sunscope/assets/js/hooks/useAppState.js

// ------------------------------------------------------------------------
//  hooks/useAppState.js - All state and side-effect logic for UTCIForecast.
//
//  Extracted from app.js to keep the main component under the AI edit
//  safe-zone. This hook owns every useState, useEffect, useCallback and
//  useRef that app.js needs, returning them as a single flat object.
//
//  Usage in app.js:
//    const state = useAppState();
//    const { forecast, isPro, visibleCols, ... } = state;
//
//  Reading order:
//    1. Location + search
//    2. Day-tab scroll refs
//    3. Pro tier
//    4. Profile + column visibility
//    5. Skin, vehicle, indoor, pollen
//    6. Table refs
//    7. Column popup + table scroll hooks
//    8. Geocoding search effect
//    9. Computation - rows, days, current row
//   10. Events - active, lens, selected-day
// ------------------------------------------------------------------------

import { useState, useEffect, useRef, useCallback } from '../../vendor/preact-hooks.js';
import {
  FREE_DAYS, FILTER_PROFILES, OUTDOORS_VARIANTS,
  profileButtonOrder, variantIcons,
  activityVariantKeys, placeVariantKeys, workVariantKeys,
  UTCI_ENVIRONMENTS, VARIANT_DEFAULT_ENV,
} from '../config.js';
import { utciCategory, VEHICLE_SPEEDS } from '../utils.js';
import { buildHourlyRows, aggregateRows } from '../compute.js';
import { useForecast } from './useForecast.js';
import { useColumnPopup } from './useColumnPopup.js';
import { useTableScroll } from './useTableScroll.js';
import { getActiveEvents, getLensEvent } from '../events.js';

function track(event, profile) {
  try {
    fetch('track.php', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(profile ? { event, profile } : { event }),
    }).catch(() => {});
  } catch (e) { /* ignore */ }
}

// ── SHARE LINK PARAMS ───────────────────────────────────────────────────
// Read once at module load, before any state initialiser or effect runs. The
// Stripe and dev-unlock effects each strip the query string on mount, so
// anything read lazily later would already be gone.
//
// Everything is validated: a link is untrusted input, and these values feed
// straight into the fetch URL and the column set. Anything unrecognised is
// dropped silently and the normal localStorage / default path takes over.
//
// Note there is deliberately no `pro` param. Pro is granted only by a
// Stripe-verified session_id or the server-checked dev token; a shareable link
// must never become an unlock. Pro-only profiles and variants are therefore
// accepted only for a visitor who is already Pro on this device.
const SHARE_PARAMS = (() => {
  const out = {};
  try {
    const p = new URLSearchParams(window.location.search);
    if (!p.has('lat') && !p.has('profile') && !p.has('day')) return out;

    const lat = parseFloat(p.get('lat'));
    const lon = parseFloat(p.get('lon'));
    if (Number.isFinite(lat) && Number.isFinite(lon) &&
        lat >= -90 && lat <= 90 && lon >= -180 && lon <= 180) {
      // Strip control characters only - place names legitimately contain
      // spaces, hyphens, apostrophes and accents.
      const raw = (p.get('name') || '').replace(/[\u0000-\u001f\u007f]/g, '').trim();
      out.location = {
        name: raw.slice(0, 60) || `${lat.toFixed(2)}°, ${lon.toFixed(2)}°`,
        lat, lon,
        country: (p.get('country') || '').slice(0, 2).toUpperCase() || '',
      };
    }

    const alreadyPro = (() => {
      try { return localStorage.getItem('sunscope_pro') === '1'; } catch (e) { return false; }
    })();

    const profile = p.get('profile');
    if (profile && Object.prototype.hasOwnProperty.call(FILTER_PROFILES, profile) &&
        (alreadyPro || !FILTER_PROFILES[profile].proOnly)) {
      out.profile = profile;
    }

    const variant = p.get('variant');
    if (variant && Object.prototype.hasOwnProperty.call(OUTDOORS_VARIANTS, variant) &&
        (alreadyPro || !OUTDOORS_VARIANTS[variant].proOnly)) {
      out.variant = variant;
    }

    const day = parseInt(p.get('day'), 10);
    if (Number.isInteger(day) && day >= 0 && day < FREE_DAYS) out.day = day;
  } catch (e) { /* malformed query string - ignore entirely */ }
  return out;
})();

export function useAppState() {

  // ── 1. LOCATION ──────────────────────────────────────────────────────
  // Precedence: share link → last saved location → London.
  const [location, setLocation] = useState(() => {
    if (SHARE_PARAMS.location) return SHARE_PARAMS.location;
    try {
      const saved = localStorage.getItem('sunscope_last_location');
      if (saved) return JSON.parse(saved);
    } catch (e) { /* ignore */ }
    return { name: 'London, England', lat: 51.509, lon: -0.126, country: 'GB' };
  });

