ca-frame-stream.H

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
#ifndef CA_FRAME_STREAM_H
#define CA_FRAME_STREAM_H
 
#include <cstddef>
#include <filesystem>
#include <fstream>
#include <iomanip>
#include <ostream>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
 
#include <ah-errors.H>
#include <tpl_array.H>
 
#include <ca-io.H>
#include <ca-tikz.H>
 
namespace Aleph {
namespace CA {
 
template <typename Sink, typename Lattice>
concept Frame_Sink = requires(Sink &sink, std::size_t step, const Lattice &frame)
{
  sink.accept(step, frame);
  sink.flush();
};
 
enum class Frame_Output_Format
{
  PGM,   
  PPM,   
  RLE,   
  CSV,   
  JSON,  
  TikZ   
};
 
struct Frame_Stream_Options
{
  std::filesystem::path directory = "ca_frames";          
  std::string prefix = "frame";                           
  Frame_Output_Format format = Frame_Output_Format::PPM;  
  std::size_t stride = 1;                                 
  std::size_t zero_pad = 6;                               
  bool write_manifest = true;                             
  RLE_Write_Options rle_options{};                        
  CSV_Options csv_options{};                              
  JSON_Write_Options json_options{};                      
  Rect_Tikz_Options tikz_options{};                       
  NetPBM_Write_Options netpbm_options{};                  
};
 
namespace ca_frame_stream_detail {
 
inline const char *extension(Frame_Output_Format format) noexcept
{
  switch (format)
    {
    case Frame_Output_Format::PGM:
      return ".pgm";
    case Frame_Output_Format::PPM:
      return ".ppm";
    case Frame_Output_Format::RLE:
      return ".rle";
    case Frame_Output_Format::CSV:
      return ".csv";
    case Frame_Output_Format::JSON:
      return ".json";
    case Frame_Output_Format::TikZ:
      return ".tex";
    }
  return ".frame";
}
 
inline const char *format_name(Frame_Output_Format format) noexcept
{
  switch (format)
    {
    case Frame_Output_Format::PGM:
      return "pgm";
    case Frame_Output_Format::PPM:
      return "ppm";
    case Frame_Output_Format::RLE:
      return "rle";
    case Frame_Output_Format::CSV:
      return "csv";
    case Frame_Output_Format::JSON:
      return "json";
    case Frame_Output_Format::TikZ:
      return "tikz";
    }
  return "unknown";
}
 
inline std::string padded_step(std::size_t step, std::size_t width)
{
  std::ostringstream out;
  out << std::setw(static_cast<int>(width)) << std::setfill('0') << step;
  return out.str();
}
 
inline std::filesystem::path format_step_path(const std::filesystem::path &pattern,
                                              const std::size_t step,
                                              const std::size_t zero_pad)
{
  std::string text = pattern.string();
  const std::string value = padded_step(step, zero_pad);
  auto replace_all = [&](const std::string &needle)
  {
    std::size_t pos = 0;
    bool changed = false;
    while ((pos = text.find(needle, pos)) != std::string::npos)
      {
        text.replace(pos, needle.size(), value);
        pos += value.size();
        changed = true;
      }
    return changed;
  };
 
  if (replace_all("{step}"))
    return std::filesystem::path(text);
  if (replace_all("{}"))
    return std::filesystem::path(text);
  return pattern;
}
 
}  // namespace ca_frame_stream_detail
 
[[nodiscard]] inline std::filesystem::path format_step_path(const std::filesystem::path &pattern,
                                                            const std::size_t step,
                                                            const std::size_t zero_pad = 6)
{
  return ca_frame_stream_detail::format_step_path(pattern, step, zero_pad);
}
 
template <typename... Sinks>
class Composite_Frame_Sink
{
  std::tuple<Sinks...> sinks_;
 
public:
  explicit Composite_Frame_Sink(Sinks... sinks) : sinks_(std::move(sinks)...) {}
 
  template <std::size_t I>
  [[nodiscard]] auto &get() noexcept
  {
    return std::get<I>(sinks_);
  }
 
  template <std::size_t I>
  [[nodiscard]] const auto &get() const noexcept
  {
    return std::get<I>(sinks_);
  }
 
  template <typename Lattice>
  void accept(const std::size_t step, const Lattice &frame)
  {
    static_assert((Frame_Sink<Sinks, Lattice> and ...),
                  "Every child sink must satisfy Frame_Sink<Sink, Lattice>");
    std::apply([&](auto &...sink)
    {
      (sink.accept(step, frame), ...);
    }, sinks_);
  }
 
  void flush()
  {
    std::apply([](auto &...sink)
    {
      (sink.flush(), ...);
    }, sinks_);
  }
};
 
class Directory_Frame_Sink
{
  Frame_Stream_Options opts_;
  Array<std::pair<std::size_t, std::filesystem::path>> written_;
 
