/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2014-2018 - Ali Bouhlel
 *
 *  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 <assert.h>
#include <string/stdstring.h>

#include "driver.h"
#include "verbosity.h"
#include "configuration.h"
#include "gfx/video_driver.h"
#include "gfx/common/win32_common.h"
#include "gfx/common/dxgi_common.h"
#include "gfx/common/d3d12_common.h"
#include "gfx/common/d3dcompiler_common.h"

static void *d3d12_gfx_init(const video_info_t *video,
                            const input_driver_t **input, void **input_data)
{
   WNDCLASSEX wndclass = {0};
   settings_t *settings = config_get_ptr();
   gfx_ctx_input_t inp = {input, input_data};
   d3d12_video_t *d3d12 = (d3d12_video_t *)calloc(1, sizeof(*d3d12));

   if (!d3d12)
      return NULL;

   win32_window_reset();
   win32_monitor_init();
   wndclass.lpfnWndProc = WndProcD3D;
   win32_window_init(&wndclass, true, NULL);

   if (!win32_set_video_mode(d3d12, video->width, video->height, video->fullscreen))
   {
      RARCH_ERR("[D3D12]: win32_set_video_mode failed.\n");
      goto error;
   }

   gfx_ctx_d3d.input_driver(NULL, settings->arrays.input_joypad_driver, input, input_data);

   d3d12->chain.vsync = video->vsync;
   d3d12->frame.rgb32 = video->rgb32;

   if (!d3d12_init_context(d3d12))
      goto error;

   if (!d3d12_init_descriptors(d3d12))
      goto error;

   if (!d3d12_init_pipeline(d3d12))
      goto error;

   if(!d3d12_init_queue(d3d12))
      return false;

   if (!d3d12_init_swapchain(d3d12, video->width, video->height, main_window.hwnd))
      goto error;


   {
      d3d12_vertex_t vertices[] =
      {
         {{ -1.0f, -1.0f}, {0.0f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}},
         {{ -1.0f,  1.0f}, {0.0f, 0.0f}, {1.0f, 1.0f, 1.0f, 1.0f}},
         {{ 1.0f, -1.0f}, {1.0f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}},
         {{ 1.0f,  1.0f}, {1.0f, 0.0f}, {1.0f, 1.0f, 1.0f, 1.0f}},
      };

      d3d12->frame.vbo_view.SizeInBytes = sizeof(vertices);
      d3d12->frame.vbo_view.StrideInBytes = sizeof(*vertices);
      d3d12_create_vertex_buffer(d3d12->device, &d3d12->frame.vbo_view, &d3d12->frame.vbo);

      {
         void *vertex_data_begin;
         D3D12_RANGE read_range = {0, 0};

         D3D12Map(d3d12->frame.vbo, 0, &read_range, &vertex_data_begin);
         memcpy(vertex_data_begin, vertices, sizeof(vertices));
         D3D12Unmap(d3d12->frame.vbo, 0, NULL);
      }

   }
   return d3d12;

error:
   RARCH_ERR("[D3D12]: failed to init video driver.\n");
   free(d3d12);
   return NULL;
}


static bool d3d12_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)
{
   D3D12_CPU_DESCRIPTOR_HANDLE rtvHandle;
   d3d12_video_t *d3d12 = (d3d12_video_t *)data;

   (void)msg;
   (void)rtvHandle;

   D3D12ResetCommandAllocator(d3d12->queue.allocator);

   D3D12ResetGraphicsCommandList(d3d12->queue.cmd, d3d12->queue.allocator, d3d12->pipe.handle);
   D3D12SetGraphicsRootSignature(d3d12->queue.cmd, d3d12->pipe.rootSignature);
   D3D12SetDescriptorHeaps(d3d12->queue.cmd, 1, &d3d12->pipe.srv_heap.handle);

   d3d12_transition(d3d12->queue.cmd, d3d12->chain.renderTargets[d3d12->chain.frame_index],
                    D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET);

   D3D12RSSetViewports(d3d12->queue.cmd, 1, &d3d12->chain.viewport);
   D3D12RSSetScissorRects(d3d12->queue.cmd, 1, &d3d12->chain.scissorRect);
   D3D12OMSetRenderTargets(d3d12->queue.cmd, 1, &d3d12->chain.desc_handles[d3d12->chain.frame_index],
                           FALSE, NULL);
   D3D12ClearRenderTargetView(d3d12->queue.cmd, d3d12->chain.desc_handles[d3d12->chain.frame_index],
                              d3d12->chain.clearcolor, 0, NULL);

   D3D12IASetPrimitiveTopology(d3d12->queue.cmd, D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);

   if (data && width && height)
   {
      if (!d3d12->frame.tex.handle || (d3d12->frame.tex.desc.Width != width)
            || (d3d12->frame.tex.desc.Height = height))
      {
         if (d3d12->frame.tex.handle)
            Release(d3d12->frame.tex.handle);

         if (d3d12->frame.tex.upload_buffer)
            Release(d3d12->frame.tex.upload_buffer);

         d3d12->frame.tex.desc.Width = width;
         d3d12->frame.tex.desc.Height = height;
         d3d12->frame.tex.desc.Format = d3d12->frame.rgb32 ? DXGI_FORMAT_B8G8R8A8_UNORM :
                                        DXGI_FORMAT_B5G6R5_UNORM;
         d3d12_create_texture(d3d12->device, &d3d12->pipe.srv_heap, 0, &d3d12->frame.tex);
      }

