import { useEffect, useState } from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useNavigate, useParams, Link } from 'react-router-dom';
import { ChevronRightIcon } from '@heroicons/react/24/outline';
import { toast } from 'sonner';
import { api } from '../lib/api';
import type { ApiResponse } from '../lib/api';
import PersianDateInput from '../components/ui/PersianDateInput';
import PriceInput from '../components/ui/PriceInput';
import { WalletChargeLink } from '../components/AppointmentActions';

interface Option { uuid: string; name?: string; full_name?: string }

interface AppointmentDetail {
  uuid: string; slot_start: number; slot_end: number; status: string; version: number;
  note?: string | null;
  patient_mobile?: string | null;
  user?: { uuid: string; mobile: string } | null;
  deposit_required?: boolean; deposit_amount_rials?: number | null;
  service_section?: Option | null; service_item?: Option | null; staff?: Option | null;
}

const isoDate = (ts: number) => {
  const d = new Date(ts * 1000);
  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
};
const isoTime = (ts: number) => {
  const d = new Date(ts * 1000);
  return `${String(d.getHours()).padStart(2, '0')}:${String(d.getMinutes()).padStart(2, '0')}`;
};
const toEpoch = (date: string, time: string) => Math.floor(new Date(`${date}T${time || '00:00'}`).getTime() / 1000);

/** ویرایش نوبت (Figma edit.pdf) — full-page edit of service specs, timing, deposit, status and notes. */
export default function AppointmentEditPage() {
  const { uuid = '' } = useParams();
  const navigate = useNavigate();
  const qc = useQueryClient();

  const { data, isLoading } = useQuery<ApiResponse<{ data: AppointmentDetail }>>({
    queryKey: ['appointment-edit', uuid],
    queryFn: () => api.get(`/api/v1/appointment/${uuid}`),
    enabled: !!uuid,
  });
  const a = data?.data?.data;

  const [sectionUuid, setSectionUuid] = useState('');
  const [itemUuid, setItemUuid] = useState('');
  const [staffUuid, setStaffUuid] = useState('');
  const [date, setDate] = useState('');
  const [start, setStart] = useState('');
  const [end, setEnd] = useState('');
  const [depositRequired, setDepositRequired] = useState(false);
  const [depositRials, setDepositRials] = useState(0);
  const [status, setStatus] = useState('');
  const [note, setNote] = useState('');

  // hydrate once the appointment arrives
  useEffect(() => {
    if (!a) return;
    setSectionUuid(a.service_section?.uuid ?? '');
    setItemUuid(a.service_item?.uuid ?? '');
    setStaffUuid(a.staff?.uuid ?? '');
    setDate(isoDate(a.slot_start));
    setStart(isoTime(a.slot_start));
    setEnd(isoTime(a.slot_end));
    setDepositRequired(!!a.deposit_required);
    setDepositRials(a.deposit_amount_rials ?? 0);
    setStatus(a.status);
    setNote(a.note ?? '');
  }, [a]);

  const sectionsQ = useQuery<ApiResponse<Option[]>>({ queryKey: ['service-sections'], queryFn: () => api.get('/api/v1/service-sections') });
  const itemsQ = useQuery<ApiResponse<Option[]>>({
    queryKey: ['service-items', sectionUuid],
    queryFn: () => api.get(`/api/v1/service-items/${sectionUuid}`),
    enabled: !!sectionUuid,
  });
  const staffQ = useQuery<ApiResponse<Option[]>>({ queryKey: ['staff-list'], queryFn: () => api.get('/api/v1/staff') });

  const save = useMutation({
    mutationFn: () => api.patch(`/api/v1/appointment/${uuid}`, {
      slot_start: toEpoch(date, start),
      slot_end: toEpoch(date, end),
      service_section_uuid: sectionUuid,
      service_item_uuid: itemUuid,
      staff_uuid: staffUuid,
      deposit_required: depositRequired,
      deposit_amount_rials: depositRequired ? depositRials : null,
      note,
      ...(status !== a?.status ? { status } : {}),
      version: a?.version,
    }),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ['appointments'] });
      toast.success('نوبت به‌روزرسانی شد');
      navigate('/admin/appointments');
    },
    onError: (e: any) => toast.error(e.message || 'خطا در ذخیره اطلاعات'),
  });

  const label = { fontSize: 12.5, color: 'var(--text-3)' } as const;
  const sel = { width: '100%', height: 38, borderRadius: 'var(--r-sm)', border: '1px solid var(--border)', background: 'var(--surface)', fontSize: 13, fontFamily: 'inherit', padding: '0 10px' } as const;

  if (isLoading || !a) return <div style={{ padding: 24, color: 'var(--text-3)', fontSize: 13 }}>در حال بارگذاری...</div>;

  const statusOptions: [string, string][] = [
    ['pending', 'ثبت شده'], ['confirmed', 'قطعی شده'], ['following_up', 'در حال پیگیری'],
    ['salon', 'سالن'], ['completed', 'ویزیت شده'], ['cancelled_by_doctor', 'لغو شده'],
  ];

  return (
    <div className="fade-in" style={{ maxWidth: 860, margin: '0 auto' }}>
      <div style={{ display: 'flex', justifyContent: 'flex-end', marginBottom: 14 }}>
        <Link to="/admin/appointments" className="btn sm ghost" style={{ color: 'var(--text-2)' }}>
          <ChevronRightIcon style={{ width: 16 }} /> بازگشت
        </Link>
      </div>

