import React, { useState } from 'react';
import { useParams, useNavigate } from 'react-router-dom';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { PencilIcon, TrashIcon, CheckCircleIcon, XCircleIcon, UserGroupIcon, CalendarDaysIcon, ClockIcon, ReceiptPercentIcon, PlusIcon } from '@heroicons/react/24/outline';
import { toast } from 'sonner';
import { api } from '../lib/api';
import type { ApiResponse, PaginatedResponse } from '../lib/api';
import type { Representation, City } from '../types';
import { formatDate, formatDateTime, formatNumber } from '../lib/utils';
import PageHeader from '../components/ui/PageHeader';
import { ActiveBadge } from '../components/ui/StatusBadge';
import ConfirmDialog from '../components/ui/ConfirmDialog';
import Modal from '../components/ui/Modal';
import SearchableSelect from '../components/ui/SearchableSelect';
import { digitsOnly } from '../lib/utils';

interface RepDoctor {
  uuid: string;
  id: number;
  name: string;
  gender: string | null;
  medical_code: string | null;
  is_active: boolean;
  owner_status?: string;
  past_count: number;
  upcoming_count: number;
  created_at: string;
}

interface RepAppointment {
  uuid: string;
  slot_start: number;
  slot_end: number;
  status: string;
  patient_name: string | null;
  doctor_uuid: string;
  doctor_name: string;
}

interface UnassignedDoctor {
  uuid: string;
  name: string;
  medical_code: string | null;
  mobile: string | null;
}

function DetailRow({ label, value }: { label: string; value: React.ReactNode }) {
  return (
    <div className="cp-info-row items-start gap-4">
      <span className="text-sm text-[var(--text-2)] w-40 shrink-0">{label}</span>
      <span className="cp-info-value">{value ?? '—'}</span>
    </div>
  );
}

function StatTile({ icon: Icon, label, value, tone }: {
  icon: React.ComponentType<{ className?: string }>;
  label: string; value: React.ReactNode; tone: 'violet' | 'green' | 'amber' | 'pink';
}) {
  return (
    <div className="cp-stat">
      <div className="cp-stat-icon" style={{ background: `var(--stat-${tone}-bg)`, color: `var(--stat-${tone}-fg)` }}>
        <Icon className="w-5 h-5" />
      </div>
      <div className="min-w-0">
        <div className="text-xs text-[var(--text-3)] mb-1">{label}</div>
        <div className="text-xl font-bold text-[var(--text)] leading-none">{value}</div>
      </div>
    </div>
  );
}

export default function RepresentationDetailPage() {
  const { uuid } = useParams<{ uuid: string }>();
  const navigate = useNavigate();
  const qc = useQueryClient();
  const [deleteOpen, setDeleteOpen] = useState(false);
  const [editOpen, setEditOpen] = useState(false);
  const [formData, setFormData] = useState({ full_name: '', city_id: '', mobile_number: '', commission_percent: '' });
  const [attachOpen, setAttachOpen] = useState(false);
  const [attachSearch, setAttachSearch] = useState('');
  const [apptScope, setApptScope] = useState<'upcoming' | 'past'>('upcoming');

  const citiesQuery = useQuery({
    queryKey: ['cities-select'],
    queryFn: () => api.get<PaginatedResponse<City>>('/api/v1/admin/cities?limit=200'),
    staleTime: 5 * 60_000,
  });
  const cities: City[] = citiesQuery.data?.data ?? [];

  const { data, isLoading } = useQuery({
    queryKey: ['representation', uuid],
    queryFn: () => api.get<ApiResponse<{ data: Representation }>>(`/api/v1/representation/${uuid}`),
    enabled: !!uuid,
  });

  const rep: Representation | undefined = (data?.data as any)?.data ?? data?.data;

  const doctorsQuery = useQuery({
    queryKey: ['representation-doctors', uuid],
    queryFn: () => api.get<PaginatedResponse<RepDoctor>>(`/api/v1/admin/representations/${uuid}/doctors?limit=100`),
    enabled: !!uuid,
  });
  const repDoctors: RepDoctor[] = doctorsQuery.data?.data ?? [];
  const repDoctorsTotal = doctorsQuery.data?.meta?.totalRecords ?? repDoctors.length;
  const upcomingTotal = repDoctors.reduce((s, d) => s + (d.upcoming_count ?? 0), 0);
  const pastTotal = repDoctors.reduce((s, d) => s + (d.past_count ?? 0), 0);

