feat: wire frontend state and data flow for multi-chart support

- Add activeChartId/charts state to page.tsx with chart fetching on mount
- ChartSelector integrated in sidebar between header and file upload
- CandleChart and SvgOverlay fetch data scoped by activeChartId
- FileUpload returns chart info, auto-selects new chart after upload
- Annotation create/delete flows include chart_id
- Export scoped by activeChartId
- Toolbox receives activeChartId prop

openspec/changes/multi-chart-management/tasks.md

@@ -34,13 +34,13 @@
 
 ## 6. Frontend State & Data Flow
 
-- [ ] 6.1 Add `activeChartId` and `charts` state to `page.tsx`
+- [x] 6.1 Add `activeChartId` and `charts` state to `page.tsx`
-- [ ] 6.2 Fetch charts list on mount via `GET /api/charts`, auto-select the most recent chart
+- [x] 6.2 Fetch charts list on mount via `GET /api/charts`, auto-select the most recent chart
-- [ ] 6.3 Pass `activeChartId` to `CandleChart` component — update it to fetch candles/annotations with `?chartId=` param
+- [x] 6.3 Pass `activeChartId` to `CandleChart` component — update it to fetch candles/annotations with `?chartId=` param
-- [ ] 6.4 Update `handleUploadSuccess` to receive the new chart from the upload response, add it to `charts` state, and set it as `activeChartId`
+- [x] 6.4 Update `handleUploadSuccess` to receive the new chart from the upload response, add it to `charts` state, and set it as `activeChartId`
-- [ ] 6.5 Update annotation create/delete flows to include `chart_id` in requests
+- [x] 6.5 Update annotation create/delete flows to include `chart_id` in requests
-- [ ] 6.6 When `activeChartId` changes, refetch candles and annotations for the new chart
+- [x] 6.6 When `activeChartId` changes, refetch candles and annotations for the new chart
-- [ ] 6.7 Update export handler to include `?chartId=` in the export URL
+- [x] 6.7 Update export handler to include `?chartId=` in the export URL
 
 ## 7. UI Polish
 

src/app/page.tsx

@@ -1,12 +1,20 @@
 'use client';
 
-import { useState, useRef, useEffect } from 'react';
+import { useState, useRef, useEffect, useCallback } from 'react';
 import Toolbox, { Tool } from '@/components/Toolbox';
 import FileUpload from '@/components/FileUpload';
 import CandleChart, { CandleChartHandle } from '@/components/CandleChart';
+import ChartSelector from '@/components/ChartSelector';
+
+interface Chart {
+  id: number;
+  name: string;
+  created_at: number;
+}
 
 interface Annotation {
   id: number;
+  chart_id: number;
   timestamp: number;
   label_type: string;
   geometry: any;
@@ -18,28 +26,83 @@ export default function Home() {
   const [selectedColor, setSelectedColor] = useState('#3b82f6');
   const [selectedLabelId, setSelectedLabelId] = useState<number | null>(null);
   const [annotations, setAnnotations] = useState<Annotation[]>([]);
+  const [charts, setCharts] = useState<Chart[]>([]);
+  const [activeChartId, setActiveChartId] = useState<number | null>(null);
   const chartRef = useRef<CandleChartHandle>(null);
 
+  // Fetch charts list
+  const fetchCharts = useCallback(async () => {
+    try {
+      const response = await fetch('/api/charts');
+      const data = await response.json();
+      setCharts(data);
+      return data as Chart[];
+    } catch (error) {
+      console.error('Failed to fetch charts:', error);
+      return [];
+    }
+  }, []);
+
+  // Fetch annotations for active chart
+  const fetchAnnotations = useCallback(async (chartId: number | null) => {
+    if (!chartId) {
+      setAnnotations([]);
+      return;
+    }
+    try {
+      const response = await fetch(`/api/annotations?chartId=${chartId}`);
+      const data = await response.json();
+      setAnnotations(data);
+    } catch (error) {
+      console.error('Failed to fetch annotations:', error);
+    }
+  }, []);
+
+  // Fetch charts on mount, auto-select the most recent
+  useEffect(() => {
+    const init = async () => {
+      const chartList = await fetchCharts();
+      if (chartList.length > 0) {
+        setActiveChartId(chartList[0].id); // sorted by created_at desc
+      }
+    };
+    init();
+  }, [fetchCharts]);
+
+  // When activeChartId changes, refetch data
+  useEffect(() => {
+    if (activeChartId !== null) {
+      chartRef.current?.refreshData();
+      fetchAnnotations(activeChartId);
+      setSelectedLabelId(null);
+    }
+  }, [activeChartId, fetchAnnotations]);
+
   const handleExport = () => {
+    if (activeChartId) {
+      window.location.href = `/api/export?chartId=${activeChartId}`;
+    } else {
       window.location.href = '/api/export';
+    }
   };
 
