homebridge-flux/src/fluxAccessory.ts

import { IAccessory } from "./models/iAccessory";
import Api = require("node-hue-api/lib/api/Api");
import Light = require("node-hue-api/lib/model/Light");
import LightState = require("node-hue-api/lib/model/lightstate/LightState");
import { Sleep } from "./sleep";
import { IConfig } from "./models/iConfig";
//@ts-ignore
import { GetTimesResult, getTimes } from "suncalc";
import HueError = require("node-hue-api/lib/HueError");

let Service: HAPNodeJS.Service;
let Characteristic: HAPNodeJS.Characteristic;
const SECONDS_IN_DAY = 86400000;
const SECONDS_IN_HOUR = 3600;

export interface IFluxProps {
    api: any;
    log: any;
    homebridge: any;
    hue: Api,
    config: IConfig;
}

export class FluxAccessory implements IAccessory {
    private _api: any;
    private _homebridge: any;
    private _log: any = {};
    private _config: IConfig;
    private _isActive: boolean;

    //Service fields
    private _switchService: HAPNodeJS.Service;
    private _infoService: HAPNodeJS.Service;

    private _hue: Api;

    private _lights: Array<Light> = [];

    private _times: GetTimesResult;

    constructor(props: IFluxProps) {
        //Assign class variables
        this._log = props.log;
        this._api = props.api;
        this._config = props.config;
        Service = props.api.hap.Service;
        Characteristic = props.api.hap.Characteristic;
        this._homebridge = props.homebridge;
        this._isActive = false;

        this._hue = props.hue;
        this.name = this._config.name;

        this._times = getTimes(new Date(), this._config.latitude, this._config.longitude);

        this.getLights();

        this.platformAccessory = new this._homebridge.platformAccessory(this.name, this.generateUUID(), this._homebridge.hap.Accessory.Categories.SWITCH);

        //@ts-ignore
        this._infoService = new Service.AccessoryInformation();
        this._infoService.setCharacteristic(Characteristic.Manufacturer, "Brandon Watson")
        this._infoService.setCharacteristic(Characteristic.Model, "F.lux")
        this._infoService.setCharacteristic(Characteristic.SerialNumber, "123-456-789");

        this._switchService = new Service.Switch(
            this.name,
            'fluxService'
        )

        this._switchService.getCharacteristic(Characteristic.On)
            //@ts-ignore
            .on("set", this.onSetEnabled)
            .on("get", this.onGetEnabled);
    }

    public name: string = "Flux";

    public platformAccessory: any;

    /**
     * Handler for switch set event
     * @param callback The callback function to call when complete
     */
    private onSetEnabled = async (activeState: boolean, callback: (error?: Error | null | undefined) => void) => {
        if (activeState) {
            this._times = getTimes(new Date(), this._config.latitude, this._config.longitude);
            this.update();
        } else {
            this._isActive = false;
        }
        return callback();
    }

    /**
     * Handler for switch get event
     * @param callback The callback function to call when complete
     */
    private onGetEnabled = (callback: (error: Error | null, value: boolean) => void) => {
        return callback(null, this._isActive);
    }


    /**
     * Called by homebridge to gather services.
     */
    public getServices = (): Array<HAPNodeJS.Service> => {
        return [this._infoService, this._switchService!];
    }

    /**
     * Popuplates internal lights array using the configuration values
     */
    private getLights = async (): Promise<void> => {
        for (const value of this._config.lights) {
            //@ts-ignore
            const light: Light = await this._hue.lights.getLightByName(value)
            this._lights.push(light);
        }
    }

    private colorTempToRgb = (kelvin: number): { red: number, green: number, blue: number } => {
        var temp = kelvin / 100;
        var red, green, blue;
        if (temp <= 66) {
            red = 255;
            green = temp;
            green = 99.4708025861 * Math.log(green) - 161.1195681661;

            if (temp <= 19) {
                blue = 0;
            } else {
                blue = temp - 10;
                blue = 138.5177312231 * Math.log(blue) - 305.0447927307;
            }
        } else {
            red = temp - 60;
            red = 329.698727446 * Math.pow(red, -0.1332047592);

