/*
 * Copyright (C) 2014,2019 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2013 Paul Davis
 *
 * 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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __libbackend_pulse_audiobackend_h__
#define __libbackend_pulse_audiobackend_h__

#include <map>
#include <set>
#include <string>
#include <vector>

#include <pthread.h>
#include <stdint.h>

#include <pulse/pulseaudio.h>

#include <boost/shared_ptr.hpp>

#include "ardour/audio_backend.h"
#include "ardour/dsp_load_calculator.h"
#include "pbd/natsort.h"

#define MaxPulseMidiEventSize (256)

namespace ARDOUR {

class PulseAudioBackend;

class PulseMidiEvent
{
public:
	PulseMidiEvent (const pframes_t timestamp, const uint8_t* data, size_t size);
	PulseMidiEvent (const PulseMidiEvent& other);

	size_t size () const { return _size; };
	pframes_t timestamp () const { return _timestamp; };
	const uint8_t* data () const { return _data; };
	const uint8_t* const_data () const { return _data; };
	bool operator< (const PulseMidiEvent& other) const { return timestamp () < other.timestamp (); };

private:
	size_t    _size;
	pframes_t _timestamp;
	uint8_t   _data[MaxPulseMidiEventSize];
};

typedef std::vector<boost::shared_ptr<PulseMidiEvent> > PulseMidiBuffer;

class PulsePort
{
protected:
	PulsePort (PulseAudioBackend& b, const std::string&, PortFlags);

public:
	virtual ~PulsePort ();

	const std::string& name () const { return _name; }
	const std::string& pretty_name () const { return _pretty_name; }
	PortFlags flags () const { return _flags; }

	int set_name (const std::string& name) { _name = name; return 0; }
	int set_pretty_name (const std::string& name) { _pretty_name = name; return 0; }

	virtual DataType type () const = 0;

	virtual void* get_buffer (pframes_t nframes) = 0;

	bool is_input () const     { return flags () & IsInput; }
	bool is_output () const    { return flags () & IsOutput; }
	bool is_physical () const  { return flags () & IsPhysical; }
	bool is_terminal () const  { return flags () & IsTerminal; }
	bool is_connected () const { return _connections.size () != 0; }

	bool is_connected (const PulsePort* port) const;
	bool is_physically_connected () const;

	int connect (PulsePort* port);
	int disconnect (PulsePort* port);
	void disconnect_all ();

	const std::set<PulsePort*>&
	get_connections () const
	{
		return _connections;
	}

	const LatencyRange
	latency_range (bool for_playback) const
	{
		return for_playback ? _playback_latency_range : _capture_latency_range;
	}

	void set_latency_range (const LatencyRange& latency_range, bool for_playback);
	void update_connected_latency (bool for_playback);

private:
	PulseAudioBackend&   _pulse_backend;
	std::string          _name;
	std::string          _pretty_name;
	const PortFlags      _flags;
	LatencyRange         _capture_latency_range;
	LatencyRange         _playback_latency_range;
	std::set<PulsePort*> _connections;

	void _connect (PulsePort*, bool);
	void _disconnect (PulsePort*, bool);
}; // class PulsePort

class PulseAudioPort : public PulsePort
{
public:
	PulseAudioPort (PulseAudioBackend& b, const std::string&, PortFlags);
	~PulseAudioPort ();

	DataType type () const { return DataType::AUDIO; };

	Sample* buffer () { return _buffer; }
	const Sample* const_buffer () const { return _buffer; }
	void* get_buffer (pframes_t nframes);

private:
	Sample _buffer[8192];
}; // class PulseAudioPort

class PulseMidiPort : public PulsePort
{
public:
	PulseMidiPort (PulseAudioBackend& b, const std::string&, PortFlags);
	~PulseMidiPort ();

	DataType type () const { return DataType::MIDI; };

	void* get_buffer (pframes_t nframes);
	const PulseMidiBuffer* const_buffer () const { return &_buffer; }

private:
	PulseMidiBuffer _buffer;
}; // class PulseMidiPort

class PulseAudioBackend : public AudioBackend
{
	friend class PulsePort;

public:
	PulseAudioBackend (AudioEngine& e, AudioBackendInfo& info);
	~PulseAudioBackend ();