  const appointmentsQuery = useQuery({
    queryKey: ['representation-appointments', uuid, apptScope],
    queryFn: () => api.get<PaginatedResponse<RepAppointment>>(`/api/v1/admin/representations/${uuid}/appointments?scope=${apptScope}&limit=50`),
    enabled: !!uuid,
  });
  const repAppointments: RepAppointment[] = appointmentsQuery.data?.data ?? [];
  const repAppointmentsTotal = appointmentsQuery.data?.meta?.totalRecords ?? repAppointments.length;

  const unassignedQuery = useQuery({
    queryKey: ['unassigned-doctors', attachSearch],
    queryFn: () => api.get<PaginatedResponse<UnassignedDoctor>>(`/api/v1/admin/doctors?unassigned=1&limit=20${attachSearch ? `&search=${encodeURIComponent(attachSearch)}` : ''}`),
    enabled: attachOpen,
  });
  const unassignedDoctors: UnassignedDoctor[] = unassignedQuery.data?.data ?? [];

  const attachMutation = useMutation({
    mutationFn: (doctorUuid: string) =>
      api.post<ApiResponse<unknown>>(`/api/v1/admin/representations/${uuid}/doctors`, { doctor_uuid: doctorUuid }),
    onSuccess: () => {
      toast.success('پزشک به نماینده متصل شد');
      setAttachOpen(false);
      setAttachSearch('');
      qc.invalidateQueries({ queryKey: ['representation-doctors', uuid] });
      qc.invalidateQueries({ queryKey: ['representations'] });
    },
    onError: (err: Error) => toast.error(err.message),
  });

  const updateMutation = useMutation({
    mutationFn: (d: Partial<Representation>) =>
      api.patch<ApiResponse<Representation>>(`/api/v1/representation/${uuid}`, d),
    onSuccess: () => {
      toast.success('اطلاعات بروزرسانی شد');
      setEditOpen(false);
      qc.invalidateQueries({ queryKey: ['representation', uuid] });
      qc.invalidateQueries({ queryKey: ['representations'] });
    },
    onError: (err: Error) => toast.error(err.message),
  });

  const toggleActiveMutation = useMutation({
    mutationFn: () =>
      api.patch<ApiResponse<Representation>>(`/api/v1/representation/${uuid}`, {
        active: !(rep?.active ?? rep?.is_active),
      }),
    onSuccess: () => {
      toast.success('وضعیت تغییر کرد');
      qc.invalidateQueries({ queryKey: ['representation', uuid] });
    },
    onError: (err: Error) => toast.error(err.message),
  });

  const deleteMutation = useMutation({
    mutationFn: () => api.delete<ApiResponse<null>>(`/api/v1/representation/${uuid}`),
    onSuccess: () => {
      toast.success('نماینده حذف شد');
      navigate('/admin/representations');
    },
    onError: (err: Error) => toast.error(err.message),
  });

  const openEdit = () => {
    if (!rep) return;
    setFormData({
      full_name: rep.full_name ?? rep.domain ?? '',
      city_id: rep.city_id ? String(rep.city_id) : '',
      mobile_number: rep.mobile_number ?? '',
      commission_percent: String(rep.commission_percent),
    });
    setEditOpen(true);
  };

  const isActive = rep?.active ?? rep?.is_active ?? false;

  if (isLoading) {
    return (
      <div>
        <PageHeader
          title="جزئیات نماینده"
          breadcrumbs={[
            { label: 'داشبورد', to: '/admin/dashboard' },
            { label: 'نمایندگان', to: '/admin/representations' },
            { label: 'جزئیات' },
          ]}
        />
        <div className="bg-[var(--surface)] rounded-2xl shadow-sm border border-[var(--border)] p-6 animate-pulse">
          <div className="space-y-4">
            {[1, 2, 3, 4, 5].map((i) => (
              <div key={i} className="h-8 bg-[var(--surface-2)] rounded" />
            ))}
          </div>
        </div>
      </div>
    );
  }

