From 48b0098c6fddda74e524dfebe6e241005ef51d3d Mon Sep 17 00:00:00 2001
From: Zach Harding <zachary.b.harding@gmail.com>
Date: Tue, 26 May 2026 11:31:19 -0400
Subject: [PATCH] equal height columns for card images

---
 src/pages/partials/cards.astro |  4 +--
 src/volatility.ts              | 61 ++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 src/volatility.ts

diff --git a/src/pages/partials/cards.astro b/src/pages/partials/cards.astro
index 3cee967..e870868 100644
--- a/src/pages/partials/cards.astro
+++ b/src/pages/partials/cards.astro
@@ -327,14 +327,14 @@ const facets = searchResults.results.slice(1).map((result: any) => {
 )}
 
 {pokemon.map((card:any) => (
-    <div class="col">
+    <div class="col equal-height-col">
         {canAddInventory && (
             <button type="button" class="btn btn-sm inventory-button position-relative float-end shadow-filter text-center p-2 fw-bold" data-card-id={card.cardId} hx-get={`/partials/card-modal?cardId=${card.cardId}`} hx-target="#cardModal" hx-trigger="click" data-bs-toggle="modal" data-bs-target="#cardModal" onclick="event.stopPropagation(); sessionStorage.setItem('openModalTab', 'nav-vendor');">
                 +/–
             </button>
         )}
         <div class="card-trigger position-relative" data-card-id={card.cardId} hx-get={`/partials/card-modal?cardId=${card.cardId}`} hx-target="#cardModal" hx-trigger="click" data-bs-toggle="modal" data-bs-target="#cardModal" onclick="const cardTitle = this.querySelector('#cardImage').getAttribute('alt'); dataLayer.push({'event': 'virtualPageview', 'pageUrl': this.getAttribute('hx-get'), 'pageTitle': cardTitle, 'previousUrl': '/pokemon'});">
-            <div class="image-grow rounded-4 card-image" data-energy={card.energyType} data-rarity={card.rarityName} data-variant={card.variant} data-name={card.productName}><img src={`/static/cards/${card.productId}.jpg`} alt={card.productName} id="cardImage" loading="lazy" decoding="async" class="img-fluid rounded-4 mb-2 w-100" onerror="this.onerror=null; this.src='/static/cards/default.jpg'; this.closest('.image-grow')?.setAttribute('data-default','true')"/><span class="position-absolute top-50 start-0 d-inline medium-icon"><FirstEditionIcon edition={card?.variant} /></span>
+            <div class="image-grow rounded-4 card-image" data-energy={card.energyType} data-rarity={card.rarityName} data-variant={card.variant} data-name={card.productName}><img src={`/static/cards/${card.productId}.jpg`} alt={card.productName} id="cardImage" loading="lazy" decoding="async" class="img-fluid rounded-4 mb-2 w-100 h-100" onerror="this.onerror=null; this.src='/static/cards/default.jpg'; this.closest('.image-grow')?.setAttribute('data-default','true')"/><span class="position-absolute top-50 start-0 d-inline medium-icon"><FirstEditionIcon edition={card?.variant} /></span>
               <div class="holo-shine"></div>
               <div class="holo-glare"></div>
             </div>
diff --git a/src/volatility.ts b/src/volatility.ts
new file mode 100644
index 0000000..36ea2c9
--- /dev/null
+++ b/src/volatility.ts
@@ -0,0 +1,61 @@
+export interface VolatilityResult {
+  label: 'High' | 'Medium' | 'Low' | '—';
+  monthlyVol: number;
+}
+
+/**
+ * Computes 30-day rolling volatility from an array of prices using
+ * log-return standard deviation scaled to a monthly expectation.
+ *
+ * @param prices - Ordered array of market prices (oldest → newest)
+ * @returns label ('High' | 'Medium' | 'Low' | '—') and monthlyVol (0–1 range)
+ */
+export function computeVolatility(prices: number[]): VolatilityResult {
+  if (prices.length < 2) return { label: '—', monthlyVol: 0 };
+
+  const returns: number[] = [];
+  for (let i = 1; i < prices.length; i++) {
+    returns.push(Math.log(prices[i] / prices[i - 1]));
+  }
+
+  const mean     = returns.reduce((a, b) => a + b, 0) / returns.length;
+  const variance = returns.reduce((sum, r) => sum + (r - mean) ** 2, 0) / (returns.length - 1);
+  const monthlyVol = Math.sqrt(variance) * Math.sqrt(30);
+
+  const label: VolatilityResult['label'] =
+    monthlyVol >= 0.30 ? 'High'
+  : monthlyVol >= 0.15 ? 'Medium'
+  : 'Low';
+
+  return { label, monthlyVol: Math.round(monthlyVol * 100) / 100 };
+}
+
+/**
+ * Groups a list of price-history rows by condition and computes volatility
+ * for each, filtered to a rolling window.
+ *
+ * @param rows      - Array of { condition, calculatedAt, marketPrice }
+ * @param windowMs  - Rolling window in milliseconds (default: 30 days)
+ */
+export function volatilityByCondition(
+  rows: Array<{ condition: string; calculatedAt: string | Date | null; marketPrice: number | string | null }>,
+  windowMs = 30 * 86_400_000,
+): Record<string, VolatilityResult> {
+  const cutoff = new Date(Date.now() - windowMs);
+  const grouped: Record<string, number[]> = {};
+
+  for (const row of rows) {
+    if (row.marketPrice == null || !row.calculatedAt) continue;
+    if (new Date(row.calculatedAt) < cutoff) continue;
+    const price = Number(row.marketPrice);
+    if (price <= 0) continue;
+    if (!grouped[row.condition]) grouped[row.condition] = [];
+    grouped[row.condition].push(price);
+  }
+
+  const result: Record<string, VolatilityResult> = {};
+  for (const [condition, prices] of Object.entries(grouped)) {
+    result[condition] = computeVolatility(prices);
+  }
+  return result;
+}
\ No newline at end of file