/*
  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/>.
*/

#include <set>

#include "ingen/Store.hpp"
#include "raul/Maid.hpp"
#include "raul/Path.hpp"

#include "ArcImpl.hpp"
#include "Broadcaster.hpp"
#include "Buffer.hpp"
#include "DuplexPort.hpp"
#include "Engine.hpp"
#include "GraphImpl.hpp"
#include "InputPort.hpp"
#include "OutputPort.hpp"
#include "PortImpl.hpp"
#include "PreProcessContext.hpp"
#include "RunContext.hpp"
#include "ThreadManager.hpp"
#include "events/Disconnect.hpp"

namespace Ingen {
namespace Server {
namespace Events {

Disconnect::Disconnect(Engine&           engine,
                       SPtr<Interface>   client,
                       int32_t           id,
                       SampleCount       timestamp,
                       const Raul::Path& tail_path,
                       const Raul::Path& head_path)
	: Event(engine, client, id, timestamp)
	, _tail_path(tail_path)
	, _head_path(head_path)
	, _graph(NULL)
	, _impl(NULL)
	, _compiled_graph(NULL)
{
}

Disconnect::~Disconnect()
{
	delete _impl;
	delete _compiled_graph;
}

Disconnect::Impl::Impl(Engine&     e,
                       GraphImpl*  graph,
                       OutputPort* t,
                       InputPort*  h)
	: _engine(e)
	, _tail(t)
	, _head(h)
	, _arc(graph->remove_arc(_tail, _head))
	, _voices(NULL)
{
	ThreadManager::assert_thread(THREAD_PRE_PROCESS);

	BlockImpl* const tail_block = _tail->parent_block();
	BlockImpl* const head_block = _head->parent_block();

	// Remove tail from head's providers
	std::set<BlockImpl*>::iterator hp = head_block->providers().find(tail_block);
	if (hp != head_block->providers().end()) {
		head_block->providers().erase(hp);
	}

	// Remove head from tail's providers
	std::set<BlockImpl*>::iterator td = tail_block->dependants().find(head_block);
	if (td != tail_block->dependants().end()) {
		tail_block->dependants().erase(td);
	}

	_head->decrement_num_arcs();

	if (_head->num_arcs() == 0) {
		if (!_head->is_driver_port()) {
			_voices = new Raul::Array<PortImpl::Voice>(_head->poly());
			_head->get_buffers(*_engine.buffer_factory(),
			                   _voices,
			                   _head->poly(),
			                   false);

			if (_head->is_a(PortType::CONTROL) ||
			    _head->is_a(PortType::CV)) {
				// Reset buffer to control value
				const float value = _head->value().get<float>();
				for (uint32_t i = 0; i < _voices->size(); ++i) {
					Buffer* buf = _voices->at(i).buffer.get();
					buf->set_block(value, 0, buf->nframes());
				}
			} else {
				for (uint32_t i = 0; i < _voices->size(); ++i) {
					_voices->at(i).buffer->clear();
				}
			}
		}
	}
}

bool
Disconnect::pre_process(PreProcessContext& ctx)
{
	std::lock_guard<std::mutex> lock(_engine.store()->mutex());

	if (_tail_path.parent().parent() != _head_path.parent().parent()
	    && _tail_path.parent() != _head_path.parent().parent()
	    && _tail_path.parent().parent() != _head_path.parent()) {
		return Event::pre_process_done(Status::PARENT_DIFFERS, _head_path);
	}

	PortImpl* tail = dynamic_cast<PortImpl*>(_engine.store()->get(_tail_path));
	if (!tail) {
		return Event::pre_process_done(Status::PORT_NOT_FOUND, _tail_path);
	}

	PortImpl* head = dynamic_cast<PortImpl*>(_engine.store()->get(_head_path));
	if (!head) {
		return Event::pre_process_done(Status::PORT_NOT_FOUND, _head_path);
	}

	BlockImpl* const tail_block = tail->parent_block();
	BlockImpl* const head_block = head->parent_block();

	if (tail_block->parent_graph() != head_block->parent_graph()) {
		// Arc to a graph port from inside the graph
		assert(tail_block->parent() == head_block || head_block->parent() == tail_block);
		if (tail_block->parent() == head_block) {
			_graph = dynamic_cast<GraphImpl*>(head_block);
		} else {
			_graph = dynamic_cast<GraphImpl*>(tail_block);
		}
	} else if (tail_block == head_block && dynamic_cast<GraphImpl*>(tail_block)) {
		// Arc from a graph input to a graph output (pass through)
		_graph = dynamic_cast<GraphImpl*>(tail_block);
	} else {
		// Normal arc between blocks with the same parent
		_graph = tail_block->parent_graph();
	}

	if (!_graph) {
		return Event::pre_process_done(Status::INTERNAL_ERROR, _head_path);
	} else if (!_graph->has_arc(tail, head)) {
		return Event::pre_process_done(Status::NOT_FOUND, _head_path);
	}

	if (tail_block == NULL || head_block == NULL) {
		return Event::pre_process_done(Status::PARENT_NOT_FOUND, _head_path);
	}

	_impl = new Impl(_engine,
	                 _graph,
	                 dynamic_cast<OutputPort*>(tail),
	                 dynamic_cast<InputPort*>(head));

	if (ctx.must_compile(_graph)) {
		_compiled_graph = CompiledGraph::compile(_graph);
	}

	return Event::pre_process_done(Status::SUCCESS);
}

bool
Disconnect::Impl::execute(RunContext& context, bool set_head_buffers)
{
	ArcImpl* const port_arc = _head->remove_arc(context, _tail);

	if (!port_arc) {
		return false;
	} else if (_head->is_driver_port()) {
		return true;
	}

	if (set_head_buffers) {
		if (_voices) {
			_engine.maid()->dispose(_head->set_voices(context, _voices));
		} else {
			_head->setup_buffers(*_engine.buffer_factory(),
			                     _head->poly(),
			                     true);
		}
		_head->connect_buffers();
	} else {
		_head->recycle_buffers();
	}

	return true;
}

void
Disconnect::execute(RunContext& context)
{
	if (_status == Status::SUCCESS) {
		if (_impl->execute(context, true)) {
			if (_compiled_graph) {
				_compiled_graph = _graph->swap_compiled_graph(_compiled_graph);
			}
		} else {
			_status = Status::NOT_FOUND;
		}
	}
}

void
Disconnect::post_process()
{
	Broadcaster::Transfer t(*_engine.broadcaster());
	if (respond() == Status::SUCCESS) {
		_engine.broadcaster()->disconnect(_tail_path, _head_path);
	}
}

void
Disconnect::undo(Interface& target)
{
	target.connect(_tail_path, _head_path);
}

} // namespace Events
} // namespace Server
} // namespace Ingen