  if (!rep) {
    return (
      <div>
        <PageHeader
          title="نماینده یافت نشد"
          breadcrumbs={[
            { label: 'داشبورد', to: '/admin/dashboard' },
            { label: 'نمایندگان', to: '/admin/representations' },
          ]}
        />
        <div className="cp-card p-12 text-center text-[var(--text-3)]">
          نماینده‌ای با این شناسه یافت نشد.
        </div>
      </div>
    );
  }

  const name = rep.full_name ?? rep.domain ?? '—';

  return (
    <div>
      <PageHeader
        title={name}
        breadcrumbs={[
          { label: 'داشبورد', to: '/admin/dashboard' },
          { label: 'نمایندگان', to: '/admin/representations' },
          { label: name },
        ]}
        action={
          <div className="flex items-center gap-2">
            <button
              onClick={() => toggleActiveMutation.mutate()}
              disabled={toggleActiveMutation.isPending}
              className={`flex items-center gap-1.5 px-3 py-2 text-sm rounded-[10px] border transition-colors disabled:opacity-50 ${
                isActive
                  ? 'border-[var(--danger)] text-[var(--danger)] hover:bg-[var(--danger-bg)]'
                  : 'border-[var(--success)] text-[var(--success)] hover:bg-[var(--success-bg)]'
              }`}
            >
              {isActive
                ? <><XCircleIcon className="w-4 h-4" /> غیرفعال کردن</>
                : <><CheckCircleIcon className="w-4 h-4" /> فعال کردن</>
              }
            </button>
            <button
              onClick={openEdit}
              className="flex items-center gap-1.5 px-3 py-2 text-sm rounded-[10px] border border-[var(--border-2)] text-[var(--text)] hover:bg-[var(--surface-2)] transition-colors"
            >
              <PencilIcon className="w-4 h-4" />
              ویرایش
            </button>
            <button
              onClick={() => setDeleteOpen(true)}
              className="flex items-center gap-1.5 px-3 py-2 text-sm rounded-[10px] border border-[var(--danger)] text-[var(--danger)] hover:bg-[var(--danger-bg)] transition-colors"
            >
              <TrashIcon className="w-4 h-4" />
              حذف
            </button>
          </div>
        }
      />

      {/* KPI tiles */}
      <div className="grid grid-cols-2 lg:grid-cols-4 gap-4 mb-6">
        <StatTile icon={UserGroupIcon} tone="violet" label="تعداد پزشکان" value={formatNumber(repDoctorsTotal)} />
        <StatTile icon={CalendarDaysIcon} tone="green" label="نوبت آینده" value={formatNumber(upcomingTotal)} />
        <StatTile icon={ClockIcon} tone="amber" label="نوبت گذشته" value={formatNumber(pastTotal)} />
        <StatTile icon={ReceiptPercentIcon} tone="pink" label="درصد کمیسیون" value={`${formatNumber(rep.commission_percent)}٪`} />
      </div>

      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Basic Info */}
        <div className="cp-card p-6">
          <h2 className="text-sm font-semibold text-[var(--text)] mb-4">اطلاعات پایه</h2>
          <DetailRow label="نام کامل" value={rep.full_name} />
          <DetailRow label="موبایل" value={
            rep.mobile_number
              ? <span dir="ltr">{rep.mobile_number}</span>
              : null
          } />
          <DetailRow label="شهر" value={rep.city ?? (rep.city_id ? `شناسه ${rep.city_id}` : null)} />
          <DetailRow label="درصد کمیسیون" value={`${formatNumber(rep.commission_percent)}٪`} />
          <DetailRow label="وضعیت" value={<ActiveBadge active={isActive} />} />
          <DetailRow label="تاریخ ثبت" value={formatDate(rep.created_at)} />
        </div>

        {/* Bank Account */}
        <div className="cp-card p-6">
          <h2 className="text-sm font-semibold text-[var(--text)] mb-4">اطلاعات بانکی</h2>
          {rep.bank_account ? (
            <>
              <DetailRow label="شماره کارت" value={
                rep.bank_account.card
                  ? <span dir="ltr" className="font-mono tracking-widest">{rep.bank_account.card}</span>
                  : null
              } />
              <DetailRow label="نام بانک" value={rep.bank_account.bank_name} />
              <DetailRow label="شماره شبا" value={
                rep.bank_account.iban
                  ? <span dir="ltr" className="font-mono text-xs">{rep.bank_account.iban}</span>
                  : null
              } />
            </>
          ) : (
            <p className="text-sm text-[var(--text-3)] text-center py-6">اطلاعات بانکی ثبت نشده</p>
          )}
        </div>
      </div>

