#include "drone_controller.hh"
#include "opengl_widget.hh"

#define TINYOBJLOADER_IMPLEMENTATION
#include "tiny_obj_loader.h"

#include <QJsonArray>
#include <QDebug>
#include <Qt3DRender/QMesh>


Waypoint::Waypoint(unsigned frame, QVector3D pos)
	:frame(frame),
	 pos(pos) {}


Waypoint::Waypoint(const QJsonObject &json)
	:Waypoint(json["frame"].toInt(),
			  QVector3D(json["position"]["lng_X"].toInt() / 100.0,
						json["position"]["alt_Y"].toInt() / 100.0,
						json["position"]["lat_Z"].toInt() / 100.0)) {}


bool Drone::mesh_initialized = false;
OpenGLMesh *Drone::mesh = nullptr;

Drone::Drone() {
	if (!mesh_initialized) {
		tinyobj::ObjReaderConfig reader_config;
		reader_config.mtl_search_path = "../mdl/"; // Path to material files
		tinyobj::ObjReader reader;
		if (!reader.ParseFromFile("../mdl/dji600.obj", reader_config)) {
			if (!reader.Error().empty()) {
				qWarning() << "Erreur lors de la lecture de ../mdl/dji600.obj";
			}
			exit(1);
		}
		// if (!reader.Warning().empty()) {
		// 	qWarning() << "TinyObjReader: " << reader.Warning();
		// }
		auto& attrib = reader.GetAttrib();
		mesh = new OpenGLMesh(QVector<float>(attrib.vertices.begin(), attrib.vertices.end()));
		mesh_initialized = true;
	}
	OpenGLWidget::instance->meshes.append(*mesh);
	mesh_id = OpenGLWidget::instance->meshes.size() - 1;
}


Drone::Drone(const QJsonObject &json)
	:Drone() {
	QJsonArray ja = json["waypoints"].toArray();
	waypoints.reserve(ja.size());
	for (const QJsonValue &o : ja) {
		waypoints.append(Waypoint(o.toObject()));
	}
}


const QVector<Waypoint> Drone::getWaypoints() const {
	return waypoints;
}


void Drone::setTo(int frame) {
	int prev = -1, next = -1;
	const Waypoint *prev_wp, *next_wp;
	for (const Waypoint &wp : waypoints) { // TODO: this can be optimized
		if (wp.frame < frame) {
			prev = wp.frame;
			prev_wp = &wp;
		} else {
			next = wp.frame;
			next_wp = &wp;
			break;
		}
	}
	OpenGLMesh &mesh = OpenGLWidget::instance->meshes[mesh_id];
	mesh.mat = QMatrix4x4();
	if (next > -1 && prev == -1) {
		mesh.mat.translate(next_wp->pos);
	} else if (prev > -1 && next == -1) {
		mesh.mat.translate(prev_wp->pos);
	} else {
		mesh.mat.translate(lerp(prev_wp->pos, next_wp->pos, (double) (frame-prev) / (next-prev)));
	}
}


DroneController::DroneController(const QJsonObject &json)
	:framerate(json["framerate"].toInt()) {

	QJsonArray ja = json["drones"].toArray();
	drones.reserve(ja.size());
	for (const QJsonValue &o : ja) {
		drones.append(Drone(o.toObject()));
	}
	for (const Drone &d : drones) {
		for (const Waypoint &wp : d.getWaypoints()) {
			if (wp.frame > duration) duration = wp.frame;
		}
	}

	connect(&timer, &QTimer::timeout, this, &DroneController::step);
	pause();
}


int DroneController::getDuration() const {
	return duration;
}


void DroneController::step() {
	// qDebug("frame %d (%d%%)", frame, (int) ((double) frame / duration * 100));
	for (Drone d : drones) {
		d.setTo(frame);
	}
	OpenGLWidget::instance->update();
	emit frameChanged(frame);
	if (frame == duration) {
		pause();
	} else {
		frame++;
	}
}


void DroneController::play() {
	if (!paused) return;
	paused = false;
	timer.start(1000. / framerate);
	qDebug() << "playing";
	emit playing();
}


void DroneController::pause() {
	if (paused) return;
	paused = true;
	timer.stop();
	qDebug() << "pausing";
	emit pausing();
}


void DroneController::suspend() {
	if (!paused) {
		pause();
		paused = false;
	}
}


void DroneController::resume() {
	if (!paused) {
		paused = true;
		play();
	}
}


void DroneController::seek(int frame) {
	if (this->frame == frame) return;
	this->frame = frame;
	step();
}