From 197a1577c2ba2d7a864ae608275bbc0646d977e1 Mon Sep 17 00:00:00 2001
From: Evan Reichard <evan@reichard.io>
Date: Mon, 16 Mar 2026 19:52:36 -0400
Subject: [PATCH] wip 14

---
 .../src/components/ReadingHistoryGraph.tsx    | 177 ++++++++++++++++++
 frontend/src/components/index.ts              |   3 +
 frontend/src/pages/HomePage.tsx               |  32 +---
 3 files changed, 183 insertions(+), 29 deletions(-)
 create mode 100644 frontend/src/components/ReadingHistoryGraph.tsx

diff --git a/frontend/src/components/ReadingHistoryGraph.tsx b/frontend/src/components/ReadingHistoryGraph.tsx
new file mode 100644
index 0000000..6e884b3
--- /dev/null
+++ b/frontend/src/components/ReadingHistoryGraph.tsx
@@ -0,0 +1,177 @@
+import type { GraphDataPoint } from '../generated/model';
+
+interface ReadingHistoryGraphProps {
+  data: GraphDataPoint[];
+  width?: number;
+  height?: number;
+}
+
+interface SVGPoint {
+  x: number;
+  y: number;
+}
+
+/**
+ * Generates bezier control points for smooth curves
+ */
+function getBezierControlPoint(
+  currentPoint: SVGPoint,
+  prevPoint: SVGPoint | null,
+  nextPoint: SVGPoint | null,
+  isReverse: boolean
+): SVGPoint {
+  // First / Last Point
+  const pPrev = prevPoint || currentPoint;
+  const pNext = nextPoint || currentPoint;
+
+  const smoothingRatio = 0.2;
+  const directionModifier = isReverse ? Math.PI : 0;
+
+  const lengthX = pNext.x - pPrev.x;
+  const lengthY = pNext.y - pPrev.y;
+
+  const length = Math.sqrt(lengthX * lengthX + lengthY * lengthY);
+  const angle = Math.atan2(lengthY, lengthX) + directionModifier;
+  const controlPointLength = length * smoothingRatio;
+
+  return {
+    x: currentPoint.x + Math.cos(angle) * controlPointLength,
+    y: currentPoint.y + Math.sin(angle) * controlPointLength,
+  };
+}
+
+/**
+ * Generates the bezier path for the graph
+ */
+function generateBezierPath(points: SVGPoint[]): string {
+  if (points.length === 0) return '';
+
+  const first = points[0];
+  let path = `M ${first.x},${first.y}`;
+
+  for (let i = 1; i < points.length; i++) {
+    const current = points[i];
+    const prev = points[i - 1];
+    const prevPrev = i - 2 >= 0 ? points[i - 2] : current;
+    const next = i + 1 < points.length ? points[i + 1] : current;
+
+    const startControl = getBezierControlPoint(prev, prevPrev, current, false);
+    const endControl = getBezierControlPoint(current, prev, next, true);
+
+    path += ` C${startControl.x},${startControl.y} ${endControl.x},${endControl.y} ${current.x},${current.y}`;
+  }
+
+  return path;
+}
+
+/**
+ * Calculate points for SVG rendering
+ */
+function calculatePoints(
+  data: GraphDataPoint[],
+  width: number,
+  height: number
+): SVGPoint[] {
+  if (data.length === 0) return [];
+
+  const maxMinutes = Math.max(...data.map((d) => d.minutes_read), 1);
+  const paddingX = width * 0.03; // 3% padding on sides
+  const paddingY = height * 0.1; // 10% padding on top/bottom
+  const usableWidth = width - paddingX * 2;
+  const usableHeight = height - paddingY * 2;
+
+  return data.map((point, index) => {
+    const x = paddingX + (index / (data.length - 1)) * usableWidth;
+    // Y is inverted (0 is top in SVG)
+    const y =
+      paddingY + usableHeight - (point.minutes_read / maxMinutes) * usableHeight;
+    return { x, y };
+  });
+}
+
+/**
+ * Formats a date string
+ */
+function formatDate(dateString: string): string {
+  const date = new Date(dateString);
+  return date.toLocaleDateString('en-US', { month: 'short', day: 'numeric' });
+}
+
+/**
+ * ReadingHistoryGraph component
+ * 
+ * Displays a bezier curve graph of daily reading totals with hover tooltips.
+ */
+export default function ReadingHistoryGraph({
+  data,
+  width = 800,
+  height = 70,
+}: ReadingHistoryGraphProps) {
+  if (!data || data.length < 2) {
+    return (
+      <div className="relative flex h-24 items-center justify-center bg-gray-100 dark:bg-gray-600">
+        <p className="text-gray-400 dark:text-gray-300">No data available</p>
+      </div>
+    );
+  }
+
+  const points = calculatePoints(data, width, height);
+  const bezierPath = generateBezierPath(points);
+
+  // Calculate fill path (closed loop for area fill)
+  const firstX = Math.min(...points.map((p) => p.x));
+  const lastX = Math.max(...points.map((p) => p.x));
+
+  const areaPath = `${bezierPath} L ${lastX},${height} L ${firstX},${height} Z`;
+
+  return (
+    <div className="relative w-full">
+      <svg
+        viewBox={`0 0 ${width} ${height}`}
+        preserveAspectRatio="none"
+        width="100%"
+        height="100%"
+        className="h-24"
+      >
+        {/* Area fill */}
+        <path
+          fill="#316BBE"
+          fillOpacity="0.5"
+          stroke="none"
+          d={areaPath}
+        />
+        {/* Bezier curve line */}
+        <path
+          fill="none"
+          stroke="#316BBE"
+          strokeWidth="2"
+          d={bezierPath}
+        />
+      </svg>
+
+      {/* Hover overlays */}
+      <div className="absolute top-0 size-full">
+        {data.map((point, i) => {
+          return (
+            <div
+              key={i}
+              className="group relative flex-1 cursor-pointer"
+              onClick={(e) => e.preventDefault()}
+            >
+              {/* Vertical indicator line on hover */}
+              <div className="absolute inset-0 flex items-center opacity-0 group-hover:opacity-100">
+                <div className="h-full w-px bg-gray-400 opacity-30" />
+              </div>
+
+              {/* Tooltip */}
+              <div className="pointer-events-none absolute bottom-full left-1/2 mb-2 hidden -translate-x-1/2 rounded-md bg-gray-800 px-3 py-2 text-xs text-white shadow-lg group-hover:block dark:bg-gray-200 dark:text-gray-900">
+                <div className="font-medium">{formatDate(point.date)}</div>
+                <div>{point.minutes_read} minutes</div>
+              </div>
+            </div>
+          );
+        })}
+      </div>
+    </div>
+  );
+}
diff --git a/frontend/src/components/index.ts b/frontend/src/components/index.ts
index fea8839..fba8417 100644
--- a/frontend/src/components/index.ts
+++ b/frontend/src/components/index.ts
@@ -1,3 +1,6 @@
+// Reading History Graph
+export { default as ReadingHistoryGraph } from './ReadingHistoryGraph';
+
 // Toast components
 export { Toast } from './Toast';
 export { ToastProvider, useToasts } from './ToastContext';
diff --git a/frontend/src/pages/HomePage.tsx b/frontend/src/pages/HomePage.tsx
index 2eef0b7..866b94e 100644
--- a/frontend/src/pages/HomePage.tsx
+++ b/frontend/src/pages/HomePage.tsx
@@ -1,6 +1,7 @@
 import { Link } from 'react-router-dom';
 import { useGetHome, useGetDocuments } from '../generated/anthoLumeAPIV1';
-import type { GraphDataPoint, LeaderboardData } from '../generated/model';
+import type { LeaderboardData } from '../generated/model';
+import ReadingHistoryGraph from '../components/ReadingHistoryGraph';
 
