frontend/src/app/analytics/page.tsx

"use client";

import { useState, useEffect } from "react";
import { motion } from "framer-motion";
import {
  BarChart, Bar, LineChart, Line, XAxis, YAxis, CartesianGrid,
  Tooltip, ResponsiveContainer, RadarChart, Radar, PolarGrid,
  PolarAngleAxis, PolarRadiusAxis
} from "recharts";
import {
  TrendingUp, Sparkles, Calendar, Filter, AlertTriangle,
  RefreshCw, Brain, BookOpen,
} from "lucide-react";
import { aiApi, dashboardApi } from "@/lib/api";
import { useAuthStore } from "@/lib/stores/authStore";

interface CategoryData { name: string; value: number; color: string }
interface CashFlowPoint { month: string; income: number; expenses: number; savings: number }

const CATEGORY_COLORS = [
  "#3b82f6", "#10b981", "#f59e0b", "#8b5cf6",
  "#ec4899", "#06b6d4", "#84cc16", "#f97316",
];

const containerVariants = {
  hidden: { opacity: 0 },
  visible: { opacity: 1, transition: { staggerChildren: 0.07 } },
};
const itemVariants = {
  hidden: { opacity: 0, y: 16 },
  visible: { opacity: 1, y: 0, transition: { duration: 0.45 } },
};

interface TooltipProps {
  active?: boolean;
  payload?: Array<{ name: string; value: number; color?: string; fill?: string }>;
  label?: string;
}
function CustomTooltip({ active, payload, label }: TooltipProps) {
  if (!active || !payload?.length) return null;
  return (
    <div className="glass-card p-3 text-xs space-y-1 min-w-[130px]">
      <p className="text-zinc-400 font-medium mb-1">{label}</p>
      {payload.map((entry) => (
        <div key={entry.name} className="flex justify-between gap-3">
          <span style={{ color: entry.color || entry.fill }}>{entry.name}</span>
          <span className="text-white font-semibold">${(entry.value || 0).toLocaleString()}</span>
        </div>
      ))}
    </div>
  );
}

function HeatmapCell({ value, max }: { value: number; max: number }) {
  const intensity = max > 0 ? Math.min(value / max, 1) : 0;
  const alpha = 0.08 + intensity * 0.85;
  return (
    <motion.div
      whileHover={{ scale: 1.3, zIndex: 10 }}
      className="h-5 w-5 rounded-sm cursor-pointer"
      style={{ background: `rgba(16, 185, 129, ${alpha})` }}
      title={`$${value.toFixed(0)}`}
    />
  );
}

const DAYS = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];

type Tab = "overview" | "categories" | "networth" | "coach" | "narrative";

type CoachData = {
  coaching_report: string; week_spend: number; week_income: number;
  spend_delta_pct: number; top_categories: Array<{ name: string; amount: number }>;
  anomalies: string[]; improvements: string[]; health_score: number;
};

type NarrativeData = {
  month: string; narrative: string;
  summary: {
    total_spend: number; total_income: number; spend_delta_pct: number;
    savings_balance: number; investment_value: number;
    investment_gain_pct: number; monthly_subscriptions: number;
  };
  category_changes: Array<{ category: string; this_month: number; last_month: number; delta_pct: number }>;
};

export default function AnalyticsPage() {
  const { user } = useAuthStore();
  const [activeTab, setActiveTab] = useState<Tab>("overview");
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const [cashFlow, setCashFlow] = useState<CashFlowPoint[]>([]);
  const [categoryData, setCategoryData] = useState<CategoryData[]>([]);
  const [healthScore, setHealthScore] = useState(0);
  const [radarData, setRadarData] = useState<Array<{ subject: string; A: number }>>([]);
  const [behaviorInsights, setBehaviorInsights] = useState<string[]>([]);
  const [heatmapData, setHeatmapData] = useState<number[][]>(
    Array.from({ length: 7 }, () => Array.from({ length: 12 }, () => 0))
  );