  // Recent locations: the most recently viewed spots, so the user can
  // hop back with one click. The list is kept newest-first with the
  // current location at the front; the UI shows the others as chips.
  const [recentLocations, setRecentLocations] = useState(() => {
    try {
      const saved = localStorage.getItem('sunscope_recent_locations');
      if (saved) return JSON.parse(saved);
    } catch (e) { /* ignore */ }
    return [];
  });

  const locKey = (l) => `${l.lat.toFixed(3)},${l.lon.toFixed(3)}`;

  const setLocationAndSave = (loc) => {
    try { localStorage.setItem('sunscope_last_location', JSON.stringify(loc)); } catch (e) { /* ignore */ }
    setRecentLocations((prev) => {
      // Make sure the spot we're switching away from lands in the recent
      // list too - otherwise the very first switch drops it on the floor
      // since it was never added to recentLocations before now.
      const withCurrent = locKey(location) !== locKey(loc)
        ? [location, ...prev.filter((l) => locKey(l) !== locKey(location))]
        : prev;
      // Keep the current spot at the front and the 3 previous distinct
      // ones behind it (4 total, so 3 chips remain after excluding current).
      const next = [loc, ...withCurrent.filter((l) => locKey(l) !== locKey(loc))].slice(0, 4);
      try { localStorage.setItem('sunscope_recent_locations', JSON.stringify(next)); } catch (e) { /* ignore */ }
      return next;
    });
    setLocation(loc);
  };

  // ── GEOLOCATION ──────────────────────────────────────────────────────
  // Without this the first-time default is London for everyone on earth.
  // Never auto-prompted: a saved location always wins, and an unrequested
  // permission dialog on load is hostile. The pin button in the header is
  // the only entry point.
  const [locating, setLocating]       = useState(false);
  const [locateError, setLocateError] = useState(null);

  const useMyLocation = () => {
    if (!navigator.geolocation) {
      setLocateError("This browser can't share your location.");
      return;
    }
    setLocating(true);
    setLocateError(null);
    navigator.geolocation.getCurrentPosition(
      (pos) => {
        // Named "My location" rather than a place name: Open-Meteo's geocoding
        // API is forward-only (?name=), with no reverse endpoint, and pulling
        // in a second provider just to label a pin isn't worth the extra host.
        // The header already prints the coordinates underneath the name.
        setLocationAndSave({
          name: 'My location',
          lat: pos.coords.latitude,
          lon: pos.coords.longitude,
          country: '',
        });
        setSelectedDay(0);
        setLocating(false);
        track('geolocate');
      },
      (err) => {
        setLocating(false);
        setLocateError(
          err.code === 1 ? 'Location permission denied.'
          : err.code === 3 ? 'Timed out finding your location.'
          : "Couldn't get your location."
        );
      },
      { timeout: 8000, maximumAge: 10 * 60 * 1000 }
    );
  };

  // Pro tier flag is read early so useForecast can pick its refresh cadence
  // (Pro: 15 min, free: 30 min). Full setup notes in the PRO TIER section below.
  // Initial state trusts only what's already in localStorage - a bare
  // ?session_id=... in the URL is verified against Stripe (see the effect
  // below) before it's ever allowed to flip this on, so pasting/guessing a
  // URL param can't grant free access.
  const [isPro, setIsPro] = useState(() => localStorage.getItem('sunscope_pro') === '1');

  const { forecast, airQuality, aqHorizon, loading, error, now, fetchedAt, liveElev, normals, retry } = useForecast(location, isPro);

  // Just returned from a Stripe Payment Link: verify the checkout session
  // server-side (verify-session.php) before granting Pro. Also records
  // which kind of purchase it was (subscription vs one-off) and the Stripe
  // customer id, so the re-check effect below knows whether/how to follow up.
  useEffect(() => {
    const params    = new URLSearchParams(window.location.search);
    const sessionId = params.get('session_id');
    if (!sessionId) return;
    window.history.replaceState({}, '', window.location.pathname);
    fetch(`verify-session.php?session_id=${encodeURIComponent(sessionId)}`)
      .then((r) => r.json())
      .then((data) => {
        if (!data.paid) return;
        try {
          localStorage.setItem('sunscope_pro', '1');
          if (data.mode) localStorage.setItem('sunscope_pro_mode', data.mode);
          if (data.customer) localStorage.setItem('sunscope_pro_customer', data.customer);
          localStorage.setItem('sunscope_pro_checked_at', String(Date.now()));
        } catch (e) { /* ignore */ }
        setIsPro(true);
      })
      .catch(() => {});
  }, []);

  // Dev-only testing unlock: ?dev=<token>, verified server-side against
  // DEV_UNLOCK_TOKEN in secrets.local.php (dev-unlock.php). Replaces the old
  // bare ?pro=1 trick - a guessed/copied URL with the wrong token does nothing.
  useEffect(() => {
    const params   = new URLSearchParams(window.location.search);
    const devToken = params.get('dev');
    if (!devToken) return;
    window.history.replaceState({}, '', window.location.pathname);
    fetch(`dev-unlock.php?token=${encodeURIComponent(devToken)}`)
      .then((r) => r.json())
      .then((data) => {
        if (!data.ok) return;
        try {
          localStorage.setItem('sunscope_pro', '1');
          localStorage.setItem('sunscope_pro_mode', 'dev');
          localStorage.removeItem('sunscope_pro_customer');
          localStorage.setItem('sunscope_pro_checked_at', String(Date.now()));
        } catch (e) { /* ignore */ }
        setIsPro(true);
      })
      .catch(() => {});
  }, []);

