#include "render.h"

#include <cstring>
#include <filesystem>
#include <format>
#include <fstream>

#ifdef _WIN32
  #include "string_.h"
  #define POPEN _popen
  #define PCLOSE _pclose
  constexpr auto PWRITE_MODE = "wb";
  constexpr auto PREAD_MODE = "r";
#elif __unix__
  #define POPEN popen
  #define PCLOSE pclose
  constexpr auto PWRITE_MODE = "w";
  constexpr auto PREAD_MODE = "r";
#endif

#include "log.h"

using namespace anm2ed::resource;
using namespace glm;

namespace anm2ed
{
  constexpr auto FFMPEG_POPEN_ERROR = "popen() (for FFmpeg) failed!\n{}";

  bool animation_render(const std::string& ffmpegPath, const std::string& path, std::vector<Texture>& frames,
                        AudioStream& audioStream, render::Type type, ivec2 size, int fps)
  {
    if (frames.empty() || size.x <= 0 || size.y <= 0 || fps <= 0 || ffmpegPath.empty() || path.empty()) return false;

    std::filesystem::path audioPath{};
    std::string audioInputArguments{};
    std::string audioOutputArguments{"-an"};
    std::string command{};

    auto remove_audio_file = [&]()
    {
      if (!audioPath.empty())
      {
        std::error_code ec;
        std::filesystem::remove(audioPath, ec);
      }
    };

    if (type != render::GIF && !audioStream.stream.empty() && audioStream.spec.freq > 0 &&
        audioStream.spec.channels > 0)
    {
      audioPath = std::filesystem::temp_directory_path() / std::format("{}.f32", path);

      std::ofstream audioFile(audioPath, std::ios::binary);

      if (audioFile)
      {
        auto data = (const char*)audioStream.stream.data();
        auto byteCount = audioStream.stream.size() * sizeof(float);
        audioFile.write(data, byteCount);
        audioFile.close();

        audioInputArguments = std::format("-f f32le -ar {0} -ac {1} -i \"{2}\"", audioStream.spec.freq,
                                          audioStream.spec.channels, audioPath.string());

        switch (type)
        {
          case render::WEBM:
            audioOutputArguments = "-c:a libopus -b:a 160k -shortest";
            break;
          case render::MP4:
            audioOutputArguments = "-c:a aac -b:a 192k -shortest";
            break;
          default:
            break;
        }
      }
      else
      {
        logger.warning("Failed to open temporary audio file; exporting video without audio.");
        remove_audio_file();
      }
    }

    command = std::format("\"{0}\" -y -f rawvideo -pix_fmt rgba -s {1}x{2} -r {3} -i pipe:0", ffmpegPath, size.x,
                          size.y, fps);

    if (!audioInputArguments.empty()) command += " " + audioInputArguments;

    switch (type)
    {
      case render::GIF:
        command +=
            " -lavfi \"split[s0][s1];[s0]palettegen=stats_mode=full[p];[s1][p]paletteuse=dither=floyd_steinberg\""
            " -loop 0";
        command += std::format(" \"{}\"", path);
        break;
      case render::WEBM:
        command += " -c:v libvpx-vp9 -crf 30 -b:v 0 -pix_fmt yuva420p -row-mt 1 -threads 0 -speed 2 -auto-alt-ref 0";
        if (!audioOutputArguments.empty()) command += " " + audioOutputArguments;
        command += std::format(" \"{}\"", path);
        break;
      case render::MP4:
        command += " -vf \"format=yuv420p,scale=trunc(iw/2)*2:trunc(ih/2)*2\" -c:v libx265 -crf 20 -preset slow"
                   " -tag:v hvc1 -movflags +faststart";
        if (!audioOutputArguments.empty()) command += " " + audioOutputArguments;
        command += std::format(" \"{}\"", path);
        break;
      default:
        return false;
    }

#if _WIN32
    command = util::string::quote(command);
#endif

    logger.command(command);

    FILE* fp = POPEN(command.c_str(), PWRITE_MODE);

    if (!fp)
    {
      remove_audio_file();
      logger.error(std::format(FFMPEG_POPEN_ERROR, strerror(errno)));
      return false;
    }

    for (auto& frame : frames)
    {
      auto frameSize = frame.pixel_size_get();

      if (fwrite(frame.pixels.data(), 1, frameSize, fp) != frameSize)
      {
        remove_audio_file();
        PCLOSE(fp);
        return false;
      }
    }

    auto code = PCLOSE(fp);
    remove_audio_file();
    return (code == 0);
  }
}