// packages/web/src/components/chat/ChatAssistant.tsx
//
// ICC Chat Assistant — conversational AI interface
// Renders messages, inline transaction tables, stats, and scan progress
//
// Usage:
//   import ChatAssistant from '@/components/chat/ChatAssistant';
//   <ChatAssistant onScanTriggered={() => refetchTransactions()} />

import { useState, useRef, useEffect, type KeyboardEvent } from 'react';
import { useChatAssistant, type ChatMessage } from '../../hooks/useChatAssistant';

interface ChatAssistantProps {
  onScanTriggered?: () => void;
  className?: string;
}

export default function ChatAssistant({ onScanTriggered, className = '' }: ChatAssistantProps) {
  const { messages, isLoading, sendMessage, clearHistory } = useChatAssistant();
  const [input, setInput] = useState('');
  const [isOpen, setIsOpen] = useState(false);
  const messagesEndRef = useRef<HTMLDivElement>(null);
  const inputRef = useRef<HTMLInputElement>(null);

  // Auto-scroll to bottom on new messages
  useEffect(() => {
    messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
  }, [messages]);

  // Focus input when panel opens
  useEffect(() => {
    if (isOpen) inputRef.current?.focus();
  }, [isOpen]);

  // Notify parent when scan is triggered
  useEffect(() => {
    const lastMsg = messages[messages.length - 1];
    if (lastMsg?.type === 'scan_started' && onScanTriggered) {
      onScanTriggered();
    }
  }, [messages, onScanTriggered]);

  const handleSend = () => {
    if (input.trim()) {
      sendMessage(input);
      setInput('');
    }
  };

  const handleKeyDown = (e: KeyboardEvent<HTMLInputElement>) => {
    if (e.key === 'Enter' && !e.shiftKey) {
      e.preventDefault();
      handleSend();
    }
  };

  // Quick action buttons
  const quickActions = [
    { label: "Scanner aujourd'hui", command: "Scanne les courriels d'aujourd'hui" },
    { label: 'Scanner 7 jours', command: 'Scanne les courriels des 7 derniers jours' },
    { label: 'Transactions', command: 'Montre les transactions récentes' },
    { label: 'Statistiques', command: 'Montre les statistiques' },
  ];

  return (
    <>
      {/* ═══ FLOATING BUTTON ═══ */}
      <button
        onClick={() => setIsOpen(!isOpen)}
        className={`fixed bottom-6 right-6 z-50 flex items-center justify-center
          w-14 h-14 rounded-full shadow-lg transition-all duration-300 ease-out
          ${isOpen
            ? 'bg-slate-700 hover:bg-slate-800 rotate-0'
            : 'bg-gradient-to-br from-blue-500 to-indigo-600 hover:from-blue-600 hover:to-indigo-700 hover:scale-110'
          }
          text-white focus:outline-none focus:ring-4 focus:ring-blue-300/50`}
        title="Assistant ICC"
      >
        {isOpen ? (
          /* X icon */
          <svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round">
            <path d="M18 6 6 18" /><path d="m6 6 12 12" />
          </svg>
        ) : (
          /* Chat sparkle icon */
          <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
            <path d="M12 3c.5 0 9 2 9 9s-2 9-9 9c-3 0-5.5-1-7-2l-4 1 1-4c-1-1.5-2-4-2-4 0-7 5-9 12-9z" />
            <path d="M9 12h.01" /><path d="M12 12h.01" /><path d="M15 12h.01" />
          </svg>
        )}

        {/* Notification dot */}
        {!isOpen && (
          <span className="absolute -top-0.5 -right-0.5 w-4 h-4 bg-red-500 rounded-full border-2 border-white flex items-center justify-center">
            <span className="text-[8px] font-bold text-white">AI</span>
          </span>
        )}
      </button>

      {/* ═══ CHAT PANEL ═══ */}
      <div
        className={`fixed bottom-24 right-6 z-50 w-[420px] max-w-[calc(100vw-2rem)]
          bg-white rounded-2xl shadow-2xl border border-slate-200/80
          flex flex-col overflow-hidden
          transition-all duration-300 ease-out origin-bottom-right
          ${isOpen
            ? 'opacity-100 scale-100 translate-y-0 pointer-events-auto'
            : 'opacity-0 scale-95 translate-y-4 pointer-events-none'
          }`}
        style={{ height: 'min(600px, calc(100vh - 8rem))' }}
      >
        {/* ─── 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-9 h-9 rounded-full bg-gradient-to-br from-blue-500 to-indigo-600
                flex items-center justify-center shadow-sm">
                <svg width="18" height="18" 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 h-3 bg-green-400 rounded-full border-2 border-white" />
            </div>
            <div>
              <h3 className="text-sm font-semibold text-slate-800">Assistant ICC</h3>
              <p className="text-[11px] text-slate-400">Gestion des virements Interac</p>
            </div>
          </div>
          <button
            onClick={clearHistory}
            className="text-slate-400 hover:text-slate-600 p-1.5 rounded-lg hover:bg-slate-100 transition-colors"
            title="Effacer l'historique"
          >
            <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 scroll-smooth"
          style={{ scrollbarWidth: 'thin', scrollbarColor: '#cbd5e1 transparent' }}>