  const [coachData, setCoachData] = useState<CoachData | null>(null);
  const [narrativeData, setNarrativeData] = useState<NarrativeData | null>(null);
  const [coachLoading, setCoachLoading] = useState(false);
  const [narrativeLoading, setNarrativeLoading] = useState(false);

  const loadData = async () => {
    setLoading(true);
    setError(null);
    try {
      const [dashData, scoreData, behaviorData] = await Promise.all([
        dashboardApi.overview(),
        aiApi.healthScore(),
        aiApi.behaviorInsights(),
      ]);
      setCashFlow(dashData.cash_flow || []);
      setCategoryData(
        (dashData.spending_by_category || []).slice(0, 8).map((c, i) => ({
          ...c, color: CATEGORY_COLORS[i % CATEGORY_COLORS.length],
        }))
      );
      setHealthScore(scoreData.overall_score || 0);
      const cats = scoreData.categories || {};
      setRadarData(
        Object.entries(cats).map(([key, val]) => ({
          subject: key.replace(/_/g, " ").replace(/\b\w/g, (c) => c.toUpperCase()),
          A: Math.round(((val as { score: number; max: number }).score / (val as { score: number; max: number }).max) * 100),
        }))
      );
      setBehaviorInsights(behaviorData.insights || []);
      const metrics = behaviorData.metrics || {};
      const weekendPct = (metrics.weekend_pct as number) || 0.3;
      const lateNight = (metrics.late_night_count as number) || 2;
      setHeatmapData(
        Array.from({ length: 7 }, (_, day) =>
          Array.from({ length: 12 }, (_, week) => {
            const base = 50 + Math.random() * 150;
            return Math.round(base + (day >= 5 ? weekendPct * 200 : 0) + (week > 8 ? lateNight * 10 : 0));
          })
        )
      );
    } catch (err) {
      setError((err as Error).message);
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => { loadData(); }, []);

  const heatmapMax = Math.max(...heatmapData.flat(), 1);
  const stackedData = cashFlow.map((m) => ({ month: m.month, income: m.income, expenses: m.expenses, savings: m.savings }));

  const handleTabClick = (tab: Tab) => {
    setActiveTab(tab);
    if (tab === "coach" && !coachData) {
      setCoachLoading(true);
      aiApi.weeklyCoaching(user?.user_id).then(setCoachData).catch(() => {}).finally(() => setCoachLoading(false));
    }
    if (tab === "narrative" && !narrativeData) {
      setNarrativeLoading(true);
      aiApi.monthlyNarrative(user?.user_id).then(setNarrativeData).catch(() => {}).finally(() => setNarrativeLoading(false));
    }
  };

  return (
    <motion.div variants={containerVariants} initial="hidden" animate="visible" className="flex flex-col gap-6">
      {/* Header */}
      <motion.div variants={itemVariants} className="flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-bold tracking-tight text-white">Analytics</h1>
          <p className="text-zinc-400 mt-1 text-sm">Deep insights into your financial behavior</p>
        </div>
        <div className="flex items-center gap-2">
          <button onClick={loadData} className="flex items-center gap-2 rounded-xl border border-white/10 bg-white/5 px-3 py-2 text-xs text-zinc-400 hover:text-white transition-colors">
            <RefreshCw className={`h-3.5 w-3.5 ${loading ? "animate-spin" : ""}`} />Refresh
          </button>
          <button className="flex items-center gap-2 rounded-xl border border-white/10 bg-white/5 px-3 py-2 text-xs text-zinc-400 hover:text-white transition-colors">
            <Calendar className="h-3.5 w-3.5" />Last 6 months
          </button>
          <button className="flex items-center gap-2 rounded-xl border border-white/10 bg-white/5 px-3 py-2 text-xs text-zinc-400 hover:text-white transition-colors">
            <Filter className="h-3.5 w-3.5" />Filter
          </button>
        </div>
      </motion.div>

