   int x                = msg_pos_x * width;
   int y                = (1.0f - msg_pos_y) * height;

   if (!vid->font_data)
      return;

   SDL_SetTextureColorMod(vid->font.tex,
         vid->font_r, vid->font_g, vid->font_b);

   for (; *msg; msg++)
   {
      SDL_Rect src_rect, dst_rect;
      int off_x, off_y, tex_x, tex_y;
      const struct font_glyph *gly =
         vid->font_driver->get_glyph(vid->font_data, (uint8_t)*msg);

      if (!gly)
         gly = vid->font_driver->get_glyph(vid->font_data, '?');

      if (!gly)
         continue;

      off_x      = gly->draw_offset_x;
      off_y      = gly->draw_offset_y;
      tex_x      = gly->atlas_offset_x;
      tex_y      = gly->atlas_offset_y;

      src_rect.x = tex_x;
      src_rect.y = tex_y;
      src_rect.w = (int)gly->width;
      src_rect.h = (int)gly->height;

      dst_rect.x = x + delta_x + off_x;
      dst_rect.y = y + delta_y + off_y;
      dst_rect.w = (int)gly->width;
      dst_rect.h = (int)gly->height;

      SDL_RenderCopyEx(vid->renderer, vid->font.tex,
            &src_rect, &dst_rect, 0, NULL, SDL_FLIP_NONE);

      delta_x += gly->advance_x;
      delta_y -= gly->advance_y;
   }
}

static void sdl2_init_renderer(sdl2_video_t *vid)
{
   unsigned flags = SDL_RENDERER_ACCELERATED;

   if (vid->video.vsync)
      flags |= SDL_RENDERER_PRESENTVSYNC;

   SDL_ClearHints();
   SDL_SetHintWithPriority(SDL_HINT_RENDER_VSYNC,
                           vid->video.vsync ? "1" : "0", SDL_HINT_OVERRIDE);
   vid->renderer = SDL_CreateRenderer(vid->window, -1, flags);

   if (!vid->renderer)
   {
      RARCH_ERR("[SDL2]: Failed to initialize renderer: %s", SDL_GetError());
      return;
   }

   SDL_SetRenderDrawColor(vid->renderer, 0, 0, 0, 255);
}

static void sdl_refresh_renderer(sdl2_video_t *vid)
{
   SDL_Rect r;

   SDL_RenderClear(vid->renderer);

   r.x      = vid->vp.x;
   r.y      = vid->vp.y;
   r.w      = (int)vid->vp.width;
   r.h      = (int)vid->vp.height;

   SDL_RenderSetViewport(vid->renderer, &r);

   /* breaks int scaling */
#if 0
   SDL_RenderSetLogicalSize(vid->renderer, vid->vp.width, vid->vp.height);
#endif
}

static void sdl_refresh_viewport(sdl2_video_t *vid)
{
   int win_w, win_h;
   settings_t *settings      = config_get_ptr();
   bool video_scale_integer  = settings->bools.video_scale_integer;

   SDL_GetWindowSize(vid->window, &win_w, &win_h);

   vid->vp.x           = 0;
   vid->vp.y           = 0;
   vid->vp.width       = win_w;
   vid->vp.height      = win_h;
   vid->vp.full_width  = win_w;
   vid->vp.full_height = win_h;

   if (video_scale_integer)
      video_viewport_get_scaled_integer(&vid->vp,
            win_w, win_h, video_driver_get_aspect_ratio(),
            vid->video.force_aspect, true);
   else if (vid->video.force_aspect)
   {
      video_viewport_get_scaled_aspect(&vid->vp, win_w, win_h, true);
   }

   vid->flags &= ~SDL2_FLAG_SHOULD_RESIZE;

   sdl_refresh_renderer(vid);
}

static void sdl_refresh_input_size(sdl2_video_t *vid, bool menu, bool rgb32,
      unsigned width, unsigned height, unsigned pitch)
{
   sdl2_tex_t *target = menu ? &vid->menu : &vid->frame;

   if (!target->tex || target->w != width || target->h != height
       || target->rgb32 != rgb32 || target->pitch != pitch)
   {
      unsigned format;

      sdl_tex_zero(target);

      if (menu)
         format = rgb32 ? SDL_PIXELFORMAT_ARGB8888 : SDL_PIXELFORMAT_RGBA4444;
      else /* this assumes the frontend will convert 0RGB1555 to RGB565 */
         format = rgb32 ? SDL_PIXELFORMAT_ARGB8888 : SDL_PIXELFORMAT_RGB565;

