// Local-Hyperion includes
#include "LedDevicePhilipsHue.h"

// jsoncpp includes
#include <json/json.h>

// qt includes
#include <QtCore/qmath.h>
#include <QUrl>
#include <QHttpRequestHeader>
#include <QEventLoop>

#include <set>

bool operator ==(CiColor p1, CiColor p2) {
	return (p1.x == p2.x) && (p1.y == p2.y) && (p1.bri == p2.bri);
}

bool operator !=(CiColor p1, CiColor p2) {
	return !(p1 == p2);
}

PhilipsHueLamp::PhilipsHueLamp(unsigned int id, QString originalState, QString modelId) :
		id(id), originalState(originalState) {
	// Hue system model ids.
	const std::set<QString> HUE_BULBS_MODEL_IDS = { "LCT001", "LCT002", "LCT003" };
	const std::set<QString> LIVING_COLORS_MODEL_IDS = { "LLC001", "LLC005", "LLC006", "LLC007", "LLC011", "LLC012",
			"LLC013", "LST001" };
	// Find id in the sets and set the appropiate color space.
	if (HUE_BULBS_MODEL_IDS.find(modelId) != HUE_BULBS_MODEL_IDS.end()) {
		colorSpace.red = {0.675f, 0.322f};
		colorSpace.green = {0.4091f, 0.518f};
		colorSpace.blue = {0.167f, 0.04f};
	} else if (LIVING_COLORS_MODEL_IDS.find(modelId) != LIVING_COLORS_MODEL_IDS.end()) {
		colorSpace.red = {0.703f, 0.296f};
		colorSpace.green = {0.214f, 0.709f};
		colorSpace.blue = {0.139f, 0.081f};
	} else {
		colorSpace.red = {1.0f, 0.0f};
		colorSpace.green = {0.0f, 1.0f};
		colorSpace.blue = {0.0f, 0.0f};
	}
	// Initialize black color.
	black = rgbToCiColor(0.0f, 0.0f, 0.0f);
	// Initialize color with black
	color = {black.x, black.y, black.bri};
}

float PhilipsHueLamp::crossProduct(CiColor p1, CiColor p2) {
	return p1.x * p2.y - p1.y * p2.x;
}

bool PhilipsHueLamp::isPointInLampsReach(CiColor p) {
	CiColor v1 = { colorSpace.green.x - colorSpace.red.x, colorSpace.green.y - colorSpace.red.y };
	CiColor v2 = { colorSpace.blue.x - colorSpace.red.x, colorSpace.blue.y - colorSpace.red.y };
	CiColor q = { p.x - colorSpace.red.x, p.y - colorSpace.red.y };
	float s = crossProduct(q, v2) / crossProduct(v1, v2);
	float t = crossProduct(v1, q) / crossProduct(v1, v2);
	if ((s >= 0.0f) && (t >= 0.0f) && (s + t <= 1.0f)) {
		return true;
	}
	return false;
}

CiColor PhilipsHueLamp::getClosestPointToPoint(CiColor a, CiColor b, CiColor p) {
	CiColor AP = { p.x - a.x, p.y - a.y };
	CiColor AB = { b.x - a.x, b.y - a.y };
	float ab2 = AB.x * AB.x + AB.y * AB.y;
	float ap_ab = AP.x * AB.x + AP.y * AB.y;
	float t = ap_ab / ab2;
	if (t < 0.0f) {
		t = 0.0f;
	} else if (t > 1.0f) {
		t = 1.0f;
	}
	return {a.x + AB.x * t, a.y + AB.y * t};
}

float PhilipsHueLamp::getDistanceBetweenTwoPoints(CiColor p1, CiColor p2) {
	// Horizontal difference.
	float dx = p1.x - p2.x;
	// Vertical difference.
	float dy = p1.y - p2.y;
	// Absolute value.
	return sqrt(dx * dx + dy * dy);
}

