ws4kp/server/scripts/modules/extendedforecast.mjs

// display extended forecast graphically
// technically uses the same data as the local forecast, we'll let the browser do the caching of that

import STATUS from './status.mjs';
import { UNITS } from './config.mjs';
import { json } from './utils/fetch.mjs';
import { DateTime } from '../vendor/auto/luxon.mjs';
import { fahrenheitToCelsius } from './utils/units.mjs';
import { getWeatherIconFromIconLink } from './icons.mjs';
import { preloadImg } from './utils/image.mjs';

/* globals WeatherDisplay, navigation */

class ExtendedForecast extends WeatherDisplay {
	constructor(navId, elemId) {
		super(navId, elemId, 'Extended Forecast', true);

		// set timings
		this.timing.totalScreens = 2;
	}

	async getData(_weatherParameters) {
		super.getData(_weatherParameters);
		const weatherParameters = _weatherParameters ?? this.weatherParameters;

		// request us or si units
		let units = 'us';
		if (navigation.units() === UNITS.metric) units = 'si';
		let forecast;
		try {
			forecast = await json(weatherParameters.forecast, {
				data: {
					units,
				},
			});
		} catch (e) {
			console.error('Unable to get extended forecast');
			console.error(e.status, e.responseJSON);
			this.setStatus(STATUS.failed);
			return;
		}
		// we only get here if there was no error above
		this.data = ExtendedForecast.parse(forecast.properties.periods);
		this.screenIndex = 0;
		this.setStatus(STATUS.loaded);
	}

	// the api provides the forecast in 12 hour increments, flatten to day increments with high and low temperatures
	static parse(fullForecast) {
	// create a list of days starting with today
		const Days = [0, 1, 2, 3, 4, 5, 6];

		const dates = Days.map((shift) => {
			const date = DateTime.local().startOf('day').plus({ days: shift });
			return date.toLocaleString({ weekday: 'short' });
		});

		// track the destination forecast index
		let destIndex = 0;
		const forecast = [];
		fullForecast.forEach((period) => {
		// create the destination object if necessary
			if (!forecast[destIndex]) {
				forecast.push({
					dayName: '', low: undefined, high: undefined, text: undefined, icon: undefined,
				});
			}
			// get the object to modify/populate
			const fDay = forecast[destIndex];
			// high temperature will always be last in the source array so it will overwrite the low values assigned below
			fDay.icon = getWeatherIconFromIconLink(period.icon);
			fDay.text = ExtendedForecast.shortenExtendedForecastText(period.shortForecast);
			fDay.dayName = dates[destIndex];

			// preload the icon
			preloadImg(fDay.icon);

			if (period.isDaytime) {
			// day time is the high temperature
				fDay.high = period.temperature;
				destIndex += 1;
			} else {
			// low temperature
				fDay.low = period.temperature;
			}
		});

		return forecast;
	}

	static shortenExtendedForecastText(long) {
		const regexList = [
			[/ and /ig, ' '],
			[/Slight /ig, ''],
			[/Chance /ig, ''],
			[/Very /ig, ''],
			[/Patchy /ig, ''],
			[/Areas /ig, ''],
			[/Dense /ig, ''],
			[/Thunderstorm/g, 'T\'Storm'],
		];
		// run all regexes
		const short = regexList.reduce((working, [regex, replace]) => working.replace(regex, replace), long);

		let conditions = short.split(' ');
		if (short.indexOf('then') !== -1) {
			conditions = short.split(' then ');
			conditions = conditions[1].split(' ');
		}

		let short1 = conditions[0].substr(0, 10);
		let short2 = '';
		if (conditions[1]) {
			if (!short1.endsWith('.')) {
				short2 = conditions[1].substr(0, 10);
			} else {
				short1 = short1.replace(/\./, '');
			}

			if (short2 === 'Blowing') {
				short2 = '';
			}
		}
		let result = short1;
		if (short2 !== '') {
			result += ` ${short2}`;
		}

		return result;
	}

	async drawCanvas() {
		super.drawCanvas();

		// determine bounds
		// grab the first three or second set of three array elements
		const forecast = this.data.slice(0 + 3 * this.screenIndex, 3 + this.screenIndex * 3);

		// create each day template
		const days = forecast.map((Day) => {
			const fill = {};
			fill.date = Day.dayName;

			let { low } = Day;
			if (low !== undefined) {
				if (navigation.units() === UNITS.metric) low = fahrenheitToCelsius(low);
				fill['value-lo'] = Math.round(low);
			}
			let { high } = Day;
			if (navigation.units() === UNITS.metric) high = fahrenheitToCelsius(high);
			fill['value-hi'] = Math.round(high);
			fill.condition = Day.text;

			// draw the icon
			fill.icon = { type: 'img', src: Day.icon };

			// return the filled template
			return this.fillTemplate('day', fill);
		});

		// empty and update the container
		const dayContainer = this.elem.querySelector('.day-container');
		dayContainer.innerHTML = '';
		dayContainer.append(...days);
		this.finishDraw();
	}
}

export default ExtendedForecast;

window.ExtendedForecast = ExtendedForecast;