            green = temp - 60;
            green = 288.1221695283 * Math.pow(green, -0.0755148492);

            blue = 255;
        }
        return {
            red: this.clamp(red, 0, 255),
            green: this.clamp(green, 0, 255),
            blue: this.clamp(blue, 0, 255)
        }
    }

    private clamp(x: number, min: number, max: number) {
        if (x < min) { return min; }
        if (x > max) { return max; }
        return x;
    }

    private isHueError = (object: any): object is HueError => {
        return '_hueError' in object;
    }

    private setLights = async (state: LightState) => {
        const promises: Array<Promise<unknown> | PromiseLike<unknown>> = [];
        this._lights.map(async (light: Light) => {
            try {
                await this._hue.lights.setLightState(light.id, state);
            } catch (err) {
                if (this.isHueError(err) && err.message === "parameter, xy, is not modifiable. Device is set to off.") {
                    //Eat this
                } else {
                    this._log(`Error while setting lights: ${err}`);
                }
            }
        });


        await Promise.all(promises);
    }

    /**
     * Helper function to generate a UUID
     */
    private generateUUID(): string { // Public Domain/MIT
        var d = new Date().getTime();
        if (typeof performance !== 'undefined' && typeof performance.now === 'function') {
            d += performance.now(); //use high-precision timer if available
        }
        return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
            var r = (d + Math.random() * 16) % 16 | 0;
            d = Math.floor(d / 16);
            return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16);
        });
    }

    private update = async (): Promise<void> => {
        this._isActive = true;
        while (this._isActive) {
            if (this._lights.length === 0) {
                await this.getLights();
            }

            const now = new Date(Date.now());
            //Pad start time by an hour before sunset
            const start = new Date(this._times.sunset.getTime() - 3 * 1000 * SECONDS_IN_HOUR);
            const end = new Date(this._times.sunrise.getTime() + 1 * SECONDS_IN_DAY);
            // const sunset = new Date('Wed, 15 Apr 2020 21:00:00 GMT');
            // const sunrise = new Date('Wed, 15 Apr 2020 23:00:00 GMT');

            const startColorTemp = this._config.startColorTemp ? this._config.startColorTemp : 4000;
            const stopColorTemp = this._config.stopColorTemp ? this._config.stopColorTemp : 1900;

            let percentageComplete = 0;
            let newTemp = 0;

            const midTime = (end.getTime() - start.getTime()) / 2;
            const mid = new Date(new Date().setTime(start.getTime() + midTime));
            const tempRange = Math.abs(startColorTemp - stopColorTemp);

            if ((start < now) && (now < mid)) {
                //Before sunset; calculate temp based on TOD
                const totalDecreaseTime = (mid.getTime() - start.getTime()) / 1000;
                const secondsFromStart = (now.getTime() - start.getTime()) / 1000;
                percentageComplete = secondsFromStart / totalDecreaseTime;
                const tempOffset = tempRange * percentageComplete;

                newTemp = startColorTemp - tempOffset;
            } else if ((mid < now) && (now < end)) {
                //After sunset; calculate temp based on TOD
                const totalIncreaseTime = (end.getTime() - mid.getTime()) / 1000;
                const secondsUntilSunrise = (end.getTime() - now.getTime()) / 1000;
                percentageComplete = secondsUntilSunrise / totalIncreaseTime;

                const tempOffset = tempRange * percentageComplete;
                newTemp = startColorTemp - tempOffset;
            }

            //Set lights
            const rgb = this.colorTempToRgb(newTemp);
            if (rgb && newTemp !== 0) {
                const lightState = new LightState();
                lightState
                    .transitionInMillis(this._config.transition ? this._config.transition : 5000)
                    .rgb(rgb.red ? rgb.red : 0, rgb.green ? rgb.green : 0, rgb.blue ? rgb.blue : 0);
                await this.setLights(lightState)
                this._log(`Adjusting light temp to ${newTemp}, ${JSON.stringify(rgb)}`)
            }

            await Sleep(this._config.delay ? this._config.delay : 60000);
        }
    }
}