/****************************************************************************
    
    lv2gui.hpp - Wrapper library to make it easier to write LV2 GUIs in C++
    
    Copyright (C) 2006-2008 Lars Luthman <lars.luthman@gmail.com>
    Modified by Dave Robillard, 2008 (URI map mixin)
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
    
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA  02110-1301  USA

****************************************************************************/

#ifndef LV2GUI_HPP
#define LV2GUI_HPP

#include <cstdlib>
#include <cstring>
#include <map>

#include <gtkmm/box.h>
#include <gtkmm/main.h>
#include <gtkmm/widget.h>

#include <lv2_ui.h>
#include <lv2_ui_presets.h>
#include <lv2_uri_map.h>
#include <lv2_event_helpers.h>
#include <lv2_osc.h>
#include <lv2types.hpp>


namespace LV2 {

  
  /** @internal
      A convenient typedef that is only used internally. */
  typedef std::vector<LV2UI_Descriptor*> GUIDescList;
    
  
  /** @internal
      This function returns the list of LV2 descriptors. It should only be 
      used internally. */
  GUIDescList& get_lv2g2g_descriptors();
  
  
  /** @defgroup guimixins GUI mixins
      These classes implement extra functionality that you may want to have
      in your GUI class, just like the @ref pluginmixins "plugin mixins" do
      for plugin classes. Some of them are template classes with a boolean
      @c Required parameter - if this is true the GUI will fail to instantiate
      unless the host supports the extension implemented by that mixin.
      For example, if you wanted a GUI that wrote a MIDI Note On event to port
      3 in the plugin whenever the user clicked a button, you could do it like
      this:

      @code
#include <lv2gui.hpp>
#include <gtkmm.h>

class MyGUI : public LV2::GUI<MyGUI, LV2::URIMap<true>, LV2::WriteMIDI<true> > {
public:
  MyGUI(const char* plugin_uri)
    : m_button("Click me!") {
    pack_start(m_button);
    m_button.signal_clicked().connect(sigc::mem_fun(*this, &MyGUI::send_event));
  }
protected:
  void send_event() {
    uint8_t noteon[] = { 0x90, 0x50, 0x40 };
    write_midi(3, 3, noteon);
  }
  Gtk::Button m_button;
};
      @endcode

      The function @c write_midi() is implemented in LV2::WriteMIDI and thus
      available in @c MyGUI. LV2::WriteMIDI requires that LV2::URIMap is also
      used (because of the way event types work in LV2) - if you don't add
      LV2::URIMap as well you will get a compilation error.
  */


  /** This extension provides no extra functions or data, it just makes sure
      that the GUI will not instantiate unless the host passes a Feature
      for the noUserResize GUI feature defined in the GUI extension (if
      @c Required is @c true).

      The actual type that your plugin class will inherit when you use 
      this mixin is the internal struct template I.
      @ingroup guimixins
  */
  template <bool Required = true>
  struct NoUserResize {
    
    /** This is the type that your plugin or GUI class will inherit when you 
	use the	NoUserResize mixin. The public and protected members defined 
	here will be available in your plugin class.
    */
    template <class Derived> struct I : public Extension<Required> {
      
      /** @internal */
      static void map_feature_handlers(FeatureHandlerMap& hmap) {
	hmap["http://ll-plugins.nongnu.org/lv2/dev/ui#noUserResize"] = 
	  &I<Derived>::handle_feature;
      }
      
      /** @internal */
      static void handle_feature(void* instance, void* data) { 
	Derived* d = reinterpret_cast<Derived*>(instance);
	I<Derived>* e = static_cast<I<Derived>*>(d);
	e->m_ok = true;
      }
      
    };
    
  };


  /** This extension provides no extra functions or data, it just makes sure
      that the GUI will not instantiate unless the host passes a Feature
      for the fixedSize GUI feature defined in the GUI extension (if
      @c Required is @c true).