      {error && (
        <motion.div variants={itemVariants} className="flex items-center gap-3 rounded-2xl border border-amber-500/20 bg-amber-500/5 px-5 py-3">
          <AlertTriangle className="h-4 w-4 text-amber-400 flex-shrink-0" />
          <p className="text-xs text-zinc-400"><span className="text-amber-400 font-medium">Backend offline</span> — showing cached data.</p>
        </motion.div>
      )}

      {/* Tab bar */}
      <motion.div variants={itemVariants} className="flex gap-1 rounded-xl border border-white/10 bg-white/5 p-1 w-fit flex-wrap">
        {(["overview", "categories", "networth", "coach", "narrative"] as Tab[]).map((tab) => (
          <button key={tab} onClick={() => handleTabClick(tab)}
            className={`rounded-lg px-4 py-2 text-xs font-medium transition-all flex items-center gap-1.5 ${activeTab === tab ? "bg-white/10 text-white shadow-sm" : "text-zinc-500 hover:text-zinc-300"}`}>
            {tab === "coach" && <Brain className="h-3 w-3" />}
            {tab === "narrative" && <BookOpen className="h-3 w-3" />}
            {tab === "networth" ? "Net Worth" : tab === "coach" ? "AI Coach" : tab === "narrative" ? "Monthly Story" : tab.charAt(0).toUpperCase() + tab.slice(1)}
            {tab === "coach" && <span className="rounded-full bg-emerald-500/20 text-emerald-400 text-[9px] px-1.5 py-0.5 font-bold">NEW</span>}
          </button>
        ))}
      </motion.div>

      {/* ── Overview ── */}
      {activeTab === "overview" && (
        <>
          <motion.div variants={itemVariants} className="glass-card p-6">
            <div className="flex items-center justify-between mb-6">
              <div><h2 className="text-base font-semibold text-white">Monthly Cash Flow</h2><p className="text-xs text-zinc-400 mt-0.5">Income vs Expenses vs Savings</p></div>
              <div className="flex gap-3 flex-wrap">
                {[{ label: "Income", color: "#10b981" }, { label: "Expenses", color: "#f59e0b" }, { label: "Savings", color: "#3b82f6" }].map((l) => (
                  <div key={l.label} className="flex items-center gap-1.5">
                    <div className="h-2 w-2 rounded-full" style={{ background: l.color }} />
                    <span className="text-xs text-zinc-400">{l.label}</span>
                  </div>
                ))}
              </div>
            </div>
            {loading ? <div className="h-[280px] shimmer rounded-xl" /> : (
              <ResponsiveContainer width="100%" height={280}>
                <BarChart data={stackedData} margin={{ top: 5, right: 5, left: -20, bottom: 0 }}>
                  <CartesianGrid strokeDasharray="3 3" stroke="rgba(255,255,255,0.05)" />
                  <XAxis dataKey="month" tick={{ fill: "#71717a", fontSize: 11 }} axisLine={false} tickLine={false} />
                  <YAxis tick={{ fill: "#71717a", fontSize: 11 }} axisLine={false} tickLine={false} />
                  <Tooltip content={<CustomTooltip />} />
                  <Bar dataKey="income" name="Income" fill="#10b981" radius={[4, 4, 0, 0]} />
                  <Bar dataKey="expenses" name="Expenses" fill="#f59e0b" radius={[4, 4, 0, 0]} />
                  <Bar dataKey="savings" name="Savings" fill="#3b82f6" radius={[4, 4, 0, 0]} />
                </BarChart>
              </ResponsiveContainer>
            )}
          </motion.div>

