// ════════════════════════════════════════════════════════════════════════
//  events.js — Cosmic & weather event engine for SunScope.
//
//  Returns the "active event" (or null) based on:
//    1. PROMO_OVERRIDE  — manually set a message for promotions etc.
//    2. Hardcoded cosmic calendar (eclipses, meteor showers, alignments)
//    3. Weather-derived events (stargazing, sunset, heat spike, storm)
//
//  To set a promo banner, edit PROMO_OVERRIDE near the top of this file.
//  Set it back to null when done.
//
//  Each event object:
//    { id, emoji, title, message, color, textColor, type }
//
//  type: 'cosmic' | 'weather' | 'promo'
// ════════════════════════════════════════════════════════════════════════

// ─── PROMO OVERRIDE ──────────────────────────────────────────────────────
// Set this to show a custom banner regardless of weather or cosmic events.
// Leave as null for automatic event detection.
//
// Example:
//   export const PROMO_OVERRIDE = {
//     id: 'promo-summer',
//     emoji: '☀️',
//     title: 'Summer Sale',
//     message: 'SunScope Extra — 20% off this weekend only.',
//     color: '#c8922a',
//     textColor: '#fff',
//     type: 'promo',
//   };
//
export const PROMO_OVERRIDE = null;

// ─── COSMIC CALENDAR ─────────────────────────────────────────────────────
// Hardcoded events — these are known years in advance.
// Each entry: { id, start: 'YYYY-MM-DD', end: 'YYYY-MM-DD', peak: 'YYYY-MM-DD' (optional), ...eventProps }
// Active if today falls within [start, end] (inclusive).
// Night-only events (meteor showers, eclipses) are marked nightOnly: true
// so the cell icons only appear in night-time rows.

const COSMIC_CALENDAR = [

  // ── METEOR SHOWERS ──────────────────────────────────────────────────
  {
    id: 'quadrantids-2026',
    emoji: '☄️',
    title: 'Quadrantid Meteor Shower',
    message: 'The Quadrantid meteor shower is active — up to 120 meteors/hour at peak. Best after midnight in a dark sky.',
    color: '#2a1a5a',
    textColor: '#e8d8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-01-01', end: '2026-01-05', peak: '2026-01-03',
  },
  {
    id: 'lyrids-2026',
    emoji: '☄️',
    title: 'Lyrid Meteor Shower',
    message: 'The Lyrid meteor shower peaks tonight — up to 20 meteors/hour from a dark sky after midnight.',
    color: '#2a1a5a',
    textColor: '#e8d8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-04-16', end: '2026-04-25', peak: '2026-04-22',
  },
  {
    id: 'eta-aquariids-2026',
    emoji: '☄️',
    title: 'Eta Aquariid Meteor Shower',
    message: 'The Eta Aquariid shower peaks tonight — fragments of Halley\'s Comet, up to 50/hour before dawn.',
    color: '#2a1a5a',
    textColor: '#e8d8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-04-19', end: '2026-05-28', peak: '2026-05-06',
  },
  {
    id: 'perseids-2026',
    emoji: '☄️',
    title: 'Perseid Meteor Shower',
    message: 'The Perseids are active — one of the best showers of the year, up to 100 meteors/hour at peak.',
    color: '#3a1a00',
    textColor: '#ffe8c0',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-07-17', end: '2026-08-24', peak: '2026-08-12',
  },
  {
    id: 'orionids-2026',
    emoji: '☄️',
    title: 'Orionid Meteor Shower',
    message: 'The Orionid shower peaks tonight — fast, bright meteors from Halley\'s Comet debris. Up to 25/hour.',
    color: '#2a1a5a',
    textColor: '#e8d8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-10-02', end: '2026-11-07', peak: '2026-10-21',
  },
  {
    id: 'leonids-2026',
    emoji: '☄️',
    title: 'Leonid Meteor Shower',
    message: 'The Leonid shower is active tonight — fast, bright meteors from comet Tempel-Tuttle.',
    color: '#2a1a5a',
    textColor: '#e8d8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-11-06', end: '2026-11-30', peak: '2026-11-17',
  },
  {
    id: 'geminids-2026',
    emoji: '☄️',
    title: 'Geminid Meteor Shower',
    message: 'The Geminids peak tonight — the best shower of the year, up to 150 meteors/hour. No moon interference.',
    color: '#3a1a00',
    textColor: '#ffe8c0',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-12-04', end: '2026-12-20', peak: '2026-12-13',
  },
  {
    id: 'ursids-2026',
    emoji: '☄️',
    title: 'Ursid Meteor Shower',
    message: 'The Ursid shower peaks tonight — a quieter festive shower near the winter solstice.',
    color: '#2a1a5a',
    textColor: '#e8d8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-12-17', end: '2026-12-26', peak: '2026-12-22',
  },

