ws4kp/server/scripts/modules/regionalforecast.js

// regional forecast and observations
// type 0 = observations, 1 = first forecast, 2 = second forecast

/* globals WeatherDisplay, utils, STATUS, icons, UNITS, draw, navigation, luxon, _StationInfo, _RegionalCities */

// eslint-disable-next-line no-unused-vars
class RegionalForecast extends WeatherDisplay {
	constructor(navId,elemId) {
		super(navId,elemId,'Regional Forecast');

		// pre-load background image (returns promise)
		this.backgroundImage = utils.image.load('images/BackGround5_1.png');

		// timings
		this.timing.totalScreens = 3;
	}

	async getData(weatherParameters) {
		super.getData();
		// pre-load the base map (returns promise)
		let src = 'images/Basemap2.png';
		if (weatherParameters.State === 'HI') {
			src = 'images/HawaiiRadarMap4.png';
		} else if (weatherParameters.State === 'AK') {
			src = 'images/AlaskaRadarMap6.png';
		}
		this.baseMap = utils.image.load(src);

		// map offset
		const offsetXY = {
			x: 240,
			y: 117,
		};
		// get user's location in x/y
		const sourceXY = this.getXYFromLatitudeLongitude(weatherParameters.latitude, weatherParameters.longitude, offsetXY.x, offsetXY.y, weatherParameters.state);

		// get latitude and longitude limits
		const minMaxLatLon = this.getMinMaxLatitudeLongitude(sourceXY.x, sourceXY.y, offsetXY.x, offsetXY.y, weatherParameters.state);

		// get a target distance
		let targetDistance = 2.5;
		if (weatherParameters.State === 'HI') targetDistance = 1;

		// make station info into an array
		const stationInfoArray = Object.keys(_StationInfo).map(key => Object.assign({}, _StationInfo[key], {Name: _StationInfo[key].City, targetDistance}));
		// combine regional cities with station info for additional stations
		// stations are intentionally after cities to allow cities priority when drawing the map
		const combinedCities = [..._RegionalCities, ...stationInfoArray];

		// Determine which cities are within the max/min latitude/longitude.
		const regionalCities = [];
		combinedCities.forEach(city => {
			if (city.Latitude > minMaxLatLon.minLat && city.Latitude < minMaxLatLon.maxLat &&
						city.Longitude > minMaxLatLon.minLon && city.Longitude < minMaxLatLon.maxLon - 1) {
				// default to 1 for cities loaded from _RegionalCities, use value calculate above for remaining stations
				const targetDistance = city.targetDistance || 1;
				// Only add the city as long as it isn't within set distance degree of any other city already in the array.
				const okToAddCity = regionalCities.reduce((acc, testCity) => {
					const distance = utils.calc.distance(city.Longitude, city.Latitude, testCity.Longitude, testCity.Latitude);
					return acc && distance >= targetDistance;
				}, true);
				if (okToAddCity) regionalCities.push(city);
			}
		});

		// get regional forecasts and observations (the two are intertwined due to the design of api.weather.gov)
		const regionalForecastPromises = regionalCities.map(async city => {
			try {
				// get the point first, then break down into forecast and observations
				const point = await utils.weather.getPoint(city.Latitude, city.Longitude);

				// start off the observation task
				const observationPromise = this.getRegionalObservation(point, city);

				const forecast = await $.ajax({
					url: point.properties.forecast,
					dataType: 'json',
					crossDomain: true,
				});

				// get XY on map for city
				const cityXY = this.getXYForCity(city, minMaxLatLon.maxLat, minMaxLatLon.minLon, weatherParameters.state);

				// wait for the regional observation if it's not done yet
				const observation = await observationPromise;
				// format the observation the same as the forecast
				const regionalObservation = {
					daytime: !!observation.icon.match(/\/day\//),
					temperature: utils.units.celsiusToFahrenheit(observation.temperature.value),
					name: city.Name,
					icon: observation.icon,
					x: cityXY.x,
					y: cityXY.y,
				};

				// return a pared-down forecast
				// 0th object is the current conditions
				// first object is the next period i.e. if it's daytime then it's the "tonight" forecast
				// second object is the following period
				// always skip the first forecast index because it's what's going on right now
				return [
					regionalObservation,
					this.buildForecast(forecast.properties.periods[1], city, cityXY),
					this.buildForecast(forecast.properties.periods[2], city, cityXY),
				];
			} catch (e) {
				console.log(`No regional forecast data for '${city.Name}'`);
				console.error(e);
				return false;
			}
		});

		// wait for the forecasts
		const regionalDataAll = await Promise.all(regionalForecastPromises);
		// filter out any false (unavailable data)
		const regionalData = regionalDataAll.filter(data => data);