          {messages.map((msg) => (
            <MessageBubble key={msg.id} message={msg} />
          ))}

          {/* Typing indicator */}
          {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-2.5">
                <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={messagesEndRef} />
        </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((action) => (
            <button
              key={action.label}
              onClick={() => sendMessage(action.command)}
              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"
            >
              {action.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
              ref={inputRef}
              type="text"
              value={input}
              onChange={(e) => setInput(e.target.value)}
              onKeyDown={handleKeyDown}
              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={handleSend}
              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>
    </>
  );
}

// ═══════════════════════════════════════════
// MESSAGE BUBBLE — renders different message types
// ═══════════════════════════════════════════

function MessageBubble({ message }: { message: ChatMessage }) {
  const isUser = message.role === 'user';

  return (
    <div className={`flex items-start gap-2 ${isUser ? 'flex-row-reverse' : ''}`}>
      {/* Avatar */}
      {!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' : ''}`}>
        {/* Bubble */}
        <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>

        {/* INLINE DATA DISPLAYS */}
        {message.data && message.type === 'transactions' && (
          <TransactionTable transactions={message.data.transactions} />
        )}
        {message.data && message.type === 'search_results' && (
          <TransactionTable transactions={message.data.transactions} />
        )}
        {message.data && message.type === 'stats' && (
          <StatsCard stats={message.data} />
        )}

        {/* Timestamp */}
        <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>
  );
}

// ═══════════════════════════════════════════
// FORMATTED TEXT — renders markdown-lite (bold, newlines)
// ═══════════════════════════════════════════

function FormattedText({ text }: { text: string }) {
  // Simple markdown: **bold**, newlines
  const parts = 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>
    );
  });

  return <>{parts}</>;
}

// ═══════════════════════════════════════════
// TRANSACTION TABLE — inline scrollable table
// ═══════════════════════════════════════════

function TransactionTable({ transactions }: { transactions: any[] }) {
  if (!transactions || transactions.length === 0) 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-[250px] overflow-y-auto"
        style={{ scrollbarWidth: 'thin' }}>
        <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.slice(0, 15).map((tx: any, i: number) => (
              <tr key={tx.id || i} className="border-b border-slate-50 hover:bg-slate-50/50">
                <td className="px-3 py-1.5 text-slate-500 whitespace-nowrap">
                  {tx.date ? 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 truncate max-w-[120px]">
                  {tx.sender || '—'}
                </td>
                <td className="px-3 py-1.5 text-right font-semibold text-slate-800 whitespace-nowrap">
                  {tx.amount ? `${Number(tx.amount).toFixed(2)} $` : '—'}
                </td>
                <td className="px-3 py-1.5 text-slate-600 truncate max-w-[100px]">
                  {tx.branch || '—'}
                </td>
                <td className="px-3 py-1.5 text-center">
                  <StatusBadge status={tx.status} />
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>
      {transactions.length > 15 && (
        <div className="px-3 py-1.5 text-[10px] text-slate-400 bg-slate-50 border-t border-slate-100 text-center">
          + {transactions.length - 15} autres transactions
        </div>
      )}
    </div>
  );
}

// ═══════════════════════════════════════════
// STATS CARD — compact stats display
// ═══════════════════════════════════════════

function StatsCard({ stats }: { stats: any }) {
  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-2">
      {/* Top-level stats */}
      <div className="flex gap-3">
        <div className="flex-1 bg-blue-50 rounded-lg p-2.5 text-center">
          <div className="text-lg font-bold text-blue-700">{stats.totalTransactions}</div>
          <div className="text-[10px] text-blue-500 font-medium">Virements</div>
        </div>
        <div className="flex-1 bg-green-50 rounded-lg p-2.5 text-center">
          <div className="text-lg font-bold text-green-700">
            {Number(stats.totalAmount).toLocaleString('fr-CA', { minimumFractionDigits: 2 })} $
          </div>
          <div className="text-[10px] text-green-500 font-medium">Total</div>
        </div>
      </div>

      {/* Top branches */}
      {stats.byBranch && stats.byBranch.length > 0 && (
        <div>
          <div className="text-[10px] font-semibold text-slate-500 mb-1">Top succursales</div>
          <div className="space-y-1">
            {stats.byBranch.slice(0, 5).map((b: any, i: number) => (
              <div key={i} className="flex items-center justify-between text-[11px]">
                <span className="text-slate-600 truncate">{b.branch}</span>
                <span className="text-slate-800 font-medium whitespace-nowrap ml-2">
                  {b.count} · {Number(b.total).toFixed(0)} $
                </span>
              </div>
            ))}
          </div>
        </div>
      )}
    </div>
  );
}

// ═══════════════════════════════════════════
// STATUS BADGE
// ═══════════════════════════════════════════

function StatusBadge({ status }: { status: string }) {
  const colors: Record<string, string> = {
    deposited: 'bg-green-100 text-green-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>
  );
}