  // ── ECLIPSES ────────────────────────────────────────────────────────
  {
    id: 'solar-eclipse-2026-aug',
    emoji: '🌑',
    title: 'Total Solar Eclipse',
    message: 'A total solar eclipse crosses Europe and North Africa today — look for rapid temperature drops and unusual animal behaviour even in partial zones.',
    color: '#1a0a2a',
    textColor: '#d8c8f8',
    type: 'cosmic',
    nightOnly: false,
    start: '2026-08-12', end: '2026-08-12',
  },
  {
    id: 'lunar-eclipse-2026-mar',
    emoji: '🌕',
    title: 'Total Lunar Eclipse',
    message: 'A total lunar eclipse is visible tonight — the Moon turns deep red (a "Blood Moon") as it passes through Earth\'s shadow.',
    color: '#3a0a0a',
    textColor: '#ffd8d8',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-03-03', end: '2026-03-03',
  },

  // ── PLANETARY EVENTS ────────────────────────────────────────────────
  {
    id: 'saturn-opposition-2026',
    emoji: '🪐',
    title: 'Saturn at Opposition',
    message: 'Saturn is at its closest and brightest tonight — visible all night long, rings tilted beautifully toward Earth.',
    color: '#1a2a3a',
    textColor: '#c8e8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-09-23', end: '2026-09-23',
  },
  {
    id: 'jupiter-opposition-2026',
    emoji: '🪐',
    title: 'Jupiter at Opposition',
    message: 'Jupiter is at its closest and brightest tonight — you can see its cloud bands with binoculars.',
    color: '#1a2a3a',
    textColor: '#c8e8ff',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-10-08', end: '2026-10-08',
  },
  {
    id: 'mars-conjunction-2026',
    emoji: '🔴',
    title: 'Mars & Venus Conjunction',
    message: 'Mars and Venus are remarkably close in the evening sky tonight — a striking pair visible to the naked eye.',
    color: '#2a1520',
    textColor: '#ffc8d8',
    type: 'cosmic',
    nightOnly: true,
    start: '2026-06-30', end: '2026-07-02',
  },

];

// ─── WEATHER-DERIVED EVENTS ───────────────────────────────────────────────
// These are computed from the actual forecast data.
// Each checker receives (rows, location) and returns an event object or null.
// rows = today's hourlyRows array. location = { lat, lon, name, country }.

function checkStargazing(rows) {
  // Great stargazing: mostly clear night hours with low cloud
  const nightRows = rows.filter(r => r.elev < -5);
  if (nightRows.length < 3) return null;
  const avgCloud = nightRows.reduce((s, r) => s + r.cc, 0) / nightRows.length;
  if (avgCloud > 30) return null;
  return {
    id: 'stargazing',
    emoji: '⭐',
    title: 'Great Stargazing Tonight',
    message: `Clear skies expected overnight at ${nightRows.length} hours with average ${Math.round(avgCloud)}% cloud — ideal conditions for stargazing.`,
    color: '#080e1a',
    textColor: '#c8dcff',
    type: 'weather',
    nightOnly: true,
  };
}

