import { useState } from 'react';
import { useMutation, useQueryClient } from '@tanstack/react-query';
import { ChevronDownIcon } from '@heroicons/react/24/outline';
import { toast } from 'sonner';
import { api } from '../../lib/api';
import { formatRial } from '../../lib/utils';
import type { SessionCardData } from '../SessionServiceCard';
import SearchableSelect from '../ui/SearchableSelect';
import PersianDateInput from '../ui/PersianDateInput';
import { Step2PaymentCard, FilesServiceBalanceWallet, TrashRed } from '../icons/FilesServiceIcons';

/** روش‌های پرداخت — همان چهار گزینه‌ی آکاردئون tauri Step2Payment. */
const METHODS: { key: string; label: string }[] = [
  { key: 'wallet', label: 'پرداخت از طریق کیف پول' },
  { key: 'pos',    label: 'پرداخت از طریق کارت خوان' },
  { key: 'cash',   label: 'پرداخت نقدی' },
  { key: 'card',   label: 'کارت به کارت' },
];
export const METHOD_LABELS: Record<string, string> = {
  wallet: 'پرداخت از کیف پول', pos: 'پرداخت کارتخوان', cash: 'پرداخت نقدی', card: 'کارت به کارت',
};

const todayISO = () => new Date().toISOString().slice(0, 10);
/** YYYY-MM-DD → unix (ظهر همان روز تا با هر timezone یک روز بماند) */
const isoToUnix = (iso: string) => Math.floor(new Date(`${iso}T12:00:00`).getTime() / 1000);

const fieldLabel: React.CSSProperties = { fontSize: 14, color: '#6B7280', marginBottom: 8, display: 'block' };
const primaryBtn: React.CSSProperties = { background: '#5559CE', color: '#fff', border: 'none', borderRadius: 4, height: 46, fontSize: 14, fontWeight: 500, cursor: 'pointer' };
const ghostBtn: React.CSSProperties = { background: 'transparent', color: '#5559CE', border: '1px solid #5559CE', borderRadius: 4, height: 46, fontSize: 14, fontWeight: 500, cursor: 'pointer' };

interface Props {
  recordUuid: string;
  session: SessionCardData;
  walletBalance: number;
  onContinue: () => void;
  onCancel: () => void;
}

/**
 * گام «پرداخت» — پورت tauri Step2Payment با دیتای واقعی:
 * تخفیف تسویه (PATCH /session/{uuid}) + پرداخت چندتکه (POST /session/{uuid}/payments).
 * بین NewSessionPage (ویزارد سه‌گامه) و SessionPaymentPage (دوگامه) مشترک است.
 */
export default function PaymentStep({ recordUuid, session, walletBalance, onContinue, onCancel }: Props) {
  const qc = useQueryClient();
  const sessionUuid = session.uuid;

  const [discountType, setDiscountType] = useState('');
  const [discountValue, setDiscountValue] = useState('');
  const [paymentDate, setPaymentDate] = useState(todayISO());
  const [expanded, setExpanded] = useState<string | null>(null);
  const [amount, setAmount] = useState('');

  const invalidate = () => {
    qc.invalidateQueries({ queryKey: ['patient-sessions', recordUuid] });
    qc.invalidateQueries({ queryKey: ['patient-wallet', recordUuid] });
  };

  const discountMut = useMutation({
    mutationFn: (body: object) => api.patch(`/api/v1/session/${sessionUuid}`, body),
    onSuccess: () => { invalidate(); toast.success('تخفیف به‌روزرسانی شد'); },
    onError: (e: Error) => toast.error(e.message),
  });

  const payMut = useMutation({
    mutationFn: (body: object) => api.post(`/api/v1/session/${sessionUuid}/payments`, body),
    onSuccess: () => { invalidate(); setAmount(''); toast.success('پرداخت ثبت شد'); },
    onError: (e: Error) => toast.error(e.message),
  });