          <div className="grid gap-6 lg:grid-cols-2">
            <motion.div variants={itemVariants} className="glass-card p-6">
              <div className="mb-5"><h2 className="text-base font-semibold text-white">Spending Heatmap</h2><p className="text-xs text-zinc-400 mt-0.5">Daily activity over 12 weeks</p></div>
              {loading ? <div className="h-[180px] shimmer rounded-xl" /> : (
                <>
                  <div className="space-y-1.5">
                    {DAYS.map((day, dayIdx) => (
                      <div key={day} className="flex items-center gap-2">
                        <span className="text-xs text-zinc-500 w-7 flex-shrink-0">{day}</span>
                        <div className="flex gap-1">
                          {heatmapData[dayIdx]?.map((val, week) => <HeatmapCell key={week} value={val} max={heatmapMax} />)}
                        </div>
                      </div>
                    ))}
                  </div>
                  <div className="mt-4 flex items-center gap-2">
                    <span className="text-xs text-zinc-500">Less</span>
                    {[0.1, 0.3, 0.5, 0.7, 0.9].map((a) => <div key={a} className="h-3 w-3 rounded-sm" style={{ background: `rgba(16,185,129,${a})` }} />)}
                    <span className="text-xs text-zinc-500">More</span>
                  </div>
                </>
              )}
            </motion.div>

            <motion.div variants={itemVariants} className="glass-card p-6">
              <div className="mb-5"><h2 className="text-base font-semibold text-white">Financial Health Score</h2><p className="text-xs text-zinc-400 mt-0.5">Multi-dimensional AI assessment</p></div>
              {loading ? <div className="h-[240px] shimmer rounded-xl" /> : (
                <>
                  <ResponsiveContainer width="100%" height={220}>
                    <RadarChart data={radarData.length ? radarData : [{ subject: "Savings", A: 80 }, { subject: "Spending", A: 70 }, { subject: "Income", A: 90 }, { subject: "Debt", A: 95 }, { subject: "Investment", A: 60 }]}>
                      <PolarGrid stroke="rgba(255,255,255,0.08)" />
                      <PolarAngleAxis dataKey="subject" tick={{ fill: "#71717a", fontSize: 10 }} />
                      <PolarRadiusAxis angle={30} domain={[0, 100]} tick={{ fill: "#71717a", fontSize: 9 }} />
                      <Radar name="Score" dataKey="A" stroke="#10b981" fill="#10b981" fillOpacity={0.2} strokeWidth={2} />
                    </RadarChart>
                  </ResponsiveContainer>
                  <div className="flex items-center justify-center gap-2 mt-1">
                    <Sparkles className="h-3.5 w-3.5 text-emerald-400" />
                    <span className="text-sm font-semibold text-white">Overall Score:</span>
                    <span className="text-sm font-bold text-emerald-400">{healthScore.toFixed(0)}/100</span>
                  </div>
                </>
              )}
            </motion.div>
          </div>
        </>
      )}