  // Subscribers (not one-off payers) can cancel in Stripe at any time, so
  // Pro access shouldn't stay granted forever once localStorage is set.
  // Re-check roughly once a day per visitor - one-off payments are skipped
  // entirely since that access is permanent by design.
  useEffect(() => {
    if (!isPro) return;
    const mode = (() => { try { return localStorage.getItem('sunscope_pro_mode'); } catch (e) { return null; } })();
    if (mode !== 'subscription') return;
    const customer = (() => { try { return localStorage.getItem('sunscope_pro_customer'); } catch (e) { return null; } })();
    if (!customer) return;
    const lastChecked = (() => { try { return Number(localStorage.getItem('sunscope_pro_checked_at')) || 0; } catch (e) { return 0; } })();
    const RECHECK_MS = 24 * 60 * 60 * 1000;
    if (Date.now() - lastChecked < RECHECK_MS) return;

    fetch(`check-subscription.php?customer=${encodeURIComponent(customer)}`)
      .then((r) => r.json())
      .then((data) => {
        try { localStorage.setItem('sunscope_pro_checked_at', String(Date.now())); } catch (e) { /* ignore */ }
        if (!data.active) {
          try {
            localStorage.removeItem('sunscope_pro');
            localStorage.removeItem('sunscope_pro_mode');
            localStorage.removeItem('sunscope_pro_customer');
          } catch (e) { /* ignore */ }
          setIsPro(false);
        }
      })
      .catch(() => {});
  }, [isPro]);

  useEffect(() => { track('visit'); }, []);

  const [searchQuery, setSearchQuery]     = useState('');
  const [searchResults, setSearchResults] = useState([]);
  const [searching, setSearching]         = useState(false);
  const [selectedDay, setSelectedDay]     = useState(SHARE_PARAMS.day ?? 0);
  const [proPromptDay, setProPromptDay]   = useState(null);
  const [proPromptSource, setProPromptSource] = useState('day');

  // ── 2. DAY-TAB SCROLL ────────────────────────────────────────────────
  const dayTabsRef = useRef(null);
  const [canScrollLeft, setCanScrollLeft]   = useState(false);
  const [canScrollRight, setCanScrollRight] = useState(false);

  useEffect(() => {
    const el = dayTabsRef.current;
    if (!el) return;
    const update = () => {
      setCanScrollLeft(el.scrollLeft > 1);
      setCanScrollRight(el.scrollLeft + el.clientWidth < el.scrollWidth - 1);
    };
    update();
    el.addEventListener('scroll', update, { passive: true });
    window.addEventListener('resize', update);
    let ro = null;
    if (typeof ResizeObserver !== 'undefined') {
      ro = new ResizeObserver(update);
      ro.observe(el);
    }
    return () => {
      el.removeEventListener('scroll', update);
      window.removeEventListener('resize', update);
      if (ro) ro.disconnect();
    };
  }, [forecast]);

  useEffect(() => {
    const el = dayTabsRef.current;
    if (!el) return;
    const activeTab = el.querySelector('.utci-day-tab.active');
    if (!activeTab) return;
    const elRect  = el.getBoundingClientRect();
    const tabRect = activeTab.getBoundingClientRect();
    if (tabRect.left < elRect.left + 8) {
      el.scrollBy({ left: tabRect.left - elRect.left - 24, behavior: 'smooth' });
    } else if (tabRect.right > elRect.right - 8) {
      el.scrollBy({ left: tabRect.right - elRect.right + 24, behavior: 'smooth' });
    }
  }, [selectedDay]);

  const scrollDayTabs = (dir) => {
    const el = dayTabsRef.current;
    if (!el) return;
    el.scrollBy({ left: dir * 200, behavior: 'smooth' });
  };

  // Drag-to-scroll for the day-tab strip, mirroring the hourly table's body
  // scroller (see useTableScroll). Unlike the table scroller, the draggable
  // surface here IS the clickable element (each day is a <button>), so a
  // plain mousedown/mouseup pair must still open that day - only a real drag
  // (movement past a small threshold) should scroll instead of select. We
  // track that with `dragged` and swallow the resulting click in capture
  // phase so a drag never also fires the tab's onClick.
  useEffect(() => {
    const el = dayTabsRef.current;
    if (!el) return;
    let isDown = false;
    let dragged = false;
    let startX = 0;
    let startScroll = 0;

    const suppressClick = (e) => {
      e.preventDefault();
      e.stopPropagation();
      el.removeEventListener('click', suppressClick, true);
    };

    const onMouseDown = (e) => {
      if (!el.contains(e.target)) return;
      if (e.button !== 0) return;
      isDown = true;
      dragged = false;
      startX = e.clientX;
      startScroll = el.scrollLeft;
    };
    const onMouseMove = (e) => {
      if (!isDown) return;
      const dx = e.clientX - startX;
      if (!dragged && Math.abs(dx) > 4) {
        dragged = true;
        // .utci-day-tabs has scroll-behavior:smooth for the chevron/snap
        // scrolls elsewhere - suspend it during drag so scrollLeft tracks
        // the pointer 1:1 instead of easing behind it.
        el.style.scrollBehavior = 'auto';
        el.style.cursor = 'grabbing';
        document.body.style.userSelect = 'none';
        document.body.style.webkitUserSelect = 'none';
        el.addEventListener('click', suppressClick, true);
      }
      if (dragged) el.scrollLeft = startScroll - dx;
    };
    const onMouseUp = () => {
      if (!isDown) return;
      isDown = false;
      el.style.scrollBehavior = '';
      el.style.cursor = '';
      document.body.style.userSelect = '';
      document.body.style.webkitUserSelect = '';
      // Safety net: normally the browser's own click (fired right after
      // mouseup, synchronously ahead of this timeout) hits suppressClick
      // first and removes it. But if mouseup lands outside every tab or a
      // click never follows for any other reason, this stops the listener
      // leaking and silently swallowing the *next* real click.
      if (dragged) setTimeout(() => el.removeEventListener('click', suppressClick, true), 0);
    };

    document.addEventListener('mousedown', onMouseDown);
    document.addEventListener('mousemove', onMouseMove);
    document.addEventListener('mouseup',   onMouseUp);
    return () => {
      document.removeEventListener('mousedown', onMouseDown);
      document.removeEventListener('mousemove', onMouseMove);
      document.removeEventListener('mouseup',   onMouseUp);
      el.removeEventListener('click', suppressClick, true);
    };
  }, [forecast]);

  // ── 3. PRO TIER ──────────────────────────────────────────────────────
  // (isPro is declared near the top so useForecast can read it; see above.)

