Scriptable - Parse Forecast API data

parse-forecast-data.js

const params = URLScheme.allParameters();
const baseUrl = params['x-success'];

const data = JSON.parse(params.data);

const maxInt = Number.MAX_SAFE_INTEGER;

// Rough precipitation descriptions
const precipDescriptions = [
  {
    mmPerHour: 0.05,
    description: 'very light',
  }, {
    mmPerHour: 0.43,
    description: 'light',
  }, {
    mmPerHour: 2.54,
    description: 'moderate',
  }, {
    mmPerHour: 10.16,
    description: 'heavy',
  }, {
    mmPerHour: 20.00,
    description: 'very heavy',
  }, {
    mmPerHour: maxInt,
    description: 'extremely heavy (like seriously dude you need to start building a fucking ark)',
  },
];

// Rough cloud cover descriptions
const cloudCoverDescriptions = [
  {
    coverage: 0.1,
    description: 'clear',
  }, {
    coverage: 0.4,
    description: 'a little cloudy',
  }, {
    coverage: 0.7,
    description: 'quite cloudy',
  }, {
    coverage: 0.9,
    description: 'very cloudy',
  }, {
    coverage: 1,
    description: 'overcast',
  },
];

// Based on Beaufort Scale
const windSpeedDescriptions = [
  {
    metresPerSecond: 0.5,
    number: 0,
    description: 'no wind',
  }, {
    metresPerSecond: 1.5,
    number: 1,
    description: 'light air',
  }, {
    metresPerSecond: 3.3,
    number: 2,
    description: 'a light breeze',
  }, {
    metresPerSecond: 5.5,
    number: 3,
    description: 'a gentle breeze',
  }, {
    metresPerSecond: 7.9,
    number: 4,
    description: 'a moderate breeze',
  }, {
    metresPerSecond: 10.7,
    number: 5,
    description: 'a fresh breeze',
  }, {
    metresPerSecond: 13.8,
    number: 6,
    description: 'a strong breeze',
  }, {
    metresPerSecond: 17.1,
    number: 7,
    description: 'near gale-force winds',
  }, {
    metresPerSecond: 20.7,
    number: 8,
    description: 'gale-force winds',
  }, {
    metresPerSecond: 24.4,
    number: 9,
    description: 'strong gale-force winds',
  }, {
    metresPerSecond: 28.4,
    number: 10,
    description: 'storm-force winds',
  }, {
    metresPerSecond: 32.6,
    number: 11,
    description: 'violent storm-force winds',
  }, {
    metresPerSecond: maxInt,
    number: 12,
    description: 'hurricane-force winds',
  },
];

// Map bearing to Cardinal direction
const windBearings = [
  {
    bearingStart:  337.5,
    bearingEnd: 22.5,
    description: 'North'
  }, {
    bearingStart:  22.5,
    bearingEnd: 67.5,
    description: 'North-East'
  }, {
    bearingStart:  67.5,
    bearingEnd: 112.5,
    description: 'East'
  }, {
    bearingStart:  112.5,
    bearingEnd: 157.5,
    description: 'South-East'
  }, {
    bearingStart:  157.5,
    bearingEnd: 202.5,
    description: 'South'
  }, {
    bearingStart:  202.5,
    bearingEnd: 247.5,
    description: 'South-West'
  }, {
    bearingStart:  247.5,
    bearingEnd: 292.5,
    description: 'West'
  }, {
    bearingStart:  292.5,
    bearingEnd: 337.5,
    description: 'North-West'
  },
];

const {
  apparentTemperature,
  cloudCover,
  precipIntensity,
  precipProbability,
  precipType,
  windBearing,
  windSpeed,
  windGust,
} = data.currently;

const roundedTemperature = Math.round(apparentTemperature);

// Start our response with the temperature
let response = `${roundedTemperature} degrees`;

// If it's going to precipitate
if (precipProbability > 0) {
  // Calculate the percantage chance of precipitation
  const precipPercent = precipProbability * 100;

  // Find the appropriate description for this rate of precipitation
  const precipDescription = precipDescriptions.find(({ mmPerHour }) => (
    precipIntensity < mmPerHour
  )).description;

  // Append to our response
  response += `, with a ${precipPercent}% chance of ${precipDescription} ${precipType}`;
} else {
  // No precipitation forecast, let's get some cloud info instead.
  const cloudCoverDescription = cloudCoverDescriptions.find(({ coverage }) => (
    cloudCover < coverage
  )).description;
  response += ` and ${cloudCoverDescription}`;
}

response += '. ';

// Find the wind speed description object
const windSpeedObj = windSpeedDescriptions.find(({ metresPerSecond }) => (
  windSpeed < metresPerSecond
));

// Find the wind gust description object
const windGustObj = windSpeedDescriptions.find(({ metresPerSecond }) => (
  windGust < metresPerSecond
));

// Find the wind bearing description object
const windBearingObj = windBearings.find(({
  bearingStart,
  bearingEnd,
}) => {
  // If we're near North
  if (bearingStart > bearingEnd) {
    return (
      (windBearing >= 0 && windBearing <= bearingEnd)
      || (windBearing <= 360 && windBearing >= bearingStart)
    );
  } else {
    return (
      windBearing >= bearingStart
      && windBearing <= bearingEnd
    );
  }
});

// Add our wind info
response += `There's ${windSpeedObj.description} from the ${windBearingObj.description}`;

// If there's a notable gust
if (
    windGustObj.number > windSpeedObj.number
    && windGustObj.number >= 6
  ) {
  response += `, gusting to ${windGustObj.description}`;
}

response += '.';

response = encodeURI(response);

const callbackUrl = `${params['x-success']}?text=${response}`;
Safari.open(callbackUrl)