import { useState, useRef, useEffect } from "react";

// ═══ MOCK DATA ═══
const mockTransactions = [
  { id: "1", date: "2026-02-23T10:30:00Z", sender: "Jean Dupont", amount: 250.00, branch: "ICC Montréal", status: "deposited" },
  { id: "2", date: "2026-02-22T14:15:00Z", sender: "Marie Tremblay", amount: 150.00, branch: "ICC Québec", status: "deposited" },
  { id: "3", date: "2026-02-22T09:00:00Z", sender: "Pierre Gagnon", amount: 500.00, branch: "ICC Gatineau", status: "pending" },
  { id: "4", date: "2026-02-21T16:45:00Z", sender: "Sophie Lavoie", amount: 75.00, branch: "ICC Sherbrooke", status: "deposited" },
  { id: "5", date: "2026-02-21T11:20:00Z", sender: "Marc Bélanger", amount: 320.00, branch: "ICC Ottawa", status: "deposited" },
  { id: "6", date: "2026-02-20T08:00:00Z", sender: "Anne Roy", amount: 180.00, branch: "ICC Toronto", status: "expired" },
  { id: "7", date: "2026-02-19T13:30:00Z", sender: "Luc Martin", amount: 425.00, branch: "ICC Montréal", status: "deposited" },
];

const mockStats = {
  totalTransactions: 847,
  totalAmount: 156234.50,
  byBranch: [
    { branch: "ICC Montréal", count: 234, total: 45230.00 },
    { branch: "ICC Québec", count: 156, total: 32100.00 },
    { branch: "ICC Gatineau", count: 98, total: 21450.00 },
    { branch: "ICC Ottawa", count: 87, total: 18900.00 },
    { branch: "ICC Toronto", count: 72, total: 15340.00 },
  ],
};

// ═══ SIMULATED AI RESPONSES ═══
function simulateResponse(text) {
  const lower = text.toLowerCase();
  if (lower.includes("scann") || lower.includes("scan")) {
    return {
      type: "scan_started",
      message: "🔍 Scan lancé pour la période du 25 janvier 2024 au 23 février 2026. Les résultats apparaîtront en temps réel dans le tableau.",
      data: { preset: "custom" },
    };
  }
  if (lower.includes("transaction") || lower.includes("virement") || lower.includes("montre")) {
    return {
      type: "transactions",
      message: "📊 847 transactions au total. Voici les 7 plus récentes:",
      data: { transactions: mockTransactions },
    };
  }
  if (lower.includes("stat") || lower.includes("combien") || lower.includes("total")) {
    return {
      type: "stats",
      message: "📈 **Résumé des virements**\n\n💰 **Total:** 847 virements — 156 234,50 $ CAD\n\n🏢 **Top succursales:** Montréal en tête avec 234 virements.",
      data: mockStats,
    };
  }
  if (lower.includes("cherch") || lower.includes("search") || lower.includes("trouve")) {
    const filtered = mockTransactions.filter((t) =>
      t.sender.toLowerCase().includes("dupont") || t.sender.toLowerCase().includes("martin")
    );
    return {
      type: "search_results",
      message: `🔍 ${filtered.length} résultat(s) trouvé(s):`,
      data: { transactions: filtered.length > 0 ? filtered : mockTransactions.slice(0, 3) },
    };
  }
  return {
    type: "message",
    message: "Je peux t'aider avec:\n• **Scanner** des courriels Interac\n• **Afficher** les transactions\n• **Statistiques** des virements\n• **Chercher** par nom ou succursale",
  };
}

// ═══ STATUS BADGE ═══
function StatusBadge({ status }) {
  const colors = {
    deposited: "bg-emerald-100 text-emerald-700",
    pending: "bg-amber-100 text-amber-700",
    expired: "bg-slate-100 text-slate-500",
    cancelled: "bg-red-100 text-red-600",
  };
  return (
    <span className={`inline-block px-2 py-0.5 rounded-full text-[10px] font-medium ${colors[status] || "bg-slate-100 text-slate-500"}`}>
      {status || "—"}
    </span>
  );
}