      <div style={{ background: 'var(--surface)', border: '1px solid var(--border)', borderRadius: 'var(--r-lg)', padding: 22 }}>
        <div style={{ fontSize: 14, fontWeight: 700, marginBottom: 12 }}>مشخصات سرویس:</div>
        <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(200px, 1fr))', gap: 12, marginBottom: 18 }}>
          <div>
            <label style={label}>بخش</label>
            <select aria-label="بخش" style={{ ...sel, marginTop: 6 }} value={sectionUuid} onChange={e => { setSectionUuid(e.target.value); setItemUuid(''); }}>
              <option value="">انتخاب بخش</option>
              {(sectionsQ.data?.data ?? []).map(o => <option key={o.uuid} value={o.uuid}>{o.name}</option>)}
            </select>
          </div>
          <div>
            <label style={label}>سرویس</label>
            <select aria-label="سرویس" style={{ ...sel, marginTop: 6 }} value={itemUuid} onChange={e => setItemUuid(e.target.value)} disabled={!sectionUuid}>
              <option value="">انتخاب سرویس</option>
              {(itemsQ.data?.data ?? []).map(o => <option key={o.uuid} value={o.uuid}>{o.name}</option>)}
            </select>
          </div>
          <div>
            <label style={label}>پرسنل</label>
            <select aria-label="پرسنل" style={{ ...sel, marginTop: 6 }} value={staffUuid} onChange={e => setStaffUuid(e.target.value)}>
              <option value="">انتخاب پرسنل</option>
              {(staffQ.data?.data ?? []).map(o => <option key={o.uuid} value={o.uuid}>{o.full_name}</option>)}
            </select>
          </div>
        </div>

        <div style={{ fontSize: 14, fontWeight: 700, marginBottom: 12 }}>زمان نوبت:</div>
        <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(160px, 1fr))', gap: 12, marginBottom: 18 }}>
          <div>
            <label style={label}>انتخاب تاریخ</label>
            <div style={{ marginTop: 6 }}><PersianDateInput value={date} onChange={setDate} /></div>
          </div>
          <div>
            <label style={label}>ساعت شروع</label>
            <div className="field" style={{ marginTop: 6 }}><input aria-label="ساعت شروع" type="time" value={start} onChange={e => setStart(e.target.value)} dir="ltr" /></div>
          </div>
          <div>
            <label style={label}>ساعت پایان</label>
            <div className="field" style={{ marginTop: 6 }}><input aria-label="ساعت پایان" type="time" value={end} onChange={e => setEnd(e.target.value)} dir="ltr" /></div>
          </div>
        </div>

        <div style={{ fontSize: 14, fontWeight: 700, marginBottom: 12 }}>بیعانه:</div>
        <div style={{ display: 'flex', alignItems: 'center', gap: 16, flexWrap: 'wrap', marginBottom: 18 }}>
          <label style={{ display: 'inline-flex', alignItems: 'center', gap: 8, fontSize: 13, cursor: 'pointer' }}>
            <input type="checkbox" checked={depositRequired} onChange={e => setDepositRequired(e.target.checked)} />
            بیعانه مورد نیاز است.
          </label>
          {depositRequired && (
            <>
              <div style={{ minWidth: 220 }}>
                <label style={label}>مبلغ بیعانه (تومان)</label>
                <div style={{ marginTop: 6 }}><PriceInput value={depositRials} onChange={setDepositRials} /></div>
              </div>
              <WalletChargeLink mobile={a.patient_mobile || a.user?.mobile || ''} />
            </>
          )}
        </div>

        <div style={{ maxWidth: 320, marginBottom: 18 }}>
          <label style={label}>انتخاب وضعیت</label>
          <select aria-label="وضعیت" style={{ ...sel, marginTop: 6 }} value={status} onChange={e => setStatus(e.target.value)}>
            {statusOptions.map(([v, l]) => <option key={v} value={v}>{l}</option>)}
          </select>
        </div>

        <label style={label}>توضیحات</label>
        <div className="field" style={{ height: 'auto', margin: '6px 0 18px' }}>
          <textarea value={note} onChange={e => setNote(e.target.value)} rows={4} placeholder="توضیحات"
            style={{ width: '100%', border: 'none', background: 'transparent', fontFamily: 'inherit', resize: 'vertical' }} />
        </div>

        <button className="btn primary" disabled={!date || !start || !end || save.isPending} onClick={() => save.mutate()}>
          ثبت اطلاعات
        </button>
      </div>
    </div>
  );
}