ClipMetadata.hpp

#pragma once
#include <halp/custom_widgets.hpp>
 
#include <string>
#include <string_view>
#include <vector>
 
namespace Process
{
inline constexpr std::string_view clip_metadata_mime = "application/x-ossia-take";
 
struct clip_file_metadata
{
  std::string path;
  halp::clip_stretch stretch{halp::clip_stretch::automatic};
  bool loop{};
};
 
inline constexpr std::string_view clip_stretch_names[]{
    "automatic",   "none",       "repitch", "repitch_fast",
    "timestretch", "timestretch_percussive"};
 
inline std::string_view to_string(halp::clip_stretch s) noexcept
{
  const auto i = std::size_t(s);
  return i < std::size(clip_stretch_names) ? clip_stretch_names[i] : clip_stretch_names[0];
}
 
inline halp::clip_stretch clip_stretch_from_string(std::string_view s) noexcept
{
  for(std::size_t i = 0; i < std::size(clip_stretch_names); i++)
    if(clip_stretch_names[i] == s)
      return halp::clip_stretch(i);
  return halp::clip_stretch::automatic;
}
 
inline std::string encode_clip_metadata(
    const std::vector<std::string>& files, halp::clip_stretch stretch, bool loop = false)
{
  std::string res;
  if(stretch == halp::clip_stretch::automatic && !loop)
    return res;
  for(const auto& f : files)
  {
    res += f;
    if(stretch != halp::clip_stretch::automatic)
    {
      res += "\tstretch=";
      res += to_string(stretch);
    }
    if(loop)
      res += "\tloop=1";
    res += '\n';
  }
  return res;
}
 
inline std::vector<clip_file_metadata> decode_clip_metadata(std::string_view data)
{
  std::vector<clip_file_metadata> res;
  while(!data.empty())
  {
    auto eol = data.find('\n');
    std::string_view line = data.substr(0, eol);
    data = eol == std::string_view::npos ? std::string_view{} : data.substr(eol + 1);
    if(!line.empty() && line.back() == '\r')
      line.remove_suffix(1);
 
    auto tab = line.find('\t');
    clip_file_metadata m;
    m.path = std::string{line.substr(0, tab)};
    if(m.path.empty())
      continue;
    while(tab != std::string_view::npos)
    {
      line.remove_prefix(tab + 1);
      tab = line.find('\t');
      const auto field = line.substr(0, tab);
      const auto eq = field.find('=');
      if(eq == std::string_view::npos)
        continue;
      const auto key = field.substr(0, eq);
      const auto value = field.substr(eq + 1);
      if(key == "stretch")
        m.stretch = clip_stretch_from_string(value);
      else if(key == "loop")
        m.loop = value == "1";
    }
    res.push_back(std::move(m));
  }
  return res;
}
 
inline const clip_file_metadata*
find_clip_metadata(const std::vector<clip_file_metadata>& meta, std::string_view path)
{
  for(const auto& m : meta)
    if(m.path == path)
      return &m;
  auto name = [](std::string_view p) {
    const auto sep = p.find_last_of("/\\");
    return sep == std::string_view::npos ? p : p.substr(sep + 1);
  };
  const auto file = name(path);
  for(const auto& m : meta)
    if(name(m.path) == file)
      return &m;
  return nullptr;
}
}