  // ── 4. PROFILE + COLUMN VISIBILITY ───────────────────────────────────
  const [activeProfile, setActiveProfile] = useState(() => {
    if (SHARE_PARAMS.profile) return SHARE_PARAMS.profile;
    try { return localStorage.getItem('sunscope_profile') || 'basic'; } catch (e) { return 'basic'; }
  });

  const [visibleCols, setVisibleCols] = useState(() => {
    try {
      const saved = SHARE_PARAMS.profile || localStorage.getItem('sunscope_profile') || 'basic';
      // If saved profile is outdoors. read columns from the saved variant - Beach. Running. etc.
      // so the column buttons match the autoloaded variant on startup.
      if (saved === 'outdoors') {
        const savedVariant = SHARE_PARAMS.variant || localStorage.getItem('sunscope_outdoors_variant') || 'urban';
        const variantCols = OUTDOORS_VARIANTS[savedVariant]?.cols
          ?? FILTER_PROFILES.outdoors.cols;
        return { ...variantCols };
      }
      // For custom profile, load from config - blank slate with only Hour on.
      if (saved === 'custom') {
        return { ...FILTER_PROFILES.custom?.cols ?? FILTER_PROFILES.basic.cols };
      }
      return { ...(FILTER_PROFILES[saved]?.cols ?? FILTER_PROFILES.basic.cols) };
    } catch (e) { return { ...FILTER_PROFILES.basic.cols }; }
  });

  const toggleCol = (col) => setVisibleCols(prev => ({ ...prev, [col]: !prev[col] }));

  const activateProfile = (key) => {
    track('profile', key);
    const profile = FILTER_PROFILES[key];
    try { localStorage.setItem('sunscope_profile', key); } catch (e) { /* ignore */ }
    setActiveProfile(key);
    // Profiles can declare a preferred forecast view (Basic opens in Quick).
    if (profile?.view) setForecastView(profile.view);
    if (key !== 'custom') {
      setVisibleCols({ ...profile.cols });
      const hasIndoor = profile.cols['indoorT'] || profile.cols['managedT'];
      // Must go through the persisting setters: the Indoors pill and column
      // read indoorMode, and its initialiser reads it back from localStorage
      // on the next load. Setting only the React state left the stored value
      // behind, so a reload restored the previous profile's Indoors state.
      setIndoorModeAndSave(hasIndoor ? 'on' : 'off');
      setIndoorManagedAndSave(false);
      if (hasIndoor) setBuildingTypeAndSave('brick');
      const defaultEnv = VARIANT_DEFAULT_ENV[key];
      if (defaultEnv) setUtciEnvAndSave(defaultEnv);
    } else {
      // Custom profile initializes from config - blank slate, user picks columns.
      const customCols = FILTER_PROFILES.custom?.cols;
      if (customCols) {
        setVisibleCols({ ...customCols });
        const hasIndoor = customCols['indoorT'] || customCols['managedT'];
        setIndoorModeAndSave(hasIndoor ? 'on' : 'off');
        setIndoorManagedAndSave(false);
      }
    }
  };

  // ── 5. SKIN, VEHICLE, INDOOR, POLLEN ─────────────────────────────────
  const [skinType, setSkinType]       = useState('II');
  const [vehicleType, setVehicleType] = useState(() => {
    try { return localStorage.getItem('sunscope_vehicle_type') || 'car'; } catch (e) { return 'car'; }
  });
  const setVehicleTypeAndSave = (v) => {
    try { localStorage.setItem('sunscope_vehicle_type', v); } catch (e) { /* ignore */ }
    setVehicleType(v);
  };
  const [vehicleVent, setVehicleVent] = useState(() => {
    try { return localStorage.getItem('sunscope_vehicle_vent') === '1'; } catch (e) { return false; }
  });
  const setVehicleVentAndSave = (v) => {
    try { localStorage.setItem('sunscope_vehicle_vent', v ? '1' : '0'); } catch (e) { /* ignore */ }
    setVehicleVent(v);
  };
  // Road-speed class (key into VEHICLE_SPEEDS): 'static' | 'urban' | 'aroad' | 'motorway'.
  const [vehicleSpeed, setVehicleSpeed] = useState(() => {
    try { return localStorage.getItem('sunscope_vehicle_speed') || 'static'; } catch (e) { return 'static'; }
  });
  const setVehicleSpeedAndSave = (v) => {
    try { localStorage.setItem('sunscope_vehicle_speed', v); } catch (e) { /* ignore */ }
    setVehicleSpeed(v);
  };

