From ddce5c15b3736dd3acc8f2b52cbffb3dbd507a0a Mon Sep 17 00:00:00 2001
From: Timothy Farrell <tim@thecookiejar.me>
Date: Fri, 24 Jul 2026 02:30:02 +0000
Subject: [PATCH] Add radar tab

---
 src/App.svelte                           |  13 +-
 src/components/PrecipitationRadar.svelte | 655 +++++++++++++++++++++++
 2 files changed, 667 insertions(+), 1 deletion(-)
 create mode 100644 src/components/PrecipitationRadar.svelte

diff --git a/src/App.svelte b/src/App.svelte
index 4bf2e60..598b66f 100644
--- a/src/App.svelte
+++ b/src/App.svelte
@@ -6,11 +6,12 @@
   import HourlyForecast from './components/HourlyForecast.svelte'
   import DailyForecast from './components/DailyForecast.svelte'
   import WeatherDetail from './components/WeatherDetail.svelte'
+  import PrecipitationRadar from './components/PrecipitationRadar.svelte'
   import NotificationBell from './components/NotificationBell.svelte'
   import SettingsDialog from './components/SettingsDialog.svelte'
   import AddLocationDialog from './components/AddLocationDialog.svelte'
 
-  let viewMode = $state('current') // 'current' | 'hourly' | 'daily' | 'detail'
+  let viewMode = $state('current') // 'current' | 'hourly' | 'daily' | 'detail' | 'radar'
   let initDone = $state(false)
   let geoError = $state('')
 
@@ -206,6 +207,11 @@
           class:active={viewMode === 'detail'}
           onclick={() => viewMode = 'detail'}
         >More</button>
+        <button
+          class="nav-btn"
+          class:active={viewMode === 'radar'}
+          onclick={() => viewMode = 'radar'}
+        >Radar</button>
       </div>
 
       <!-- Desktop tab bar -->
@@ -214,6 +220,7 @@
         <button class="tab-btn" class:active={viewMode === 'hourly'} onclick={() => viewMode = 'hourly'}>Hourly</button>
         <button class="tab-btn" class:active={viewMode === 'daily'} onclick={() => viewMode = 'daily'}>7-Day Forecast</button>
         <button class="tab-btn" class:active={viewMode === 'detail'} onclick={() => viewMode = 'detail'}>Details</button>
+        <button class="tab-btn" class:active={viewMode === 'radar'} onclick={() => viewMode = 'radar'}>Radar</button>
       </div>
 
       <!-- Content area -->
@@ -234,6 +241,10 @@
           <div class="animate-fade-in">
             <WeatherDetail />
           </div>
+        {:else if viewMode === 'radar'}
+          <div class="animate-fade-in">
+            <PrecipitationRadar />
+          </div>
         {/if}
       </div>
     {/if}
diff --git a/src/components/PrecipitationRadar.svelte b/src/components/PrecipitationRadar.svelte
new file mode 100644
index 0000000..84dd69c
--- /dev/null
+++ b/src/components/PrecipitationRadar.svelte
@@ -0,0 +1,655 @@
+<script>
+  import { app } from '../lib/stores/app.svelte.js'
+
+  // --- Radar data ---
+  let radarData = $state(null)
+  let loading = $state(true)
+  let error = $state('')
+  let currentIdx = $state(0)
+  let playing = $state(false)
+  let zoom = $state(6)
+  let panX = $state(0)
+  let panY = $state(0)
+  let dragging = $state(false)
+  let dragStart = $state({ x: 0, y: 0 })
+  let dragBase = $state({ x: 0, y: 0 })
+  let animRef = null
+
+  const TILE_SIZE = 256
+  const RADAR_COLOR = 4
+
+  const loc = $derived(app.selectedLocation)
+
+  // --- Load radar metadata ---
+  $effect(() => {
+    if (loc) {
+      panX = 0
+      panY = 0
+      loadRadar()
+    }
+    return () => { if (animRef) clearTimeout(animRef) }
+  })
+
+  async function loadRadar() {
+    loading = true
+    error = ''
+    try {
+      const res = await fetch('https://api.rainviewer.com/public/weather-maps.json')
+      if (!res.ok) throw new Error(`Radar API error: ${res.status}`)
+      radarData = await res.json()
+      const pastLen = radarData?.radar?.past?.length || 0