-  const handleUploadSuccess = () => {
+  const handleUploadSuccess = (chart: { id: number; name: string }) => {
-    // Refresh chart data after successful upload
+    // Add new chart to list and select it
-    chartRef.current?.refreshData();
+    const newChart: Chart = {
+      id: chart.id,
+      name: chart.name,
+      created_at: Math.floor(Date.now() / 1000),
+    };
+    setCharts((prev) => [newChart, ...prev]);
+    setActiveChartId(chart.id);
   };
 
   const handleAnnotationChange = async () => {
-    // Refresh chart when annotations change
     await chartRef.current?.refreshData();
-    // Fetch annotations for sidebar
+    await fetchAnnotations(activeChartId);
-    const response = await fetch('/api/annotations');
-    const data = await response.json();
-    setAnnotations(data);
   };
 
   const handleLabelDelete = async (id: number) => {
-    // Remove from local state
     setAnnotations(annotations.filter((a) => a.id !== id));
     if (selectedLabelId === id) {
       setSelectedLabelId(null);
@@ -50,19 +113,24 @@ export default function Home() {
     setSelectedLabelId(id === -1 ? null : id);
   };
 
-  // Fetch annotations on mount
+  const handleSelectChart = (chartId: number) => {
-  useEffect(() => {
+    setActiveChartId(chartId);
-    const fetchAnnotations = async () => {
+  };
+
+  const handleDeleteChart = async (chartId: number) => {
     try {
-        const response = await fetch('/api/annotations');
+      const response = await fetch(`/api/charts/${chartId}`, { method: 'DELETE' });
-        const data = await response.json();
+      if (response.ok) {
-        setAnnotations(data);
+        const remaining = charts.filter((c) => c.id !== chartId);
+        setCharts(remaining);
+        if (activeChartId === chartId) {
+          setActiveChartId(remaining.length > 0 ? remaining[0].id : null);
+        }
+      }
     } catch (error) {
-        console.error('Failed to fetch annotations:', error);
+      console.error('Failed to delete chart:', error);
     }
   };
-    fetchAnnotations();
-  }, []);
 
   // Keyboard handler for Delete/Backspace key
   useEffect(() => {
@@ -100,7 +168,15 @@ export default function Home() {
             Manage Annotation Types
           </a>
         </div>
-        <div className="p-6">
+        <div className="p-6 pb-3">
+          <ChartSelector
+            charts={charts}
+            activeChartId={activeChartId}
+            onSelectChart={handleSelectChart}
+            onDeleteChart={handleDeleteChart}
+          />
+        </div>
+        <div className="px-6 pb-3">
           <FileUpload onUploadSuccess={handleUploadSuccess} />
         </div>
         <div className="px-6 pb-6">
@@ -114,6 +190,7 @@ export default function Home() {
             selectedLabelId={selectedLabelId}
             onLabelSelect={handleLabelSelect}
             onLabelDelete={handleLabelDelete}
+            activeChartId={activeChartId}
           />
         </div>
       </aside>
@@ -127,6 +204,7 @@ export default function Home() {
           selectedColor={selectedColor}
           selectedLabelId={selectedLabelId}
           onLabelSelect={handleLabelSelect}
+          activeChartId={activeChartId}
         />
       </main>
     </div>

src/components/CandleChart.tsx

@@ -42,6 +42,7 @@ interface CandleChartProps {
   selectedColor: string;
   selectedLabelId?: number | null;
   onLabelSelect?: (id: number) => void;
+  activeChartId?: number | null;
 }
 
 export interface CandleChartHandle {
@@ -49,7 +50,7 @@ export interface CandleChartHandle {
 }
 