function checkSunset(rows, location) {
  // Perfect sunset: clear low cloud near sunset hour, good visibility
  const sunsetRows = rows.filter(r => r.elev > -3 && r.elev < 8);
  if (sunsetRows.length === 0) return null;
  const avgCloud = sunsetRows.reduce((s, r) => s + r.cc, 0) / sunsetRows.length;
  // We want some high cloud (colour) but not low cloud (obstruction)
  const avgLowCloud = sunsetRows.reduce((s, r) => s + (r.ccLow || 0), 0) / sunsetRows.length;
  if (avgLowCloud > 25) return null;
  if (avgCloud < 5 || avgCloud > 75) return null; // pure clear = less dramatic
  return {
    id: 'perfect-sunset',
    emoji: '🌅',
    title: 'Spectacular Sunset Conditions',
    message: `Low cloud is clear near the horizon but high cloud will scatter the light — conditions are ideal for a vivid sunset near ${location.name}.`,
    color: '#3a1a00',
    textColor: '#ffe0b0',
    type: 'weather',
    nightOnly: false,
  };
}

function checkHeatSpike(rows) {
  const maxTemp = Math.max(...rows.map(r => r.Ta).filter(isFinite));
  if (maxTemp < 30) return null;
  const severity = maxTemp >= 36 ? 'extreme' : maxTemp >= 33 ? 'severe' : 'notable';
  const msgs = {
    notable: `Temperatures reaching ${maxTemp.toFixed(1)}°C — above seasonal norms. Stay hydrated and avoid prolonged sun exposure.`,
    severe:  `Heat warning: ${maxTemp.toFixed(1)}°C expected today. Risk of heat exhaustion for vulnerable people — keep cool and hydrated.`,
    extreme: `Extreme heat alert: ${maxTemp.toFixed(1)}°C forecast. Risk of heat stroke — avoid outdoor activity during peak hours.`,
  };
  return {
    id: 'heat-spike',
    emoji: '🔥',
    title: severity === 'extreme' ? 'Extreme Heat Alert' : severity === 'severe' ? 'Heat Warning' : 'Heat Spike Today',
    message: msgs[severity],
    color: severity === 'extreme' ? '#3a0000' : severity === 'severe' ? '#4a1000' : '#5a2000',
    textColor: '#ffd0b0',
    type: 'weather',
    nightOnly: false,
  };
}

function checkStorm(rows) {
  const maxGust = Math.max(...rows.map(r => r.gust ?? r.va ?? 0).filter(isFinite));
  const maxPrecip = Math.max(...rows.map(r => r.precip ?? 0).filter(isFinite));
  if (maxGust < 15 && maxPrecip < 5) return null;
  const isStorm = maxGust >= 20 || maxPrecip >= 10;
  return {
    id: 'storm',
    emoji: '🌩️',
    title: isStorm ? 'Storm Conditions Forecast' : 'Blustery & Wet Today',
    message: isStorm
      ? `Storm-level conditions expected — gusts to ${maxGust.toFixed(0)} m/s with heavy precipitation. Take care outdoors.`
      : `Unsettled day ahead — windy with gusts to ${maxGust.toFixed(0)} m/s and ${maxPrecip.toFixed(1)} mm/h rain at peak.`,
    color: '#1a2030',
    textColor: '#c0d8f0',
    type: 'weather',
    nightOnly: false,
  };
}

function checkFrost(rows) {
  const minTemp = Math.min(...rows.map(r => r.Ta).filter(isFinite));
  if (minTemp > 2) return null;
  return {
    id: 'frost',
    emoji: '❄️',
    title: minTemp <= 0 ? 'Freezing Conditions' : 'Frost Risk Tonight',
    message: minTemp <= 0
      ? `Temperatures dropping to ${minTemp.toFixed(1)}°C — ice on roads and surfaces is likely. Allow extra travel time.`
      : `Temperatures near freezing tonight (${minTemp.toFixed(1)}°C) — frost possible on exposed surfaces and vehicles.`,
    color: '#0a1a2a',
    textColor: '#c8e8ff',
    type: 'weather',
    nightOnly: false,
  };
}

// ─── ALMANAC CALENDAR ────────────────────────────────────────────────────
// Extended calendar used for the "What's Coming" panel.
// Includes all events from COSMIC_CALENDAR plus multi-year entries.
// Each entry has a latHint: null = global, 'north' = better from northern
// latitudes, 'south' = southern, 'path:...' = specific eclipse path note.

