shootismoke/common

// Sh**t! I Smoke
// Copyright (C) 2018-2021  Marcelo S. Coelho, Amaury M.

// Sh**t! I Smoke is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Sh**t! I Smoke is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Sh**t! I Smoke.  If not, see <http://www.gnu.org/licenses/>.

import { convert, Pollutant, ugm3 } from '@shootismoke/convert';
import { OpenAQResult, OpenAQResults } from '@shootismoke/dataproviders';

type PollutantData = { effects: string; name: string };

/**
 * Definitions and effects of various pollutants.
 *
 * @see https://www.sciencedirect.com/topics/chemistry/air-pollutant
 */
const pollutantData: Partial<Record<Pollutant, PollutantData>> = {
    bc: {
        effects:
            'Black carbon is a potent climate-warming component of particulate matter formed by the incomplete combustion of fossil fuels, wood and other fuels.',
        name: 'Black Carbon',
    },
    c6h6: {
        effects:
            'Hydrocarbons are the primary pollutants that produce photochemical smog.',
        name: 'Hydrocarbons',
    },
    ch4: {
        effects: 'Partly responsible for the atmospheric greenhouse effect.',
        name: 'Methane',
    },
    co: {
        effects:
            'Carbon monoxide reduces the oxygen-carrying capacity of the blood by combining with haemoglobin, thus deprives tissues of O2.',
        name: 'Carbon monoxide',
    },
    // FIXME Add co2
    // co2: {
    //     effects: 'Partly responsible for the atmospheric greenhouse effect',
    // },
    no: {
        effects:
            'Nitrogen oxides cause eye, throat, and lung irritation. Primary pollutants that produce photochemical smog and acid rain, destroy ozone at the stratosphere.',
        name: 'Nitrogen oxides',
    },
    no2: {
        effects:
            'Nitrogen oxides cause eye, throat, and lung irritation. Primary pollutants that produce photochemical smog and acid rain, destroy ozone at the stratosphere.',
        name: 'Nitrogen oxides',
    },
    o3: {
        effects:
            'Ozone causes eye, throat, and lung irritation, impairs lung function.',
        name: 'Ozone',
    },
    pm10: {
        effects:
            'Particulate matters under 10μm (PM10), may cause breathing difficulties.',
        name: 'Particulates',
    },
    pm25: {
        effects:
            'Particulate matters under 2.5μm (PM2.5), may cause breathing difficulties.',
        name: 'Particulates',
    },
    so2: {
        effects:
            'Sulfur dioxide causes eye, throat, and lung irritation. Primary pollutants that produce acid rain.',
        name: 'Sulfur dioxide',
    },
};

/**
 * Get metadata about a pollutant.
 *
 * @param pollutant - The pollutant to get the data.
 */
export function getPollutantData(pollutant: Pollutant): PollutantData {
    const polData = pollutantData[pollutant];

    if (!polData) {
        throw new Error('All pollutants are in pollutantData. qed.');
    }

    return polData;
}

/**
 * From a set of OpenAQResults pollutant data, filter only the ones that can be
 * converted to USA EPA, and sort the set.
 *
 * @param results - The OpenAQResults data for all pollutants.
 */
function getSortedOpenAQResults(results: OpenAQResults): OpenAQResult[] {
    // We attempt to sort the pollutants by AQI.
    const unsorted = results
        // Since we can only convert ugm3, we filter those results.
        .filter(({ unit }) => unit === ugm3)
        // Only these pollutants can be converted to usaEpa
        .filter(({ parameter }) =>
            ['o3', 'pm10', 'pm25', 'co', 'so2', 'no2'].includes(parameter)
        );

    // Sort the array by AQI.
    unsorted.sort(
        (a, b) =>
            convert(b.parameter, b.unit, 'usaEpa', b.value) -
            convert(a.parameter, a.unit, 'usaEpa', a.value)
    );

    return unsorted;
}

/**
 * From a set of OpenAQResults pollutant data, get the AQI, that is, the AQI of
 * the primary pollutant.
 *
 * @param OpenAQResults - The OpenAQResults data for all pollutants.
 */
export function getAQI(results: OpenAQResults): number | undefined {
    const sorted = getSortedOpenAQResults(results);

    if (sorted[0]) {
        try {
            return convert(
                sorted[0].parameter,
                sorted[0].unit,
                'usaEpa',
                sorted[0].value
            );
        } catch (err) {
            // convert() throws if the unit is not supported. We just silently
            // return an error.
            return;
        }
    }
}

/**
 * From a set of OpenAQResults pollutant data, find the primary pollutant.
 *
 * @param results - The OpenAQResults data for all pollutants.
 */
export function primaryPollutant(
    results: OpenAQResults
): OpenAQResult | undefined {
    const sorted = getSortedOpenAQResults(results);

    if (sorted[0]) {
        return sorted[0];
    }
}