      The actual type that your plugin class will inherit when you use 
      this mixin is the internal struct template I.
      @ingroup guimixins
  */
  template <bool Required = true>
  struct FixedSize {
    
    /** This is the type that your plugin or GUI class will inherit when you 
	use the	FixedSize mixin. The public and protected members defined 
	here will be available in your plugin class.
    */
    template <class Derived> struct I : public Extension<Required> {
      
      /** @internal */
      static void map_feature_handlers(FeatureHandlerMap& hmap) {
	hmap["http://ll-plugins.nongnu.org/lv2/dev/ui#fixedSize"] = 
	  &I<Derived>::handle_feature;
      }
      
      /** @internal */
      static void handle_feature(void* instance, void* data) {
	Derived* d = reinterpret_cast<Derived*>(instance);
	I<Derived>* e = static_cast<I<Derived>*>(d);
	e->m_ok = true;
      }
    
    };
    
  };


  /** Preset GUI extension - the host will tell the GUI what presets are
      available and which one of them is currently active, the GUI can request 
      saving and using presets.

      The actual type that your plugin class will inherit when you use 
      this mixin is the internal struct template I.
      @ingroup guimixins
  */
  template <bool Required = true>
  struct Presets {
    
    /** This is the type that your plugin or GUI class will inherit when you 
	use the	Presets mixin. The public and protected members defined 
	here will be available in your plugin class.
    */
    template <class Derived> struct I : public Extension<Required> {
      
      /** @internal */
      I() : m_hdesc(0), m_host_support(false) { }
	
	/** @internal */
	static void map_feature_handlers(FeatureHandlerMap& hmap) {
	  hmap[LV2_UI_PRESETS_URI] = &I<Derived>::handle_feature;
	}
	
	/** @internal */
	static void handle_feature(void* instance, void* data) {
	  Derived* d = reinterpret_cast<Derived*>(instance);
	  I<Derived>* e = static_cast<I<Derived>*>(d);
	  e->m_hdesc = static_cast<LV2UI_Presets_Feature*>(data);
	  e->m_ok = (e->m_hdesc != 0);
	  e->m_host_support = (e->m_hdesc != 0);
	}
	
	
	/** This is called by the host to let the GUI know that a new 
	    preset has been added or renamed.
	    @param number The number of the added preset.
	    @param name The name of the added preset.
	*/
	void preset_added(uint32_t    number, 
			   char const* name) {
	  
	}
	
	/** This is called by the host to let the GUI know that a previously 
	    existing preset has been removed.
	    @param number The number of the removed preset.
	*/
	void preset_removed(uint32_t number) {
	  
	}
	
	/** This is called by the host to let the GUI know that all previously
	    existing presets have been removed. 
	*/
	void presets_cleared() {
	  
	}
	
	/** This is called by the host to let the GUI know that the current 
	    preset has changed. If the number is equal to 
	    @c LV2_UI_PRESETS_NOPRESET there is no current preset.
	    @param number The number of the active preset, or 
	                  LV2_UI_PRESETS_NOPRESET if there is no active preset.
	*/
	void current_preset_changed(uint32_t number) {
	  
	}
	
	/** @internal
	    Returns the plugin descriptor for this extension.
	*/
	static void const* extension_data(char const* uri) {
	  static LV2UI_Presets_GDesc desc = { &_preset_added,
					      &_preset_removed,
					      &_presets_cleared,
					      &_current_preset_changed };
	  if (!std::strcmp(uri, LV2_UI_PRESETS_URI))
	    return &desc;
	  return 0;
	}
	
    protected:
	
	/** You can call this to request that the host changes the current 
	    preset to @c preset. */
	void change_preset(uint32_t preset) {
	  if (m_hdesc)
	    m_hdesc->change_preset(static_cast<Derived*>(this)->controller(), 
				   preset);
	}
	
	/** You can call this to request that the host saves the current state
	    of the plugin instance to a preset with the given number and name.
	*/
	void save_preset(uint32_t preset, char const* name) {
	  if (m_hdesc)
	    m_hdesc->save_preset(static_cast<Derived*>(this)->controller(), 
				 preset, name);
	}
      
        /** Returns @c true if the host supports the Preset feature, @c false
	    if it does not. */
        bool host_supports_presets() const {
	  return m_host_support;
	}
	
    private:
	
	static void _preset_added(LV2UI_Handle gui, 
				   uint32_t     number, 
				   char const*  name) {
	  static_cast<Derived*>(gui)->preset_added(number, name);
	}
	
	static void _preset_removed(LV2UI_Handle gui, 
				     uint32_t     number) {
	  static_cast<Derived*>(gui)->preset_removed(number);
	}
	
	static void _presets_cleared(LV2UI_Handle gui) {
	  static_cast<Derived*>(gui)->presets_cleared();
	}
	
	static void _current_preset_changed(LV2UI_Handle gui, 
					     uint32_t     number) {
	  static_cast<Derived*>(gui)->current_preset_changed(number);
	}
	
	
	LV2UI_Presets_Feature* m_hdesc;
        bool m_host_support;
	
    };

  };

  
  /** A mixin that allows easy sending of MIDI from GUI to plugin. 