	/* AUDIOBACKEND API */

	std::string name () const;
	bool is_realtime () const;

	std::vector<DeviceStatus> enumerate_devices () const;
	std::vector<float> available_sample_rates (const std::string& device) const;
	std::vector<uint32_t> available_buffer_sizes (const std::string& device) const;
	uint32_t available_input_channel_count (const std::string& device) const;
	uint32_t available_output_channel_count (const std::string& device) const;

	bool can_change_sample_rate_when_running () const;
	bool can_change_buffer_size_when_running () const;

	int set_device_name (const std::string&);
	int set_sample_rate (float);
	int set_buffer_size (uint32_t);
	int set_interleaved (bool yn);
	int set_input_channels (uint32_t);
	int set_output_channels (uint32_t);
	int set_systemic_input_latency (uint32_t);
	int set_systemic_output_latency (uint32_t);

	int set_systemic_midi_input_latency (std::string const, uint32_t) { return 0; }
	int set_systemic_midi_output_latency (std::string const, uint32_t) { return 0; }

	int reset_device () { return 0; };

	/* Retrieving parameters */
	std::string device_name () const;
	float       sample_rate () const;
	uint32_t    buffer_size () const;
	bool        interleaved () const;
	uint32_t    input_channels () const;
	uint32_t    output_channels () const;
	uint32_t    systemic_input_latency () const;
	uint32_t    systemic_output_latency () const;
	uint32_t    systemic_midi_input_latency (std::string const) const { return 0; }
	uint32_t    systemic_midi_output_latency (std::string const) const { return 0; }

	/* External control app */
	std::string control_app_name () const;
	void launch_control_app ();

	/* MIDI */
	std::vector<std::string>  enumerate_midi_options () const;
	std::vector<DeviceStatus> enumerate_midi_devices () const;
	int                       set_midi_option (const std::string&);
	std::string               midi_option () const;

	int set_midi_device_enabled (std::string const, bool) { return 0; }
	bool midi_device_enabled (std::string const) const { return true; }
	bool can_set_systemic_midi_latencies () const { return false; }

	/* State Control */
protected:
	int _start (bool for_latency_measurement);

public:
	int    stop ();
	int    freewheel (bool);
	float  dsp_load () const;
	size_t raw_buffer_size (DataType t);

	/* Process time */
	samplepos_t sample_time ();
	samplepos_t sample_time_at_cycle_start ();
	pframes_t   samples_since_cycle_start ();

	int create_process_thread (boost::function<void()> func);
	int      join_process_threads ();
	bool     in_process_thread ();
	uint32_t process_thread_count ();

	void update_latencies ();

	/* PORTENGINE API */

	void* private_handle () const;
	const std::string& my_name () const;

	uint32_t    port_name_size () const;
	int         set_port_name (PortHandle, const std::string&);
	std::string get_port_name (PortHandle) const;
	PortFlags   get_port_flags (PortHandle) const;
	PortHandle  get_port_by_name (const std::string&) const;

	int get_port_property (PortHandle, const std::string& key, std::string& value, std::string& type) const;
	int set_port_property (PortHandle, const std::string& key, const std::string& value, const std::string& type);

	int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>&) const;

	DataType port_data_type (PortHandle) const;

	PortHandle register_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
	void unregister_port (PortHandle);

	int connect (const std::string& src, const std::string& dst);
	int disconnect (const std::string& src, const std::string& dst);
	int connect (PortHandle, const std::string&);
	int disconnect (PortHandle, const std::string&);
	int disconnect_all (PortHandle);

	bool connected (PortHandle, bool process_callback_safe);
	bool connected_to (PortHandle, const std::string&, bool process_callback_safe);
	bool physically_connected (PortHandle, bool process_callback_safe);
	int get_connections (PortHandle, std::vector<std::string>&, bool process_callback_safe);

	/* MIDI */
	int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t const** buf, void* port_buffer, uint32_t event_index);
	int midi_event_put (void* port_buffer, pframes_t timestamp, const uint8_t* buffer, size_t size);
	uint32_t get_midi_event_count (void* port_buffer);
	void midi_clear (void* port_buffer);

	/* Monitoring */

	bool can_monitor_input () const;
	int  request_input_monitoring (PortHandle, bool);
	int  ensure_input_monitoring (PortHandle, bool);
	bool monitoring_input (PortHandle);

