US-025: Add accessibility to CareerConstellation

src/components/CareerConstellation.tsx

@@ -1,6 +1,6 @@
-import React, { useRef, useEffect, useState } from 'react'
+import React, { useRef, useEffect, useState, useCallback } from 'react'
 import * as d3 from 'd3'
-import { constellationNodes, constellationLinks } from '@/data/constellation'
+import { constellationNodes, constellationLinks, roleSkillMappings } from '@/data/constellation'
 import type { ConstellationNode } from '@/types/pmr'
 
 interface CareerConstellationProps {
@@ -16,11 +16,12 @@ const ROLE_RADIUS = 24
 const SKILL_RADIUS = 10
 const COLLIDE_RADIUS = 30
 
-// Domain color mapping for skill nodes
+const prefersReducedMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches
+
 const domainColorMap: Record<string, string> = {
-  clinical: '#059669',    // var(--success)
+  clinical: '#059669',
-  technical: '#0D6E6E',   // var(--accent)
+  technical: '#0D6E6E',
-  leadership: '#D97706',  // var(--amber)
+  leadership: '#D97706',
 }
 
 function getHeight(width: number): number {
@@ -29,7 +30,6 @@ function getHeight(width: number): number {
   return DESKTOP_HEIGHT
 }
 
-// D3 simulation node extends ConstellationNode with x/y
 interface SimNode extends ConstellationNode {
   x: number
   y: number
@@ -45,6 +45,28 @@ interface SimLink {
   strength: number
 }
 
+function buildScreenReaderDescription(): string {
+  const roleNodes = constellationNodes.filter(n => n.type === 'role')
+  const skillNodes = constellationNodes.filter(n => n.type === 'skill')
+
+  const roleDescriptions = roleNodes.map(role => {
+    const mapping = roleSkillMappings.find(m => m.roleId === role.id)
+    const skillNames = mapping
+      ? mapping.skillIds
+          .map(sid => skillNodes.find(s => s.id === sid)?.label)
+          .filter(Boolean)
+          .join(', ')
+      : ''
+    const yearRange = role.endYear
+      ? `${role.startYear}–${role.endYear}`
+      : `${role.startYear}–present`
+    return `${role.label} at ${role.organization} (${yearRange}): ${skillNames}`
+  })
+
+  return `Career constellation graph with ${roleNodes.length} roles and ${skillNodes.length} skills. ` +
+    roleDescriptions.join('. ') + '.'
+}
+
 const CareerConstellation: React.FC<CareerConstellationProps> = ({
   onRoleClick,
   onSkillClick,
@@ -53,11 +75,25 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
   const containerRef = useRef<HTMLDivElement>(null)
   const simulationRef = useRef<d3.Simulation<SimNode, SimLink> | null>(null)
   const [dimensions, setDimensions] = useState({ width: 800, height: DESKTOP_HEIGHT })
+  const [focusedNodeId, setFocusedNodeId] = useState<string | null>(null)
 
-  // Store callbacks in refs so D3 event handlers can access latest versions
   const callbacksRef = useRef({ onRoleClick, onSkillClick })
   callbacksRef.current = { onRoleClick, onSkillClick }
 
+  const roleNodes = constellationNodes.filter(n => n.type === 'role')
+  const srDescription = buildScreenReaderDescription()
+
+  const handleNodeKeyDown = useCallback((e: React.KeyboardEvent, nodeId: string, nodeType: 'role' | 'skill') => {
+    if (e.key === 'Enter' || e.key === ' ') {
+      e.preventDefault()
+      if (nodeType === 'role') {
+        onRoleClick(nodeId)
+      } else {
+        onSkillClick(nodeId)
+      }
+    }
+  }, [onRoleClick, onSkillClick])
+
   useEffect(() => {
     const container = containerRef.current
     if (!container) return
@@ -82,12 +118,10 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
 
     const { width, height } = dimensions
 
-    // Stop previous simulation
     if (simulationRef.current) {
       simulationRef.current.stop()
     }
 
-    // Clear previous content
     svg.selectAll('*').remove()
 
     // Defs with radial gradient
@@ -107,7 +141,7 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
       .attr('fill', 'url(#constellation-bg)')
       .attr('rx', 6)
 
-    // Prepare node and link data (deep copy to avoid mutation)
+    // Prepare data
     const nodes: SimNode[] = constellationNodes.map(n => ({
       ...n,
       x: 0,
@@ -122,23 +156,19 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
       strength: l.strength,
     }))
 
-    // Compute chronological x positions for role nodes
+    const simRoleNodes = nodes.filter(n => n.type === 'role')
-    const roleNodes = nodes.filter(n => n.type === 'role')
+    const years = simRoleNodes.map(n => n.startYear ?? 2016)
-    const years = roleNodes.map(n => n.startYear ?? 2016)
     const minYear = Math.min(...years)
     const maxYear = Math.max(...years)
     const padding = 80
 
-    // Scale: startYear → x position (left-to-right chronologically)
     const xScale = d3.scaleLinear()
       .domain([minYear, maxYear])
       .range([padding, width - padding])
 
-    // Create container groups for layering: links below, nodes above
     const linkGroup = svg.append('g').attr('class', 'links')
     const nodeGroup = svg.append('g').attr('class', 'nodes')
 
-    // Draw links
     const linkSelection = linkGroup.selectAll('line')
       .data(links)
       .join('line')
@@ -146,14 +176,22 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
       .attr('stroke-width', 1)
       .attr('stroke-opacity', 0.3)
 