+      if (pastLen > 0) currentIdx = pastLen - 1
+    } catch (e) {
+      error = e.message || 'Failed to load radar'
+    } finally {
+      loading = false
+    }
+  }
+
+  // --- Frame data ---
+  const pastFrames = $derived(radarData?.radar?.past || [])
+  const nowcastFrames = $derived(radarData?.radar?.nowcast || [])
+  const allFrames = $derived([...pastFrames, ...nowcastFrames])
+  const totalFrames = $derived(allFrames.length)
+  const frame = $derived(allFrames[currentIdx] || null)
+
+  // --- Tile coordinate helpers ---
+  function tileX(lon, z) {
+    return ((lon + 180) / 360) * Math.pow(2, z)
+  }
+
+  function tileY(lat, z) {
+    const rad = (lat * Math.PI) / 180
+    return (1 - Math.log(Math.tan(rad) + 1 / Math.cos(rad)) / Math.PI) * Math.pow(2, z - 1)
+  }
+
+  // Center tile coordinates (floating point, for smooth positioning)
+  const cx = $derived(loc ? tileX(loc.lon, zoom) : 0)
+  const cy = $derived(loc ? tileY(loc.lat, zoom) : 0)
+
+  // Pixel offset of location within the center tile
+  const pxOff = $derived((cx - Math.floor(cx)) * TILE_SIZE)
+  const pyOff = $derived((cy - Math.floor(cy)) * TILE_SIZE)
+
+  // --- Build tile grid (5x5 for panning leeway) ---
+  const tiles = $derived.by(() => {
+    if (!loc) return []
+    const tcx = Math.floor(cx)
+    const tcy = Math.floor(cy)
+    const maxTile = Math.pow(2, zoom)
+    const result = []
+    for (let row = -2; row <= 2; row++) {
+      for (let col = -2; col <= 2; col++) {
+        const tx = tcx + col
+        const ty = tcy + row
+        if (tx < 0 || tx >= maxTile || ty < 0 || ty >= maxTile) continue
+        result.push({
+          tx,
+          ty,
+          col,
+          row,
+        })
+      }
+    }
+    return result
+  })
+
+  function osmUrl(tx, ty) {
+    const s = ['a', 'b', 'c'][(tx + ty) % 3]
+    return `https://${s}.tile.openstreetmap.org/${zoom}/${tx}/${ty}.png`
+  }
+
+  function radarUrl(tx, ty) {
+    if (!frame) return ''
+    return `https://tilecache.rainviewer.com${frame.path}/256/${zoom}/${tx}/${ty}/${RADAR_COLOR}/1_1.png`
+  }
+
+  // --- Playback ---
+  function togglePlay() {
+    playing = !playing
+    if (playing) tick()
+    else if (animRef) { clearTimeout(animRef); animRef = null }
+  }
+
+  function tick() {
+    if (!playing || totalFrames === 0) return
+    currentIdx = (currentIdx + 1) % totalFrames
+    animRef = setTimeout(tick, 600)
+  }
+
+  function stepBack() {
+    playing = false; if (animRef) { clearTimeout(animRef); animRef = null }
+    currentIdx = currentIdx > 0 ? currentIdx - 1 : totalFrames - 1
+  }
+
+  function stepForward() {
+    playing = false; if (animRef) { clearTimeout(animRef); animRef = null }
+    currentIdx = (currentIdx + 1) % totalFrames
+  }
+
+  function zoomIn() {
+    if (zoom < 11) { zoom++; panX = 0; panY = 0 }
+  }
+
+  function zoomOut() {
+    if (zoom > 2) { zoom--; panX = 0; panY = 0 }
+  }
+
+  // --- Pan ---
+  function onPointerDown(e) {
+    // Don't start drag if clicking a button/control
+    if (e.target.closest('button, input')) return
+    dragging = true
+    dragStart = { x: e.clientX, y: e.clientY }
+    dragBase = { x: panX, y: panY }
+    e.currentTarget.setPointerCapture(e.pointerId)
+  }
+
+  function onPointerMove(e) {
+    if (!dragging) return
+    panX = dragBase.x + (e.clientX - dragStart.x)
+    panY = dragBase.y + (e.clientY - dragStart.y)
+  }
+
+  function onPointerUp() {
+    dragging = false
+  }
+
+  // --- Helpers ---
+  function fmtTime(ts) {
+    if (!ts) return ''
+    return new Date(ts * 1000).toLocaleTimeString('en-US', { hour: 'numeric', minute: '2-digit' })
+  }
+
+  function fmtDate(ts) {
+    if (!ts) return ''
+    return new Date(ts * 1000).toLocaleDateString('en-US', { month: 'short', day: 'numeric' })