      The actual type that your plugin class will inherit when you use 
      this mixin is the internal struct template I.
      @ingroup guimixins
  */
  template <bool Required = true>
  struct WriteMIDI {
    
    enum {
      EVENT_BUFFER_SIZE = 4
    };
    
    /** This is the type that your plugin or GUI class will inherit when you 
	use the	WriteMIDI mixin. The public and protected members defined 
	here will be available in your plugin class.
    */
    template <class Derived> struct I : Extension<Required> {

      /** @internal */
      I() : m_midi_type(0) {
	m_buffer = lv2_event_buffer_new(sizeof(LV2_Event) + EVENT_BUFFER_SIZE, 
					0);
      }
      
      /** @internal */
      bool check_ok() {
	Derived* d = static_cast<Derived*>(this);
	m_midi_type = d->
	  uri_to_id(LV2_EVENT_URI, "http://lv2plug.in/ns/ext/midi#MidiEvent");
	m_event_buffer_format = d->
	  uri_to_id(LV2_UI_URI, "http://lv2plug.in/ns/extensions/ui#Events");
	return !Required || (m_midi_type && m_event_buffer_format);
      }
      
    protected:
      
      /** This function can be used to write a MIDI event to an event input port
	  in the plugin.
	  @param port The port index.
	  @param size The number of bytes in the MIDI event.
	  @param data The MIDI data for the event. This should point to an array
	              of @c size bytes.
	  @return @c true if the event could be written to the plugin port, 
	          @c false if it couldn't (for example if the host doesn't
		     support MIDI events).
      */
      bool write_midi(uint32_t port, uint32_t size, const uint8_t* data) {
	if (m_midi_type == 0)
	  return false;
	LV2_Event_Buffer* buffer;
	if (size <= 4)
	  buffer = m_buffer;
	else
	  buffer = lv2_event_buffer_new(sizeof(LV2_Event) + size, 0);
 	lv2_event_buffer_reset(m_buffer, 0, m_buffer->data);
	LV2_Event_Iterator iter;
	lv2_event_begin(&iter, m_buffer);
	lv2_event_write(&iter, 0, 0, m_midi_type, size, data);
	static_cast<Derived*>(this)->
	  write(port, m_buffer->header_size + m_buffer->capacity, 
		m_event_buffer_format, m_buffer);
	if (size > 4)
	  std::free(buffer);
	return true;
      }
      
      uint32_t m_midi_type;
      uint32_t m_event_buffer_format;
      LV2_Event_Buffer* m_buffer;
      
    };
    
  };  
  
  
  /** @internal
      A mixin that allows easy sending of OSC from GUI to plugin. 

      The actual type that your plugin class will inherit when you use 
      this mixin is the internal struct template I.
      
      Do NOT use this. It may change in the future.
      @ingroup guimixins
  */
  template <bool Required = true>
  struct WriteOSC {
    
    /** This is the type that your plugin or GUI class will inherit when you 
	use the	WriteOSC mixin. The public and protected members defined 
	here will be available in your plugin class.
    */
    template <class Derived> struct I : Extension<Required> {
      
      I() : m_osc_type(0) {
	m_buffer = lv2_event_buffer_new(sizeof(LV2_Event) + 256, 0);
      }
      
      bool check_ok() {
	Derived* d = static_cast<Derived*>(this);
	m_osc_type = d->
	  uri_to_id(LV2_EVENT_URI, "http://lv2plug.in/ns/ext/osc#OscEvent");
	m_event_buffer_format = d->
	  uri_to_id(LV2_UI_URI, "http://lv2plug.in/ns/extensions/ui#Events");
	return !Required || (m_osc_type && m_event_buffer_format);
      }
      
    protected:
      