// ═══ TRANSACTION TABLE ═══
function TransactionTable({ transactions }) {
  if (!transactions?.length) return null;
  return (
    <div className="mt-2 rounded-xl border border-slate-200 overflow-hidden bg-white shadow-sm">
      <div className="overflow-x-auto max-h-[220px] overflow-y-auto">
        <table className="w-full text-[11px]">
          <thead className="bg-slate-50 sticky top-0">
            <tr className="border-b border-slate-200">
              <th className="px-3 py-2 text-left font-semibold text-slate-600">Date</th>
              <th className="px-3 py-2 text-left font-semibold text-slate-600">Expéditeur</th>
              <th className="px-3 py-2 text-right font-semibold text-slate-600">Montant</th>
              <th className="px-3 py-2 text-left font-semibold text-slate-600">Succursale</th>
              <th className="px-3 py-2 text-center font-semibold text-slate-600">Statut</th>
            </tr>
          </thead>
          <tbody>
            {transactions.map((tx, i) => (
              <tr key={tx.id || i} className="border-b border-slate-50 hover:bg-blue-50/30 transition-colors">
                <td className="px-3 py-1.5 text-slate-500 whitespace-nowrap">
                  {new Date(tx.date).toLocaleDateString("fr-CA", { day: "2-digit", month: "short" })}
                </td>
                <td className="px-3 py-1.5 text-slate-800 font-medium">{tx.sender}</td>
                <td className="px-3 py-1.5 text-right font-semibold text-slate-800 whitespace-nowrap">
                  {Number(tx.amount).toFixed(2)} $
                </td>
                <td className="px-3 py-1.5 text-slate-600">{tx.branch}</td>
                <td className="px-3 py-1.5 text-center"><StatusBadge status={tx.status} /></td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>
    </div>
  );
}

// ═══ STATS CARD ═══
function StatsCard({ stats }) {
  if (!stats) return null;
  return (
    <div className="mt-2 rounded-xl border border-slate-200 overflow-hidden bg-white shadow-sm p-3 space-y-3">
      <div className="flex gap-3">
        <div className="flex-1 bg-blue-50 rounded-lg p-3 text-center">
          <div className="text-xl font-bold text-blue-700">{stats.totalTransactions}</div>
          <div className="text-[10px] text-blue-500 font-semibold uppercase tracking-wide">Virements</div>
        </div>
        <div className="flex-1 bg-emerald-50 rounded-lg p-3 text-center">
          <div className="text-xl font-bold text-emerald-700">
            {Number(stats.totalAmount).toLocaleString("fr-CA", { minimumFractionDigits: 2 })} $
          </div>
          <div className="text-[10px] text-emerald-500 font-semibold uppercase tracking-wide">Total</div>
        </div>
      </div>
      {stats.byBranch?.length > 0 && (
        <div>
          <div className="text-[10px] font-semibold text-slate-500 uppercase tracking-wide mb-1.5">Top succursales</div>
          <div className="space-y-1.5">
            {stats.byBranch.slice(0, 5).map((b, i) => {
              const pct = (b.total / stats.totalAmount) * 100;
              return (
                <div key={i}>
                  <div className="flex items-center justify-between text-[11px] mb-0.5">
                    <span className="text-slate-600">{b.branch}</span>
                    <span className="text-slate-800 font-medium">{b.count} · {Number(b.total).toLocaleString("fr-CA")} $</span>
                  </div>
                  <div className="h-1.5 bg-slate-100 rounded-full overflow-hidden">
                    <div className="h-full bg-blue-400 rounded-full transition-all" style={{ width: `${pct}%` }} />
                  </div>
                </div>
              );
            })}
          </div>
        </div>
      )}
    </div>
  );
}

// ═══ FORMATTED TEXT ═══
function FormattedText({ text }) {
  return (
    <>
      {text.split("\n").map((line, i) => {
        const formatted = line.replace(/\*\*(.*?)\*\*/g, '<strong class="font-semibold">$1</strong>');
        return (
          <span key={i}>
            {i > 0 && <br />}
            <span dangerouslySetInnerHTML={{ __html: formatted }} />
          </span>
        );
      })}
    </>
  );
}