  const [outdoorsVariant, setOutdoorsVariant] = useState(() => {
    if (SHARE_PARAMS.variant) return SHARE_PARAMS.variant;
    try { return localStorage.getItem('sunscope_outdoors_variant') || 'urban'; } catch (e) { return 'urban'; }
  });
  const setOutdoorsVariantAndSave = (v) => {
    try { localStorage.setItem('sunscope_outdoors_variant', v); } catch (e) { /* ignore */ }
    setOutdoorsVariant(v);
    // Every Places / Activities / Work variant carries a wide, specific column
    // set - Quick view can only show a handful of those, so open the detailed
    // table. (Basic goes the other way; see FILTER_PROFILES.basic.view.)
    setForecastView('table');
    // Sync the column toggle buttons to the variants own cols so the UI matches
    // the autoloaded selection - eg Beach selects Dew. Sun. UV-B and Running selects RH. Pollen. UTCI.
    const variantCols = OUTDOORS_VARIANTS[v]?.cols;
    if (variantCols) {
      setVisibleCols({ ...variantCols });
      const hasIndoor = variantCols['indoorT'] || variantCols['managedT'];
      setIndoorModeAndSave(hasIndoor ? 'on' : 'off');
    }
    // Auto-set UTCI environment modifier to match the selected variant.
    const defaultEnv = VARIANT_DEFAULT_ENV[v] ?? 'open';
    setUtciEnvAndSave(defaultEnv);
    // The Driver profile is about cab comfort - default the vehicle model to a
    // truck cab travelling at A-road speed.
    if (v === 'driver') {
      setVehicleTypeAndSave('truck');
      setVehicleSpeedAndSave('aroad');
    }
  };

  const activeCols = activeProfile === 'outdoors'
    ? (OUTDOORS_VARIANTS[outdoorsVariant]?.cols ?? FILTER_PROFILES.outdoors.cols)
    : (FILTER_PROFILES[activeProfile]?.cols ?? FILTER_PROFILES.basic.cols);

  const [buildingType, setBuildingType] = useState(() => {
    try {
      const saved = localStorage.getItem('sunscope_building_type');
      if (saved) return saved;
      // Fall back to office if the saved variant is office and no explicit building saved
      const savedVariant = localStorage.getItem('sunscope_outdoors_variant') || '';
      if (savedVariant === 'office') return 'office';
    } catch (e) { /* ignore */ }
    return 'brick';
  });
  const setBuildingTypeAndSave = (v) => {
    try { localStorage.setItem('sunscope_building_type', v); } catch (e) { /* ignore */ }
    setBuildingType(v);
  };
  const [furColor, setFurColor] = useState(() => {
    try { return localStorage.getItem('sunscope_fur_color') || 'brown'; } catch (e) { return 'brown'; }
  });
  const setFurColorAndSave = (v) => {
    try { localStorage.setItem('sunscope_fur_color', v); } catch (e) { /* ignore */ }
    setFurColor(v);
  };
  const [indoorManaged, setIndoorManaged] = useState(() => {
    try { return localStorage.getItem('sunscope_indoor_managed') === '1'; } catch (e) { return false; }
  });
  const setIndoorManagedAndSave = (v) => {
    try { localStorage.setItem('sunscope_indoor_managed', v ? '1' : '0'); } catch (e) { /* ignore */ }
    setIndoorManaged(v);
  };
  const [indoorMode, setIndoorMode] = useState(() => {
    try {
      const profile = localStorage.getItem('sunscope_profile') || 'basic';
      const cols = profile === 'outdoors'
        ? (OUTDOORS_VARIANTS[localStorage.getItem('sunscope_outdoors_variant') || 'urban']?.cols
            ?? FILTER_PROFILES.outdoors.cols)
        : (FILTER_PROFILES[profile]?.cols ?? FILTER_PROFILES.basic.cols);
      const offered = !!(cols['indoorT'] || cols['managedT']);
      // A profile that has no Indoors columns has no Indoors pill either, so
      // an 'on' left over from a profile that did would show the column with
      // no way to turn it off. The profile decides whether it's available;
      // the saved value only decides the state within a profile that offers it.
      if (!offered) return 'off';
      const saved = localStorage.getItem('sunscope_indoor_mode');
      return saved || 'on';
    } catch (e) { return 'off'; }
  });
  const setIndoorModeAndSave = (v) => {
    try { localStorage.setItem('sunscope_indoor_mode', v); } catch (e) { /* ignore */ }
    setIndoorMode(v);
  };

  const [pollenType, setPollenType] = useState(() => {
    try { return localStorage.getItem('sunscope_pollen_type') || 'all_pollen'; } catch (e) { return 'all_pollen'; }
  });
  const setPollenTypeAndSave = (v) => {
    try { localStorage.setItem('sunscope_pollen_type', v); } catch (e) { /* ignore */ }
    setPollenType(v);
  };

  const [utciEnv, setUtciEnv] = useState(() => {
    try {
      const saved = localStorage.getItem('sunscope_utci_env');
      if (saved && UTCI_ENVIRONMENTS[saved]) return saved;
      // No saved env - derive from the saved variant only when the outdoors
      // profile is active. Other profiles (Basic, Vehicle etc.) always open.
      const savedProfile = localStorage.getItem('sunscope_profile') || 'basic';
      if (savedProfile === 'outdoors') {
        const savedVariant = localStorage.getItem('sunscope_outdoors_variant') || '';
        return VARIANT_DEFAULT_ENV[savedVariant] ?? 'open';
      }
      return 'open';
    } catch (e) { return 'open'; }
  });
  const setUtciEnvAndSave = (v) => {
    try { localStorage.setItem('sunscope_utci_env', v); } catch (e) { /* ignore */ }
    setUtciEnv(v);
  };
  
  const [showDecimals, setShowDecimals] = useState(() => {
    try { const s = localStorage.getItem('sunscope_show_decimals'); return s === null ? false : s !== '0'; } catch (e) { return false; }
  });
  const toggleShowDecimals = () => setShowDecimals(v => {
    const next = !v;
    try { localStorage.setItem('sunscope_show_decimals', next ? '1' : '0'); } catch (e) { /* ignore */ }
    return next;
  });