		// test for data present
		if (regionalData.length === 0) {
			this.setStatus(STATUS.noData);
			return;
		}

		// return the weather data and offsets
		this.data = {
			regionalData,
			offsetXY,
			sourceXY,
		};

		this.setStatus(STATUS.loaded);
	}

	buildForecast (forecast, city, cityXY) {
		return {
			daytime: forecast.isDaytime,
			temperature: forecast.temperature||0,
			name: city.Name,
			icon: forecast.icon,
			x: cityXY.x,
			y: cityXY.y,
			time: forecast.startTime,
		};
	}

	async getRegionalObservation (point, city) {
		try {
			// get stations
			const stations = await $.ajax({
				type: 'GET',
				url: point.properties.observationStations,
				dataType: 'json',
				crossDomain: true,
			});

			// get the first station
			const station = stations.features[0].id;
			// get the observation data
			const observation = await $.ajax({
				type: 'GET',
				url: `${station}/observations/latest`,
				dataType: 'json',
				crossDomain: true,
			});
			// return the observation
			return observation.properties;
		} catch (e) {
			console.log(`Unable to get regional observations for ${city.Name}`);
			console.error(e);
			return false;
		}
	}

	// utility latitude/pixel conversions
	getXYFromLatitudeLongitude (Latitude, Longitude, OffsetX, OffsetY, state) {
		if (state === 'AK') return this.getXYFromLatitudeLongitudeAK(...arguments);
		if (state === 'HI') return this.getXYFromLatitudeLongitudeHI(...arguments);
		let y = 0;
		let x = 0;
		const ImgHeight = 1600;
		const ImgWidth = 2550;

		y = (50.5 - Latitude) * 55.2;
		y -= OffsetY; // Centers map.
		// Do not allow the map to exceed the max/min coordinates.
		if (y > (ImgHeight - (OffsetY * 2))) {
			y = ImgHeight - (OffsetY * 2);
		} else if (y < 0) {
			y = 0;
		}

		x = ((-127.5 - Longitude) * 41.775) * -1;
		x -= OffsetX; // Centers map.
		// Do not allow the map to exceed the max/min coordinates.
		if (x > (ImgWidth - (OffsetX * 2))) {
			x = ImgWidth - (OffsetX * 2);
		} else if (x < 0) {
			x = 0;
		}

		return { x, y };
	}

	getXYFromLatitudeLongitudeAK (Latitude, Longitude, OffsetX, OffsetY) {
		let y = 0;
		let x = 0;
		const ImgHeight = 1142;
		const ImgWidth = 1200;

		y = (73.0 - Latitude) * 56;
		y -= OffsetY; // Centers map.
		// Do not allow the map to exceed the max/min coordinates.
		if (y > (ImgHeight - (OffsetY * 2))) {
			y = ImgHeight - (OffsetY * 2);
		} else if (y < 0) {
			y = 0;
		}

		x = ((-175.0 - Longitude) * 25.0) * -1;
		x -= OffsetX; // Centers map.
		// Do not allow the map to exceed the max/min coordinates.
		if (x > (ImgWidth - (OffsetX * 2))) {
			x = ImgWidth - (OffsetX * 2);
		} else if (x < 0) {
			x = 0;
		}

		return { x, y };
	}

	getXYFromLatitudeLongitudeHI (Latitude, Longitude, OffsetX, OffsetY) {
		let y = 0;
		let x = 0;
		const ImgHeight = 571;
		const ImgWidth = 600;

		y = (25 - Latitude) * 55.2;
		y -= OffsetY; // Centers map.
		// Do not allow the map to exceed the max/min coordinates.
		if (y > (ImgHeight - (OffsetY * 2))) {
			y = ImgHeight - (OffsetY * 2);
		} else if (y < 0) {
			y = 0;
		}

		x = ((-164.5 - Longitude) * 41.775) * -1;
		x -= OffsetX; // Centers map.
		// Do not allow the map to exceed the max/min coordinates.
		if (x > (ImgWidth - (OffsetX * 2))) {
			x = ImgWidth - (OffsetX * 2);
		} else if (x < 0) {
			x = 0;
		}

		return { x, y };
	}

	getMinMaxLatitudeLongitude (X, Y, OffsetX, OffsetY, state) {
		if (state === 'AK') return this.getMinMaxLatitudeLongitudeAK(...arguments);
		if (state === 'HI') return this.getMinMaxLatitudeLongitudeHI(...arguments);
		const maxLat = ((Y / 55.2) - 50.5) * -1;
		const minLat = (((Y + (OffsetY * 2)) / 55.2) - 50.5) * -1;
		const minLon = (((X * -1) / 41.775) + 127.5) * -1;
		const maxLon = ((((X + (OffsetX * 2)) * -1) / 41.775) + 127.5) * -1;