      bool write_osc(uint32_t port, const char* path, const char* types, ...) {
	if (m_osc_type == 0)
	  return false;
	// XXX handle all sizes here - this is dangerous
	lv2_event_buffer_reset(m_buffer, 0, m_buffer->data);
	LV2_Event_Iterator iter;
	lv2_event_begin(&iter, m_buffer);
	va_list ap;
	va_start(ap, types);
	uint32_t size = lv2_osc_event_vsize(path, types, ap);
	va_end(ap);
	if (!size)
	  return false;
	va_start(ap, types);
	bool success = lv2_osc_buffer_vappend(&iter, 0, 0, m_osc_type, 
					      path, types, size, ap);
	va_end(ap);
	if (success) {
	  static_cast<Derived*>(this)->
	    write(port, m_buffer->header_size + m_buffer->capacity, 
		  m_event_buffer_format, m_buffer);
	  return true;
	}
	return false;
      }
      
      uint32_t m_osc_type;
      uint32_t m_event_buffer_format;
      LV2_Event_Buffer* m_buffer;
      
    };
    
  };  
  
  
  /** This is the base class for a plugin GUI. You should inherit it and 
      override any public member functions you want to provide 
      implementations for. All subclasses must have a constructor with 
      the signature
      
      @code
      MyGUI(char const* plugin_uri);
      @endcode
      
      where @c plugin_uri is the URI of the plugin that this GUI will
      control (not the URI for the GUI itself).

      You can extend your GUI classes, for example adding support for
      GUI extensions, by passing @ref guimixins "GUI mixin classes" as template
      parameters to GUI (second template parameter and onwards).
  */
  template<class Derived, class Ext1 = End, class Ext2 = End, class Ext3 = End,
           class Ext4 = End, class Ext5 = End, class Ext6 = End,
	   class Ext7 = End, class Ext8 = End, class Ext9 = End>
  class GUI : public Gtk::HBox, public MixinTree<Derived, 
						 Ext1, Ext2, Ext3, Ext4, 
						 Ext5, Ext6, Ext7, Ext8, Ext9> {
  public:
    
    /** @internal
	The constructor for the GUI class. You should never use it directly.
    */
    inline GUI() {
      m_ctrl = s_ctrl;
      m_wfunc = s_wfunc;
      m_features = s_features;
      m_bundle_path = s_bundle_path;
      s_ctrl = 0;
      s_wfunc = 0;
      s_features = 0;
      s_bundle_path = 0;
      if (m_features) {
	FeatureHandlerMap hmap;
	Derived::map_feature_handlers(hmap);
	for (const Feature* const* iter = m_features; *iter != 0; ++iter) {
	  FeatureHandlerMap::iterator miter;
	  miter = hmap.find((*iter)->URI);
	  if (miter != hmap.end())
	    miter->second(static_cast<Derived*>(this), (*iter)->data);
	}
      }
    }
    
    /** Override this if you want your GUI to do something when a control port
	value changes in the plugin instance. */
    inline void port_event(uint32_t port, uint32_t buffer_size, 
			   uint32_t format, void const* buffer) { }
    
    /** Use this template function to register a class as a LV2 GUI. */
    static int register_class(char const* uri) {
      LV2UI_Descriptor* desc = new LV2UI_Descriptor;
      std::memset(desc, 0, sizeof(LV2UI_Descriptor));
      desc->URI = strdup(uri);
      desc->instantiate = &Derived::create_ui_instance;
      desc->cleanup = &Derived::delete_ui_instance;
      desc->port_event = &Derived::_port_event;
      desc->extension_data = &Derived::extension_data;
      get_lv2g2g_descriptors().push_back(desc);
      return get_lv2g2g_descriptors().size() - 1;
    }
    
  protected:
    
    /** Send a chunk of data to a plugin port. The format of the chunk is
	determined by the port type and the transfer mechanisms used, you
	should probably use a wrapper function instead such as write_control().
    */
    inline void write(uint32_t port, uint32_t buffer_size, 
		      uint32_t format, void const* buffer) {
      (*m_wfunc)(m_ctrl, port, buffer_size, format, buffer);
    }
    
    /** Set the value of a control input port in the plugin instance. */
    inline void write_control(uint32_t port, float value) {
      write(port, sizeof(float), 0, &value);
    }
    
    /** Get the feature array that was passed by the host. This may only
	be valid while the constructor is running. */
    inline LV2::Feature const* const* features() {
      return m_features;
    }
    
