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, ActivityItem, ClientCreate } from '@/types';
import {
  ArrowLeft, Edit3, Trash2, Phone, Mail, MapPin, Building2,
  Briefcase, Gift, Heart, Star, Users, Calendar, Send,
  CheckCircle2, Sparkles, Clock, Activity, FileText, UserPlus, RefreshCw,
  Paperclip, Target,
} from 'lucide-react';
import { usePinnedClients } from '@/hooks/usePinnedClients';
import { cn, formatDate, getRelativeTime, getInitials } from '@/lib/utils';
import Badge, { EventTypeBadge, EmailStatusBadge, StageBadge } from '@/components/Badge';
import { PageLoader } from '@/components/LoadingSpinner';
import Modal from '@/components/Modal';
import ClientForm from '@/components/ClientForm';
import EmailComposeModal from '@/components/EmailComposeModal';
import ClientNotes from '@/components/ClientNotes';
import LogInteractionModal from '@/components/LogInteractionModal';
import MeetingPrepModal from '@/components/MeetingPrepModal';
import EngagementBadge from '@/components/EngagementBadge';
import DuplicatesModal from '@/components/DuplicatesModal';
import ClientDocuments from '@/components/ClientDocuments';
import ClientGoals from '@/components/ClientGoals';
import ClientReferrals from '@/components/ClientReferrals';
import type { Interaction } from '@/types';

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 [activities, setActivities] = useState<ActivityItem[]>([]);
  const [activeTab, setActiveTab] = useState<'info' | 'notes' | 'activity' | 'events' | 'emails' | 'documents' | 'goals' | 'referrals'>('info');
  const [, setInteractions] = useState<Interaction[]>([]);
  const [showEdit, setShowEdit] = useState(false);
  const [showCompose, setShowCompose] = useState(false);
  const [showLogInteraction, setShowLogInteraction] = useState(false);
  const [showMeetingPrep, setShowMeetingPrep] = useState(false);
  const [showDuplicates, setShowDuplicates] = useState(false);
  const [deleting, setDeleting] = useState(false);
  const { togglePin, isPinned } = usePinnedClients();

  useEffect(() => {
    if (id) {
      fetchClient(id);
      api.getEvents({ clientId: id }).then(setEvents).catch(() => {});
      api.getEmails({ clientId: id }).then(setEmails).catch(() => {});
      api.getClientActivity(id).then(setActivities).catch(() => {});
      api.getClientInteractions(id).then(setInteractions).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: ClientCreate) => {
    await updateClient(client.id, data);
    setShowEdit(false);
  };