      {/* Doctors of this representation */}
      <div className="cp-card p-6 mt-6">
        <div className="flex items-center justify-between mb-4 flex-wrap gap-2">
          <div className="flex items-center gap-2">
            <UserGroupIcon className="w-5 h-5 text-[var(--text-3)]" />
            <h2 className="text-sm font-semibold text-[var(--text)]">پزشکان این نماینده</h2>
            <span className="badge violet">{formatNumber(repDoctorsTotal)}</span>
          </div>
          <button className="btn primary sm inline-flex items-center gap-1" onClick={() => setAttachOpen(true)}>
            <PlusIcon className="w-4 h-4" /> افزودن پزشک
          </button>
        </div>
        {doctorsQuery.isLoading ? (
          <p className="text-sm text-[var(--text-3)] text-center py-8">در حال بارگذاری…</p>
        ) : repDoctors.length === 0 ? (
          <div className="text-center py-10">
            <UserGroupIcon className="w-10 h-10 mx-auto text-[var(--text-3)] mb-2" />
            <p className="text-sm text-[var(--text-3)]">این نماینده هنوز پزشکی ندارد</p>
            <button className="btn primary sm mt-3 inline-flex items-center gap-1" onClick={() => setAttachOpen(true)}>
              <PlusIcon className="w-4 h-4" /> افزودن اولین پزشک
            </button>
          </div>
        ) : (
          <div className="table-wrap">
            <table className="t">
              <thead>
                <tr>
                  <th>نام پزشک</th>
                  <th>کد نظام</th>
                  <th>نوبت گذشته</th>
                  <th>نوبت آینده</th>
                  <th>وضعیت</th>
                </tr>
              </thead>
              <tbody>
                {repDoctors.map((d) => (
                  <tr key={d.uuid} style={{ cursor: 'pointer' }} onClick={() => navigate(`/admin/doctors/${d.uuid}`)}>
                    <td><b>{d.name}</b></td>
                    <td style={{ fontFamily: 'monospace' }} className="text-[var(--text-3)]"><span dir="ltr">{d.medical_code ?? '—'}</span></td>
                    <td>{formatNumber(d.past_count)}</td>
                    <td>{d.upcoming_count > 0 ? <span className="badge green">{formatNumber(d.upcoming_count)}</span> : <span className="text-[var(--text-3)]">۰</span>}</td>
                    <td><ActiveBadge active={d.is_active} /></td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        )}
      </div>

      {/* Appointments of this representation */}
      <div className="cp-card p-6 mt-6">
        <div className="flex items-center justify-between mb-4 flex-wrap gap-2">
          <div className="flex items-center gap-2">
            <CalendarDaysIcon className="w-5 h-5 text-[var(--text-3)]" />
            <h2 className="text-sm font-semibold text-[var(--text)]">نوبت‌های این نماینده</h2>
            {!appointmentsQuery.isLoading && <span className="badge blue">{formatNumber(repAppointmentsTotal)}</span>}
          </div>
          <div className="seg">
            <button className={apptScope === 'upcoming' ? 'on' : ''} onClick={() => setApptScope('upcoming')}>آینده</button>
            <button className={apptScope === 'past' ? 'on' : ''} onClick={() => setApptScope('past')}>گذشته</button>
          </div>
        </div>
        {appointmentsQuery.isLoading ? (
          <p className="text-sm text-[var(--text-3)] text-center py-8">در حال بارگذاری…</p>
        ) : repAppointments.length === 0 ? (
          <div className="text-center py-10">
            <CalendarDaysIcon className="w-10 h-10 mx-auto text-[var(--text-3)] mb-2" />
            <p className="text-sm text-[var(--text-3)]">
              {apptScope === 'upcoming' ? 'نوبت آینده‌ای ثبت نشده است' : 'نوبت گذشته‌ای وجود ندارد'}
            </p>
          </div>
        ) : (
          <div className="table-wrap">
            <table className="t">
              <thead>
                <tr>
                  <th>پزشک</th>
                  <th>بیمار</th>
                  <th>زمان</th>
                  <th>وضعیت</th>
                </tr>
              </thead>
              <tbody>
                {repAppointments.map((a) => (
                  <tr key={a.uuid} style={{ cursor: 'pointer' }} onClick={() => navigate(`/admin/doctors/${a.doctor_uuid}`)}>
                    <td><b>{a.doctor_name}</b></td>
                    <td>{a.patient_name ?? '—'}</td>
                    <td><span dir="ltr">{formatDateTime(a.slot_start)}</span></td>
                    <td><span className="badge gray">{a.status}</span></td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        )}
      </div>

