ws4kp/server/scripts/modules/regionalforecast-utils.mjs

import { getWeatherRegionalIconFromIconLink } from './icons.mjs';
import { preloadImg } from './utils/image.mjs';
import { json } from './utils/fetch.mjs';

const buildForecast = (forecast, city, cityXY) => ({
	daytime: forecast.isDaytime,
	temperature: forecast.temperature || 0,
	name: formatCity(city.city),
	icon: forecast.icon,
	x: cityXY.x,
	y: cityXY.y,
	time: forecast.startTime,
});

const getRegionalObservation = async (point, city) => {
	try {
		// get stations
		const stations = await json(`https://api.weather.gov/gridpoints/${point.wfo}/${point.x},${point.y}/stations`);

		// get the first station
		const station = stations.features[0].id;
		// get the observation data
		const observation = await json(`${station}/observations/latest`);
		// preload the image
		if (!observation.properties.icon) return false;
		preloadImg(getWeatherRegionalIconFromIconLink(observation.properties.icon, !observation.properties.daytime));
		// return the observation
		return observation.properties;
	} catch (e) {
		console.log(`Unable to get regional observations for ${city.Name ?? city.city}`);
		console.error(e.status, e.responseJSON);
		return false;
	}
};

// utility latitude/pixel conversions
const getXYFromLatitudeLongitude = (Latitude, Longitude, OffsetX, OffsetY, state) => {
	if (state === 'AK') return getXYFromLatitudeLongitudeAK(Latitude, Longitude, OffsetX, OffsetY);
	if (state === 'HI') return getXYFromLatitudeLongitudeHI(Latitude, Longitude, OffsetX, OffsetY);
	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 };
};

const 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 };
};

const 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 };
};

const getMinMaxLatitudeLongitude = (X, Y, OffsetX, OffsetY, state) => {
	if (state === 'AK') return getMinMaxLatitudeLongitudeAK(X, Y, OffsetX, OffsetY);
	if (state === 'HI') return getMinMaxLatitudeLongitudeHI(X, Y, OffsetX, OffsetY);
	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,
	};
};

const 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,
	};
};

const 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,
	};
};

const getXYForCity = (City, MaxLatitude, MinLongitude, state) => {
	if (state === 'AK') getXYForCityAK(City, MaxLatitude, MinLongitude);
	if (state === 'HI') getXYForCityHI(City, MaxLatitude, MinLongitude);
	let x = (City.lon - MinLongitude) * 57;
	let y = (MaxLatitude - City.lat) * 70;

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

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

	return { x, y };
};

const getXYForCityAK = (City, MaxLatitude, MinLongitude) => {
	let x = (City.lon - MinLongitude) * 37;
	let y = (MaxLatitude - City.lat) * 70;

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

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

const getXYForCityHI = (City, MaxLatitude, MinLongitude) => {
	let x = (City.lon - MinLongitude) * 57;
	let y = (MaxLatitude - City.lat) * 70;

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

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

	return { x, y };
};

// to fit on the map, remove anything after punctuation and then limit to 15 characters
const formatCity = (city) => city.match(/[^-;/\\,]*/)[0].substr(0, 12);

export {
	buildForecast,
	getRegionalObservation,
	getXYFromLatitudeLongitude,
	getMinMaxLatitudeLongitude,
	getXYForCity,
	formatCity,
};