feat: add assessment trends API endpoint for 30-day chart data

Returns trend arrays (scores, wellness, depression, mood), vocal radar
data, heatmap data, and trend direction for the analytics dashboard.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Sonra0

src/app/api/elderly/[id]/assessment/trends/route.ts

@@ -0,0 +1,144 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getCurrentUser } from "@/lib/auth";
+import { getProfileAccess } from "@/lib/access";
+import { prisma } from "@/lib/prisma";
+
+export async function GET(
+  _req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const user = await getCurrentUser();
+  if (!user)
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+
+  const { id } = await params;
+  const role = await getProfileAccess(user, id);
+  if (!role)
+    return NextResponse.json({ error: "Not found" }, { status: 404 });
+
+  const thirtyDaysAgo = new Date();
+  thirtyDaysAgo.setDate(thirtyDaysAgo.getDate() - 30);
+
+  const sessions = await prisma.assessmentSession.findMany({
+    where: {
+      elderlyProfileId: id,
+      status: "COMPLETED",
+      createdAt: { gte: thirtyDaysAgo },
+    },
+    include: { answers: { orderBy: { orderIndex: "asc" } } },
+    orderBy: { createdAt: "asc" },
+  });
+
+  // Build trend arrays
+  const dates: string[] = [];
+  const scores: (number | null)[] = [];
+  const severities: (string | null)[] = [];
+  const wellnessScores: (number | null)[] = [];
+  const depressionIndices: (number | null)[] = [];
+  const moodScores: (number | null)[] = [];
+
+  // Vocal biomarker radar data (from latest session with vocalAnalysis)
+  let latestVocal: Record<string, number> | null = null;
+
+  // Heatmap: weekly mood data
+  const heatmapData: { day: string; week: number; value: number }[] = [];
+
+  for (const session of sessions) {
+    const dateStr = new Date(session.createdAt).toISOString().split("T")[0];
+    dates.push(dateStr);
+    scores.push(session.overallScore);
+    severities.push(session.severity);
+
+    // Extract vocal analysis data if present
+    const vocal = session.vocalAnalysis as Record<string, unknown> | null;
+    if (vocal) {
+      wellnessScores.push(
+        typeof vocal.wellnessScore === "number" ? vocal.wellnessScore : null
+      );
+      depressionIndices.push(
+        typeof vocal.depressionIndex === "number"
+          ? vocal.depressionIndex
+          : null
+      );
+      moodScores.push(
+        typeof vocal.moodScore === "number" ? vocal.moodScore : null
+      );
+
+      // Keep track of latest vocal data for radar chart
+      const radarData: Record<string, number> = {};
+      if (typeof vocal.parkinsonsRisk === "number")
+        radarData.parkinsons = vocal.parkinsonsRisk;
+      if (typeof vocal.depressionIndex === "number")
+        radarData.depression = vocal.depressionIndex;
+      if (typeof vocal.wellnessScore === "number")
+        radarData.wellness = vocal.wellnessScore;
+      if (typeof vocal.moodScore === "number")
+        radarData.mood = vocal.moodScore;
+      if (typeof vocal.speechFluency === "number")
+        radarData.speechFluency = vocal.speechFluency;
+      latestVocal = radarData;
+    } else {
+      wellnessScores.push(null);
+      depressionIndices.push(null);
+      moodScores.push(null);
+    }
+
+    // Heatmap data
+    const d = new Date(session.createdAt);
+    const weekNum = Math.floor(
+      (d.getTime() - thirtyDaysAgo.getTime()) / (7 * 24 * 60 * 60 * 1000)
+    );
+    const dayName = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"][
+      d.getDay()
+    ];
+    const wellnessVal =
+      typeof (vocal as Record<string, unknown> | null)?.wellnessScore ===
+      "number"
+        ? ((vocal as Record<string, unknown>).wellnessScore as number)
+        : session.overallScore ?? 0;
+    heatmapData.push({ day: dayName, week: weekNum, value: wellnessVal });
+  }
+
+  // Compute trend direction from last 7 scores
+  let trend: "improving" | "declining" | "stable" = "stable";
+  const recentScores = scores.filter((s) => s !== null).slice(-7);
+  if (recentScores.length >= 3) {
+    const first = recentScores.slice(0, Math.ceil(recentScores.length / 2));
+    const second = recentScores.slice(Math.ceil(recentScores.length / 2));
+    const avgFirst = first.reduce((a, b) => a + b, 0) / first.length;
+    const avgSecond = second.reduce((a, b) => a + b, 0) / second.length;
+    const diff = avgSecond - avgFirst;
+    if (diff > 5) trend = "improving";
+    else if (diff < -5) trend = "declining";
+  }
+
+  // Latest session for detail view
+  const latestSession = sessions.length > 0 ? sessions[sessions.length - 1] : null;
+
+  return NextResponse.json({
+    trend,
+    trends: {
+      dates,
+      scores,
+      severities,
+      wellnessScores,
+      depressionIndices,
+      moodScores,
+    },
+    vocalRadar: latestVocal,
+    heatmap: heatmapData,
+    latestSession: latestSession
+      ? {
+          id: latestSession.id,
+          date: latestSession.date,
+          overallScore: latestSession.overallScore,
+          severity: latestSession.severity,
+          summary: latestSession.summary,
+          emotionalResponse: latestSession.emotionalResponse,
+          vocalAnalysis: latestSession.vocalAnalysis,
+          answers: latestSession.answers,
+        }
+      : null,
+    sessionCount: sessions.length,
+  });
+}