CiColor PhilipsHueLamp::rgbToCiColor(float red, float green, float blue) {
	// Apply gamma correction.
	float r = (red > 0.04045f) ? powf((red + 0.055f) / (1.0f + 0.055f), 2.4f) : (red / 12.92f);
	float g = (green > 0.04045f) ? powf((green + 0.055f) / (1.0f + 0.055f), 2.4f) : (green / 12.92f);
	float b = (blue > 0.04045f) ? powf((blue + 0.055f) / (1.0f + 0.055f), 2.4f) : (blue / 12.92f);
	// Convert to XYZ space.
	float X = r * 0.649926f + g * 0.103455f + b * 0.197109f;
	float Y = r * 0.234327f + g * 0.743075f + b * 0.022598f;
	float Z = r * 0.0000000f + g * 0.053077f + b * 1.035763f;
	// Convert to x,y space.
	float cx = X / (X + Y + Z);
	float cy = Y / (X + Y + Z);
	if (isnan(cx)) {
		cx = 0.0f;
	}
	if (isnan(cy)) {
		cy = 0.0f;
	}
	// Brightness is simply Y in the XYZ space.
	CiColor xy = { cx, cy, Y };
	// Check if the given XY value is within the color reach of our lamps.
	if (!isPointInLampsReach(xy)) {
		// It seems the color is out of reach let's find the closes color we can produce with our lamp and send this XY value out.
		CiColor pAB = getClosestPointToPoint(colorSpace.red, colorSpace.green, xy);
		CiColor pAC = getClosestPointToPoint(colorSpace.blue, colorSpace.red, xy);
		CiColor pBC = getClosestPointToPoint(colorSpace.green, colorSpace.blue, xy);
		// Get the distances per point and see which point is closer to our Point.
		float dAB = getDistanceBetweenTwoPoints(xy, pAB);
		float dAC = getDistanceBetweenTwoPoints(xy, pAC);
		float dBC = getDistanceBetweenTwoPoints(xy, pBC);
		float lowest = dAB;
		CiColor closestPoint = pAB;
		if (dAC < lowest) {
			lowest = dAC;
			closestPoint = pAC;
		}
		if (dBC < lowest) {
			lowest = dBC;
			closestPoint = pBC;
		}
		// Change the xy value to a value which is within the reach of the lamp.
		xy.x = closestPoint.x;
		xy.y = closestPoint.y;
	}
	return xy;
}

LedDevicePhilipsHue::LedDevicePhilipsHue(const std::string& output, bool switchOffOnBlack) :
		host(output.c_str()), username("newdeveloper"), switchOffOnBlack(switchOffOnBlack) {
	http = new QHttp(host);
	timer.setInterval(3000);
	timer.setSingleShot(true);
	connect(&timer, SIGNAL(timeout()), this, SLOT(restoreStates()));
}

LedDevicePhilipsHue::~LedDevicePhilipsHue() {
	delete http;
}

int LedDevicePhilipsHue::write(const std::vector<ColorRgb> & ledValues) {
	// Save light states if not done before.
	if (!areStatesSaved()) {
		saveStates((unsigned int) ledValues.size());
		switchOn((unsigned int) ledValues.size());
	}
	// If there are less states saved than colors given, then maybe something went wrong before.
	if (lamps.size() != ledValues.size()) {
		restoreStates();
		return 0;
	}
	// Iterate through colors and set light states.
	unsigned int idx = 0;
	for (const ColorRgb& color : ledValues) {
		// Get lamp.
		PhilipsHueLamp& lamp = lamps.at(idx);
		// Scale colors from [0, 255] to [0, 1] and convert to xy space.
		CiColor xy = lamp.rgbToCiColor(color.red / 255.0f, color.green / 255.0f, color.blue / 255.0f);
		// Write color if color has been changed.
		if (xy != lamp.color) {
			// Switch on if the lamp has been previously switched off.
			if (switchOffOnBlack && lamp.color == lamp.black) {

			}
			// Send adjust color and brightness command in JSON format.
			put(getStateRoute(lamp.id),
					QString("{\"xy\": [%1, %2], \"bri\": %3}").arg(xy.x).arg(xy.y).arg(qRound(xy.bri * 255.0f)));