const ALMANAC_CALENDAR = [
  // 2026 events (covers rest of year from today)
  {
    id: 'lunar-eclipse-2026-mar',
    emoji: '🌕',
    title: 'Total Lunar Eclipse',
    desc: 'The Moon turns deep red as it passes through Earth\'s shadow. Visible from Europe, Africa, and the Americas.',
    start: '2026-03-03', peak: '2026-03-03',
    color: '#3a0a0a', textColor: '#ffd8d8',
    latHint: null,
    type: 'eclipse',
  },
  {
    id: 'lyrids-2026',
    emoji: '☄️',
    title: 'Lyrid Meteor Shower',
    desc: 'Up to 20 meteors/hour at peak. Active Apr 16–25, best after midnight from a dark site.',
    start: '2026-04-16', peak: '2026-04-22',
    color: '#2a1a5a', textColor: '#e8d8ff',
    latHint: 'north',
    type: 'meteor',
  },
  {
    id: 'eta-aquariids-2026',
    emoji: '☄️',
    title: 'Eta Aquariid Meteor Shower',
    desc: 'Debris from Halley\'s Comet — up to 50/hour before dawn. Best from southern latitudes but visible worldwide.',
    start: '2026-04-19', peak: '2026-05-06',
    color: '#2a1a5a', textColor: '#e8d8ff',
    latHint: 'south',
    type: 'meteor',
  },
  {
    id: 'mars-conjunction-2026',
    emoji: '🔴',
    title: 'Mars & Venus Conjunction',
    desc: 'Mars and Venus appear strikingly close in the evening sky — a beautiful naked-eye pairing.',
    start: '2026-06-30', peak: '2026-07-01',
    color: '#2a1520', textColor: '#ffc8d8',
    latHint: null,
    type: 'planetary',
  },
  {
    id: 'perseids-2026',
    emoji: '☄️',
    title: 'Perseid Meteor Shower',
    desc: 'One of the best showers of the year — up to 100/hour at peak, no need for a telescope.',
    start: '2026-07-17', peak: '2026-08-12',
    color: '#3a1a00', textColor: '#ffe8c0',
    latHint: 'north',
    type: 'meteor',
  },
  {
    id: 'solar-eclipse-2026-aug',
    emoji: '🌑',
    title: 'Total Solar Eclipse',
    desc: 'The path of totality crosses Spain, Iceland, and Greenland. Partial eclipse visible across most of Europe.',
    start: '2026-08-12', peak: '2026-08-12',
    color: '#1a0a2a', textColor: '#d8c8f8',
    latHint: 'path:Spain, Iceland, Greenland — partial eclipse across UK & Europe',
    type: 'eclipse',
  },
  {
    id: 'saturn-opposition-2026',
    emoji: '🪐',
    title: 'Saturn at Opposition',
    desc: 'Saturn is at its closest and brightest — rings tilted beautifully toward Earth. Visible all night.',
    start: '2026-09-23', peak: '2026-09-23',
    color: '#1a2a3a', textColor: '#c8e8ff',
    latHint: null,
    type: 'planetary',
  },
  {
    id: 'orionids-2026',
    emoji: '☄️',
    title: 'Orionid Meteor Shower',
    desc: 'Fast, bright meteors from Halley\'s Comet — up to 25/hour. Active Oct 2 – Nov 7.',
    start: '2026-10-02', peak: '2026-10-21',
    color: '#2a1a5a', textColor: '#e8d8ff',
    latHint: null,
    type: 'meteor',
  },
  {
    id: 'jupiter-opposition-2026',
    emoji: '🪐',
    title: 'Jupiter at Opposition',
    desc: 'Jupiter at its closest — you can see its cloud bands and four Galilean moons with binoculars.',
    start: '2026-10-08', peak: '2026-10-08',
    color: '#1a2a3a', textColor: '#c8e8ff',
    latHint: null,
    type: 'planetary',
  },
  {
    id: 'leonids-2026',
    emoji: '☄️',
    title: 'Leonid Meteor Shower',
    desc: 'Fast, bright meteors from comet Tempel-Tuttle. Up to 15/hour at peak.',
    start: '2026-11-06', peak: '2026-11-17',
    color: '#2a1a5a', textColor: '#e8d8ff',
    latHint: null,
    type: 'meteor',
  },
  {
    id: 'geminids-2026',
    emoji: '☄️',
    title: 'Geminid Meteor Shower',
    desc: 'The finest shower of the year — up to 150 meteors/hour, visible even before midnight.',
    start: '2026-12-04', peak: '2026-12-13',
    color: '#3a1a00', textColor: '#ffe8c0',
    latHint: 'north',
    type: 'meteor',
  },
  {
    id: 'ursids-2026',
    emoji: '☄️',
    title: 'Ursid Meteor Shower',
    desc: 'A quieter shower near the winter solstice — circumpolar, so best from northern latitudes.',
    start: '2026-12-17', peak: '2026-12-22',
    color: '#2a1a5a', textColor: '#e8d8ff',
    latHint: 'north',
    type: 'meteor',
  },
];