		return { minLat, maxLat, minLon, maxLon };
	}

	getMinMaxLatitudeLongitudeAK (X, Y, OffsetX, OffsetY) {
		const maxLat = ((Y / 56) - 73.0) * -1;
		const minLat = (((Y + (OffsetY * 2)) / 56) - 73.0) * -1;
		const minLon = (((X * -1) / 25) + 175.0) * -1;
		const maxLon = ((((X + (OffsetX * 2)) * -1) / 25) + 175.0) * -1;

		return { minLat, maxLat, minLon, maxLon };
	}

	getMinMaxLatitudeLongitudeHI (X, Y, OffsetX, OffsetY) {
		const maxLat = ((Y / 55.2) - 25) * -1;
		const minLat = (((Y + (OffsetY * 2)) / 55.2) - 25) * -1;
		const minLon = (((X * -1) / 41.775) + 164.5) * -1;
		const maxLon = ((((X + (OffsetX * 2)) * -1) / 41.775) + 164.5) * -1;

		return { minLat, maxLat, minLon, maxLon };
	}

	getXYForCity (City, MaxLatitude, MinLongitude, state) {
		if (state === 'AK') this.getXYForCityAK(...arguments);
		if (state === 'HI') this.getXYForCityHI(...arguments);
		let x = (City.Longitude - MinLongitude) * 57;
		let y = (MaxLatitude - City.Latitude) * 70;

		if (y < 30) y = 30;
		if (y > 282) y = 282;

		if (x < 40) x = 40;
		if (x > 580) x = 580;

		return { x, y };
	}

	getXYForCityAK (City, MaxLatitude, MinLongitude) {
		let x = (City.Longitude - MinLongitude) * 37;
		let y = (MaxLatitude - City.Latitude) * 70;

		if (y < 30) y = 30;
		if (y > 282) y = 282;

		if (x < 40) x = 40;
		if (x > 580) x = 580;
		return { x, y };
	}

	getXYForCityHI (City, MaxLatitude, MinLongitude) {
		let x = (City.Longitude - MinLongitude) * 57;
		let y = (MaxLatitude - City.Latitude) * 70;

		if (y < 30) y = 30;
		if (y > 282) y = 282;

		if (x < 40) x = 40;
		if (x > 580) x = 580;

		return { x, y };
	}

	async drawCanvas() {
		super.drawCanvas();
		// break up data into useful values
		const {regionalData: data, sourceXY, offsetXY} = this.data;

		// fixed offset for all y values when drawing to the map
		const mapYOff = 90;

		const {DateTime} = luxon;
		// draw the header graphics
		this.context.drawImage(await this.backgroundImage, 0, 0);
		draw.horizontalGradientSingle(this.context, 0, 30, 500, 90, draw.topColor1, draw.topColor2);
		draw.triangle(this.context, 'rgb(28, 10, 87)', 500, 30, 450, 90, 500, 90);

		// draw the appropriate title
		if (this.screenIndex === 0) {
			draw.titleText(this.context, 'Regional', 'Observations');
		} else {
			let forecastDate = DateTime.fromISO(data[0][this.screenIndex].time);

			// get the name of the day
			const dayName = forecastDate.toLocaleString({weekday: 'long'});
			// draw the title
			if (data[0][this.screenIndex].daytime) {
				draw.titleText(this.context, 'Forecast for', dayName);
			} else {
				draw.titleText(this.context, 'Forecast for', dayName + ' Night');
			}
		}

		// draw the map
		this.context.drawImage(await this.baseMap, sourceXY.x, sourceXY.y, (offsetXY.x * 2), (offsetXY.y * 2), 0, mapYOff, 640, 312);
		await Promise.all(data.map(async city => {
			const period = city[this.screenIndex];
			// draw the icon if possible
			const icon = icons.getWeatherRegionalIconFromIconLink(period.icon, !period.daytime);
			if (icon) {
				this.gifs.push(await utils.image.superGifAsync({
					src: icon,
					max_width: 42,
					loop_delay: 100,
					auto_play: true,
					canvas: this.canvas,
					x: period.x,
					y: period.y - 15+mapYOff,
				}));
			}

			// City Name
			draw.text(this.context, 'Star4000', '20px', '#ffffff', period.x - 40, period.y - 15+mapYOff, period.name, 2);

			// Temperature
			let temperature = period.temperature;
			if (navigation.units() === UNITS.metric) temperature = Math.round(utils.units.fahrenheitToCelsius(temperature));
			draw.text(this.context, 'Star4000 Large Compressed', '28px', '#ffff00', period.x - (temperature.toString().length * 15), period.y + 20+mapYOff, temperature, 2);
		}));

		this.finishDraw();
		this.setStatus(STATUS.loaded);

	}
}