import { useEffect, useState } from 'react';
import { useParams, useNavigate, Link } from 'react-router-dom';
import { useClientsStore } from '@/stores/clients';
import { api } from '@/lib/api';
import type { Event, Email } from '@/types';
import {
  ArrowLeft, Edit3, Trash2, Phone, Mail, MapPin, Building2,
  Briefcase, Gift, Heart, Star, Users, Calendar, Send,
  CheckCircle2, Sparkles, Clock,
} from 'lucide-react';
import { cn, formatDate, getRelativeTime, getInitials } from '@/lib/utils';
import Badge, { EventTypeBadge, EmailStatusBadge } from '@/components/Badge';
import { PageLoader } from '@/components/LoadingSpinner';
import Modal from '@/components/Modal';
import ClientForm from '@/components/ClientForm';
import EmailComposeModal from '@/components/EmailComposeModal';

export default function ClientDetailPage() {
  const { id } = useParams<{ id: string }>();
  const navigate = useNavigate();
  const { selectedClient, isLoading, fetchClient, updateClient, deleteClient, markContacted } = useClientsStore();
  const [events, setEvents] = useState<Event[]>([]);
  const [emails, setEmails] = useState<Email[]>([]);
  const [activeTab, setActiveTab] = useState<'info' | 'events' | 'emails'>('info');
  const [showEdit, setShowEdit] = useState(false);
  const [showCompose, setShowCompose] = useState(false);
  const [deleting, setDeleting] = useState(false);

  useEffect(() => {
    if (id) {
      fetchClient(id);
      api.getEvents({ clientId: id }).then(setEvents).catch(() => {});
      api.getEmails({ clientId: id }).then(setEmails).catch(() => {});
    }
  }, [id, fetchClient]);

  if (isLoading || !selectedClient) return <PageLoader />;

  const client = selectedClient;

  const handleDelete = async () => {
    if (!confirm('Delete this client? This cannot be undone.')) return;
    setDeleting(true);
    try {
      await deleteClient(client.id);
      navigate('/clients');
    } catch {
      setDeleting(false);
    }
  };

  const handleMarkContacted = async () => {
    await markContacted(client.id);
  };

  const handleUpdate = async (data: any) => {
    await updateClient(client.id, data);
    setShowEdit(false);
  };

  const tabs: { key: 'info' | 'events' | 'emails'; label: string; count?: number; icon: typeof Users }[] = [
    { key: 'info', label: 'Info', icon: Users },
    { key: 'events', label: 'Events', count: events.length, icon: Calendar },
    { key: 'emails', label: 'Emails', count: emails.length, icon: Mail },
  ];

  return (
    <div className="max-w-4xl mx-auto space-y-6 animate-fade-in">
      {/* Header */}
      <div className="flex items-start gap-4">
        <button onClick={() => navigate('/clients')} className="mt-1 p-2 rounded-lg text-slate-400 hover:bg-slate-100 hover:text-slate-600 transition-colors">
          <ArrowLeft className="w-5 h-5" />
        </button>
        <div className="flex-1">
          <div className="flex items-center gap-4">
            <div className="w-16 h-16 bg-blue-100 text-blue-700 rounded-2xl flex items-center justify-center text-xl font-bold">
              {getInitials(client.firstName, client.lastName)}
            </div>
            <div className="flex-1">
              <h1 className="text-2xl font-bold text-slate-900">
                {client.firstName} {client.lastName}
              </h1>
              {client.company && (
                <p className="text-slate-500">
                  {client.role ? `${client.role} at ` : ''}{client.company}
                </p>
              )}
              {client.tags && client.tags.length > 0 && (
                <div className="flex flex-wrap gap-1.5 mt-2">
                  {client.tags.map((tag) => <Badge key={tag} color="blue">{tag}</Badge>)}
                </div>
              )}
            </div>
          </div>
        </div>
        <div className="flex gap-2">
          <button onClick={handleMarkContacted} className="flex items-center gap-2 px-3 py-2 bg-emerald-50 text-emerald-700 rounded-lg text-sm font-medium hover:bg-emerald-100 transition-colors">
            <CheckCircle2 className="w-4 h-4" />
            Contacted
          </button>
          <button onClick={() => setShowCompose(true)} className="flex items-center gap-2 px-3 py-2 bg-blue-50 text-blue-700 rounded-lg text-sm font-medium hover:bg-blue-100 transition-colors">
            <Sparkles className="w-4 h-4" />
            Generate Email
          </button>
          <button onClick={() => setShowEdit(true)} className="p-2 rounded-lg text-slate-400 hover:bg-slate-100 hover:text-slate-600 transition-colors">
            <Edit3 className="w-4 h-4" />
          </button>
          <button onClick={handleDelete} disabled={deleting} className="p-2 rounded-lg text-slate-400 hover:bg-red-50 hover:text-red-600 transition-colors">
            <Trash2 className="w-4 h-4" />
          </button>
        </div>
      </div>

      {/* Tabs */}
      <div className="border-b border-slate-200">
        <div className="flex gap-6">
          {tabs.map(({ key, label, count, icon: Icon }) => (
            <button
              key={key}
              onClick={() => setActiveTab(key)}
              className={cn(
                'flex items-center gap-2 pb-3 border-b-2 text-sm font-medium transition-colors',
                activeTab === key
                  ? 'border-blue-600 text-blue-600'
                  : 'border-transparent text-slate-500 hover:text-slate-700'
              )}
            >
              <Icon className="w-4 h-4" />
              {label}
              {count !== undefined && count > 0 && (
                <span className="px-1.5 py-0.5 bg-slate-100 text-slate-600 rounded-full text-xs">{count}</span>
              )}
            </button>
          ))}
        </div>
      </div>