// Returns a location-aware visibility note for an almanac entry.
// lat = user's latitude.
function getVisibilityNote(entry, lat) {
  if (!entry.latHint) return null;
  if (entry.latHint.startsWith('path:')) {
    return entry.latHint.replace('path:', '').trim();
  }
  if (entry.latHint === 'north') {
    if (lat >= 45) return 'Well placed for your latitude';
    if (lat >= 20) return 'Visible from your location';
    return 'Better from northern latitudes';
  }
  if (entry.latHint === 'south') {
    if (lat <= 10) return 'Well placed for your latitude';
    if (lat <= 40) return 'Visible from your location';
    return 'Better from southern latitudes';
  }
  return null;
}

// ─── MAIN ALMANAC EXPORT ─────────────────────────────────────────────────
// Returns events with peak dates in the next `days` days (default 90),
// sorted by peak date, with a visibility note added.
export function getUpcomingEvents(location, days = 90) {
  const today = new Date();
  today.setHours(0, 0, 0, 0);
  const cutoff = new Date(today);
  cutoff.setDate(cutoff.getDate() + days);
  const todayStr = today.toISOString().slice(0, 10);
  const cutoffStr = cutoff.toISOString().slice(0, 10);

  return ALMANAC_CALENDAR
    .filter(ev => ev.peak >= todayStr && ev.peak <= cutoffStr)
    .sort((a, b) => a.peak.localeCompare(b.peak))
    .map(ev => ({
      ...ev,
      visibilityNote: getVisibilityNote(ev, location?.lat ?? 51),
      daysUntil: Math.round((new Date(ev.peak + 'T00:00Z') - today) / 86400000),
    }));
}

// ─── CELL TAG LOGIC ──────────────────────────────────────────────────────
// For timetable cell icons: given an active event and a row,
// should this hour show the event icon?
export function shouldShowCellTag(event, row) {
  if (!event) return false;
  if (event.type === 'promo') return false;
  // Night-only events only badge night rows
  if (event.nightOnly && row.elev >= -5) return false;
  // Weather events: storm/frost badge all hours; heat badges daytime only
  if (event.id === 'heat-spike' && row.elev < 0) return false;
  return true;
}

// ─── MAIN EXPORT ─────────────────────────────────────────────────────────
// Call this once per render with today's rows and location.
// Returns the single highest-priority active event, or null.
//
// Priority order:
//   1. PROMO_OVERRIDE (manual)
//   2. Cosmic calendar events (sorted by priority: eclipse > meteor > planetary)
//   3. Weather events (heat > storm > frost > sunset > stargazing)

export function getActiveEvent(todayRows, location) {
  // 1. Manual promo override
  if (PROMO_OVERRIDE) return PROMO_OVERRIDE;

  // 2. Cosmic calendar
  const today = new Date();
  const todayStr = today.toISOString().slice(0, 10);
  const cosmicHit = COSMIC_CALENDAR.find(ev => todayStr >= ev.start && todayStr <= ev.end);
  if (cosmicHit) return cosmicHit;

  // 3. Weather-derived (needs forecast data)
  if (!todayRows || todayRows.length === 0) return null;

  return (
    checkHeatSpike(todayRows) ||
    checkStorm(todayRows) ||
    checkFrost(todayRows) ||
    checkSunset(todayRows, location) ||
    checkStargazing(todayRows)
  );
}