    /** Get the filesystem path to the bundle that contains this GUI. */
    inline char const* bundle_path() const {
      return m_bundle_path;
    }
    
  public:
    /** Get the controller - a handle on the plugin instance this GUI
	is controlling. You only need it if you want to handle extensions
	yourself. */
    inline void* controller() {
      return m_ctrl;
    }
    
    
  private:
    
    // This is quite ugly but needed to allow these mixins to call 
    // protected functions in the GUI class, which we want.
    friend class WriteMIDI<true>::I<Derived>;
    friend class WriteMIDI<false>::I<Derived>;
    friend class WriteOSC<true>::I<Derived>;
    friend class WriteOSC<false>::I<Derived>;
    
    /** @internal
	This function creates an instance of a plugin GUI. It is used 
	as the instantiate() callback in the LV2 descriptor. You should not use
	it directly. */
    static LV2UI_Handle create_ui_instance(struct _LV2UI_Descriptor const* 
					   descriptor,
					   char const* plugin_uri,
					   char const* bundle_path,
					   LV2UI_Write_Function write_func,
					   LV2UI_Controller ctrl,
					   LV2UI_Widget* widget,
					   Feature const* const* features) {
      
      // copy some data to static variables so the subclasses don't have to
      // bother with it - this is threadsafe since hosts are not allowed
      // to instantiate the same plugin concurrently
      s_ctrl = ctrl;
      s_wfunc = write_func;
      s_features = features;
      s_bundle_path = bundle_path;
      
      // this is needed to initialise gtkmm stuff in case we're running in
      // a Gtk+ or PyGtk host or some other language
      Gtk::Main::init_gtkmm_internals();
      
      // create the GUI object
      Derived* t = new Derived(plugin_uri);
      *widget = static_cast<Gtk::Widget*>(t)->gobj();
      
      // check that everything is OK
      if (t->check_ok())
	return reinterpret_cast<LV2UI_Handle>(t);
      delete t;
      return 0;
    }
    

    /** @internal
	This function destroys an instance of a GUI. It is used as the
	cleanup() callback in the LV2UI descriptor. You should not use it 
	directly. */
    static void delete_ui_instance(LV2UI_Handle instance) {
      delete static_cast<Derived*>(instance);
    }
    
    
    /** @internal
	This is the main port_event() callback. You should not use it directly.
    */
    static void _port_event(LV2UI_Handle instance, uint32_t port, 
			    uint32_t buffer_size, uint32_t format, 
			    void const* buffer) {
      static_cast<Derived*>(instance)->port_event(port, buffer_size, 
						  format, buffer);
    }
    

    void* m_ctrl;
    LV2UI_Write_Function m_wfunc;
    LV2::Feature const* const* m_features;
    char const* m_bundle_path;
    
    static void* s_ctrl;
    static LV2UI_Write_Function s_wfunc;
    static LV2::Feature const* const* s_features;
    static char const* s_bundle_path;
    
  };

  
  /* Yes, static variables are messy. */
  template<class Derived, class Ext1, class Ext2, class Ext3, class Ext4,
           class Ext5, class Ext6, class Ext7, class Ext8, class Ext9>
  void* GUI<Derived, Ext1, Ext2, Ext3, Ext4, 
	    Ext5, Ext6, Ext7, Ext8, Ext9>::s_ctrl = 0; 
  
  template<class Derived, class Ext1, class Ext2, class Ext3, class Ext4,
           class Ext5, class Ext6, class Ext7, class Ext8, class Ext9>
  LV2UI_Write_Function GUI<Derived, Ext1, Ext2, Ext3, Ext4, 
			   Ext5, Ext6, Ext7, Ext8, Ext9>::s_wfunc = 0;
  
  template<class Derived, class Ext1, class Ext2, class Ext3, class Ext4,
           class Ext5, class Ext6, class Ext7, class Ext8, class Ext9>
  LV2::Feature const* const* GUI<Derived, Ext1, Ext2, Ext3, Ext4, 
				 Ext5, Ext6, Ext7, Ext8, Ext9>::s_features = 0;
  
  template<class Derived, class Ext1, class Ext2, class Ext3, class Ext4,
           class Ext5, class Ext6, class Ext7, class Ext8, class Ext9>
  char const* GUI<Derived, Ext1, Ext2, Ext3, Ext4, 
		  Ext5, Ext6, Ext7, Ext8, Ext9>::s_bundle_path = 0;
  

}


#endif