  const tabs: { key: typeof activeTab; label: string; count?: number; icon: typeof Users }[] = [
    { key: 'info', label: 'Info', icon: Users },
    { key: 'notes', label: 'Notes', icon: FileText },
    { key: 'documents', label: 'Documents', icon: Paperclip },
    { key: 'goals', label: 'Goals', icon: Target },
    { key: 'referrals', label: 'Referrals', icon: UserPlus },
    { key: 'activity', label: 'Timeline', count: activities.length, icon: Activity },
    { 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 flex-col sm:flex-row items-start gap-4">
        <button onClick={() => navigate('/clients')} className="mt-1 p-2 rounded-lg text-slate-400 hover:bg-slate-100 dark:hover:bg-slate-700 hover:text-slate-600 dark:hover:text-slate-300 transition-colors">
          <ArrowLeft className="w-5 h-5" />
        </button>
        <div className="flex-1 min-w-0">
          <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 flex-shrink-0">
              {getInitials(client.firstName, client.lastName)}
            </div>
            <div className="flex-1 min-w-0">
              <div className="flex items-center gap-3">
                <h1 className="text-2xl font-bold text-slate-900 dark:text-slate-100">
                  {client.firstName} {client.lastName}
                </h1>
                <EngagementBadge clientId={client.id} />
              </div>
              {client.company && (
                <p className="text-slate-500 dark:text-slate-400">
                  {client.role ? `${client.role} at ` : ''}{client.company}
                </p>
              )}
              <div className="flex flex-wrap gap-1.5 mt-2">
                <StageBadge stage={client.stage} onClick={async () => {
                  const stages = ['lead', 'prospect', 'onboarding', 'active', 'inactive'];
                  const currentIdx = stages.indexOf(client.stage || 'lead');
                  const nextStage = stages[(currentIdx + 1) % stages.length];
                  await updateClient(client.id, { stage: nextStage as ClientCreate['stage'] });
                }} />
                {client.tags && client.tags.length > 0 && (
                  client.tags.map((tag) => <Badge key={tag} color="blue">{tag}</Badge>)
                )}
              </div>
            </div>
          </div>
        </div>
        <div className="flex flex-wrap 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" />
            <span className="hidden sm:inline">Contacted</span>
          </button>
          <button onClick={() => setShowLogInteraction(true)} className="flex items-center gap-2 px-3 py-2 bg-indigo-50 text-indigo-700 dark:bg-indigo-900/30 dark:text-indigo-300 rounded-lg text-sm font-medium hover:bg-indigo-100 dark:hover:bg-indigo-900/50 transition-colors">
            <Phone className="w-4 h-4" />
            <span className="hidden sm:inline">Log Interaction</span>
          </button>
          <button onClick={() => setShowMeetingPrep(true)} className="flex items-center gap-2 px-3 py-2 bg-purple-50 text-purple-700 dark:bg-purple-900/30 dark:text-purple-300 rounded-lg text-sm font-medium hover:bg-purple-100 dark:hover:bg-purple-900/50 transition-colors">
            <Briefcase className="w-4 h-4" />
            <span className="hidden sm:inline">Meeting Prep</span>
          </button>
          <button onClick={() => setShowCompose(true)} className="flex items-center gap-2 px-3 py-2 bg-blue-50 text-blue-700 dark:bg-blue-900/30 dark:text-blue-300 rounded-lg text-sm font-medium hover:bg-blue-100 dark:hover:bg-blue-900/50 transition-colors">
            <Sparkles className="w-4 h-4" />
            <span className="hidden sm:inline">Generate Email</span>
          </button>
          <button onClick={() => setShowDuplicates(true)} className="flex items-center gap-2 px-3 py-2 bg-amber-50 text-amber-700 dark:bg-amber-900/30 dark:text-amber-300 rounded-lg text-sm font-medium hover:bg-amber-100 dark:hover:bg-amber-900/50 transition-colors">
            <Users className="w-4 h-4" />
            <span className="hidden sm:inline">Duplicates</span>
          </button>
          <button
            onClick={() => togglePin(client.id)}
            className={`p-2 rounded-lg transition-colors ${isPinned(client.id) ? 'text-amber-500 bg-amber-50 dark:bg-amber-900/30' : 'text-slate-400 hover:bg-slate-100 dark:hover:bg-slate-700 hover:text-amber-500'}`}
            title={isPinned(client.id) ? 'Unpin from dashboard' : 'Pin to dashboard'}
          >
            <Star className={`w-4 h-4 ${isPinned(client.id) ? 'fill-amber-500' : ''}`} />
          </button>
          <button onClick={() => setShowEdit(true)} className="p-2 rounded-lg text-slate-400 hover:bg-slate-100 dark:hover:bg-slate-700 hover:text-slate-600 dark:hover:text-slate-300 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 dark:border-slate-700">
        <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 dark:text-blue-400 dark:border-blue-400'
                  : 'border-transparent text-slate-500 dark:text-slate-400 hover:text-slate-700 dark:hover:text-slate-300'
              )}
            >
              <Icon className="w-4 h-4" />
              {label}
              {count !== undefined && count > 0 && (
                <span className="px-1.5 py-0.5 bg-slate-100 dark:bg-slate-700 text-slate-600 dark:text-slate-300 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 dark:bg-slate-800 border border-slate-200 dark:border-slate-700 rounded-xl p-5 space-y-4">
            <h3 className="font-semibold text-slate-900 dark:text-slate-100">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 dark:bg-slate-800 border border-slate-200 dark:border-slate-700 rounded-xl p-5 space-y-4">
            <h3 className="font-semibold text-slate-900 dark:text-slate-100">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 dark:bg-slate-800 border border-slate-200 dark:border-slate-700 rounded-xl p-5 md:col-span-2">
              <h3 className="font-semibold text-slate-900 dark:text-slate-100 mb-2">Notes</h3>
              <p className="text-sm text-slate-700 dark:text-slate-300 whitespace-pre-wrap">{client.notes}</p>
            </div>
          )}
        </div>
      )}

      {activeTab === 'notes' && (
        <ClientNotes clientId={client.id} />
      )}