  [[nodiscard]] std::filesystem::path frame_path(std::size_t step) const
  {
    return opts_.directory
         / (opts_.prefix + "_" + ca_frame_stream_detail::padded_step(step, opts_.zero_pad)
            + ca_frame_stream_detail::extension(opts_.format));
  }
 
  template <typename Lattice>
  void write_one(std::ostream &out, const Lattice &frame) const
  {
    switch (opts_.format)
      {
      case Frame_Output_Format::PGM:
        write_pgm(out, frame, opts_.netpbm_options);
        break;
      case Frame_Output_Format::PPM:
        write_ppm(out, frame, opts_.netpbm_options);
        break;
      case Frame_Output_Format::RLE:
        write_rle(out, frame, opts_.rle_options);
        break;
      case Frame_Output_Format::CSV:
        write_csv(out, frame, opts_.csv_options);
        break;
      case Frame_Output_Format::JSON:
        write_json(out, frame, opts_.json_options);
        break;
      case Frame_Output_Format::TikZ:
        render_lattice_tikz(out, frame, opts_.tikz_options);
        break;
      }
  }
 
public:
  explicit Directory_Frame_Sink(Frame_Stream_Options opts) : opts_(std::move(opts))
  {
    ah_domain_error_if(opts_.stride == 0) << "Directory_Frame_Sink: stride must be positive";
    std::error_code ec;
    std::filesystem::create_directories(opts_.directory, ec);
    ah_runtime_error_if(ec) << "Directory_Frame_Sink: cannot create directory '"
                            << opts_.directory.string() << "': " << ec.message();
  }
 
  [[nodiscard]] const Frame_Stream_Options &options() const noexcept
  {
    return opts_;
  }
 
  [[nodiscard]] const Array<std::pair<std::size_t, std::filesystem::path>> &written_frames() const noexcept
  {
    return written_;
  }
 
  template <typename Lattice>
  void accept(std::size_t step, const Lattice &frame)
  {
    if (step % opts_.stride != 0)
      return;
    const std::filesystem::path path = frame_path(step);
    std::ofstream out(path, std::ios::binary);
    ah_runtime_error_if(not out) << "Directory_Frame_Sink::accept: cannot open '" << path.string()
                                 << "'";
    write_one(out, frame);
    ah_runtime_error_if(not out) << "Directory_Frame_Sink::accept: write failed for '"
                                 << path.string() << "'";
    written_.append(std::pair{step, path});
  }
 
  void flush() const
  {
    if (not opts_.write_manifest)
      return;
    const std::filesystem::path path = opts_.directory / "manifest.csv";
    std::ofstream out(path);
    ah_runtime_error_if(not out) << "Directory_Frame_Sink::flush: cannot open '" << path.string()
                                 << "'";
    out << "step,format,path\n";
    for (const auto &[step, frame] : written_)
      {
        // Escape the path as a quoted CSV field so commas, quotes or
        // other separator-like characters in the path do not corrupt
        // the manifest layout. Internal '"' are doubled per RFC 4180.
        const std::string raw = frame.string();
        std::string quoted;
        quoted.reserve(raw.size() + 2);
        quoted.push_back('"');
        for (const char c : raw)
          {
            if (c == '"')
              quoted.push_back('"');
            quoted.push_back(c);
          }
        quoted.push_back('"');
        out << step << ',' << ca_frame_stream_detail::format_name(opts_.format) << ',' << quoted
            << '\n';
      }
    ah_runtime_error_if(not out) << "Directory_Frame_Sink::flush: write failed for '"
                                 << path.string() << "'";
  }
 
  [[nodiscard]] std::string montage_command_hint(const std::string &output_file = "ca.mp4",
                                                 unsigned fps = 24) const
  {
    std::ostringstream cmd;
    cmd << "ffmpeg -y -framerate " << fps << " -i "
        << (opts_.directory
            / (opts_.prefix + "_%0" + std::to_string(opts_.zero_pad) + "d"
               + ca_frame_stream_detail::extension(opts_.format)))
             .string()
        << " -pix_fmt yuv420p " << output_file;
    return cmd.str();
  }
};
 
}  // namespace CA
}  // namespace Aleph
 
#endif  // CA_FRAME_STREAM_H