      {/* Tab Content */}
      {activeTab === 'info' && (
        <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
          {/* Contact Info */}
          <div className="bg-white border border-slate-200 rounded-xl p-5 space-y-4">
            <h3 className="font-semibold text-slate-900">Contact Information</h3>
            {client.email && (
              <div className="flex items-center gap-3 text-sm">
                <Mail className="w-4 h-4 text-slate-400" />
                <a href={`mailto:${client.email}`} className="text-blue-600 hover:underline">{client.email}</a>
              </div>
            )}
            {client.phone && (
              <div className="flex items-center gap-3 text-sm">
                <Phone className="w-4 h-4 text-slate-400" />
                <span className="text-slate-700">{client.phone}</span>
              </div>
            )}
            {(client.street || client.city) && (
              <div className="flex items-start gap-3 text-sm">
                <MapPin className="w-4 h-4 text-slate-400 mt-0.5" />
                <span className="text-slate-700">
                  {[client.street, client.city, client.state, client.zip].filter(Boolean).join(', ')}
                </span>
              </div>
            )}
            {client.company && (
              <div className="flex items-center gap-3 text-sm">
                <Building2 className="w-4 h-4 text-slate-400" />
                <span className="text-slate-700">{client.company}</span>
              </div>
            )}
            {client.industry && (
              <div className="flex items-center gap-3 text-sm">
                <Briefcase className="w-4 h-4 text-slate-400" />
                <span className="text-slate-700">{client.industry}</span>
              </div>
            )}
            <div className="flex items-center gap-3 text-sm">
              <Clock className="w-4 h-4 text-slate-400" />
              <span className="text-slate-500">Last contacted: {getRelativeTime(client.lastContacted)}</span>
            </div>
          </div>

          {/* Personal */}
          <div className="bg-white border border-slate-200 rounded-xl p-5 space-y-4">
            <h3 className="font-semibold text-slate-900">Personal Details</h3>
            {client.birthday && (
              <div className="flex items-center gap-3 text-sm">
                <Gift className="w-4 h-4 text-pink-500" />
                <span className="text-slate-700">Birthday: {formatDate(client.birthday)}</span>
              </div>
            )}
            {client.anniversary && (
              <div className="flex items-center gap-3 text-sm">
                <Heart className="w-4 h-4 text-purple-500" />
                <span className="text-slate-700">Anniversary: {formatDate(client.anniversary)}</span>
              </div>
            )}
            {client.interests && client.interests.length > 0 && (
              <div>
                <div className="flex items-center gap-2 text-sm text-slate-500 mb-2">
                  <Star className="w-4 h-4" />
                  Interests
                </div>
                <div className="flex flex-wrap gap-1.5">
                  {client.interests.map((i) => <Badge key={i} color="green">{i}</Badge>)}
                </div>
              </div>
            )}
            {client.family?.spouse && (
              <div className="flex items-center gap-3 text-sm">
                <Users className="w-4 h-4 text-slate-400" />
                <span className="text-slate-700">Spouse: {client.family.spouse}</span>
              </div>
            )}
            {client.family?.children && client.family.children.length > 0 && (
              <div className="text-sm text-slate-700 ml-7">
                Children: {client.family.children.join(', ')}
              </div>
            )}
          </div>

          {/* Notes */}
          {client.notes && (
            <div className="bg-white border border-slate-200 rounded-xl p-5 md:col-span-2">
              <h3 className="font-semibold text-slate-900 mb-2">Notes</h3>
              <p className="text-sm text-slate-700 whitespace-pre-wrap">{client.notes}</p>
            </div>
          )}
        </div>
      )}

      {activeTab === 'events' && (
        <div className="bg-white border border-slate-200 rounded-xl divide-y divide-slate-100">
          {events.length === 0 ? (
            <p className="px-5 py-8 text-center text-sm text-slate-400">No events for this client</p>
          ) : (
            events.map((event) => (
              <div key={event.id} className="flex items-center gap-3 px-5 py-4">
                <EventTypeBadge type={event.type} />
                <div className="flex-1 min-w-0">
                  <p className="text-sm font-medium text-slate-900">{event.title}</p>
                  <p className="text-xs text-slate-500">{formatDate(event.date)} {event.recurring && '· Recurring'}</p>
                </div>
              </div>
            ))
          )}
        </div>
      )}

      {activeTab === 'emails' && (
        <div className="bg-white border border-slate-200 rounded-xl divide-y divide-slate-100">
          {emails.length === 0 ? (
            <p className="px-5 py-8 text-center text-sm text-slate-400">No emails for this client</p>
          ) : (
            emails.map((email) => (
              <Link key={email.id} to={`/emails?id=${email.id}`} className="flex items-center gap-3 px-5 py-4 hover:bg-slate-50 transition-colors">
                <EmailStatusBadge status={email.status} />
                <div className="flex-1 min-w-0">
                  <p className="text-sm font-medium text-slate-900 truncate">{email.subject}</p>
                  <p className="text-xs text-slate-500">{formatDate(email.createdAt)}</p>
                </div>
              </Link>
            ))
          )}
        </div>
      )}

      {/* Edit Modal */}
      <Modal isOpen={showEdit} onClose={() => setShowEdit(false)} title="Edit Client" size="lg">
        <ClientForm initialData={client} onSubmit={handleUpdate} />
      </Modal>

      {/* Email Compose Modal */}
      <EmailComposeModal
        isOpen={showCompose}
        onClose={() => setShowCompose(false)}
        clientId={client.id}
        clientName={`${client.firstName} ${client.lastName}`}
        onGenerated={(email) => setEmails((prev) => [email, ...prev])}
      />
    </div>
  );
}