      SDL_SetHintWithPriority(SDL_HINT_RENDER_SCALE_QUALITY,
                              (menu ? "nearest" : (vid->video.smooth ? "linear" : "nearest")),
                              SDL_HINT_OVERRIDE);

      target->tex = SDL_CreateTexture(vid->renderer, format,
                                      SDL_TEXTUREACCESS_STREAMING, width, height);

      if (!target->tex)
      {
         RARCH_ERR("[SDL2]: Failed to create %s texture: %s\n", menu ? "menu" : "main",
                   SDL_GetError());
         return;
      }

      if (menu)
         SDL_SetTextureBlendMode(target->tex, SDL_BLENDMODE_BLEND);

      target->w = width;
      target->h = height;
      target->pitch = pitch;
      target->rgb32 = rgb32;

      /* If target is menu, do not override 'active'
       * state (this should only be set by
       * sdl2_poke_texture_enable()) */
      if (!menu)
         target->active = true;
   }
}

static void *sdl2_gfx_init(const video_info_t *video,
      input_driver_t **input, void **input_data)
{
   int i;
   unsigned flags;
   sdl2_video_t *vid            = NULL;
   uint32_t sdl_subsystem_flags = SDL_WasInit(0);
   settings_t *settings         = config_get_ptr();
#if defined(HAVE_X11) || defined(HAVE_WAYLAND)
   const char *video_driver     = NULL;
#endif

#ifdef HAVE_X11
   XInitThreads();
#endif

   /* Initialise graphics subsystem, if required */
   if (sdl_subsystem_flags == 0)
   {
      if (SDL_Init(SDL_INIT_VIDEO) < 0)
         return NULL;
   }
   else if ((sdl_subsystem_flags & SDL_INIT_VIDEO) == 0)
   {
      if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0)
         return NULL;
   }

   vid = (sdl2_video_t*)calloc(1, sizeof(*vid));
   if (!vid)
      return NULL;

   RARCH_LOG("[SDL2]: Available renderers (change with $SDL_RENDER_DRIVER):\n");
   for (i = 0; i < SDL_GetNumRenderDrivers(); ++i)
   {
      SDL_RendererInfo renderer;
      if (SDL_GetRenderDriverInfo(i, &renderer) == 0)
         RARCH_LOG("\t%s\n", renderer.name);
   }

   RARCH_LOG("[SDL2]: Available displays:\n");
   for (i = 0; i < SDL_GetNumVideoDisplays(); ++i)
   {
      SDL_DisplayMode mode;

      if (SDL_GetCurrentDisplayMode(i, &mode) < 0)
         RARCH_LOG("\tDisplay #%i mode: unknown.\n", i);
      else
         RARCH_LOG("\tDisplay #%i mode: %ix%i@%ihz.\n", i, mode.w, mode.h,
                   mode.refresh_rate);
   }

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

   if (video->fullscreen)
      flags = settings->bools.video_windowed_fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : SDL_WINDOW_FULLSCREEN;
   else
      flags = SDL_WINDOW_RESIZABLE;

   vid->window = SDL_CreateWindow("", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                                  video->width, video->height, flags);

   if (!vid->window)
   {
      RARCH_ERR("[SDL2]: Failed to init SDL window: %s\n", SDL_GetError());
      goto error;
   }

   vid->video         = *video;
   vid->video.smooth  = video->smooth;
   vid->flags        |=  SDL2_FLAG_SHOULD_RESIZE;

   sdl_tex_zero(&vid->frame);
   sdl_tex_zero(&vid->menu);

   if (video->fullscreen)
      SDL_ShowCursor(SDL_DISABLE);

   sdl2_init_renderer(vid);
   sdl2_init_font(vid,
         settings->paths.path_font,
         settings->floats.video_font_size);

#if defined(_WIN32)
   sdl2_set_handles(vid->window, RARCH_DISPLAY_WIN32);
#elif defined(HAVE_COCOA)
   sdl2_set_handles(vid->window, RARCH_DISPLAY_OSX);
#else
#if defined(HAVE_X11) || defined(HAVE_WAYLAND)
   video_driver = SDL_GetCurrentVideoDriver();
#endif
#ifdef HAVE_X11
   if (strcmp(video_driver, "x11") == 0)
      sdl2_set_handles(vid->window, RARCH_DISPLAY_X11);
   else
#endif
#ifdef HAVE_WAYLAND
   if (strcmp(video_driver, "wayland") == 0)
      sdl2_set_handles(vid->window, RARCH_DISPLAY_WAYLAND);
   else
#endif
      sdl2_set_handles(vid->window, RARCH_DISPLAY_NONE);
#endif

   sdl_refresh_viewport(vid);