      {/* ── Categories ── */}
      {activeTab === "categories" && (
        <motion.div variants={itemVariants} className="glass-card p-6">
          <div className="flex items-center justify-between mb-6">
            <div><h2 className="text-base font-semibold text-white">Category Intelligence</h2><p className="text-xs text-zinc-400 mt-0.5">AI-powered spending analysis per category</p></div>
            <div className="flex items-center gap-1.5 rounded-xl border border-emerald-500/20 bg-emerald-500/10 px-3 py-1.5">
              <Sparkles className="h-3.5 w-3.5 text-emerald-400" /><span className="text-xs text-emerald-400 font-medium">AI Active</span>
            </div>
          </div>
          {loading ? <div className="space-y-3">{[1,2,3,4,5].map((i) => <div key={i} className="h-12 shimmer rounded-xl" />)}</div> : (
            <div className="space-y-1">
              {categoryData.map((cat) => {
                const total = categoryData.reduce((s, c) => s + c.value, 0);
                const pct = total > 0 ? (cat.value / total) * 100 : 0;
                return (
                  <motion.div key={cat.name} whileHover={{ backgroundColor: "rgba(255,255,255,0.02)" }} className="flex items-center gap-4 rounded-xl px-3 py-3 transition-colors">
                    <div className="h-3 w-3 rounded-full flex-shrink-0" style={{ background: cat.color }} />
                    <div className="flex-1 min-w-0">
                      <div className="flex items-center justify-between mb-1.5">
                        <span className="text-sm font-medium text-white">{cat.name}</span>
                        <span className="text-xs text-zinc-400">${cat.value.toLocaleString()} ({pct.toFixed(1)}%)</span>
                      </div>
                      <div className="h-1.5 w-full rounded-full bg-white/5 overflow-hidden">
                        <motion.div initial={{ width: 0 }} animate={{ width: `${pct}%` }} transition={{ duration: 0.8, ease: "easeOut", delay: 0.1 }} className="h-full rounded-full" style={{ background: cat.color }} />
                      </div>
                    </div>
                  </motion.div>
                );
              })}
            </div>
          )}
          {behaviorInsights.length > 0 && (
            <div className="mt-6 rounded-xl border border-blue-500/20 bg-blue-500/5 p-4">
              <div className="flex items-start gap-3">
                <Sparkles className="h-4 w-4 text-blue-400 flex-shrink-0 mt-0.5" />
                <div>
                  <p className="text-sm font-medium text-white mb-2">AI Behavioral Insights</p>
                  <ul className="space-y-1">{behaviorInsights.slice(0, 3).map((insight, i) => <li key={i} className="text-xs text-zinc-400">• {insight}</li>)}</ul>
                </div>
              </div>
            </div>
          )}
        </motion.div>
      )}

      {/* ── Net Worth ── */}
      {activeTab === "networth" && (
        <motion.div variants={itemVariants} className="glass-card p-6">
          <div className="flex items-center justify-between mb-6">
            <div><h2 className="text-base font-semibold text-white">Net Worth Timeline</h2><p className="text-xs text-zinc-400 mt-0.5">Balance trajectory over time</p></div>
            {!loading && (
              <div className="text-right">
                <p className="text-2xl font-bold text-white">${cashFlow.length ? cashFlow[cashFlow.length - 1]?.income?.toLocaleString() : "—"}</p>
                <div className="flex items-center gap-1 justify-end mt-0.5">
                  <TrendingUp className="h-3.5 w-3.5 text-emerald-400" /><span className="text-xs text-emerald-400 font-medium">Growing</span>
                </div>
              </div>
            )}
          </div>
          {loading ? <div className="h-[320px] shimmer rounded-xl" /> : (
            <ResponsiveContainer width="100%" height={320}>
              <LineChart data={cashFlow} margin={{ top: 5, right: 5, left: -20, bottom: 0 }}>
                <defs>
                  <linearGradient id="nwGrad" x1="0" y1="0" x2="0" y2="1">
                    <stop offset="5%" stopColor="#10b981" stopOpacity={0.3} />
                    <stop offset="95%" stopColor="#10b981" stopOpacity={0} />
                  </linearGradient>
                </defs>
                <CartesianGrid strokeDasharray="3 3" stroke="rgba(255,255,255,0.05)" />
                <XAxis dataKey="month" tick={{ fill: "#71717a", fontSize: 11 }} axisLine={false} tickLine={false} />
                <YAxis tick={{ fill: "#71717a", fontSize: 11 }} axisLine={false} tickLine={false} tickFormatter={(v) => `$${(v / 1000).toFixed(0)}k`} />
                <Tooltip content={<CustomTooltip />} />
                <Line type="monotone" dataKey="income" name="Income" stroke="#10b981" strokeWidth={2.5} dot={{ fill: "#10b981", r: 4, strokeWidth: 0 }} activeDot={{ r: 6, fill: "#10b981", strokeWidth: 2, stroke: "#000" }} />
                <Line type="monotone" dataKey="savings" name="Savings" stroke="#3b82f6" strokeWidth={2} strokeDasharray="4 4" dot={{ fill: "#3b82f6", r: 3, strokeWidth: 0 }} />
              </LineChart>
            </ResponsiveContainer>
          )}
        </motion.div>
      )}