+  }
+
+  const isPast = $derived(currentIdx < pastFrames.length)
+  const frameLabel = $derived(isPast ? 'Past' : 'Forecast')
+</script>
+
+<div class="radar-section">
+  <h3 class="section-title">Precipitation Radar</h3>
+
+  {#if error && !loc}
+    <div class="radar-status radar-status-err">
+      <span>⚠️ {error}</span>
+      <button class="btn btn-ghost btn-sm" onclick={loadRadar}>Retry</button>
+    </div>
+  {:else}
+    <div
+      class="radar-viewport"
+      class:dragging
+      onpointerdown={onPointerDown}
+      onpointermove={onPointerMove}
+      onpointerup={onPointerUp}
+      onpointerleave={onPointerUp}
+      style="touch-action: none"
+      role="img"
+      aria-label="Precipitation radar map"
+    >
+      <!-- Tile layers (OSM always renders if loc exists) -->
+      {#if loc}
+        <div
+          class="radar-layer"
+          style="transform: translate({panX - pxOff}px, {panY - pyOff}px)"
+        >
+          {#each tiles as t (t.col + '_' + t.row)}
+            <!-- Base map (OSM) -->
+            <img
+              class="radar-tile tile-base"
+              src={osmUrl(t.tx, t.ty)}
+              alt=""
+              loading="lazy"
+              style="grid-column: {t.col + 3}; grid-row: {t.row + 3}"
+              draggable="false"
+            />
+            <!-- Precipitation overlay -->
+            {#if frame}
+              <img
+                class="radar-tile tile-overlay"
+                src={radarUrl(t.tx, t.ty)}
+                alt=""
+                loading="lazy"
+                style="grid-column: {t.col + 3}; grid-row: {t.row + 3}"
+                draggable="false"
+              />
+            {/if}
+          {/each}
+        </div>
+
+        <!-- Location marker -->
+        <div class="location-marker" title={loc?.name || ''}>
+          <span class="marker-dot"></span>
+        </div>
+
+        <!-- Location label -->
+        {#if loc?.name}
+          <div class="marker-label-badge">{loc.name}</div>
+        {/if}
+      {/if}
+
+      <!-- Loading overlay -->
+      {#if loading}
+        <div class="radar-overlay">
+          <span class="loading-spinner">⏳</span>
+          <span class="text-xs text-muted">Loading radar...</span>
+        </div>
+      {/if}
+
+      <!-- Error banner (inline) -->
+      {#if error}
+        <div class="radar-error-banner">
+          <span class="text-xs">⚠️ {error}</span>
+          <button class="btn btn-ghost btn-sm" onclick={loadRadar}>Retry</button>
+        </div>
+      {/if}
+
+      <!-- Zoom controls -->
+      <div class="zoom-ctrl">
+        <button class="zoom-btn" onclick={zoomIn} disabled={zoom >= 11} aria-label="Zoom in">+</button>
+        <span class="zoom-level text-xs text-muted">{zoom}</span>
+        <button class="zoom-btn" onclick={zoomOut} disabled={zoom <= 2} aria-label="Zoom out">−</button>
+      </div>
+    </div>
+
+    <!-- Timeline -->
+    {#if frame}
+      <div class="timeline">
+        <div class="tl-controls">
+          <button class="ctrl-btn" onclick={stepBack} aria-label="Previous" title="Previous">⏮</button>
+          <button class="ctrl-btn play-btn" onclick={togglePlay} aria-label={playing ? 'Pause' : 'Play'}>
+            {playing ? '⏸' : '▶'}
+          </button>
+          <button class="ctrl-btn" onclick={stepForward} aria-label="Next" title="Next">⏭</button>
+        </div>
+
+        <div class="tl-slider">
+          <input
+            type="range"
+            min="0"
+            max={totalFrames - 1}
+            value={currentIdx}
+            oninput={(e) => {
+              playing = false
+              if (animRef) { clearTimeout(animRef); animRef = null }