      {
         unsigned i;
         const uint8_t *in  = frame;
         uint8_t       *out = NULL;

         D3D12Map(d3d12->frame.tex.upload_buffer, 0, NULL, &out);
         out += d3d12->frame.tex.layout.Offset;

         for (i = 0; i < height; i++)
         {
            memcpy(out, in, width * (d3d12->frame.rgb32 ? 4 : 2));
            in += pitch;
            out += d3d12->frame.tex.layout.Footprint.RowPitch;
         }

         D3D12Unmap(d3d12->frame.tex.upload_buffer, 0, NULL);
      }

      d3d12_upload_texture(d3d12->queue.cmd, &d3d12->frame.tex);
      D3D12IASetVertexBuffers(d3d12->queue.cmd, 0, 1, &d3d12->frame.vbo_view);
      D3D12SetGraphicsRootDescriptorTable(d3d12->queue.cmd, 0,
                                          d3d12->frame.tex.gpu_descriptor); /* set texture */
      D3D12DrawInstanced(d3d12->queue.cmd, 4, 1, 0, 0);
   }


   if (d3d12->menu.enabled && d3d12->menu.tex.handle)
   {
      if(d3d12->menu.tex.dirty)
         d3d12_upload_texture(d3d12->queue.cmd, &d3d12->menu.tex);
#if 0
         D3D12IASetVertexBuffers(d3d12->queue.cmd, 0, 1, &d3d12->frame.vbo_view);
#endif
      D3D12SetGraphicsRootDescriptorTable(d3d12->queue.cmd, 0,
                                          d3d12->menu.tex.gpu_descriptor); /* set texture */
      D3D12DrawInstanced(d3d12->queue.cmd, 4, 1, 0, 0);
   }


   d3d12_transition(d3d12->queue.cmd, d3d12->chain.renderTargets[d3d12->chain.frame_index],
                    D3D12_RESOURCE_STATE_RENDER_TARGET, D3D12_RESOURCE_STATE_PRESENT);
   D3D12CloseGraphicsCommandList(d3d12->queue.cmd);

   D3D12ExecuteGraphicsCommandLists(d3d12->queue.handle, 1, &d3d12->queue.cmd);

#if 1
   DXGIPresent(d3d12->chain.handle, !!d3d12->chain.vsync, 0);
#else
   DXGI_PRESENT_PARAMETERS pp = {0};
   DXGIPresent1(d3d12->swapchain, 0, 0, &pp);
#endif

   /* wait_for_previous_frame */
   D3D12SignalCommandQueue(d3d12->queue.handle, d3d12->queue.fence, d3d12->queue.fenceValue);

   if (D3D12GetCompletedValue(d3d12->queue.fence) < d3d12->queue.fenceValue)
   {
      D3D12SetEventOnCompletion(d3d12->queue.fence, d3d12->queue.fenceValue, d3d12->queue.fenceEvent);
      WaitForSingleObject(d3d12->queue.fenceEvent, INFINITE);
   }

   d3d12->queue.fenceValue++;
   d3d12->chain.frame_index = DXGIGetCurrentBackBufferIndex(d3d12->chain.handle);

   if (msg && *msg)
      gfx_ctx_d3d.update_window_title(NULL, video_info);

   return true;
}

static void d3d12_gfx_set_nonblock_state(void *data, bool toggle)
{
   d3d12_video_t *d3d12 = (d3d12_video_t *)data;
   d3d12->chain.vsync = !toggle;
}

static bool d3d12_gfx_alive(void *data)
{
   (void)data;
   bool quit;
   bool resize;
   unsigned width;
   unsigned height;
   win32_check_window(&quit, &resize, &width, &height);
   return true;
}

static bool d3d12_gfx_focus(void *data)
{
   return win32_has_focus();
}

static bool d3d12_gfx_suppress_screensaver(void *data, bool enable)
{
   (void)data;
   (void)enable;
   return false;
}

static bool d3d12_gfx_has_windowed(void *data)
{
   (void)data;
   return true;
}

static void d3d12_gfx_free(void *data)
{
   d3d12_video_t *d3d12 = (d3d12_video_t *)data;

   Release(d3d12->frame.vbo);
   if (d3d12->frame.tex.handle)
   Release(d3d12->frame.tex.handle);
   if (d3d12->frame.tex.upload_buffer)
   Release(d3d12->frame.tex.upload_buffer);

   if (d3d12->menu.tex.handle)
      Release(d3d12->menu.tex.handle);

   if (d3d12->menu.tex.handle)
      Release(d3d12->menu.tex.upload_buffer);