   *input      = NULL;
   *input_data = NULL;

   return vid;

error:
   sdl2_gfx_free(vid);
   return NULL;
}

static void check_window(sdl2_video_t *vid)
{
   SDL_Event event;

   SDL_PumpEvents();
   while (SDL_PeepEvents(&event, 1,
            SDL_GETEVENT, SDL_QUIT, SDL_WINDOWEVENT) > 0)
   {
      switch (event.type)
      {
         case SDL_QUIT:
            vid->flags |= SDL2_FLAG_QUITTING;
            break;

         case SDL_WINDOWEVENT:
            if (event.window.event == SDL_WINDOWEVENT_RESIZED)
               vid->flags |= SDL2_FLAG_SHOULD_RESIZE;
            break;
         default:
            break;
      }
   }
}

static bool sdl2_gfx_frame(void *data, const void *frame, unsigned width,
      unsigned height, uint64_t frame_count,
      unsigned pitch, const char *msg, video_frame_info_t *video_info)
{
   char title[128];
   sdl2_video_t *vid  = (sdl2_video_t*)data;
#ifdef HAVE_MENU
   bool menu_is_alive = (video_info->menu_st_flags & MENU_ST_FLAG_ALIVE) ? true : false;
#endif

   if (vid->flags & SDL2_FLAG_SHOULD_RESIZE)
      sdl_refresh_viewport(vid);

   if (frame)
   {
      SDL_RenderClear(vid->renderer);
      sdl_refresh_input_size(vid, false, vid->video.rgb32, width, height, pitch);
      SDL_UpdateTexture(vid->frame.tex, NULL, frame, pitch);
   }

   SDL_RenderCopyEx(vid->renderer, vid->frame.tex, NULL, NULL, vid->rotation, NULL, SDL_FLIP_NONE);

#ifdef HAVE_MENU
   menu_driver_frame(menu_is_alive, video_info);
#endif

   if (vid->menu.active)
      SDL_RenderCopy(vid->renderer, vid->menu.tex, NULL, NULL);

   if (msg)
      sdl2_render_msg(vid, msg);

   SDL_RenderPresent(vid->renderer);

   title[0] = '\0';

   video_driver_get_window_title(title, sizeof(title));

   if (title[0])
      SDL_SetWindowTitle((SDL_Window*)video_driver_display_userdata_get(), title);

   return true;
}

static void sdl2_gfx_set_nonblock_state(void *data, bool toggle,
      bool adaptive_vsync_enabled, unsigned swap_interval)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   vid->video.vsync  = !toggle;
   sdl_refresh_renderer(vid);
}

static bool sdl2_gfx_alive(void *data)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   check_window(vid);
   if (vid->flags & SDL2_FLAG_QUITTING)
      return false;
   return true;
}

static bool sdl2_gfx_focus(void *data)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   unsigned flags = (SDL_WINDOW_INPUT_FOCUS | SDL_WINDOW_MOUSE_FOCUS);
   return (SDL_GetWindowFlags(vid->window) & flags) == flags;
}

#if !defined(HAVE_X11)
static bool sdl2_gfx_suspend_screensaver(void *data, bool enable) { return false; }
#endif

/* TODO/FIXME - implement */
static bool sdl2_gfx_has_windowed(void *data) { return true; }

static void sdl2_gfx_free(void *data)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   if (!vid)
      return;

   if (vid->renderer)
      SDL_DestroyRenderer(vid->renderer);

   if (vid->window)
      SDL_DestroyWindow(vid->window);

   if (vid->font_data)
      vid->font_driver->free(vid->font_data);

   free(vid);
}

static void sdl2_gfx_set_rotation(void *data, unsigned rotation)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;

   if (vid)
      vid->rotation = 270 * rotation;
}

static void sdl2_gfx_viewport_info(void *data, struct video_viewport *vp)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   *vp = vid->vp;
}

static bool sdl2_gfx_read_viewport(void *data, uint8_t *buffer, bool is_idle)
{
   SDL_Surface *surf = NULL, *bgr24 = NULL;
   sdl2_video_t *vid = (sdl2_video_t*)data;

   if (!is_idle)
      video_driver_cached_frame();

   surf  = SDL_GetWindowSurface(vid->window);
   bgr24 = SDL_ConvertSurfaceFormat(surf, SDL_PIXELFORMAT_BGR24, 0);

   if (!bgr24)
   {
      RARCH_WARN("Failed to convert viewport data to BGR24: %s", SDL_GetError());
      return false;
   }

   memcpy(buffer, bgr24->pixels, bgr24->h * bgr24->pitch);

   return true;
}

static void sdl2_poke_set_filtering(void *data, unsigned index, bool smooth, bool ctx_scaling)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   vid->video.smooth = smooth;

   sdl_tex_zero(&vid->frame);
}

static void sdl2_poke_set_aspect_ratio(void *data, unsigned aspect_ratio_idx)
{
   sdl2_video_t *vid    = (sdl2_video_t*)data;