// ═══ MESSAGE BUBBLE ═══
function MessageBubble({ message }) {
  const isUser = message.role === "user";
  return (
    <div className={`flex items-start gap-2 ${isUser ? "flex-row-reverse" : ""}`}>
      {!isUser && (
        <div className="w-7 h-7 rounded-full bg-gradient-to-br from-blue-500 to-indigo-600 flex-shrink-0 flex items-center justify-center shadow-sm">
          <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="white" strokeWidth="3" strokeLinecap="round">
            <path d="M12 2L15 8l6 1-4 4 1 6-6-3-6 3 1-6-4-4 6-1z" />
          </svg>
        </div>
      )}
      <div className={`max-w-[85%] ${isUser ? "ml-auto" : ""}`}>
        <div
          className={`rounded-2xl px-4 py-2.5 text-[13px] leading-relaxed ${
            isUser
              ? "bg-blue-500 text-white rounded-tr-md"
              : message.type === "error"
              ? "bg-red-50 text-red-700 border border-red-200 rounded-tl-md"
              : message.type === "scan_started"
              ? "bg-blue-50 text-blue-800 border border-blue-200 rounded-tl-md"
              : "bg-slate-100 text-slate-700 rounded-tl-md"
          }`}
        >
          <FormattedText text={message.content} />
        </div>
        {message.data && (message.type === "transactions" || message.type === "search_results") && (
          <TransactionTable transactions={message.data.transactions} />
        )}
        {message.data && message.type === "stats" && <StatsCard stats={message.data} />}
        <div className={`text-[10px] text-slate-400 mt-1 ${isUser ? "text-right" : ""}`}>
          {message.timestamp.toLocaleTimeString("fr-CA", { hour: "2-digit", minute: "2-digit" })}
        </div>
      </div>
    </div>
  );
}

// ═══ MAIN APP ═══
export default function ICCChatDemo() {
  const [isOpen, setIsOpen] = useState(true);
  const [input, setInput] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const [messages, setMessages] = useState([
    {
      id: "welcome",
      role: "assistant",
      content:
        "Bonjour! 👋 Je suis ton assistant ICC. Tu peux me demander:\n\n• **Scanner** — \"Scanne les courriels du 25 janvier 2024 à aujourd'hui\"\n• **Voir les transactions** — \"Montre-moi les virements\"\n• **Statistiques** — \"Combien de virements au total?\"\n• **Chercher** — \"Cherche les virements de Jean Dupont\"",
      type: "message",
      timestamp: new Date(),
    },
  ]);
  const endRef = useRef(null);

  useEffect(() => {
    endRef.current?.scrollIntoView({ behavior: "smooth" });
  }, [messages]);

  const send = async () => {
    if (!input.trim() || isLoading) return;
    const text = input.trim();
    setInput("");

    setMessages((prev) => [
      ...prev,
      { id: `u-${Date.now()}`, role: "user", content: text, timestamp: new Date() },
    ]);
    setIsLoading(true);

    // Simulate AI processing delay
    await new Promise((r) => setTimeout(r, 800 + Math.random() * 700));

    const response = simulateResponse(text);
    setMessages((prev) => [
      ...prev,
      { id: `a-${Date.now()}`, role: "assistant", ...response, timestamp: new Date() },
    ]);
    setIsLoading(false);
  };

  const quickActions = [
    { label: "Scanner aujourd'hui", cmd: "Scanne les courriels d'aujourd'hui" },
    { label: "Transactions", cmd: "Montre les transactions récentes" },
    { label: "Statistiques", cmd: "Statistiques" },
    { label: "Chercher", cmd: "Cherche Jean Dupont" },
  ];

  return (
    <div className="min-h-screen bg-gradient-to-br from-slate-100 via-slate-50 to-blue-50 flex items-center justify-center p-4 font-sans">
      {/* Background pattern */}
      <div className="fixed inset-0 opacity-[0.02]" style={{
        backgroundImage: "radial-gradient(circle at 1px 1px, #000 1px, transparent 0)",
        backgroundSize: "32px 32px",
      }} />

      {/* Demo label */}
      <div className="fixed top-6 left-1/2 -translate-x-1/2 z-10 bg-white/80 backdrop-blur-sm border border-slate-200 rounded-full px-5 py-2 shadow-sm">
        <span className="text-sm font-medium text-slate-600">
          💬 ICC Chat Assistant — <span className="text-blue-600">Démo interactive</span>
        </span>
      </div>

      {/* Chat Panel */}
      <div
        className={`w-[430px] max-w-full bg-white rounded-2xl shadow-2xl border border-slate-200/80 flex flex-col overflow-hidden transition-all duration-300`}
        style={{ height: "min(640px, calc(100vh - 6rem))" }}
      >
        {/* Header */}
        <div className="flex items-center justify-between px-5 py-3.5 border-b border-slate-100 bg-gradient-to-r from-slate-50 to-blue-50/50">
          <div className="flex items-center gap-3">
            <div className="relative">
              <div className="w-10 h-10 rounded-full bg-gradient-to-br from-blue-500 to-indigo-600 flex items-center justify-center shadow-md">
                <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="white" strokeWidth="2.5" strokeLinecap="round">
                  <path d="M12 2L15 8l6 1-4 4 1 6-6-3-6 3 1-6-4-4 6-1z" />
                </svg>
              </div>
              <span className="absolute -bottom-0.5 -right-0.5 w-3.5 h-3.5 bg-green-400 rounded-full border-2 border-white" />
            </div>
            <div>
              <h3 className="text-sm font-bold text-slate-800">Assistant ICC</h3>
              <p className="text-[11px] text-slate-400">Gestion intelligente des virements Interac</p>
            </div>
          </div>
          <button
            onClick={() => setMessages([messages[0]])}
            className="text-slate-400 hover:text-slate-600 p-2 rounded-lg hover:bg-slate-100 transition-colors"
            title="Effacer"
          >
            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
              <path d="M3 6h18" /><path d="M19 6v14c0 1-1 2-2 2H7c-1 0-2-1-2-2V6" />
              <path d="M8 6V4c0-1 1-2 2-2h4c1 0 2 1 2 2v2" />
            </svg>
          </button>
        </div>

