clap_plugin.h

// SPDX-FileCopyrightText: © 2025-2026 Alexandros Theodotou <alex@zrythm.org>
// SPDX-License-Identifier: LicenseRef-ZrythmLicense
 
#pragma once
 
#include "plugins/plugin.h"
 
#include <QTimer>
 
#include <clap/clap.h>
#include <clap/helpers/host.hh>
 
namespace zrythm::plugins
{
 
using ClapHostBase = clap::helpers::Host<
  clap::helpers::MisbehaviourHandler::Terminate,
  clap::helpers::CheckingLevel::Maximal>;

class ClapPlugin : public Plugin, public ClapHostBase
{
  Q_OBJECT
  QML_ELEMENT
  QML_UNCREATABLE ("")
 
public:
  ClapPlugin (
    dsp::ProcessorBase::ProcessorBaseDependencies dependencies,
    PluginHostWindowFactory                       host_window_factory,
    QObject *                                     parent = nullptr);
  Q_DISABLE_COPY_MOVE (ClapPlugin)
  ~ClapPlugin () override;
 
  // clap_host
  void requestRestart () noexcept override;
  void requestProcess () noexcept override;
  void requestCallback () noexcept override;
 
  // clap_host_gui
  bool implementsGui () const noexcept override { return true; }
  void guiResizeHintsChanged () noexcept override;
  bool guiRequestResize (uint32_t width, uint32_t height) noexcept override;
  bool guiRequestShow () noexcept override;
  bool guiRequestHide () noexcept override;
  void guiClosed (bool wasDestroyed) noexcept override;
 
  // clap_host_timer_support
  bool implementsTimerSupport () const noexcept override { return true; }
  bool timerSupportRegisterTimer (uint32_t periodMs, clap_id * timerId) noexcept
    override;
  bool timerSupportUnregisterTimer (clap_id timerId) noexcept override;
 
  // clap_host_log
  bool implementsLog () const noexcept override { return true; }
  void logLog (clap_log_severity severity, const char * message)
    const noexcept override;
 
  // clap_host_latency
  bool implementsLatency () const noexcept override { return false; }
  void latencyChanged () noexcept override;
 
  // clap_host_thread_check
  bool threadCheckIsMainThread () const noexcept override;
  bool threadCheckIsAudioThread () const noexcept override;
 
  // clap_host_params
  bool implementsParams () const noexcept override { return true; }
  void paramsRescan (clap_param_rescan_flags flags) noexcept override;
  void
  paramsClear (clap_id paramId, clap_param_clear_flags flags) noexcept override;
  void paramsRequestFlush () noexcept override;
 
  // clap_host_posix_fd_support
  bool implementsPosixFdSupport () const noexcept override { return true; }
  bool posixFdSupportRegisterFd (int fd, clap_posix_fd_flags_t flags) noexcept
    override;
  bool
  posixFdSupportModifyFd (int fd, clap_posix_fd_flags_t flags) noexcept override;
  bool posixFdSupportUnregisterFd (int fd) noexcept override;
 
  // clap_host_thread_pool
  bool implementsThreadPool () const noexcept override { return true; }
  bool threadPoolRequestExec (uint32_t numTasks) noexcept override;
 
  // clap_host_state
  bool implementsState () const noexcept override { return true; }
  void stateMarkDirty () noexcept override;
 
  // clap_host_preset_load
  bool implementsPresetLoad () const noexcept override { return true; }
  void presetLoadLoaded (
    uint32_t     locationKind,
    const char * location,
    const char * loadKey) noexcept override;
  void presetLoadOnError (
    uint32_t     locationKind,
    const char * location,
    const char * loadKey,
    int32_t      osError,
    const char * msg) noexcept override;
 
  // ============================================================================
  // Plugin Interface Implementation
  // ============================================================================
 
  units::sample_u32_t get_single_playback_latency () const override;
 
protected:
  void prepare_for_processing_impl (
    units::sample_rate_t sample_rate,
    units::sample_u32_t  max_block_length) override;
 
  void
  process_impl (dsp::graph::EngineProcessTimeInfo time_info) noexcept override;
 
  void release_resources_impl () override;
 
Q_SIGNALS:
  void paramsChanged ();
  void paramAdjusted (clap_id paramId);
  void pluginLoadedChanged (bool pluginLoaded);
 
private Q_SLOTS:
  void on_configuration_changed (
    PluginConfiguration * config,
    bool                  generateNewPluginPortsAndParams);

  void on_ui_visibility_changed ();
 
private:
  bool load_plugin (
    const std::filesystem::path &path,
    int64_t                      plugin_unique_id,
    bool                         generate_new_ports = true);
  void unload_current_plugin ();
 
  void create_ports_from_clap_plugin ();
 
  void show_editor ();
  void hide_editor ();
 
  static constexpr auto kStateKey = "state"sv;
  friend void           to_json (nlohmann::json &j, const ClapPlugin &p);
  friend void           from_json (const nlohmann::json &j, ClapPlugin &p);

  QByteArray save_state_to_byte_array () const;
 
  std::string save_state_impl () const override;
  void        load_state_impl (const std::string &base64_state) override;

  void apply_state_from_byte_array (const QByteArray &data);
 
private:
  class ClapPluginImpl;
  std::unique_ptr<ClapPluginImpl> pimpl_;

  std::optional<QByteArray> state_to_apply_;

  std::unordered_map<dsp::ProcessorParameter *, clap_id> zrythm_to_clap_;
};
 
} // namespace zrythm::plugins