/*
  This file is part of Ingen.
  Copyright 2007-2016 David Robillard <http://drobilla.net/>

  Ingen is free software: you can redistribute it and/or modify it under the
  terms of the GNU Affero General Public License as published by the Free
  Software Foundation, either version 3 of the License, or any later version.

  Ingen 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 Affero General Public License for details.

  You should have received a copy of the GNU Affero General Public License
  along with Ingen.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef INGEN_ENGINE_BLOCKIMPL_HPP
#define INGEN_ENGINE_BLOCKIMPL_HPP

#include "BufferRef.hpp"
#include "NodeImpl.hpp"
#include "State.hpp"
#include "types.hpp"

#include <ingen/Properties.hpp>
#include <ingen/Resource.hpp>
#include <ingen/URI.hpp>
#include <lilv/lilv.h>
#include <lv2/urid/urid.h>
#include <raul/Array.hpp>
#include <raul/Maid.hpp>

#include <boost/intrusive/slist_hook.hpp>

#include <cstdint>
#include <memory>
#include <optional>
#include <set>

namespace raul {
class Symbol;
} // namespace raul

namespace ingen {

enum class PortType;

class Node;

namespace server {

class BufferFactory;
class Engine;
class GraphImpl;
class PluginImpl;
class PortImpl;
class RunContext;
class Worker;

/** A Block in a Graph (which is also a Block).
 *
 * This is what is often called a "Module" in modular synthesizers.  A Block is
 * a unit with input/output ports, a process() method, and some other things.
 *
 * \ingroup engine
 */
class BlockImpl : public NodeImpl
                , public boost::intrusive::slist_base_hook<> // In GraphImpl
{
public:
	using Ports = raul::Array<PortImpl*>;

	BlockImpl(PluginImpl*         plugin,
	          const raul::Symbol& symbol,
	          bool                polyphonic,
	          GraphImpl*          parent,
	          SampleRate          rate);

	~BlockImpl() override;

	GraphType graph_type() const override { return GraphType::BLOCK; }

	/** Activate this Block.
	 *
	 * This function must be called in a non-realtime thread before it is
	 * inserted in to a graph.  Any non-realtime actions that need to be
	 * done before the Block is ready for use should be done here.
	 */
	virtual void activate(BufferFactory& bufs);

	/** Deactivate this Block.
	 *
	 * This function must be called in a non-realtime thread after the
	 * block has been removed from its graph (i.e. processing is finished).
	 */
	virtual void deactivate();

	/** Duplicate this Node. */
	virtual BlockImpl* duplicate(Engine&             engine,
	                             const raul::Symbol& symbol,
	                             GraphImpl*          parent) { return nullptr; }

	/** Return true iff this block is activated */
	bool activated() const { return _activated; }

	/** Return true iff this block is enabled (not bypassed). */
	bool enabled() const { return _enabled; }

	/** Enable or disable (bypass) this block. */
	void set_enabled(bool e) { _enabled = e; }

	/** Load a preset from the world for this block. */
	virtual StatePtr load_preset(const URI& uri) { return {}; }

	/** Restore `state`. */
	virtual void
	apply_state(const std::unique_ptr<Worker>& worker, const LilvState* state)
	{}

	/** Save current state as preset. */
	virtual std::optional<Resource>
	save_preset(const URI& bundle, const Properties& props)
	{
		return std::nullopt;
	}

	/** Learn the next incoming MIDI event (for internals) */
	virtual void learn() {}

	/** Do any necessary preparation in the process thread before process(). */
	virtual void pre_process(RunContext& ctx);

	/** Run block for an entire process cycle (calls run()). */
	virtual void process(RunContext& ctx);

	/** Bypass block for an entire process cycle (called from process()). */
	virtual void bypass(RunContext& ctx);

	/** Run block for a portion of process cycle (called from process()). */
	virtual void run(RunContext& ctx) = 0;

	/** Do whatever needs doing in the process thread after process() is called */
	virtual void post_process(RunContext& ctx);

	/** Set the buffer of a port to a given buffer (e.g. connect plugin to buffer) */
	virtual void set_port_buffer(uint32_t         voice,
	                             uint32_t         port_num,
	                             const BufferRef& buf,
	                             SampleCount      offset);

	Node*             port(uint32_t index)      const override;
	virtual PortImpl* port_impl(uint32_t index) const { return (*_ports)[index]; }

	/** Get a port by symbol. */
	virtual PortImpl* port_by_symbol(const char* symbol);

	/** Blocks that are connected to this Block's inputs. */
	std::set<BlockImpl*>&       providers() { return _providers; }
	const std::set<BlockImpl*>& providers() const { return _providers; }

	/** Blocks that are connected to this Block's outputs. */
	std::set<BlockImpl*>&       dependants() { return _dependants; }
	const std::set<BlockImpl*>& dependants() const { return _dependants; }

	/** Flag block as polyphonic.
	 *
	 * Note this will not actually allocate voices etc., prepare_poly
	 * and apply_poly must be called after this function to truly make
	 * a block polyphonic.
	 */
	virtual void set_polyphonic(bool p) { _polyphonic = p; }

	bool prepare_poly(BufferFactory& bufs, uint32_t poly) override;
	bool apply_poly(RunContext& ctx, uint32_t poly) override;

	/** Information about the Plugin this Block is an instance of.
	 * Not the best name - not all blocks come from plugins (ie Graph)
	 */
	const Resource* plugin() const override;

	/** Information about the Plugin this Block is an instance of.
	 * Not the best name - not all blocks come from plugins (ie Graph)
	 */
	virtual const PluginImpl* plugin_impl() const;

	virtual void plugin(PluginImpl* pi) { _plugin = pi; }

	virtual void set_buffer_size(RunContext&    ctx,
	                             BufferFactory& bufs,
	                             LV2_URID       type,
	                             uint32_t       size);

	/** The Graph this Block belongs to. */
	GraphImpl* parent_graph() const override
	{
		return reinterpret_cast<GraphImpl*>(_parent);
	}

	uint32_t num_ports() const override { return _ports ? _ports->size() : 0; }

	virtual uint32_t polyphony() const { return _polyphony; }

	/** Mark used during graph compilation */
	enum class Mark { UNVISITED, VISITING, VISITED };
	Mark get_mark() const { return _mark; }
	void set_mark(Mark m) { _mark = m; }

protected:
	PortImpl* nth_port_by_type(uint32_t n, bool input, PortType type);

	PluginImpl*              _plugin;
	raul::managed_ptr<Ports> _ports; ///< Access in audio thread only
	uint32_t                 _polyphony;
	std::set<BlockImpl*>     _providers; ///< Blocks connected to this one's input ports
	std::set<BlockImpl*>     _dependants; ///< Blocks this one's output ports are connected to
	Mark                     _mark{Mark::UNVISITED}; ///< Mark for graph walks
	bool                     _polyphonic;
	bool                     _activated{false};
	bool                     _enabled{true};
};

} // namespace server
} // namespace ingen

#endif // INGEN_ENGINE_BLOCKIMPL_HPP