+              currentIdx = Number(e.target.value)
+            }}
+            aria-label="Radar timeline"
+          />
+        </div>
+
+        <div class="tl-info">
+          <span class="tl-time">{fmtTime(frame.time)}</span>
+          <span class="tl-date text-muted">{fmtDate(frame.time)}</span>
+          <span class="tl-badge" class:tl-past={isPast} class:tl-future={!isPast}>{frameLabel}</span>
+          <span class="text-muted text-xs">{currentIdx + 1}/{totalFrames}</span>
+        </div>
+      </div>
+    {:else if !loading}
+      <div class="radar-status">
+        <p class="text-muted">No radar data available.</p>
+        <button class="btn btn-ghost btn-sm" onclick={loadRadar}>Reload</button>
+      </div>
+    {/if}
+  {/if}
+</div>
+
+<style>
+  .radar-section {
+    margin-bottom: 4px;
+  }
+
+  .section-title {
+    font-size: 1rem;
+    font-weight: 600;
+    margin-bottom: 12px;
+    color: var(--color-text-secondary);
+  }
+
+  .radar-status,
+  .radar-status-err {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 12px;
+    padding: 48px 16px;
+    background: var(--color-surface-card);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-lg);
+    text-align: center;
+  }
+
+  .radar-status-err {
+    border-color: rgba(239, 68, 68, 0.3);
+  }
+
+  /* Loading overlay on top of map */
+  .radar-overlay {
+    position: absolute;
+    inset: 0;
+    background: rgba(10, 22, 40, 0.75);
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 8px;
+    z-index: 10;
+    pointer-events: none;
+  }
+
+  /* Error banner on top of map */
+  .radar-error-banner {
+    position: absolute;
+    top: 12px;
+    left: 12px;
+    right: 12px;
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 8px 12px;
+    background: rgba(239, 68, 68, 0.15);
+    border: 1px solid rgba(239, 68, 68, 0.3);
+    border-radius: var(--radius-sm);
+    z-index: 10;
+    gap: 8px;
+  }
+
+  .loading-spinner {
+    font-size: 2rem;
+    animation: spin 1.5s linear infinite;
+  }
+
+  @keyframes spin {
+    from { transform: rotate(0deg); }
+    to { transform: rotate(360deg); }
+  }
+
+  /* ── Viewport ── */
+  .radar-viewport {
+    position: relative;
+    width: 100%;
+    height: 420px;
+    overflow: hidden;
+    background: #aad3df;
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-lg);
+    cursor: grab;
+    user-select: none;
+    -webkit-user-select: none;
+  }
+
+  .radar-viewport.dragging {
+    cursor: grabbing;
+  }
+
+  .radar-layer {
+    display: grid;
+    grid-template-columns: repeat(5, 256px);
+    grid-template-rows: repeat(5, 256px);
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    margin-left: -640px;
+    margin-top: -640px;
+  }
+
+  .radar-tile {
+    width: 256px;
+    height: 256px;
+    display: block;
+    pointer-events: none;
+    grid-area: auto;
+  }
+
+  .tile-base {
+    z-index: 0;
+  }
+
+  .tile-overlay {
+    z-index: 1;
+  }
+
+  /* ── Location marker ── */
+  .location-marker {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    pointer-events: none;
+    z-index: 5;
+  }
+
+  .marker-dot {
+    display: block;
+    width: 14px;
+    height: 14px;
+    background: var(--color-primary);
+    border: 3px solid #fff;
+    border-radius: 50%;
+    box-shadow: 0 0 12px rgba(56, 189, 248, 0.7);
+    animation: marker-pulse 2s ease-in-out infinite;
+  }
+
+  @keyframes marker-pulse {
+    0%, 100% { box-shadow: 0 0 8px rgba(56, 189, 248, 0.4); }
+    50% { box-shadow: 0 0 20px rgba(56, 189, 248, 0.9); }
+  }
+
+  .marker-label-badge {
+    position: absolute;
+    top: calc(50% + 12px);
+    left: 50%;
+    transform: translateX(-50%);
+    background: rgba(0, 0, 0, 0.75);
+    color: #fff;
+    padding: 3px 10px;
+    border-radius: 4px;
+    font-size: 0.75rem;
