sunscope/assets/js/compute.js

// ════════════════════════════════════════════════════════════════════════
//  compute.js — Build the per-hour display rows from the raw API data.
//
//  Pure-ish function: feed in (forecast, airQuality, location, vehicleType,
//  vehicleVent, buildingType) and get back { hourlyRows, days, utcOffsetMs }.
//
//  Open-Meteo with timezone=auto returns local wall-clock strings like
//  "2026-05-13T14:00" — no Z suffix. Two forms are used in each row:
//    • String slices (iso.slice(...)) for display & day grouping
//    • A true UTC Date (dt) for solarElevationDeg (which uses .getUTC*).
// ════════════════════════════════════════════════════════════════════════

import {
  vaporPressureHpa, solarElevationDeg, calcTmrt, utciApprox,
  calcConcreteTemp, calcVehicleInteriorTemp,
  calcIndoorTempPass, calcManagedIndoorTempPass,
} from './physics.js';
import { windCompass8, uvSplit, cloudCategory, precipPenalty } from './utils.js';

export function buildHourlyRows({ forecast, airQuality, location, vehicleType, vehicleVent, buildingType }) {
  const utcOffsetMs = (forecast?.utc_offset_seconds ?? 0) * 1000;

  // Build a fast lookup map from the air quality hourly data: ISO string → index.
  // Normalise to "YYYY-MM-DDTHH" (13 chars) so forecast timestamps like
  // "2026-05-17T14:00" match AQ timestamps like "2026-05-17T14".
  const aqTimeMap = {};
  if (airQuality?.hourly?.time) {
    airQuality.hourly.time.forEach((t, i) => { aqTimeMap[t.slice(0, 13)] = i; });
  }
  const getAq = (field, iso) => {
    if (!airQuality?.hourly?.[field]) return null;
    const i = aqTimeMap[iso.slice(0, 13)];
    if (i === undefined) return null;
    return airQuality.hourly[field][i] ?? null;
  };

  const hourlyRows = forecast ? forecast.hourly.time.map((iso, i) => {
    const h = forecast.hourly;
    const Ta   = h.temperature_2m[i];
    const RH   = h.relative_humidity_2m[i];
    const dew  = h.dew_point_2m ? h.dew_point_2m[i] : null;
    const va   = h.wind_speed_10m[i];
    const wd   = h.wind_direction_10m ? h.wind_direction_10m[i] : null;
    const gust = h.wind_gusts_10m    ? h.wind_gusts_10m[i]    : null;
    const dir  = h.direct_radiation[i]    || 0;
    const dif  = h.diffuse_radiation[i]   || 0;
    const glob = h.shortwave_radiation[i] || 0;
    const cc     = h.cloud_cover[i];
    const ccLow  = h.cloud_cover_low  ? h.cloud_cover_low[i]  : null;
    const ccMid  = h.cloud_cover_mid  ? h.cloud_cover_mid[i]  : null;
    const ccHigh = h.cloud_cover_high ? h.cloud_cover_high[i] : null;
    const uv     = h.uv_index ? (h.uv_index[i] || 0) : 0;
    const precip = h.precipitation[i] || 0;
    const snow   = h.snowfall[i] || 0;
    const soilT0 = h.soil_temperature_0cm    ? h.soil_temperature_0cm[i]    : null;
    const soilT6 = h.soil_temperature_6cm    ? h.soil_temperature_6cm[i]    : null;
    const soilM  = h.soil_moisture_0_to_1cm  ? h.soil_moisture_0_to_1cm[i]  : null;
    const concreteT = calcConcreteTemp(Ta, glob, va);
    // iso is a local wall-clock string e.g. "2026-05-13T14:00" (no Z).
    // For display we slice the string directly — no Date object needed.
    // For solarElevationDeg (which uses .getUTC* internally) we need the
    // true UTC instant: treat the local time as UTC then subtract the offset.
    // e.g. Brisbane UTC+10: local 14:00 → parse as UTC 14:00 → subtract 10h → UTC 04:00 ✓
    const dt   = new Date(Date.parse(iso + 'Z') - utcOffsetMs);
    const elev = solarElevationDeg(location.lat, location.lon, dt);
    const vehicleT = calcVehicleInteriorTemp(Ta, glob, elev, vehicleType, vehicleVent);
    const eh       = vaporPressureHpa(Ta, RH);
    const Tmrt     = calcTmrt(Ta, dir, dif, glob, elev);
    const utci     = utciApprox(Ta, Tmrt, va, eh);
    const utciAdj = utci + precipPenalty(precip, snow, va);
    // Derived
    const compass = windCompass8(wd);
    const { uvA, uvB } = uvSplit(uv, elev);
    const cloudCat = cloudCategory(cc, ccLow, ccMid, ccHigh);
    // Visibility from the main forecast API (metres → km).
    const visKm        = (() => { const v = h.visibility ? h.visibility[i] : null; return v != null ? v / 1000 : null; })();
    const aqi          = getAq('european_aqi', iso);
    const grassPollen  = getAq('grass_pollen', iso);
    const birchPollen  = getAq('birch_pollen', iso);
    const alderPollen  = getAq('alder_pollen', iso);
    const mugwortPollen= getAq('mugwort_pollen', iso);
    const olivePollen  = getAq('olive_pollen', iso);
    const ragweedPollen= getAq('ragweed_pollen', iso);
    return {
      iso, dt, Ta, RH, dew, va, wd, gust, dir, dif, glob,
      cc, ccLow, ccMid, ccHigh, cloudCat,
      uv, uvA, uvB,
      precip, snow,
      soilT0, soilT6, soilM, concreteT, vehicleT,
      elev, Tmrt, utci, utciAdj, eh, compass,
      visKm, aqi,
      grassPollen, birchPollen, alderPollen, mugwortPollen, olivePollen, ragweedPollen,
    };
  }) : [];

  // Two-pass indoor temperature: needs the full hourly arrays so thermal
  // lag can look back at previous hours. Run after hourlyRows is built,
  // then stamp each row with its indoorT value.
  if (hourlyRows.length > 0) {
    const TaArr   = hourlyRows.map(r => r.Ta);
    const globArr = hourlyRows.map(r => r.glob);
    const elevArr = hourlyRows.map(r => r.elev);
    const indoorTemps = calcIndoorTempPass(TaArr, globArr, elevArr, buildingType);
    const managedTemps = calcManagedIndoorTempPass(TaArr, globArr, elevArr, buildingType);
    hourlyRows.forEach((r, i) => { r.indoorT = indoorTemps[i]; r.managedT = managedTemps[i]; });
  }

  // Group those hourly rows into days for the day tabs.
  const days = [];
  hourlyRows.forEach(row => {
    const key = row.iso.slice(0, 10);
    let day = days.find(d => d.key === key);
    if (!day) { day = { key, rows: [] }; days.push(day); }
    day.rows.push(row);
  });

  return { hourlyRows, days, utcOffsetMs };
}