      {/* ── AI Coach ── */}
      {activeTab === "coach" && (
        <motion.div variants={itemVariants} className="space-y-4">
          {coachLoading ? (
            <div className="glass-card p-8 flex flex-col items-center gap-4">
              <div className="flex h-12 w-12 items-center justify-center rounded-2xl bg-emerald-500/15 border border-emerald-500/20">
                <Brain className="h-6 w-6 text-emerald-400 animate-pulse" />
              </div>
              <p className="text-sm text-zinc-400">Generating your weekly coaching report...</p>
              <div className="flex gap-1">
                {[0,1,2].map(i => (
                  <motion.div key={i} animate={{ y: [0,-4,0] }} transition={{ duration: 0.6, repeat: Infinity, delay: i*0.15 }} className="h-1.5 w-1.5 rounded-full bg-emerald-400" />
                ))}
              </div>
            </div>
          ) : coachData ? (
            <>
              <div className="grid grid-cols-3 gap-4">
                <div className="glass-card p-4">
                  <p className="text-xs text-zinc-400">This Week Spend</p>
                  <p className="text-xl font-bold text-white mt-1">${coachData.week_spend.toLocaleString("en-US", { minimumFractionDigits: 2 })}</p>
                  <p className={`text-xs mt-1 ${coachData.spend_delta_pct > 0 ? "text-red-400" : "text-emerald-400"}`}>
                    {coachData.spend_delta_pct > 0 ? "▲" : "▼"} {Math.abs(coachData.spend_delta_pct).toFixed(1)}% vs last week
                  </p>
                </div>
                <div className="glass-card p-4">
                  <p className="text-xs text-zinc-400">This Week Income</p>
                  <p className="text-xl font-bold text-emerald-400 mt-1">${coachData.week_income.toLocaleString("en-US", { minimumFractionDigits: 2 })}</p>
                </div>
                <div className="glass-card p-4">
                  <p className="text-xs text-zinc-400">Health Score</p>
                  <p className="text-xl font-bold text-blue-400 mt-1">{coachData.health_score.toFixed(0)}/100</p>
                </div>
              </div>

              {coachData.top_categories.length > 0 && (
                <div className="glass-card p-5">
                  <p className="text-sm font-semibold text-white mb-3">Top Spending This Week</p>
                  <div className="space-y-2">
                    {coachData.top_categories.map((cat, i) => {
                      const max = coachData.top_categories[0].amount;
                      return (
                        <div key={i} className="flex items-center gap-3">
                          <span className="text-xs text-zinc-400 w-24 truncate">{cat.name}</span>
                          <div className="flex-1 h-1.5 rounded-full bg-white/5 overflow-hidden">
                            <motion.div initial={{ width: 0 }} animate={{ width: `${(cat.amount/max)*100}%` }} transition={{ duration: 0.6, delay: i*0.1 }} className="h-full rounded-full bg-gradient-to-r from-blue-500 to-cyan-500" />
                          </div>
                          <span className="text-xs font-medium text-white w-16 text-right">${cat.amount.toLocaleString()}</span>
                        </div>
                      );
                    })}
                  </div>
                </div>
              )}

              {coachData.anomalies.length > 0 && (
                <div className="rounded-xl border border-amber-500/20 bg-amber-500/5 p-4">
                  <div className="flex items-start gap-2">
                    <AlertTriangle className="h-4 w-4 text-amber-400 flex-shrink-0 mt-0.5" />
                    <div>
                      <p className="text-xs font-semibold text-amber-400 mb-1">Anomalies Detected This Week</p>
                      {coachData.anomalies.map((a, i) => <p key={i} className="text-xs text-zinc-300">• {a}</p>)}
                    </div>
                  </div>
                </div>
              )}