// ─── LENS OVERLAY RENDERER ───────────────────────────────────────────────
// Returns SVG group content for the event overlay in the big ScopeReticle.
// Rendered INSIDE the lens clip and BELOW the glass shine/shade layers.
// cx, cy = lens centre; lensR = lens radius.


export function getLensOverlaySVG(event, cx, cy, lensR) {
  if (!event) return null;
  const id = event.id;

  if (event.emoji === '☄️') {
    return [
      '<g opacity="0.55" clip-path="url(#scope-lens-clip)">',
      `<line x1="${cx-60}" y1="${cy-50}" x2="${cx-20}" y2="${cy-20}" stroke="#ffe8a0" stroke-width="1.5" stroke-linecap="round" opacity="0.9"/>`,
      `<line x1="${cx-40}" y1="${cy-70}" x2="${cx+5}" y2="${cy-30}" stroke="#fff0c0" stroke-width="1" stroke-linecap="round" opacity="0.7"/>`,
      `<line x1="${cx+30}" y1="${cy-60}" x2="${cx+65}" y2="${cy-25}" stroke="#ffe8a0" stroke-width="1.8" stroke-linecap="round" opacity="0.8"/>`,
      `<line x1="${cx-10}" y1="${cy-40}" x2="${cx+30}" y2="${cy-5}" stroke="#fff0c0" stroke-width="0.9" stroke-linecap="round" opacity="0.65"/>`,
      `<line x1="${cx-70}" y1="${cy-20}" x2="${cx-35}" y2="${cy+10}" stroke="#ffe8a0" stroke-width="1.2" stroke-linecap="round" opacity="0.6"/>`,
      '</g>',
    ].join('\n');
  }

  if (id.includes('solar-eclipse')) {
    return [
      '<g clip-path="url(#scope-lens-clip)">',
      `<radialGradient id="corona-glow" cx="${cx}" cy="${cy-20}" r="38" gradientUnits="userSpaceOnUse">`,
      '<stop offset="0%" stop-color="rgba(255,220,100,0)" />',
      '<stop offset="55%" stop-color="rgba(255,220,100,0.55)" />',
      '<stop offset="100%" stop-color="rgba(255,180,40,0)" />',
      '</radialGradient>',
      `<circle cx="${cx}" cy="${cy-20}" r="38" fill="url(#corona-glow)" opacity="0.8" />`,
      `<circle cx="${cx}" cy="${cy-20}" r="18" fill="rgba(5,2,15,0.88)" />`,
      '</g>',
    ].join('\n');
  }

  if (id.includes('lunar-eclipse')) {
    return [
      '<g clip-path="url(#scope-lens-clip)">',
      `<radialGradient id="blood-moon-glow" cx="${cx}" cy="${cy-30}" r="30" gradientUnits="userSpaceOnUse">`,
      '<stop offset="0%" stop-color="rgba(180,30,10,0.7)" />',
      '<stop offset="100%" stop-color="rgba(120,10,5,0)" />',
      '</radialGradient>',
      `<circle cx="${cx}" cy="${cy-30}" r="30" fill="url(#blood-moon-glow)" />`,
      `<circle cx="${cx}" cy="${cy-30}" r="16" fill="rgba(160,25,10,0.75)" />`,
      `<circle cx="${cx}" cy="${cy-30}" r="16" fill="none" stroke="rgba(220,60,20,0.5)" stroke-width="1.5" />`,
      '</g>',
    ].join('\n');
  }

  if (event.emoji === '🪐') {
    return [
      '<g clip-path="url(#scope-lens-clip)" opacity="0.65">',
      `<circle cx="${cx+20}" cy="${cy-35}" r="10" fill="rgba(210,185,130,0.7)" />`,
      `<ellipse cx="${cx+20}" cy="${cy-35}" rx="18" ry="4.5" fill="none" stroke="rgba(200,170,100,0.65)" stroke-width="2.5" />`,
      '</g>',
    ].join('\n');
  }

  if (event.emoji === '🔴') {
    return [
      '<g clip-path="url(#scope-lens-clip)" opacity="0.6">',
      `<circle cx="${cx+30}" cy="${cy-30}" r="7" fill="rgba(200,80,40,0.75)" />`,
      `<circle cx="${cx-20}" cy="${cy-45}" r="5" fill="rgba(220,160,80,0.7)" />`,
      '</g>',
    ].join('\n');
  }

