#include <stdio.h>
#include <string.h>
#include <malloc.h>

#include <retro_inline.h>
#include <retro_math.h>
#include <formats/image.h>

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

#include <libtransistor/nx.h>

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

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

#include "../font_driver.h"

#include "../../configuration.h"
#include "../../command.h"
#include "../../driver.h"

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

#ifndef HAVE_THREADS
#include "../../tasks/tasks_internal.h"
#endif

typedef struct
{
   bool vsync;
   bool rgb32;
   unsigned width, height;
   unsigned rotation;
   struct video_viewport vp;

	struct {
		bool enable;
		bool fullscreen;

		uint32_t *pixels;

		unsigned width;
		unsigned height;

		struct scaler_ctx scaler;
	} menu_texture;
} switch_video_t;

static uint32_t image[1280*720];

static bool has_initialized = false;
static surface_t surface;
static revent_h vsync_h;

static void *switch_init(const video_info_t *video,
      const input_driver_t **input, void **input_data)
{
   unsigned x, y;
   switch_video_t *sw = (switch_video_t*)calloc(1, sizeof(*sw));
   if (!sw)
      return NULL;

   RARCH_LOG("loading switch gfx driver, width: %d, height: %d\n", video->width, video->height);

   if (has_initialized)
	   RARCH_LOG("global graphics were already initialized; skipping...\n");
   else
   {
      result_t r = display_init();
      if (r != RESULT_OK)
      {
         free(sw);
         return NULL;
      }
      r = display_open_layer(&surface);

      if (r != RESULT_OK)
      {
         display_finalize();
         free(sw);
         return NULL;
      }
      r = display_get_vsync_event(&vsync_h);

      if (r != RESULT_OK)
      {
         display_finalize();
         free(sw);
         return NULL;
      }

      atexit(display_finalize);
      has_initialized = true;
   }

   sw->vp.x           = 0;
   sw->vp.y           = 0;
   sw->vp.width       = 1280;
   sw->vp.height      = 720;
   sw->vp.full_width  = 1280;
   sw->vp.full_height = 720;
   video_driver_set_size(&sw->vp.width, &sw->vp.height);

   sw->vsync = video->vsync;

   sw->rgb32 = video->rgb32;
   
   *input = NULL;
   *input_data = NULL;

   for(x = 0; x < 1280; x++)
   {
      for(y = 0; y < 720; y++)
         image[(y*1280)+x] = 0xFF000000;
   }

   return sw;
}

static void switch_wait_vsync(switch_video_t *sw)
{
	uint32_t handle_idx;
	svcWaitSynchronization(&handle_idx, &vsync_h, 1, 33333333);
	svcResetSignal(vsync_h);
}

static bool switch_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)
{
	static uint64_t last_frame = 0;
	
   unsigned x, y;
   result_t r;
   uint64_t begin, done_copying, post_vsync, pre_swizzle, post_swizzle,
            copy_ms, swizzle_ms, vsync_ms;
   int tgtw, tgth, centerx, centery;
   uint32_t *out_buffer   = NULL;
   switch_video_t *sw     = data;
   int xsf                = 1280 / width;
   int ysf                = 720  / height;
   int sf                 = xsf;

   if (ysf < sf)
      sf = ysf;

   tgtw                   = width * sf;
   tgth                   = height * sf;
   centerx                = (1280-tgtw)/2;
   centery                = (720-tgth)/2;

   begin                  = svcGetSystemTick();

   for(x = 0; x < width; x++)
   {
      for(y = 0; y < height; y++)
      {
	 unsigned subx, suby;
         uint32_t pixel = 0;

         if (sw->rgb32)
         {
            const uint32_t *frame_pixels = frame;
            pixel = frame_pixels[(y*pitch/sizeof(uint32_t)) + x];
         }
	 else
	 {
            const uint16_t *frame_pixels = frame;
            uint32_t spixel = frame_pixels[(y*pitch/sizeof(uint16_t)) + x];
            uint8_t r       = (spixel >> 11) & 31;
            uint8_t g       = (spixel >> 5) & 63;
            uint8_t b       = (spixel >> 0) & 31;
            r               = (r * 256) / 32;
            g               = (g * 256) / 64;
            b               = (b * 256) / 32;
            pixel           = (r << 0) | (g << 8) | (b << 16) | (0xFF << 24);
         }

         for (subx = 0; subx < xsf; subx++)
            for (suby = 0; suby < ysf; suby++)
               image[(((y*sf)+suby+centery)*1280) 
                  + ((x*sf)+subx+centerx)] = pixel;
      }
   }

#if defined(HAVE_MENU)
   if (sw->menu_texture.enable)
	{
		menu_driver_frame(video_info);

		if (sw->menu_texture.pixels)
		{
#if 0
			if (sw->menu_texture.fullscreen)
         {
#endif
				scaler_ctx_scale(&sw->menu_texture.scaler, image, sw->menu_texture.pixels);
#if 0
         }
         else
         {
         }
#endif
		}
	}
#endif
   
   done_copying = svcGetSystemTick();