        {/* Messages */}
        <div className="flex-1 overflow-y-auto px-4 py-3 space-y-3" style={{ scrollbarWidth: "thin" }}>
          {messages.map((msg) => (
            <MessageBubble key={msg.id} message={msg} />
          ))}

          {isLoading && (
            <div className="flex items-start gap-2">
              <div className="w-7 h-7 rounded-full bg-gradient-to-br from-blue-500 to-indigo-600 flex-shrink-0 flex items-center justify-center">
                <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="white" strokeWidth="3" strokeLinecap="round">
                  <path d="M12 2L15 8l6 1-4 4 1 6-6-3-6 3 1-6-4-4 6-1z" />
                </svg>
              </div>
              <div className="bg-slate-100 rounded-2xl rounded-tl-md px-4 py-3">
                <div className="flex gap-1.5">
                  <span className="w-2 h-2 bg-slate-400 rounded-full animate-bounce" style={{ animationDelay: "0ms" }} />
                  <span className="w-2 h-2 bg-slate-400 rounded-full animate-bounce" style={{ animationDelay: "150ms" }} />
                  <span className="w-2 h-2 bg-slate-400 rounded-full animate-bounce" style={{ animationDelay: "300ms" }} />
                </div>
              </div>
            </div>
          )}
          <div ref={endRef} />
        </div>

        {/* Quick Actions */}
        <div className="px-4 py-2 border-t border-slate-100 bg-slate-50/50 flex gap-1.5 overflow-x-auto" style={{ scrollbarWidth: "none" }}>
          {quickActions.map((a) => (
            <button
              key={a.label}
              onClick={() => { setInput(a.cmd); setTimeout(() => { setInput(""); setMessages((prev) => [...prev, { id: `u-${Date.now()}`, role: "user", content: a.cmd, timestamp: new Date() }]); setIsLoading(true); setTimeout(() => { const r = simulateResponse(a.cmd); setMessages((prev) => [...prev, { id: `a-${Date.now()}`, role: "assistant", ...r, timestamp: new Date() }]); setIsLoading(false); }, 800 + Math.random() * 700); }, 50); }}
              disabled={isLoading}
              className="flex-shrink-0 px-3 py-1.5 text-[11px] font-medium rounded-full border border-slate-200 bg-white text-slate-600 hover:bg-blue-50 hover:border-blue-200 hover:text-blue-700 disabled:opacity-40 transition-colors whitespace-nowrap"
            >
              {a.label}
            </button>
          ))}
        </div>

        {/* Input */}
        <div className="px-4 py-3 border-t border-slate-100 bg-white">
          <div className="flex items-center gap-2 bg-slate-50 rounded-xl border border-slate-200 px-3 py-1.5 focus-within:border-blue-300 focus-within:ring-2 focus-within:ring-blue-100 transition-all">
            <input
              type="text"
              value={input}
              onChange={(e) => setInput(e.target.value)}
              onKeyDown={(e) => { if (e.key === "Enter") { e.preventDefault(); send(); } }}
              placeholder="Écris une commande..."
              disabled={isLoading}
              className="flex-1 bg-transparent text-sm text-slate-700 placeholder:text-slate-400 focus:outline-none py-1.5 disabled:opacity-50"
            />
            <button
              onClick={send}
              disabled={!input.trim() || isLoading}
              className="flex-shrink-0 w-8 h-8 rounded-lg bg-blue-500 text-white flex items-center justify-center hover:bg-blue-600 disabled:bg-slate-200 disabled:text-slate-400 transition-colors"
            >
              <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
                <path d="m22 2-7 20-4-9-9-4z" /><path d="M22 2 11 13" />
              </svg>
            </button>
          </div>
        </div>
      </div>
    </div>
  );
}