-    // Draw nodes
     const nodeSelection = nodeGroup.selectAll<SVGGElement, SimNode>('g')
       .data(nodes)
       .join('g')
       .attr('class', d => `node node-${d.type}`)
       .style('cursor', 'pointer')
+      .attr('data-node-id', d => d.id)
+
+    // Role nodes: large circles with focus ring support
+    nodeSelection.filter(d => d.type === 'role')
+      .append('circle')
+      .attr('class', 'focus-ring')
+      .attr('r', ROLE_RADIUS + 4)
+      .attr('fill', 'none')
+      .attr('stroke', 'transparent')
+      .attr('stroke-width', 2)
 
-    // Role nodes: large circles with org color + white text
     nodeSelection.filter(d => d.type === 'role')
       .append('circle')
       .attr('r', ROLE_RADIUS)
@@ -172,7 +210,7 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
       .attr('pointer-events', 'none')
       .text(d => d.shortLabel ?? d.label.slice(0, 8))
 
-    // Skill nodes: smaller circles, color-coded by domain
+    // Skill nodes
     nodeSelection.filter(d => d.type === 'skill')
       .append('circle')
       .attr('r', SKILL_RADIUS)
@@ -181,7 +219,6 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
       .attr('stroke-width', 1.5)
       .attr('fill-opacity', 0.85)
 
-    // Skill labels (short labels for readability)
     nodeSelection.filter(d => d.type === 'skill')
       .append('text')
       .attr('text-anchor', 'middle')
@@ -212,9 +249,29 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
 
     simulationRef.current = simulation
 
-    // Update positions on each tick
+    if (prefersReducedMotion) {
+      // Run simulation to completion synchronously — no animation
+      simulation.stop()
+      for (let i = 0; i < 300; i++) {
+        simulation.tick()
+      }
+
+      // Constrain and render final positions
+      nodes.forEach(d => {
+        const r = d.type === 'role' ? ROLE_RADIUS : SKILL_RADIUS
+        d.x = Math.max(r, Math.min(width - r, d.x))
+        d.y = Math.max(r, Math.min(height - r, d.y))
+      })
+
+      linkSelection
+        .attr('x1', d => (d.source as SimNode).x)
+        .attr('y1', d => (d.source as SimNode).y)
+        .attr('x2', d => (d.target as SimNode).x)
+        .attr('y2', d => (d.target as SimNode).y)
+
+      nodeSelection.attr('transform', d => `translate(${d.x},${d.y})`)
+    } else {
       simulation.on('tick', () => {
-      // Constrain nodes within bounds
         nodes.forEach(d => {
           const r = d.type === 'role' ? ROLE_RADIUS : SKILL_RADIUS
           d.x = Math.max(r, Math.min(width - r, d.x))
@@ -229,13 +286,31 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
 
         nodeSelection.attr('transform', d => `translate(${d.x},${d.y})`)
       })
+    }
 
-    // Cleanup
     return () => {
       simulation.stop()
     }
   }, [dimensions])
 
+  // Update focus ring when focusedNodeId changes
+  useEffect(() => {
+    if (!svgRef.current) return
+    const svg = d3.select(svgRef.current)
+
+    // Reset all focus rings
+    svg.selectAll('.focus-ring')
+      .attr('stroke', 'transparent')
+
+    // Highlight focused node
+    if (focusedNodeId) {
+      svg.selectAll<SVGGElement, SimNode>('g.node')
+        .filter(d => d.id === focusedNodeId)
+        .select('.focus-ring')
+        .attr('stroke', '#0D6E6E')
+    }
+  }, [focusedNodeId])
+
   return (
     <div
       ref={containerRef}
@@ -243,6 +318,7 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
         width: '100%',
         borderRadius: 'var(--radius-sm)',
         overflow: 'hidden',
+        position: 'relative',
       }}
     >
       <svg
@@ -254,6 +330,66 @@ const CareerConstellation: React.FC<CareerConstellationProps> = ({
         aria-label="Career constellation showing roles and skills across career timeline"
         style={{ display: 'block' }}
       />
+      {/* Screen-reader-only description */}
+      <p
+        style={{
+          position: 'absolute',
+          width: 1,
+          height: 1,
+          padding: 0,
+          margin: -1,
+          overflow: 'hidden',
+          clip: 'rect(0,0,0,0)',
+          whiteSpace: 'nowrap',
+          border: 0,
+        }}
+      >
+        {srDescription}
+      </p>
+      {/* Keyboard-navigable role buttons (visually hidden, positioned over SVG) */}
+      <div
+        role="group"
+        aria-label="Career roles — use Tab to navigate, Enter to view details"
+        style={{
+          position: 'absolute',
+          top: 0,
+          left: 0,
+          width: '100%',
+          height: '100%',
+          pointerEvents: 'none',
+        }}
+      >
+        {roleNodes.map(role => {
+          const yearRange = role.endYear
+            ? `${role.startYear}–${role.endYear}`
+            : `${role.startYear}–present`
+          return (
+            <button
+              key={role.id}
+              type="button"
+              aria-label={`${role.label} at ${role.organization}, ${yearRange}. Press Enter to view details.`}
+              style={{
+                position: 'absolute',
+                width: 48,
+                height: 48,
+                top: '50%',
+                left: '50%',
+                transform: 'translate(-50%, -50%)',
+                background: 'transparent',
+                border: 'none',
+                cursor: 'pointer',
+                pointerEvents: 'auto',
+                padding: 0,
+                opacity: 0,
+              }}
+              onFocus={() => setFocusedNodeId(role.id)}
+              onBlur={() => setFocusedNodeId(null)}
+              onClick={() => onRoleClick(role.id)}
+              onKeyDown={e => handleNodeKeyDown(e, role.id, 'role')}
+            />
+          )
+        })}
+      </div>
     </div>
   )
 }