// Copyright 2009 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <algorithm>
#include <atomic>
#include <mutex>
#include <string>

#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "Common/Logging/Log.h"
#include "Common/StringUtil.h"

#include "Core/ConfigManager.h"
#include "Core/HW/Memmap.h"

#include "VideoBackends/Software/EfbCopy.h"
#include "VideoBackends/Software/SWOGLWindow.h"
#include "VideoBackends/Software/SWRenderer.h"

#include "VideoCommon/BoundingBox.h"
#include "VideoCommon/Fifo.h"
#include "VideoCommon/ImageWrite.h"
#include "VideoCommon/OnScreenDisplay.h"
#include "VideoCommon/VideoConfig.h"

static u8* s_xfbColorTexture[2];
static int s_currentColorTexture = 0;

SWRenderer::~SWRenderer()
{
  delete[] s_xfbColorTexture[0];
  delete[] s_xfbColorTexture[1];
}

void SWRenderer::Init()
{
  s_xfbColorTexture[0] = new u8[MAX_XFB_WIDTH * MAX_XFB_HEIGHT * 4];
  s_xfbColorTexture[1] = new u8[MAX_XFB_WIDTH * MAX_XFB_HEIGHT * 4];

  s_currentColorTexture = 0;
}

void SWRenderer::Shutdown()
{
  g_Config.bRunning = false;
  UpdateActiveConfig();
}

void SWRenderer::RenderText(const std::string& pstr, int left, int top, u32 color)
{
  SWOGLWindow::s_instance->PrintText(pstr, left, top, color);
}

u8* SWRenderer::GetNextColorTexture()
{
  return s_xfbColorTexture[!s_currentColorTexture];
}

u8* SWRenderer::GetCurrentColorTexture()
{
  return s_xfbColorTexture[s_currentColorTexture];
}

void SWRenderer::SwapColorTexture()
{
  s_currentColorTexture = !s_currentColorTexture;
}

void SWRenderer::UpdateColorTexture(EfbInterface::yuv422_packed* xfb, u32 fbWidth, u32 fbHeight)
{
  if (fbWidth * fbHeight > MAX_XFB_WIDTH * MAX_XFB_HEIGHT)
  {
    ERROR_LOG(VIDEO, "Framebuffer is too large: %ix%i", fbWidth, fbHeight);
    return;
  }

  u32 offset = 0;
  u8* TexturePointer = GetNextColorTexture();

  for (u16 y = 0; y < fbHeight; y++)
  {
    for (u16 x = 0; x < fbWidth; x += 2)
    {
      // We do this one color sample (aka 2 RGB pixles) at a time
      int Y1 = xfb[x].Y - 16;
      int Y2 = xfb[x + 1].Y - 16;
      int U = int(xfb[x].UV) - 128;
      int V = int(xfb[x + 1].UV) - 128;

      // We do the inverse BT.601 conversion for YCbCr to RGB
      // http://www.equasys.de/colorconversion.html#YCbCr-RGBColorFormatConversion
      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y1 + 1.596f * V), 0, 255);
      TexturePointer[offset++] =
          MathUtil::Clamp(int(1.164f * Y1 - 0.392f * U - 0.813f * V), 0, 255);
      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y1 + 2.017f * U), 0, 255);
      TexturePointer[offset++] = 255;

      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y2 + 1.596f * V), 0, 255);
      TexturePointer[offset++] =
          MathUtil::Clamp(int(1.164f * Y2 - 0.392f * U - 0.813f * V), 0, 255);
      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y2 + 2.017f * U), 0, 255);
      TexturePointer[offset++] = 255;
    }
    xfb += fbWidth;
  }
  SwapColorTexture();
}

// Called on the GPU thread
void SWRenderer::SwapImpl(u32 xfbAddr, u32 fbWidth, u32 fbStride, u32 fbHeight,
                          const EFBRectangle& rc, float Gamma)
{
  if (!Fifo::WillSkipCurrentFrame())
  {
    if (g_ActiveConfig.bUseXFB)
    {
      EfbInterface::yuv422_packed* xfb = (EfbInterface::yuv422_packed*)Memory::GetPointer(xfbAddr);
      UpdateColorTexture(xfb, fbWidth, fbHeight);
    }
    else
    {
      EfbInterface::BypassXFB(GetCurrentColorTexture(), fbWidth, fbHeight, rc, Gamma);
    }

    // Save screenshot
    if (s_bScreenshot)
    {
      std::lock_guard<std::mutex> lk(s_criticalScreenshot);

      if (TextureToPng(GetCurrentColorTexture(), fbWidth * 4, s_sScreenshotName, fbWidth, fbHeight,
                       false))
        OSD::AddMessage("Screenshot saved to " + s_sScreenshotName);

      // Reset settings
      s_sScreenshotName.clear();
      s_bScreenshot = false;
      s_screenshotCompleted.Set();
    }

    if (SConfig::GetInstance().m_DumpFrames)
    {
      static int frame_index = 0;
      TextureToPng(GetCurrentColorTexture(), fbWidth * 4,
                   StringFromFormat("%sframe%i_color.png",
                                    File::GetUserPath(D_DUMPFRAMES_IDX).c_str(), frame_index),
                   fbWidth, fbHeight, true);
      frame_index++;
    }
  }

  OSD::DoCallbacks(OSD::CallbackType::OnFrame);

  DrawDebugText();

  SWOGLWindow::s_instance->ShowImage(GetCurrentColorTexture(), fbWidth * 4, fbWidth, fbHeight, 1.0);

  UpdateActiveConfig();

  // virtual XFB is not supported
  if (g_ActiveConfig.bUseXFB)
    g_ActiveConfig.bUseRealXFB = true;
}

u32 SWRenderer::AccessEFB(EFBAccessType type, u32 x, u32 y, u32 InputData)
{
  u32 value = 0;

  switch (type)
  {
  case PEEK_Z:
  {
    value = EfbInterface::GetDepth(x, y);
    break;
  }
  case PEEK_COLOR:
  {
    u32 color = 0;
    EfbInterface::GetColor(x, y, (u8*)&color);

    // rgba to argb
    value = (color >> 8) | (color & 0xff) << 24;
    break;
  }
  default:
    break;
  }

  return value;
}

u16 SWRenderer::BBoxRead(int index)
{
  return BoundingBox::coords[index];
}

void SWRenderer::BBoxWrite(int index, u16 value)
{
  BoundingBox::coords[index] = value;
}

TargetRectangle SWRenderer::ConvertEFBRectangle(const EFBRectangle& rc)
{
  TargetRectangle result;
  result.left = rc.left;
  result.top = rc.top;
  result.right = rc.right;
  result.bottom = rc.bottom;
  return result;
}

void SWRenderer::ClearScreen(const EFBRectangle& rc, bool colorEnable, bool alphaEnable,
                             bool zEnable, u32 color, u32 z)
{
  EfbCopy::ClearEfb();
}