  const applyDiscount = () => {
    if (!discountType || !discountValue) return;
    discountMut.mutate({ discount_type: discountType, discount_value: Number(discountValue) });
  };
  const removeDiscount = () => {
    setDiscountType(''); setDiscountValue('');
    discountMut.mutate({ discount_type: null });
  };
  const submitPayment = (method: string) => {
    if (!amount) return;
    payMut.mutate({ method, amount_rials: Number(amount), paid_at: isoToUnix(paymentDate) });
  };

  const finalPrice = session.final_price_rials ?? 0;
  const discountRials = session.discount_rials ?? 0;
  const debt = session.patient_debt_rials ?? 0;
  const payments = session.payments ?? [];

  return (
    <>
      {/* هزینه سرویس */}
      <div style={{ display: 'flex', alignItems: 'center', gap: 12, margin: '12px 0 16px' }}>
        <Step2PaymentCard />
        <span style={{ fontSize: 14, color: '#F97316', fontWeight: 700 }}>هزینه سرویس:</span>
        <span className="dark:text-[#D7D8ED]" style={{ fontSize: 14, fontWeight: 700, color: '#525252' }}>{formatRial(finalPrice)}</span>
      </div>

      {/* تخفیف — port of tauri DiscountInput (نوع + مقدار + ثبت) */}
      <span style={fieldLabel}>تخفیف:</span>
      <div style={{ display: 'flex', alignItems: 'stretch', gap: 8 }}>
        <div className="bg-white dark:bg-[#222433] dark:border-[#35343D]" style={{ flex: 1, minWidth: 0, display: 'flex', alignItems: 'center', border: '1px solid #e0e0e0', borderRadius: 8, marginBottom: 16 }}>
          <div style={{ minWidth: 150, borderLeft: '1px solid #e0e0e0', padding: '0 4px' }}>
            <SearchableSelect
              options={[{ value: 'percent', label: 'درصدی' }, { value: 'fixed', label: 'مبلغ ثابت' }]}
              value={discountType}
              onChange={(v) => setDiscountType(v ? String(v) : '')}
              placeholder="مبلغ تخفیف"
            />
          </div>
          <input
            type="number"
            min={0}
            dir="ltr"
            placeholder="مقدار تخفیف را وارد نمایید"
            value={discountValue}
            onChange={(e) => setDiscountValue(e.target.value)}
            style={{ flex: 1, minWidth: 0, height: 40, padding: '0 12px', fontSize: 13, border: 'none', outline: 'none', background: 'transparent', color: 'inherit' }}
          />
          <button
            type="button"
            onClick={applyDiscount}
            disabled={discountMut.isPending || !discountType || !discountValue}
            style={{ height: 40, minWidth: 72, border: 'none', borderRadius: '0 4px 4px 0', background: '#E8EBFF', color: '#3B3F9F', fontSize: 13, fontWeight: 600, cursor: 'pointer' }}
          >
            ثبت
          </button>
        </div>
        <div
          onClick={removeDiscount}
          style={{ display: 'flex', alignItems: 'center', gap: 4, flexShrink: 0, cursor: 'pointer', marginBottom: 16, minWidth: 120, justifyContent: 'center' }}
        >
          <TrashRed color="#EF4444" size={18} />
          <span className="dark:text-[#A1A1A1]" style={{ fontSize: 13, color: '#6B7280' }}>حذف تخفیف</span>
        </div>
      </div>

      <p style={{ fontSize: 13, marginBottom: 16 }}>
        <span className="dark:text-[#D7D8ED]" style={{ color: '#2f2f2f' }}>مبلغ تخفیف:</span>{' '}
        <span style={{ color: '#D32F2F' }}>{formatRial(discountRials)}</span>
      </p>

      {/* تاریخ پرداخت */}
      <span className="dark:text-[#A1A1A1]" style={{ ...fieldLabel, color: '#3b3b3b' }}>تاریخ پرداخت</span>
      <PersianDateInput value={paymentDate} onChange={setPaymentDate} />