#if 0
   if (frame_count > 6000)
   {
      display_finalize();
      exit(0);
   }
#endif

   if (msg && strlen(msg) > 0)
      RARCH_LOG("message: %s\n", msg);

   do {
	   if (sw->vsync) /* vsync seems to sometimes return before the buffer has actually been dequeued? */
		   switch_wait_vsync(sw);
	   
	   post_vsync = svcGetSystemTick();
	   
	   r = surface_dequeue_buffer(&surface, &out_buffer);
   } while(r != RESULT_OK);

   pre_swizzle  = svcGetSystemTick();
   gfx_slow_swizzling_blit(out_buffer, image, 1280, 720, 0, 0);
   post_swizzle = svcGetSystemTick();

   r = surface_queue_buffer(&surface);

   if (r != RESULT_OK)
      return false;

   copy_ms    = (done_copying - begin) / 19200;
   swizzle_ms = (post_swizzle - pre_swizzle) / 19200;
   vsync_ms   = (post_vsync - done_copying) / 19200;

   RARCH_LOG("frame %d benchmark: copy %ld ms, swizzle %ld ms, vsync %ld ms\n", frame_count, copy_ms, swizzle_ms, vsync_ms);

   last_frame = svcGetSystemTick();
   return true;
}

static void switch_set_nonblock_state(void *data, bool toggle)
{
   switch_video_t *sw = data;
   sw->vsync = !toggle;
}

static bool switch_alive(void *data)
{
	(void) data;
	return true;
}

static bool switch_focus(void *data)
{
	(void) data;
	return true;
}

static bool switch_suppress_screensaver(void *data, bool enable)
{
	(void) data;
	(void) enable;
	return false;
}

static bool switch_has_windowed(void *data)
{
	(void) data;
	return false;
}

static void switch_free(void *data)
{
	switch_video_t *sw = data;
	free(sw);
}

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

   return false;
}

static void switch_set_rotation(void *data, unsigned rotation)
{
   switch_video_t *sw = data;
   if (!sw)
      return;
   sw->rotation = rotation;
}

static void switch_viewport_info(void *data, struct video_viewport *vp)
{
   switch_video_t *sw = data;
   *vp = sw->vp;
}

static bool switch_read_viewport(void *data, uint8_t *buffer, bool is_idle)
{
   (void) data;
   (void) buffer;

   return true;
}

static void switch_set_texture_frame(
      void *data, const void *frame, bool rgb32,
      unsigned width, unsigned height, float alpha)
{
   switch_video_t *sw = data;

   if (  !sw->menu_texture.pixels         || 
         sw->menu_texture.width  != width ||
         sw->menu_texture.height != height)
   {
      if (sw->menu_texture.pixels)
         free(sw->menu_texture.pixels);

      sw->menu_texture.pixels = malloc(width * height * 4);
      if (!sw->menu_texture.pixels)
      {
         RARCH_ERR("failed to allocate buffer for menu texture\n");
         return;
      }

      sw->menu_texture.width = width;
      sw->menu_texture.height = height;

      struct scaler_ctx *sctx = &sw->menu_texture.scaler;
      scaler_ctx_gen_reset(sctx);

      sctx->in_width = width;
      sctx->in_height = height;
      sctx->in_stride = width * 4;
      sctx->in_fmt = SCALER_FMT_ARGB8888;

      sctx->out_width = 1280;
      sctx->out_height = 720;
      sctx->out_stride = 1280 * 4;
      sctx->out_fmt = SCALER_FMT_ARGB8888;

      sctx->scaler_type = SCALER_TYPE_POINT;

      if (!scaler_ctx_gen_filter(sctx))
      {
         RARCH_ERR("failed to generate scaler for menu texture\n");
         return;
      }
   }

   if (rgb32)
      memcpy(sw->menu_texture.pixels, frame, width * height * 4);
   else
      conv_rgb565_argb8888(sw->menu_texture.pixels, frame,
            width, height,
            width * sizeof(uint32_t), width * sizeof(uint16_t));
}

static void switch_set_texture_enable(void *data, bool enable, bool full_screen)
{
	switch_video_t *sw = data;
	sw->menu_texture.enable = enable;
	sw->menu_texture.fullscreen = full_screen;
}

static const video_poke_interface_t switch_poke_interface = {
	NULL, /* set_coords */
	NULL, /* set_mvp */
	NULL, /* load_texture */
	NULL, /* unload_texture */
	NULL, /* set_video_mode */
	NULL, /* 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 */
	NULL, /* set_aspect_ratio */
	NULL, /* apply_state_changes */
	switch_set_texture_frame,
	switch_set_texture_enable,
	NULL, /* set_osd_msg */
	NULL, /* show_mouse */
	NULL, /* grab_mouse_toggle */
	NULL, /* get_current_shader */
	NULL, /* get_current_software_framebuffer */
	NULL, /* get_hw_render_interface */
};

static void switch_get_poke_interface(void *data,
      const video_poke_interface_t **iface)
{
   (void) data;
   *iface = &switch_poke_interface;
}

video_driver_t video_switch = {
	switch_init,
	switch_frame,
	switch_set_nonblock_state,
	switch_alive,
	switch_focus,
	switch_suppress_screensaver,
	switch_has_windowed,
	switch_set_shader,
	switch_free,
	"switch",
	NULL, /* set_viewport */
	switch_set_rotation,
	switch_viewport_info,
	switch_read_viewport,
	NULL, /* read_frame_raw */
#ifdef HAVE_OVERLAY
	NULL, /* overlay_interface */
#endif
	switch_get_poke_interface,
};