 const CandleChart = forwardRef<CandleChartHandle, CandleChartProps>(
-  ({ activeTool, onAnnotationChange, selectedColor, selectedLabelId, onLabelSelect }, ref) => {
+  ({ activeTool, onAnnotationChange, selectedColor, selectedLabelId, onLabelSelect, activeChartId }, ref) => {
     const chartContainerRef = useRef<HTMLDivElement>(null);
     const chartRef = useRef<IChartApi | null>(null);
     const seriesRef = useRef<ISeriesApi<'Candlestick'> | null>(null);
@@ -68,7 +69,8 @@ const CandleChart = forwardRef<CandleChartHandle, CandleChartProps>(
     // Fetch candles from API
     const fetchCandles = async () => {
       try {
-        const response = await fetch('/api/candles');
+        const url = activeChartId ? `/api/candles?chartId=${activeChartId}` : '/api/candles';
+        const response = await fetch(url);
         const data = await response.json();
         setCandles(data);
         setIsEmpty(data.length === 0);
@@ -82,7 +84,8 @@ const CandleChart = forwardRef<CandleChartHandle, CandleChartProps>(
     // Fetch annotations from API
     const fetchAnnotations = async () => {
       try {
-        const response = await fetch('/api/annotations');
+        const url = activeChartId ? `/api/annotations?chartId=${activeChartId}` : '/api/annotations';
+        const response = await fetch(url);
         const data = await response.json();
         setAnnotations(data);
         return data;
@@ -308,6 +311,7 @@ const CandleChart = forwardRef<CandleChartHandle, CandleChartProps>(
               body: JSON.stringify({
                 timestamp: nearestCandle.time,
                 label_type: activeTool,
+                chart_id: activeChartId,
               }),
             });
 
@@ -410,6 +414,7 @@ const CandleChart = forwardRef<CandleChartHandle, CandleChartProps>(
           activeTool={activeTool}
           onAnnotationChange={onAnnotationChange}
           selectedColor={selectedColor}
+          activeChartId={activeChartId}
         />
       </div>
     );

src/components/FileUpload.tsx

@@ -5,7 +5,7 @@ import { Button } from '@/components/ui/button';
 import { Upload } from 'lucide-react';
 
 interface FileUploadProps {
-  onUploadSuccess: () => void;
+  onUploadSuccess: (chart: { id: number; name: string }) => void;
 }
 
 export default function FileUpload({ onUploadSuccess }: FileUploadProps) {
@@ -36,7 +36,7 @@ export default function FileUpload({ onUploadSuccess }: FileUploadProps) {
           type: 'success',
           text: `Successfully uploaded ${data.count} candle records`,
         });
-        onUploadSuccess();
+        onUploadSuccess(data.chart);
       } else {
         setMessage({
           type: 'error',

src/components/SvgOverlay.tsx

@@ -23,6 +23,7 @@ interface SvgOverlayProps {
   activeTool: string | null;
   onAnnotationChange?: () => void;
   selectedColor: string;
+  activeChartId?: number | null;
 }
 
 interface Point {
@@ -42,6 +43,7 @@ export default function SvgOverlay({
   activeTool,
   onAnnotationChange,
   selectedColor,
+  activeChartId,
 }: SvgOverlayProps) {
   const svgRef = useRef<SVGSVGElement>(null);
   const [dimensions, setDimensions] = useState({ width: 0, height: 0 });
@@ -54,7 +56,8 @@ export default function SvgOverlay({
   // Fetch annotations
   const fetchAnnotations = async () => {
     try {
-      const response = await fetch('/api/annotations');
+      const url = activeChartId ? `/api/annotations?chartId=${activeChartId}` : '/api/annotations';
+      const response = await fetch(url);
       const data = await response.json();
       setAnnotations(data);
     } catch (error) {
@@ -232,6 +235,7 @@ export default function SvgOverlay({
             body: JSON.stringify({
               timestamp: drawingLine.start.time,
               label_type: 'line',
+              chart_id: activeChartId,
               color: selectedColor,
               geometry: {
                 startTime: drawingLine.start.time,

src/components/Toolbox.tsx

@@ -36,6 +36,7 @@ interface ToolboxProps {
   selectedLabelId?: number | null;
   onLabelSelect?: (id: number) => void;
   onLabelDelete?: (id: number) => void;
+  activeChartId?: number | null;
 }
 
 export default function Toolbox({
@@ -48,6 +49,7 @@ export default function Toolbox({
   selectedLabelId = null,
   onLabelSelect,
   onLabelDelete,
+  activeChartId,
 }: ToolboxProps) {
   const [labelsExpanded, setLabelsExpanded] = useState(true);
   const [searchText, setSearchText] = useState('');