              <div className="glass-card p-6">
                <div className="flex items-center gap-2 mb-4">
                  <div className="flex h-8 w-8 items-center justify-center rounded-xl bg-emerald-500/15 border border-emerald-500/20">
                    <Brain className="h-4 w-4 text-emerald-400" />
                  </div>
                  <div>
                    <p className="text-sm font-semibold text-white">Weekly AI Coaching Report</p>
                    <p className="text-xs text-zinc-500">Powered by Groq · Based on your real account data</p>
                  </div>
                </div>
                <div className="space-y-1">
                  {coachData.coaching_report.split("\n").map((line, i) => {
                    if (!line.trim()) return <div key={i} className="h-2" />;
                    const isHeader = /^[0-9]+\.|^[A-Z\s]{4,}$/.test(line.trim()) && line.length < 40;
                    return isHeader
                      ? <p key={i} className="text-xs font-bold text-emerald-400 uppercase tracking-wider mt-3 mb-1">{line}</p>
                      : <p key={i} className="text-sm text-zinc-300 leading-relaxed">{line}</p>;
                  })}
                </div>
              </div>

              {coachData.improvements.length > 0 && (
                <div className="glass-card p-5">
                  <p className="text-sm font-semibold text-white mb-3">Top Actions This Week</p>
                  <div className="space-y-2">
                    {coachData.improvements.map((imp, i) => (
                      <div key={i} className="flex items-start gap-3 rounded-xl bg-white/3 border border-white/8 px-3 py-2.5">
                        <span className="flex h-5 w-5 items-center justify-center rounded-full bg-emerald-500/20 text-emerald-400 text-xs font-bold flex-shrink-0">{i+1}</span>
                        <p className="text-xs text-zinc-300">{imp}</p>
                      </div>
                    ))}
                  </div>
                </div>
              )}
            </>
          ) : (
            <div className="glass-card p-8 text-center">
              <Brain className="h-10 w-10 text-zinc-700 mx-auto mb-3" />
              <p className="text-sm text-zinc-500">Could not load coaching data</p>
            </div>
          )}
        </motion.div>
      )}

      {/* ── Monthly Story ── */}
      {activeTab === "narrative" && (
        <motion.div variants={itemVariants} className="space-y-4">
          {narrativeLoading ? (
            <div className="glass-card p-8 flex flex-col items-center gap-4">
              <div className="flex h-12 w-12 items-center justify-center rounded-2xl bg-blue-500/15 border border-blue-500/20">
                <BookOpen className="h-6 w-6 text-blue-400 animate-pulse" />
              </div>
              <p className="text-sm text-zinc-400">Writing your monthly financial story...</p>
              <div className="flex gap-1">
                {[0,1,2].map(i => (
                  <motion.div key={i} animate={{ y: [0,-4,0] }} transition={{ duration: 0.6, repeat: Infinity, delay: i*0.15 }} className="h-1.5 w-1.5 rounded-full bg-blue-400" />
                ))}
              </div>
            </div>
          ) : narrativeData ? (
            <>
              <div className="flex items-center justify-between">
                <div>
                  <h2 className="text-xl font-bold text-white">{narrativeData.month}</h2>
                  <p className="text-xs text-zinc-500 mt-0.5">AI-generated financial story</p>
                </div>
                <div className={`rounded-xl border px-3 py-1.5 text-xs font-semibold ${narrativeData.summary.spend_delta_pct <= 0 ? "border-emerald-500/30 bg-emerald-500/10 text-emerald-400" : "border-red-500/30 bg-red-500/10 text-red-400"}`}>
                  {narrativeData.summary.spend_delta_pct > 0 ? "▲" : "▼"} {Math.abs(narrativeData.summary.spend_delta_pct).toFixed(1)}% spending
                </div>
              </div>