      {/* Attach Doctor Modal */}
      <Modal open={attachOpen} title="افزودن پزشک به نماینده"
        onClose={() => { setAttachOpen(false); setAttachSearch(''); }}
        footer={<button onClick={() => { setAttachOpen(false); setAttachSearch(''); }} className="btn ghost sm">بستن</button>}
      >
        <input
          type="text"
          className="input w-full mb-3"
          placeholder="جستجوی پزشک (نام یا موبایل)…"
          value={attachSearch}
          onChange={(e) => setAttachSearch(e.target.value)}
        />
        {unassignedQuery.isLoading ? (
          <p className="text-sm text-[var(--text-3)] text-center py-6">در حال بارگذاری…</p>
        ) : unassignedDoctors.length === 0 ? (
          <p className="text-sm text-[var(--text-3)] text-center py-6">پزشکِ بدون نماینده‌ای یافت نشد</p>
        ) : (
          <div style={{ maxHeight: 360, overflowY: 'auto' }}>
            {unassignedDoctors.map((d) => (
              <div key={d.uuid} className="flex items-center justify-between py-2 border-b border-[var(--border)]">
                <div>
                  <b className="text-sm">{d.name}</b>
                  <div className="text-xs text-[var(--text-3)]" dir="ltr">{d.medical_code ?? d.mobile ?? '—'}</div>
                </div>
                <button className="btn primary sm" disabled={attachMutation.isPending}
                  onClick={() => attachMutation.mutate(d.uuid)}>افزودن</button>
              </div>
            ))}
          </div>
        )}
      </Modal>

      {/* Edit Modal */}
      <Modal open={editOpen} title="ویرایش نماینده"
        onClose={() => setEditOpen(false)}
        footer={
          <>
            <button onClick={() => setEditOpen(false)}
              className="btn ghost sm">
              لغو
            </button>
            <button
              onClick={() => updateMutation.mutate({
                full_name: formData.full_name,
                city_id: formData.city_id ? parseInt(formData.city_id) : null,
                mobile_number: formData.mobile_number || null,
                commission_percent: parseFloat(formData.commission_percent) || rep.commission_percent,
              } as any)}
              disabled={updateMutation.isPending}
              className="btn primary sm">
              {updateMutation.isPending ? 'در حال ذخیره...' : 'ذخیره'}
            </button>
          </>
        }
      >
        <div className="space-y-4">
          <div>
            <label className="">نام کامل</label>
            <input value={formData.full_name} onChange={(e) => setFormData((p) => ({ ...p, full_name: e.target.value }))}
              className="cp-input h-11" />
          </div>
          <div>
            <label className="">شهر</label>
            <SearchableSelect
              options={cities.map(c => ({ value: String(c.id), label: c.name }))}
              value={formData.city_id || null}
              onChange={(v) => setFormData(p => ({ ...p, city_id: v ? String(v) : '' }))}
              placeholder="انتخاب شهر"
              isClearable
            />
          </div>
          <div>
            <label className="">موبایل</label>
            <input value={formData.mobile_number} onChange={(e) => setFormData((p) => ({ ...p, mobile_number: e.target.value }))}
              dir="ltr" className="cp-input h-11" />
          </div>
          <div>
            <label className="">درصد کمیسیون</label>
            <input value={formData.commission_percent} onChange={(e) => setFormData((p) => ({ ...p, commission_percent: digitsOnly(e.target.value, 3) }))}
              type="text" inputMode="numeric" dir="ltr"
              className="cp-input h-11" />
          </div>
        </div>
      </Modal>

      <ConfirmDialog
        open={deleteOpen}
        title="حذف نماینده"
        message={`آیا از حذف نماینده "${name}" اطمینان دارید؟`}
        confirmLabel="حذف"
        danger
        loading={deleteMutation.isPending}
        onConfirm={() => deleteMutation.mutate()}
        onCancel={() => setDeleteOpen(false)}
      />
    </div>
  );
}