		}
		// Switch lamp off if switchOffOnBlack is enabled and the lamp is currently on.
		if (switchOffOnBlack) {
			// From black to a color.
			if (lamp.color == lamp.black && xy != lamp.black) {
				put(getStateRoute(lamp.id), QString("{\"on\": true}"));
			}
			// From a color to black.
			else if (lamp.color != lamp.black && xy == lamp.black) {
				put(getStateRoute(lamp.id), QString("{\"on\": false}"));
			}
		}
		// Remember last color.
		lamp.color = xy;
		// Next light id.
		idx++;
	}
	timer.start();
	return 0;
}

int LedDevicePhilipsHue::switchOff() {
	timer.stop();
	// If light states have been saved before, ...
	if (areStatesSaved()) {
		// ... restore them.
		restoreStates();
	}
	return 0;
}

void LedDevicePhilipsHue::put(QString route, QString content) {
	QString url = QString("/api/%1/%2").arg(username).arg(route);
	QHttpRequestHeader header("PUT", url);
	header.setValue("Host", host);
	header.setValue("Accept-Encoding", "identity");
	header.setValue("Connection", "keep-alive");
	header.setValue("Content-Length", QString("%1").arg(content.size()));
	QEventLoop loop;
	// Connect requestFinished signal to quit slot of the loop.
	loop.connect(http, SIGNAL(requestFinished(int, bool)), SLOT(quit()));
	// Perfrom request
	http->request(header, content.toAscii());
	// Go into the loop until the request is finished.
	loop.exec();
}

QByteArray LedDevicePhilipsHue::get(QString route) {
	QString url = QString("/api/%1/%2").arg(username).arg(route);
	// Event loop to block until request finished.
	QEventLoop loop;
	// Connect requestFinished signal to quit slot of the loop.
	loop.connect(http, SIGNAL(requestFinished(int, bool)), SLOT(quit()));
	// Perfrom request
	http->get(url);
	// Go into the loop until the request is finished.
	loop.exec();
	// Read all data of the response.
	return http->readAll();
}

QString LedDevicePhilipsHue::getStateRoute(unsigned int lightId) {
	return QString("lights/%1/state").arg(lightId);
}

QString LedDevicePhilipsHue::getRoute(unsigned int lightId) {
	return QString("lights/%1").arg(lightId);
}

void LedDevicePhilipsHue::saveStates(unsigned int nLights) {
	// Clear saved lamps.
	lamps.clear();
	// Use json parser to parse reponse.
	Json::Reader reader;
	Json::FastWriter writer;
	// Iterate lights.
	for (unsigned int i = 0; i < nLights; i++) {
		// Read the response.
		QByteArray response = get(getRoute(i + 1));
		// Parse JSON.
		Json::Value json;
		if (!reader.parse(QString(response).toStdString(), json)) {
			// Error occured, break loop.
			break;
		}
		// Get state object values which are subject to change.
		Json::Value state(Json::objectValue);
		state["on"] = json["state"]["on"];
		if (json["state"]["on"] == true) {
			state["xy"] = json["state"]["xy"];
			state["bri"] = json["state"]["bri"];
		}
		// Determine the model id.
		QString modelId = QString(writer.write(json["modelid"]).c_str()).trimmed().replace("\"", "");
		QString originalState = QString(writer.write(state).c_str()).trimmed();
		// Save state object.
		lamps.push_back(PhilipsHueLamp(i + 1, originalState, modelId));
	}
}

void LedDevicePhilipsHue::switchOn(unsigned int nLights) {
	for (PhilipsHueLamp lamp : lamps) {
		put(getStateRoute(lamp.id), "{\"on\": true}");
	}
}

void LedDevicePhilipsHue::restoreStates() {
	for (PhilipsHueLamp lamp : lamps) {
		put(getStateRoute(lamp.id), lamp.originalState);
	}
	// Clear saved light states.
	lamps.clear();
}

bool LedDevicePhilipsHue::areStatesSaved() {
	return !lamps.empty();
}