  // ── Welcome / "How it works" popup ───────────────────────────────────
  // Auto-shows on first visit (no seen flag), can be reopened anytime via
  // the footer link. Reopening does NOT clear the flag.
  const [welcomeOpen, setWelcomeOpen] = useState(() => {
    try { return localStorage.getItem('sunscope_welcome_seen') !== '1'; }
    catch (e) { return false; }
  });
  useEffect(() => {
    if (welcomeOpen && (() => { try { return localStorage.getItem('sunscope_welcome_seen') !== '1'; } catch (e) { return false; } })()) {
      track('welcome_shown');
    }
  }, []);
  const closeWelcome = () => {
    try { localStorage.setItem('sunscope_welcome_seen', '1'); } catch (e) { /* ignore */ }
    setWelcomeOpen(false);
  };
  const openWelcome = () => setWelcomeOpen(true);

  // ── Weekly subscribe nudge (free users only) ─────────────────────────
  // At most once every 7 days, and never on the first visit - the welcome
  // popup owns that moment. The last-shown date lives in localStorage;
  // subscribing (isPro) suppresses it entirely.
  const NUDGE_KEY      = 'sunscope_nudge_last';
  const NUDGE_COOLDOWN = 7 * 24 * 60 * 60 * 1000;
  const [weeklyNudgeOpen, setWeeklyNudgeOpen] = useState(false);
  useEffect(() => {
    if (isPro || welcomeOpen) return;
    let last = 0;
    try {
      last = Number(localStorage.getItem(NUDGE_KEY)) || 0;
      // First run for an existing user: start the clock, don't nudge yet.
      if (!last) { localStorage.setItem(NUDGE_KEY, String(Date.now())); return; }
    } catch (e) { return; }
    if (Date.now() - last < NUDGE_COOLDOWN) return;
    setWeeklyNudgeOpen(true);
    track('weekly_nudge_shown');
  }, [isPro, welcomeOpen]);
  const closeWeeklyNudge = () => {
    try { localStorage.setItem(NUDGE_KEY, String(Date.now())); } catch (e) { /* ignore */ }
    setWeeklyNudgeOpen(false);
  };

  // Restore-access modal ("Already subscribed?").
  const [restoreOpen, setRestoreOpen] = useState(false);
  const openRestore  = () => setRestoreOpen(true);
  const closeRestore = () => setRestoreOpen(false);

  // Profile & config flyout panel (right-side drawer).
  const [panelOpen, setPanelOpen] = useState(false);
  const openPanel  = () => setPanelOpen(true);
  const closePanel = () => setPanelOpen(false);

  const [showUnits, setShowUnits] = useState(() => {
    try {
      const s = localStorage.getItem('sunscope_show_units');
      if (s !== null) return s !== '0';
      return typeof window !== 'undefined' ? window.innerWidth >= 640 : true;
    } catch (e) { return true; }
  });
  const toggleShowUnits = () => setShowUnits(v => {
    const next = !v;
    try { localStorage.setItem('sunscope_show_units', next ? '1' : '0'); } catch (e) { /* ignore */ }
    return next;
  });

  // Rotates the hourly table: off = hours down the side, on = hours along
  // the top with the metrics down the side. Off by default — the tall
  // layout is the one most people expect from a forecast table.
  const [tableRotated, setTableRotated] = useState(() => {
    try { return localStorage.getItem('sunscope_table_rotated') === '1'; } catch (e) { return false; }
  });
  const setTableRotatedAndSave = (next) => {
    try { localStorage.setItem('sunscope_table_rotated', next ? '1' : '0'); } catch (e) { /* ignore */ }
    setTableRotated(!!next);
  };

  // Table row interval: 1 = every hour, 2/3/4 = clock-aligned buckets. Default 2.
  const [tableInterval, setTableIntervalState] = useState(() => {
    try { const n = parseInt(localStorage.getItem('sunscope_table_interval'), 10); return [1, 2, 3, 4].includes(n) ? n : 2; } catch (e) { return 2; }
  });
  const setTableInterval = (n) => setTableIntervalState(() => {
    const next = [1, 2, 3, 4].includes(n) ? n : 2;
    try { localStorage.setItem('sunscope_table_interval', String(next)); } catch (e) { /* ignore */ }
    return next;
  });

  const [forecastView, setForecastViewState] = useState(() => {
    try { const s = localStorage.getItem('sunscope_forecast_view'); return s === 'table' ? 'table' : 'simple'; } catch (e) { return 'simple'; }
  });
  const setForecastView = (v) => {
    try { localStorage.setItem('sunscope_forecast_view', v); } catch (e) { /* ignore */ }
    setForecastViewState(v);
  };

  const searchTimeout = useRef(null);