+    font-weight: 500;
+    white-space: nowrap;
+    pointer-events: none;
+    z-index: 5;
+  }
+
+  /* ── Zoom controls ── */
+  .zoom-ctrl {
+    position: absolute;
+    bottom: 12px;
+    right: 12px;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 2px;
+    z-index: 6;
+  }
+
+  .zoom-btn {
+    width: 34px;
+    height: 34px;
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-sm);
+    background: var(--color-surface);
+    color: var(--color-text);
+    font-size: 1.1rem;
+    font-weight: 600;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: background var(--transition);
+  }
+
+  .zoom-btn:hover:not(:disabled) {
+    background: var(--color-surface-hover);
+  }
+
+  .zoom-btn:disabled {
+    opacity: 0.4;
+    cursor: not-allowed;
+  }
+
+  .zoom-level {
+    padding: 2px 4px;
+  }
+
+  /* ── Timeline ── */
+  .timeline {
+    margin-top: 12px;
+    padding: 12px 16px;
+    background: var(--color-surface-card);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-lg);
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 12px;
+  }
+
+  .tl-controls {
+    display: flex;
+    gap: 4px;
+    align-items: center;
+  }
+
+  .ctrl-btn {
+    width: 34px;
+    height: 34px;
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-sm);
+    background: var(--color-surface);
+    color: var(--color-text);
+    font-size: 0.85rem;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: background var(--transition);
+  }
+
+  .ctrl-btn:hover {
+    background: var(--color-surface-hover);
+  }
+
+  .play-btn {
+    width: 38px;
+    height: 38px;
+    background: var(--color-primary);
+    border-color: var(--color-primary);
+    font-size: 0.8rem;
+  }
+
+  .play-btn:hover {
+    background: var(--color-primary-hover);
+  }
+
+  .tl-slider {
+    flex: 1;
+    min-width: 120px;
+  }
+
+  .tl-slider input[type='range'] {
+    width: 100%;
+    height: 6px;
+    -webkit-appearance: none;
+    appearance: none;
+    background: var(--color-border);
+    border-radius: 3px;
+    outline: none;
+    cursor: pointer;
+  }
+
+  .tl-slider input[type='range']::-webkit-slider-thumb {
+    -webkit-appearance: none;
+    width: 16px;
+    height: 16px;
+    border-radius: 50%;
+    background: var(--color-primary);
+    border: 2px solid #fff;
+    cursor: pointer;
+    box-shadow: 0 0 6px rgba(56, 189, 248, 0.5);
+  }
+
+  .tl-slider input[type='range']::-moz-range-thumb {
+    width: 16px;
+    height: 16px;
+    border-radius: 50%;
+    background: var(--color-primary);
+    border: 2px solid #fff;
+    cursor: pointer;
+  }
+
+  .tl-info {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    width: 100%;
+    flex-wrap: wrap;
+  }
+
+  .tl-time {
+    font-weight: 600;
+    font-size: 0.95rem;
+    color: var(--color-primary);
+  }
+
+  .tl-date {
+    font-size: 0.82rem;
+  }
+
+  .tl-badge {
+    font-size: 0.7rem;
+    font-weight: 600;
+    padding: 2px 8px;
+    border-radius: 10px;
+    text-transform: uppercase;
+    letter-spacing: 0.04em;
+  }
+
+  .tl-past {
+    background: rgba(96, 165, 250, 0.15);
+    color: var(--color-rain);
+  }
+
+  .tl-future {
+    background: rgba(52, 211, 153, 0.15);
+    color: var(--color-success);
+  }
+
+  /* ── Responsive ── */
+  @media (max-width: 1023px) {
+    .radar-viewport {
+      height: 320px;
+      border-radius: var(--radius-md);
+    }
+
+    .timeline {
+      padding: 10px 12px;
+      gap: 8px;
+    }
+  }
+
+  @media (max-width: 480px) {
+    .radar-viewport {
+      height: 280px;
+    }
+
+    .zoom-btn {
+      width: 30px;
+      height: 30px;
+      font-size: 1rem;
+    }
+
+    .ctrl-btn {
+      width: 30px;
+      height: 30px;
+    }
+
+    .play-btn {
+      width: 34px;
+      height: 34px;
+    }
+  }
+</style>