 interface InfoCardProps {
   title: string;
@@ -139,34 +140,7 @@ function LeaderboardCard({ name, data }: LeaderboardCardProps) {
   );
 }
 
-function GraphVisualization({ data }: { data: GraphDataPoint[] }) {
-  if (!data || data.length === 0) {
-    return (
-      <div className="relative flex h-24 items-center justify-center bg-gray-100 dark:bg-gray-600">
-        <p className="text-gray-400 dark:text-gray-300">No data available</p>
-      </div>
-    );
-  }
 
-  // Simple bar visualization (could be enhanced with SVG bezier curve like SSR)
-  const maxMinutes = Math.max(...data.map(d => d.minutes_read), 1);
-
-  return (
-    <div className="relative flex h-24 items-end justify-between bg-gray-100 p-2 dark:bg-gray-600">
-      {data.map((point, i) => (
-        <div
-          key={i}
-          className="group relative mx-0.5 flex-1 bg-blue-500 transition-colors hover:bg-blue-600"
-          style={{ height: `${(point.minutes_read / maxMinutes) * 100}%` }}
-        >
-          <div className="pointer-events-none absolute bottom-full left-0 mb-1 w-full text-center text-xs text-gray-600 opacity-0 group-hover:opacity-100 dark:text-gray-300">
-            {point.minutes_read} min
-          </div>
-        </div>
-      ))}
-    </div>
-  );
-}
 
 export default function HomePage() {
   const { data: homeData, isLoading: homeLoading } = useGetHome();
@@ -190,7 +164,7 @@ export default function HomePage() {
           <p className="absolute left-5 top-3 w-max border-b border-gray-200 text-sm font-semibold text-gray-700 dark:border-gray-500 dark:text-white">
             Daily Read Totals
           </p>
-          <GraphVisualization data={graphData || []} />
+          <ReadingHistoryGraph data={graphData || []} />
         </div>
       </div>