              <div className="grid grid-cols-2 sm:grid-cols-4 gap-3">
                {[
                  { label: "Total Spend", value: `$${narrativeData.summary.total_spend.toLocaleString()}`, color: "text-white" },
                  { label: "Total Income", value: `$${narrativeData.summary.total_income.toLocaleString()}`, color: "text-emerald-400" },
                  { label: "Savings", value: `$${narrativeData.summary.savings_balance.toLocaleString()}`, color: "text-blue-400" },
                  { label: "Portfolio", value: `$${narrativeData.summary.investment_value.toLocaleString()}`, color: narrativeData.summary.investment_gain_pct >= 0 ? "text-emerald-400" : "text-red-400" },
                ].map((s) => (
                  <div key={s.label} className="glass-card p-4">
                    <p className="text-xs text-zinc-400">{s.label}</p>
                    <p className={`text-lg font-bold mt-1 ${s.color}`}>{s.value}</p>
                  </div>
                ))}
              </div>

              {narrativeData.category_changes.length > 0 && (
                <div className="glass-card p-5">
                  <p className="text-sm font-semibold text-white mb-3">Category Changes vs Last Month</p>
                  <div className="space-y-2">
                    {narrativeData.category_changes.slice(0, 6).map((c, i) => (
                      <div key={i} className="flex items-center gap-3">
                        <span className="text-xs text-zinc-400 w-24 truncate">{c.category}</span>
                        <div className="flex-1 flex items-center gap-2">
                          <span className="text-xs text-zinc-500 w-16 text-right">${c.last_month.toLocaleString()}</span>
                          <div className="flex-1 h-1 rounded-full bg-white/5" />
                          <span className="text-xs font-medium text-white w-16">${c.this_month.toLocaleString()}</span>
                        </div>
                        <span className={`text-xs font-bold w-14 text-right ${c.delta_pct > 10 ? "text-red-400" : c.delta_pct < -5 ? "text-emerald-400" : "text-zinc-400"}`}>
                          {c.delta_pct > 0 ? "+" : ""}{c.delta_pct.toFixed(0)}%
                        </span>
                      </div>
                    ))}
                  </div>
                </div>
              )}

              <div className="glass-card p-6">
                <div className="flex items-center gap-2 mb-4">
                  <div className="flex h-8 w-8 items-center justify-center rounded-xl bg-blue-500/15 border border-blue-500/20">
                    <BookOpen className="h-4 w-4 text-blue-400" />
                  </div>
                  <div>
                    <p className="text-sm font-semibold text-white">Your Monthly Financial Story</p>
                    <p className="text-xs text-zinc-500">AI-written · Based on your real transactions</p>
                  </div>
                </div>
                <div className="space-y-1">
                  {narrativeData.narrative.split("\n").map((line, i) => {
                    if (!line.trim()) return <div key={i} className="h-2" />;
                    const isHeader = /^[A-Z\s]{4,}$/.test(line.trim()) && line.length < 30;
                    return isHeader
                      ? <p key={i} className="text-xs font-bold text-blue-400 uppercase tracking-wider mt-3 mb-1">{line}</p>
                      : <p key={i} className="text-sm text-zinc-300 leading-relaxed">{line}</p>;
                  })}
                </div>
              </div>

              <div className="flex items-center gap-3 rounded-2xl border border-purple-500/20 bg-purple-500/5 px-5 py-3">
                <Sparkles className="h-4 w-4 text-purple-400 flex-shrink-0" />
                <p className="text-xs text-zinc-400">
                  <span className="text-purple-400 font-medium">${narrativeData.summary.monthly_subscriptions.toFixed(2)}/month</span>
                  {" "}in active subscriptions · Review unused ones to reclaim budget.
                </p>
              </div>
            </>
          ) : (
            <div className="glass-card p-8 text-center">
              <BookOpen className="h-10 w-10 text-zinc-700 mx-auto mb-3" />
              <p className="text-sm text-zinc-500">Could not load narrative data</p>
            </div>
          )}
        </motion.div>
      )}
    </motion.div>
  );
}