/* This file is part of Machina.
 * Copyright 2007-2011 David Robillard <http://drobilla.net>
 *
 * Machina 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.
 *
 * Machina 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 Machina.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <cmath>
#include <iostream>
#include <map>

#include <glibmm/ustring.h>

#include "machina/Loader.hpp"
#include "machina/Machine.hpp"

#include "machina-config.h"
#include "ActionFactory.hpp"
#include "Edge.hpp"
#include "Node.hpp"

using namespace Raul;
using namespace std;

#define NS_MACHINA "http://drobilla.net/ns/machina#"
#define NS_RDF     "http://www.w3.org/1999/02/22-rdf-syntax-ns#"

namespace Machina {

Loader::Loader(Sord::World& rdf_world)
	: _rdf_world(rdf_world)
{
	_rdf_world.add_prefix("xsd", "http://www.w3.org/2001/XMLSchema#");
	_rdf_world.add_prefix("", "http://drobilla.net/ns/machina#");
}

/** Load (create) all objects from RDF into the engine.
 *
 * @param uri URI of machine (resolvable URI to an RDF document).
 * @return Loaded Machine.
 */
SharedPtr<Machine>
Loader::load(const Glib::ustring& uri)
{
	using Glib::ustring;

	SharedPtr<Machine> machine;

	ustring document_uri = uri;

	// If "URI" doesn't contain a colon, try to resolve as a filename
	if (uri.find(":") == ustring::npos) {
		document_uri = "file://" + document_uri;
	}

	const string machine_uri = string("<>");

	cout << "[Loader] Loading " << document_uri << endl;

	machine = SharedPtr<Machine>(new Machine(TimeUnit::beats(MACHINA_PPQN)));

	typedef std::map<Sord::Node, SharedPtr<Node> > Created;
	Created created;

	Sord::Model model(_rdf_world, document_uri);
	SerdEnv* env = serd_env_new(NULL);
	model.load_file(env, SERD_TURTLE, document_uri);
	serd_env_free(env);

	Sord::Node nil;

	Sord::URI rdf_type(_rdf_world,             NS_RDF "type");
	Sord::URI machina_SelectorNode(_rdf_world, NS_MACHINA "initialNode");
	Sord::URI machina_node(_rdf_world,         NS_MACHINA "node");
	Sord::URI machina_initialNode(_rdf_world,  NS_MACHINA "initialNode");
	Sord::URI machina_duration(_rdf_world,     NS_MACHINA "duration");
	Sord::URI machina_edge(_rdf_world,         NS_MACHINA "edge");
	Sord::URI machina_tail(_rdf_world,         NS_MACHINA "tail");
	Sord::URI machina_head(_rdf_world,         NS_MACHINA "head");
	Sord::URI machina_probability(_rdf_world,  NS_MACHINA "probability");

	Sord::Node machine_node = Sord::URI(_rdf_world, ".");

	/* Get initial nodes */
	for (Sord::Iter i = model.find(machine_node, machina_initialNode, nil);
	     !i.end(); ++i) {
		const Sord::Node& node_id = i.get_object();
		Sord::Iter d = model.find(node_id, machina_duration, nil);
		SharedPtr<Node> node(
			new Node(
				TimeStamp(TimeUnit(TimeUnit::BEATS, MACHINA_PPQN),
				          d.get_object().to_float()),
				true));

		Sord::Iter s = model.find(node_id, rdf_type, machina_SelectorNode);
		if (!s.end()) {
			node->set_selector(true);
		}

		machine->add_node(node);
		created[node_id] = node;
	}

	/* Get remaining (non-initial) nodes */
	for (Sord::Iter i = model.find(machine_node, machina_node, nil);
	     !i.end(); ++i) {
		const Sord::Node& node_id = i.get_object();
		Sord::Iter d = model.find(node_id, machina_duration, nil);
		if (created.find(node_id) == created.end()) {
			SharedPtr<Node> node(new Node(
				TimeStamp(TimeUnit(TimeUnit::BEATS, MACHINA_PPQN),
				          d.get_object().to_float()),
				false));
			machine->add_node(node);
			created[node_id] = node;
		}
	}

#if 0
	cerr << "FIXME: Load actions" << endl;
	/* Get note actions */

	query = Query(_rdf_world, ustring(
		"SELECT DISTINCT ?node ?note WHERE {\n"
		"	?node :enterAction [ a :MidiAction; :midiNote ?note ] ;\n"
		"	      :exitAction  [ a :MidiAction; :midiNote ?note ] .\n"
		"}\n"));

	results = query.run(_rdf_world, model);
	for (; !results->finished(); results->next()) {
		Created::iterator node_i = created.find((const char*)results->get("node"));
		if (node_i != created.end()) {
			SharedPtr<Node> node = node_i->second;
			const int note_num = results->get("note").to_int();
			if (note_num >= 0 && note_num <= 127) {
				node->set_enter_action(ActionFactory::note_on((unsigned char)note_num));
				node->set_exit_action(ActionFactory::note_off((unsigned char)note_num));
			} else {
				cerr << "WARNING:  MIDI note number out of range, ignoring." << endl;
			}
		} else {
			cerr << "WARNING:  Found note for unknown states.  Ignoring." << endl;
		}
	}
#endif

	/* Get edges */
	for (Sord::Iter i = model.find(machine_node, machina_edge, nil);
	     !i.end(); ++i) {
		Sord::Node edge = i.get_object();
		Sord::Iter t    = model.find(edge, machina_tail, nil);
		Sord::Iter h    = model.find(edge, machina_head, nil);
		Sord::Iter p    = model.find(edge, machina_probability, nil);

		Sord::Node tail        = t.get_object();
		Sord::Node head        = h.get_object();
		Sord::Node probability = p.get_object();

		float prob = probability.to_float();

		Created::iterator tail_i = created.find(tail);
		Created::iterator head_i = created.find(head);

		if (tail_i != created.end() && head_i != created.end()) {
			const SharedPtr<Node> tail = tail_i->second;
			const SharedPtr<Node> head = head_i->second;

			SharedPtr<Edge> edge(new Edge(tail, head));
			edge->set_probability(prob);
			tail->add_edge(edge);

		} else {
			cerr << "[Loader] WARNING: Ignored edge between unknown nodes "
				<< tail << " -> " << head << endl;
		}

	}

	if (machine && machine->nodes().size() > 0) {
		machine->reset(machine->time());
		return machine;
	} else {
		return SharedPtr<Machine>();
	}
}

} // namespace Machina