   Release(d3d12->pipe.srv_heap.handle);
   Release(d3d12->pipe.rtv_heap.handle);
   Release(d3d12->pipe.rootSignature);
   Release(d3d12->pipe.handle);

   Release(d3d12->queue.fence);
   Release(d3d12->chain.renderTargets[0]);
   Release(d3d12->chain.renderTargets[1]);
   Release(d3d12->chain.handle);

   Release(d3d12->queue.cmd);
   Release(d3d12->queue.allocator);
   Release(d3d12->queue.handle);

   Release(d3d12->factory);
   Release(d3d12->device);
   Release(d3d12->adapter);

   win32_monitor_from_window();
   win32_destroy_window();

   free(d3d12);
}

static bool d3d12_gfx_set_shader(void *data,
                                 enum rarch_shader_type type, const char *path)
{
   (void)data;
   (void)type;
   (void)path;

   return false;
}

static void d3d12_gfx_set_rotation(void *data,
                                   unsigned rotation)
{
   (void)data;
   (void)rotation;
}

static void d3d12_gfx_viewport_info(void *data,
                                    struct video_viewport *vp)
{
   (void)data;
   (void)vp;
}

static bool d3d12_gfx_read_viewport(void *data, uint8_t *buffer, bool is_idle)
{
   (void)data;
   (void)buffer;

   return true;
}

static void d3d12_set_menu_texture_frame(void *data,
      const void *frame, bool rgb32, unsigned width, unsigned height,
      float alpha)
{
   d3d12_video_t *d3d12 = (d3d12_video_t *)data;

   if (!d3d12->menu.tex.handle || (d3d12->menu.tex.desc.Width != width)
         || (d3d12->menu.tex.desc.Height = height))
   {
      if (d3d12->menu.tex.handle)
         Release(d3d12->menu.tex.handle);

      if (d3d12->menu.tex.upload_buffer)
         Release(d3d12->menu.tex.upload_buffer);

      d3d12->menu.tex.desc.Width = width;
      d3d12->menu.tex.desc.Height = height;
      d3d12->menu.tex.desc.Format = rgb32 ? DXGI_FORMAT_B8G8R8A8_UNORM : DXGI_FORMAT_B4G4R4A4_UNORM;
      d3d12_create_texture(d3d12->device, &d3d12->pipe.srv_heap, 1, &d3d12->menu.tex);
   }

   {
      unsigned i, j;
      uint8_t *out  = NULL;

      D3D12Map(d3d12->menu.tex.upload_buffer, 0, NULL, &out);
      out += d3d12->menu.tex.layout.Offset;

      if(rgb32)
      {
         const uint32_t *in = frame;
         for (i = 0; i < height; i++)
         {
            memcpy(out, in, width * sizeof(*in));
            in += width;
            out += d3d12->menu.tex.layout.Footprint.RowPitch;
         }
      }
      else
      {
         const uint16_t *in = frame;
         for (i = 0; i < height; i++)
         {
            for (j = 0; j < width; j++)
            {
               unsigned r = ((in[j] >> 12) & 0xF);
               unsigned g = ((in[j] >>  8) & 0xF);
               unsigned b = ((in[j] >>  4) & 0xF);
               unsigned a = ((in[j] >>  0) & 0xF);

               ((uint16_t*)out)[j] = (b << 0) | (g << 4) | (r << 8) |(a << 12);
            }
            in += width;
            out += d3d12->menu.tex.layout.Footprint.RowPitch;
         }

      }

      D3D12Unmap(d3d12->menu.tex.upload_buffer, 0, NULL);
   }
   d3d12->menu.tex.dirty = true;
   d3d12->menu.alpha = alpha;
}
static void d3d12_set_menu_texture_enable(void *data,
      bool state, bool full_screen)
{
   d3d12_video_t *d3d12 = (d3d12_video_t *)data;

   d3d12->menu.enabled            = state;
   d3d12->menu.fullscreen         = full_screen;
}


static const video_poke_interface_t d3d12_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 */
   d3d12_set_menu_texture_frame, /* set_texture_frame */
   d3d12_set_menu_texture_enable, /* 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 d3d12_gfx_get_poke_interface(void *data,
      const video_poke_interface_t **iface)
{
   *iface = &d3d12_poke_interface;
}

video_driver_t video_d3d12 =
{
   d3d12_gfx_init,
   d3d12_gfx_frame,
   d3d12_gfx_set_nonblock_state,
   d3d12_gfx_alive,
   d3d12_gfx_focus,
   d3d12_gfx_suppress_screensaver,
   d3d12_gfx_has_windowed,
   d3d12_gfx_set_shader,
   d3d12_gfx_free,
   "d3d12",
   NULL, /* set_viewport */
   d3d12_gfx_set_rotation,
   d3d12_gfx_viewport_info,
   d3d12_gfx_read_viewport,
   NULL, /* read_frame_raw */

#ifdef HAVE_OVERLAY
   NULL, /* overlay_interface */
#endif
   d3d12_gfx_get_poke_interface,
};