   /* FIXME: Why is vid NULL here when starting content? */
   if (!vid)
      return;

   vid->video.force_aspect = true;
   vid->flags             |= SDL2_FLAG_SHOULD_RESIZE;
}

static void sdl2_poke_apply_state_changes(void *data)
{
   sdl2_video_t *vid       = (sdl2_video_t*)data;
   vid->flags             |= SDL2_FLAG_SHOULD_RESIZE;
}

static void sdl2_poke_set_texture_frame(void *data,
      const void *frame, bool rgb32,
      unsigned width, unsigned height, float alpha)
{
   if (frame)
   {
      sdl2_video_t *vid = (sdl2_video_t*)data;

      sdl_refresh_input_size(vid, true, rgb32, width, height,
            width * (rgb32 ? 4 : 2));

      SDL_UpdateTexture(vid->menu.tex, NULL, frame, (int)vid->menu.pitch);
   }
}

static void sdl2_poke_texture_enable(void *data,
      bool enable, bool full_screen)
{
   sdl2_video_t *vid   = (sdl2_video_t*)data;

   if (!vid)
      return;

   vid->menu.active = enable;
}

static void sdl2_poke_set_osd_msg(void *data, const char *msg,
      const struct font_params *params, void *font)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   sdl2_render_msg(vid, msg);
}

static void sdl2_show_mouse(void *data, bool state) { SDL_ShowCursor(state); }
static void sdl2_grab_mouse_toggle(void *data)
{
   sdl2_video_t *vid = (sdl2_video_t*)data;
   SDL_SetWindowGrab(vid->window, SDL_GetWindowGrab(vid->window));
}
static uint32_t sdl2_get_flags(void *data) { return 0; }

static video_poke_interface_t sdl2_video_poke_interface = {
   sdl2_get_flags,
   NULL, /* load_texture */
   NULL, /* unload_texture */
   NULL, /* set_video_mode */
   NULL, /* get_refresh_rate */
   sdl2_poke_set_filtering,
   NULL, /* get_video_output_size */
   NULL, /* get_video_output_prev */
   NULL, /* get_video_output_next */
   NULL, /* get_current_framebuffer */
   NULL, /* get_proc_address */
   sdl2_poke_set_aspect_ratio,
   sdl2_poke_apply_state_changes,
   sdl2_poke_set_texture_frame,
   sdl2_poke_texture_enable,
   sdl2_poke_set_osd_msg,
   sdl2_show_mouse,
   sdl2_grab_mouse_toggle,
   NULL, /* get_current_shader */
   NULL, /* get_current_software_framebuffer */
   NULL, /* get_hw_render_interface */
   NULL, /* set_hdr_max_nits */
   NULL, /* set_hdr_paper_white_nits */
   NULL, /* set_hdr_contrast */
   NULL, /* set_hdr_expand_gamut */
};

static void sdl2_gfx_poke_interface(void *data, const video_poke_interface_t **iface)
{
   (void)data;
   *iface = &sdl2_video_poke_interface;
}

static bool sdl2_gfx_set_shader(void *data,
      enum rarch_shader_type type, const char *path)
{
   (void)data;
   (void)type;
   (void)path;

   return false;
}

video_driver_t video_sdl2 = {
   sdl2_gfx_init,
   sdl2_gfx_frame,
   sdl2_gfx_set_nonblock_state,
   sdl2_gfx_alive,
   sdl2_gfx_focus,
#ifdef HAVE_X11
   x11_suspend_screensaver,
#else
   sdl2_gfx_suspend_screensaver,
#endif
   sdl2_gfx_has_windowed,
   sdl2_gfx_set_shader,
   sdl2_gfx_free,
   "sdl2",
   NULL, /* set_viewport */
   sdl2_gfx_set_rotation,
   sdl2_gfx_viewport_info,
   sdl2_gfx_read_viewport,
   NULL, /* read_frame_raw */
#ifdef HAVE_OVERLAY
   NULL, /* get_overlay_interface */
#endif
   sdl2_gfx_poke_interface,
   NULL, /* wrap_type_to_enum */
#ifdef HAVE_GFX_WIDGETS
   NULL  /* gfx_widgets_enabled */
#endif
};