  if (id === 'stargazing') {
    const stars = [
      [cx-50,cy-55,1.8],[cx+40,cy-65,1.4],[cx-20,cy-70,1.0],
      [cx+65,cy-40,1.6],[cx-60,cy-30,1.2],[cx+50,cy-55,1.0],
      [cx-35,cy-45,1.4],[cx+20,cy-50,1.8],[cx-75,cy-50,1.0],
    ];
    const dots = stars.map(([x,y,r]) => `<circle cx="${x}" cy="${y}" r="${r}" fill="rgba(255,255,255,0.9)" />`).join('');
    return `<g clip-path="url(#scope-lens-clip)" opacity="0.7">${dots}</g>`;
  }

  if (id === 'perfect-sunset') {
    return [
      '<g clip-path="url(#scope-lens-clip)" opacity="0.5">',
      `<radialGradient id="sunset-lens-glow" cx="${cx}" cy="${cy+20}" r="${lensR}" gradientUnits="userSpaceOnUse">`,
      '<stop offset="0%" stop-color="rgba(255,120,20,0.7)" />',
      '<stop offset="50%" stop-color="rgba(255,60,10,0.25)" />',
      '<stop offset="100%" stop-color="rgba(200,20,0,0)" />',
      '</radialGradient>',
      `<circle cx="${cx}" cy="${cy}" r="${lensR}" fill="url(#sunset-lens-glow)" />`,
      '</g>',
    ].join('\n');
  }

  if (id === 'heat-spike') {
    return [
      '<g clip-path="url(#scope-lens-clip)" opacity="0.35">',
      `<path d="M ${cx-lensR+10} ${cy+30} Q ${cx-20} ${cy+15} ${cx+20} ${cy+30} Q ${cx+60} ${cy+45} ${cx+lensR-10} ${cy+30}" fill="none" stroke="rgba(255,120,20,0.6)" stroke-width="2" />`,
      `<path d="M ${cx-lensR+10} ${cy+45} Q ${cx-10} ${cy+30} ${cx+30} ${cy+45} Q ${cx+65} ${cy+60} ${cx+lensR-10} ${cy+45}" fill="none" stroke="rgba(255,100,10,0.5)" stroke-width="2" />`,
      `<path d="M ${cx-lensR+20} ${cy+60} Q ${cx+10} ${cy+45} ${cx+40} ${cy+60} Q ${cx+70} ${cy+75} ${cx+lensR-20} ${cy+60}" fill="none" stroke="rgba(255,80,0,0.4)" stroke-width="1.5" />`,
      '</g>',
    ].join('\n');
  }

  if (id === 'storm') {
    const lines = [-55,-30,-5,20,45,65].map(x =>
      `<line x1="${cx+x}" y1="${cy-lensR+10}" x2="${cx+x-15}" y2="${cy+lensR-10}" stroke="rgba(140,180,220,0.6)" stroke-width="1" stroke-linecap="round" />`
    ).join('');
    return `<g clip-path="url(#scope-lens-clip)" opacity="0.45">${lines}</g>`;
  }

  if (id === 'frost') {
    const crystals = [[-50,40],[0,55],[50,40],[-30,65],[30,65]].map(([dx,dy]) =>
      `<g transform="translate(${cx+dx},${cy+dy})">` +
      '<line x1="-6" y1="0" x2="6" y2="0" stroke="rgba(180,220,255,0.8)" stroke-width="1" />' +
      '<line x1="0" y1="-6" x2="0" y2="6" stroke="rgba(180,220,255,0.8)" stroke-width="1" />' +
      '<line x1="-4" y1="-4" x2="4" y2="4" stroke="rgba(180,220,255,0.7)" stroke-width="0.8" />' +
      '<line x1="4" y1="-4" x2="-4" y2="4" stroke="rgba(180,220,255,0.7)" stroke-width="0.8" />' +
      '</g>'
    ).join('');
    return `<g clip-path="url(#scope-lens-clip)" opacity="0.5">${crystals}</g>`;
  }

  return null;
}