	/* Latency management */

	void set_latency_range (PortHandle, bool for_playback, LatencyRange);
	LatencyRange get_latency_range (PortHandle, bool for_playback);

	/* Discovering physical ports */

	bool port_is_physical (PortHandle) const;
	void get_physical_outputs (DataType type, std::vector<std::string>&);
	void get_physical_inputs (DataType type, std::vector<std::string>&);
	ChanCount n_physical_outputs () const;
	ChanCount n_physical_inputs () const;

	/* Getting access to the data buffer for a port */

	void* get_buffer (PortHandle, pframes_t);

	void* main_process_thread ();

private:
	std::string _instance_name;

	/* pulse */
	struct pa_stream*            p_stream;
	struct pa_context*           p_context;
	struct pa_threaded_mainloop* p_mainloop;

	int  init_pulse ();
	void close_pulse (bool unlock = false);
	int  sync_pulse (pa_operation*);
	bool cork_pulse (bool);

	static void context_state_cb (pa_context*, void*);
	static void stream_state_cb (pa_stream*, void*);
	static void stream_request_cb (pa_stream*, size_t, void*);
	static void stream_latency_update_cb (pa_stream*, void*);
	static void stream_xrun_cb (pa_stream*, void*);
	static void stream_operation_cb (pa_stream*, int, void*);

	bool _operation_succeeded;

	bool _run;    /* keep going or stop, ardour thread */
	bool _active; /* is running, process thread */
	bool _freewheel;
	bool _freewheeling;

	uint64_t _last_process_start;

	/* audio settings */
	float    _samplerate;
	size_t   _samples_per_period;
	uint32_t _systemic_audio_output_latency;

	static const size_t _max_buffer_size;

	/* processing */
	float                     _dsp_load;
	ARDOUR::DSPLoadCalculator _dsp_load_calc;
	samplecnt_t               _processed_samples;
	pthread_t                 _main_thread;

	/* process threads */
	static void*           pulse_process_thread (void*);
	std::vector<pthread_t> _threads;

	struct ThreadData {
		PulseAudioBackend*      engine;
		boost::function<void()> f;
		size_t                  stacksize;

		ThreadData (PulseAudioBackend* e, boost::function<void()> fp, size_t stacksz)
			: engine (e), f (fp), stacksize (stacksz) {}
	};

	/* port engine */
	PortHandle add_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
	int  register_system_ports ();
	void unregister_ports (bool system_only = false);
	void update_system_port_latecies ();

	std::vector<PulsePort*> _system_outputs;

	struct SortByPortName {
		bool operator() (const PulsePort* lhs, const PulsePort* rhs) const
		{
			return PBD::naturally_less (lhs->name ().c_str (), rhs->name ().c_str ());
		}
	};

	typedef std::map<std::string, PulsePort*>    PortMap;   // fast lookup in _ports
	typedef std::set<PulsePort*, SortByPortName> PortIndex; // fast lookup in _ports
	PortMap   _portmap;
	PortIndex _ports;

	struct PortConnectData {
		std::string a;
		std::string b;
		bool        c;

		PortConnectData (const std::string& a, const std::string& b, bool c)
			: a (a), b (b), c (c) {}
	};

	std::vector<PortConnectData*> _port_connection_queue;
	pthread_mutex_t               _port_callback_mutex;
	bool                          _port_change_flag;

	void
	port_connect_callback (const std::string& a, const std::string& b, bool conn)
	{
		pthread_mutex_lock (&_port_callback_mutex);
		_port_connection_queue.push_back (new PortConnectData (a, b, conn));
		pthread_mutex_unlock (&_port_callback_mutex);
	}

	void
	port_connect_add_remove_callback ()
	{
		pthread_mutex_lock (&_port_callback_mutex);
		_port_change_flag = true;
		pthread_mutex_unlock (&_port_callback_mutex);
	}

	bool
	valid_port (PortHandle port) const
	{
		return std::find (_ports.begin (), _ports.end (), static_cast<PulsePort*> (port)) != _ports.end ();
	}

	PulsePort*
	find_port (const std::string& port_name) const
	{
		PortMap::const_iterator it = _portmap.find (port_name);
		if (it == _portmap.end ()) {
			return NULL;
		}
		return (*it).second;
	}
}; // class PulseAudioBackend

} // namespace

#endif /* __libbackend_pulse_audiobackend_h__ */