  // Derived selectors used by profile controls
  const activityOptions = activityVariantKeys.map((k) => {
    const v = OUTDOORS_VARIANTS[k];
    const locked = v.proOnly && !isPro;
    return {
      value: k,
      label: `${variantIcons[k]} ${v.name}${locked ? ' 🔒' : ''}`,
      name:  v.name,
      scene: v.scene,
      icon:  v.icon,
      disabled: locked,
    };
  });
  const placeOptions = placeVariantKeys.map((k) => {
    const v = OUTDOORS_VARIANTS[k];
    const locked = v.proOnly && !isPro;
    return {
      value: k,
      label: `${variantIcons[k]} ${v.name}${locked ? ' 🔒' : ''}`,
      name:  v.name,
      scene: v.scene,
      icon:  v.icon,
      disabled: locked,
    };
  });
  const workOptions = workVariantKeys.map((k) => {
    const v = k === 'farming'
      ? { name: FILTER_PROFILES.farming.label, proOnly: false, scene: FILTER_PROFILES.farming.scene, icon: FILTER_PROFILES.farming.icon }
      : OUTDOORS_VARIANTS[k];
    const locked = v.proOnly && !isPro;
    const iconGlyph = k === 'farming' ? FILTER_PROFILES.farming.icon : variantIcons[k];
    return {
      value: k,
      label: `${iconGlyph} ${v.name}${locked ? ' 🔒' : ''}`,
      name:  v.name,
      scene: v.scene,
      icon:  v.icon || iconGlyph,
      disabled: locked,
    };
  });

  const activityValue = activeProfile === 'outdoors' && activityVariantKeys.includes(outdoorsVariant)
    ? outdoorsVariant
    : 'off';
  const activityLabel = activityOptions.find((o) => o.value === activityValue)?.name;
  const placeValue    = activeProfile === 'outdoors' && placeVariantKeys.includes(outdoorsVariant)
    ? outdoorsVariant
    : 'off';
  const placeLabel    = placeOptions.find((o) => o.value === placeValue)?.name;
  const workValue     = activeProfile === 'farming'
    ? 'farming'
    : activeProfile === 'outdoors' && workVariantKeys.includes(outdoorsVariant)
      ? outdoorsVariant
      : 'off';
  const workLabel     = workOptions.find((o) => o.value === workValue)?.name;

  // ── 6. TABLE REFS ────────────────────────────────────────────────────
  const headStickyRef = useRef(null);
  const headTrackRef  = useRef(null);
  const headTableRef  = useRef(null);
  const bodyScrollRef = useRef(null);
  const bodyTableRef  = useRef(null);
  const tableWrapRef  = useRef(null);

  // ── 7. COLUMN POPUP + TABLE SCROLL ───────────────────────────────────
  const {
    colPopup, colPopupRef,
    handleThClick, handleThEnter, handleThLeave,
    handlePopupEnter, handlePopupLeave,
    eventTagPopup, eventTagPopupRef,
    evSlideIndex, evTransition, evSlideTo,
    handleEventTagClick, handleEventTagEnter, handleEventTagLeave,
    handleEventTagPopupEnter, handleEventTagPopupLeave,
    closePopup, closeEventTagPopup,
  } = useColumnPopup();

  const {
    tableCanScrollLeft,
    tableCanScrollRight,
    handleBodyScroll,
  } = useTableScroll({
    headTableRef, bodyTableRef, bodyScrollRef, headTrackRef, tableWrapRef,
    forecast, visibleCols, selectedDay, skinType, vehicleType,
    indoorMode, indoorManaged, showDecimals, showUnits,
    // The rotated table is a single table with CSS-only sticky edges, so
    // none of this hook's dual-table syncing applies to it.
    rotated: tableRotated,
  });

  // ── 8. GEOCODING SEARCH ───────────────────────────────────────────────
  useEffect(() => {
    if (searchQuery.length < 2) { setSearchResults([]); return; }
    if (searchTimeout.current) clearTimeout(searchTimeout.current);
    searchTimeout.current = setTimeout(async () => {
      setSearching(true);
      try {
        const r = await fetch(
          `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(searchQuery)}&count=6&language=en&format=json`
        );
        const j = await r.json();
        setSearchResults(j.results || []);
      } catch { setSearchResults([]); }
      finally { setSearching(false); }
    }, 300);
  }, [searchQuery]);

  // ── 8b. SHARE LINK ───────────────────────────────────────────────────
  // Keep the address bar in step with what's on screen so the page can be
  // bookmarked, pinned to a home screen, or sent to someone else.
  //
  // replaceState, not pushState: the back button should leave the app, not
  // walk backwards through every profile the user tried.
  const buildShareUrl = () => {
    const p = new URLSearchParams();
    p.set('lat', location.lat.toFixed(4));
    p.set('lon', location.lon.toFixed(4));
    if (location.name) p.set('name', location.name);
    if (location.country) p.set('country', location.country);
    p.set('profile', activeProfile);
    if (activeProfile === 'outdoors') p.set('variant', outdoorsVariant);
    if (selectedDay > 0) p.set('day', String(selectedDay));
    return `${window.location.origin}${window.location.pathname}?${p}`;
  };

  // Skip the first run. The Stripe and dev-unlock effects both strip the query
  // string on mount; syncing before they do would put params back and undo it.
  const urlSyncReady = useRef(false);
  useEffect(() => {
    if (!urlSyncReady.current) { urlSyncReady.current = true; return; }
    try {
      window.history.replaceState({}, '', buildShareUrl());
    } catch (e) { /* ignore - some embedded webviews block this */ }
  }, [location, activeProfile, outdoorsVariant, selectedDay]);