      {activeTab === 'documents' && (
        <ClientDocuments clientId={client.id} />
      )}

      {activeTab === 'goals' && (
        <ClientGoals clientId={client.id} />
      )}

      {activeTab === 'referrals' && (
        <ClientReferrals clientId={client.id} clientName={`${client.firstName} ${client.lastName}`} />
      )}

      {activeTab === 'activity' && (
        <div className="bg-white dark:bg-slate-800 border border-slate-200 dark:border-slate-700 rounded-xl">
          {activities.length === 0 ? (
            <p className="px-5 py-8 text-center text-sm text-slate-400">No activity recorded yet</p>
          ) : (
            <div className="relative">
              {activities.map((item, index) => {
                const iconMap: Record<string, { icon: typeof Mail; color: string; bg: string }> = {
                  email_sent: { icon: Send, color: 'text-emerald-600', bg: 'bg-emerald-100 dark:bg-emerald-900/30' },
                  email_drafted: { icon: FileText, color: 'text-amber-600', bg: 'bg-amber-100 dark:bg-amber-900/30' },
                  event_created: { icon: Calendar, color: 'text-blue-600', bg: 'bg-blue-100 dark:bg-blue-900/30' },
                  client_contacted: { icon: CheckCircle2, color: 'text-emerald-600', bg: 'bg-emerald-100 dark:bg-emerald-900/30' },
                  client_created: { icon: UserPlus, color: 'text-purple-600', bg: 'bg-purple-100 dark:bg-purple-900/30' },
                  client_updated: { icon: RefreshCw, color: 'text-slate-600', bg: 'bg-slate-100 dark:bg-slate-700' },
                  interaction: { icon: Phone, color: 'text-indigo-600 dark:text-indigo-400', bg: 'bg-indigo-100 dark:bg-indigo-900/30' },
                };
                const { icon: Icon, color, bg } = iconMap[item.type] || iconMap.client_updated;
                
                return (
                  <div key={item.id} className="flex gap-4 px-5 py-4 relative">
                    {/* Timeline line */}
                    {index < activities.length - 1 && (
                      <div className="absolute left-[2.15rem] top-14 bottom-0 w-px bg-slate-200" />
                    )}
                    {/* Icon */}
                    <div className={`w-8 h-8 rounded-full flex items-center justify-center flex-shrink-0 ${bg} relative z-10`}>
                      <Icon className={`w-4 h-4 ${color}`} />
                    </div>
                    {/* Content */}
                    <div className="flex-1 min-w-0">
                      <p className="text-sm font-medium text-slate-900">{item.title}</p>
                      {item.description && (
                        <p className="text-xs text-slate-500 mt-0.5 line-clamp-2">{item.description}</p>
                      )}
                      <p className="text-xs text-slate-400 mt-1">{formatDate(item.date)}</p>
                    </div>
                  </div>
                );
              })}
            </div>
          )}
        </div>
      )}

      {activeTab === 'events' && (
        <div className="bg-white dark:bg-slate-800 border border-slate-200 dark:border-slate-700 rounded-xl divide-y divide-slate-100 dark:divide-slate-700">
          {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 dark:bg-slate-800 border border-slate-200 dark:border-slate-700 rounded-xl divide-y divide-slate-100 dark:divide-slate-700">
          {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])}
      />

      {/* Meeting Prep Modal */}
      <MeetingPrepModal
        isOpen={showMeetingPrep}
        onClose={() => setShowMeetingPrep(false)}
        clientId={client.id}
        clientName={`${client.firstName} ${client.lastName}`}
      />

      {/* Log Interaction Modal */}
      <LogInteractionModal
        isOpen={showLogInteraction}
        onClose={() => setShowLogInteraction(false)}
        clientId={client.id}
        clientName={`${client.firstName} ${client.lastName}`}
        onCreated={() => {
          // Refresh interactions and activity
          if (id) {
            api.getClientInteractions(id).then(setInteractions).catch(() => {});
            api.getClientActivity(id).then(setActivities).catch(() => {});
            fetchClient(id); // refresh lastContactedAt
          }
        }}
      />

      {/* Duplicates Modal */}
      <DuplicatesModal
        isOpen={showDuplicates}
        onClose={() => setShowDuplicates(false)}
        clientId={client.id}
        clientName={`${client.firstName} ${client.lastName}`}
        onMerged={() => {
          if (id) fetchClient(id);
        }}
      />
    </div>
  );
}