  // Share button: native sheet where available, clipboard everywhere else.
  // `shareState` drives the transient "Link copied" confirmation.
  const [shareState, setShareState] = useState(null); // null | 'copied' | 'failed'
  const shareForecast = async () => {
    const url = buildShareUrl();
    track('share');
    try {
      if (navigator.share) {
        await navigator.share({ title: `SunScope - ${location.name}`, url });
        return;
      }
      await navigator.clipboard.writeText(url);
      setShareState('copied');
    } catch (e) {
      // AbortError just means the user dismissed the native share sheet.
      if (e && e.name === 'AbortError') return;
      setShareState('failed');
    }
    setTimeout(() => setShareState(null), 2200);
  };

  // ── 9. COMPUTATION ───────────────────────────────────────────────────
  const { hourlyRows, days, utcOffsetMs } = buildHourlyRows({
    forecast, airQuality, location, vehicleType, vehicleVent,
    vehicleSpeed: (VEHICLE_SPEEDS[vehicleSpeed] ?? VEHICLE_SPEEDS.static).mph,
    buildingType, furColor, utciEnv,
  });

  const visible = days[selectedDay]?.rows || [];
  // Rows actually rendered in the table - bucketed by the interval selector.
  // `visible` stays full-resolution so the dial, glance and event detection
  // keep seeing every hour.
  const tableRows = aggregateRows(visible, tableInterval);

  const nowLocalISO = new Date(now.getTime() + utcOffsetMs).toISOString().slice(0, 13);
  const currentRow  = hourlyRows.length > 0
    ? (hourlyRows.find(row => row.iso.slice(0, 13) === nowLocalISO)
      ?? hourlyRows.reduce((best, row) =>
        Math.abs(row.dt - now) < Math.abs(best.dt - now) ? row : best))
    : null;
  const currentCat  = currentRow
    ? utciCategory(currentRow.utciAdj)
    : { bg: '#4a4228', fg: '#ede4cc', label: 'No data' };

  // ── 10. EVENTS ────────────────────────────────────────────────────────
  // Events surface as the .event-note strip above the nav (see app.js). It
  // is in flow rather than an overlay, so there is no dismiss or snooze
  // state to track.
  const todayRows       = days[0]?.rows || [];
  const activeEvents    = getActiveEvents(todayRows, location);
  const lensEvent       = getLensEvent(activeEvents);
  const selectedDayEvents = getActiveEvents(visible, location);

  // ── RETURN ALL STATE + HANDLERS ───────────────────────────────────────
  return {
    // location
    location, setLocationAndSave, recentLocations,
    useMyLocation, locating, locateError, setLocateError,
    // share
    shareForecast, shareState, buildShareUrl,
    // forecast
    forecast, airQuality, aqHorizon, loading, error, now, fetchedAt, normals, retry,
    // search
    searchQuery, setSearchQuery,
    searchResults, setSearchResults,
    searching,
    // day selection
    selectedDay, setSelectedDay,
    proPromptDay, setProPromptDay,
    proPromptSource, setProPromptSource,
    // day-tab scroll
    dayTabsRef, canScrollLeft, canScrollRight, scrollDayTabs,
    // pro
    isPro, setIsPro,
    // profile
    activeProfile, setActiveProfile,
    activateProfile, activeCols,
    visibleCols, setVisibleCols, toggleCol,
    activityOptions, placeOptions, workOptions,
    activityValue, activityLabel,
    placeValue, placeLabel,
    workValue, workLabel,
    // skin, vehicle, indoor, pollen
    skinType, setSkinType,
    vehicleType, setVehicleType: setVehicleTypeAndSave,
    vehicleVent, setVehicleVent: setVehicleVentAndSave,
    vehicleSpeed, setVehicleSpeed: setVehicleSpeedAndSave,
    outdoorsVariant, setOutdoorsVariantAndSave,
    buildingType, setBuildingType: setBuildingTypeAndSave,
    furColor, setFurColor: setFurColorAndSave,
    indoorManaged, setIndoorManaged: setIndoorManagedAndSave,
    indoorMode, setIndoorMode: setIndoorModeAndSave,
    pollenType, setPollenTypeAndSave,
    utciEnv, setUtciEnv: setUtciEnvAndSave,
	showDecimals, toggleShowDecimals,
    welcomeOpen, closeWelcome, openWelcome,
    weeklyNudgeOpen, closeWeeklyNudge,
    restoreOpen, openRestore, closeRestore,
    panelOpen, openPanel, closePanel,
    showUnits, toggleShowUnits,
    tableInterval, setTableInterval,
    tableRotated, setTableRotated: setTableRotatedAndSave,
    forecastView, setForecastView,
    // table refs
    headStickyRef, headTrackRef, headTableRef,
    bodyScrollRef, bodyTableRef, tableWrapRef,
    // column popup
    colPopup, colPopupRef,
    handleThClick, handleThEnter, handleThLeave,
    handlePopupEnter, handlePopupLeave,
    eventTagPopup, eventTagPopupRef,
    evSlideIndex, evTransition, evSlideTo,
    handleEventTagClick, handleEventTagEnter, handleEventTagLeave,
    handleEventTagPopupEnter, handleEventTagPopupLeave,
    closePopup, closeEventTagPopup,
    // table scroll
    tableCanScrollLeft, tableCanScrollRight, handleBodyScroll,
    // computation
    hourlyRows, days, utcOffsetMs,
    visible, tableRows, nowLocalISO, currentRow, currentCat,
    liveElev,
    // events
    activeEvents, lensEvent, selectedDayEvents,
  };
}