      {/* روش‌های پرداخت */}
      <span className="dark:text-[#A1A1A1]" style={{ ...fieldLabel, color: '#3b3b3b', marginTop: 24 }}>انتخاب روش های پرداخت:</span>
      <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
        <div style={{ display: 'flex', gap: 4 }}>
          <FilesServiceBalanceWallet />
          <span style={{ fontSize: 14, color: '#F97316', marginBottom: 8, fontWeight: 600 }}>موجودی کیف پول:</span>
        </div>
        <span className="dark:text-[#D7D8ED]" style={{ fontSize: 14, fontWeight: 600, color: '#525252', marginBottom: 4 }}>{formatRial(walletBalance)}</span>
      </div>

      {/* آکاردئون چهار روش — باز شدن هر روش: مبلغ + ثبت پرداخت */}
      <div style={{ marginTop: 8 }}>
        {METHODS.map((m) => {
          const open = expanded === m.key;
          return (
            <div key={m.key} className="dark:border-[#35343D]" style={{ borderBottom: '1px solid #e0e0e0' }}>
              <button
                type="button"
                aria-expanded={open}
                onClick={() => { setExpanded(open ? null : m.key); setAmount(''); }}
                style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', width: '100%', padding: '14px 4px', background: 'transparent', border: 'none', cursor: 'pointer' }}
              >
                <span className="dark:text-[#D7D8ED]" style={{ fontSize: 14, fontWeight: 600, color: '#111827' }}>{m.label}</span>
                <ChevronDownIcon style={{ width: 16, color: '#6B7280', transform: open ? 'rotate(180deg)' : undefined, transition: 'transform .15s' }} />
              </button>
              {open && (
                <div style={{ display: 'flex', gap: 8, padding: '0 4px 14px' }}>
                  <input
                    type="number"
                    min={1}
                    dir="ltr"
                    className="input"
                    placeholder="مبلغ (تومان)"
                    value={amount}
                    onChange={(e) => setAmount(e.target.value)}
                    style={{ flex: 1, height: 40 }}
                  />
                  <button
                    type="button"
                    onClick={() => submitPayment(m.key)}
                    disabled={payMut.isPending || !amount}
                    style={{ ...primaryBtn, height: 40, padding: '0 20px', borderRadius: 8 }}
                  >
                    ثبت پرداخت
                  </button>
                </div>
              )}
            </div>
          );
        })}
      </div>

      {/* پرداخت شده‌ها — باکس خط‌چین tauri */}
      <div className="dark:border-[#404040] dark:bg-[#222433]" style={{ border: '1px dashed #C7C9F4', borderRadius: 8, padding: 16, marginTop: 16, background: '#fff' }}>
        <span className="dark:text-[#6A6AD9]" style={{ fontSize: 16, fontWeight: 500, color: '#636bd4', display: 'block', marginBottom: 16 }}>پرداخت شده ها:</span>
        {payments.length === 0 ? (
          <span className="dark:text-[#A1A1A1]" style={{ fontSize: 13, color: '#6B7280' }}>پرداختی ثبت نشده است</span>
        ) : (
          <div style={{ display: 'flex', flexDirection: 'column', gap: 8 }}>
            {payments.map((p) => (
              <div key={p.uuid} className="dark:border-[#404040]" style={{ display: 'flex', alignItems: 'center', gap: 32, padding: '4px 0', borderBottom: '1px solid #e0e0e0' }}>
                <span style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
                  <span className="dark:bg-[#6A6AD9]" style={{ width: 8, height: 8, borderRadius: '50%', background: '#636bd4' }} />
                  <span className="dark:text-[#D7D8ED]" style={{ fontSize: 14, color: '#111827' }}>{METHOD_LABELS[p.method] ?? p.method}</span>
                </span>
                <span className="dark:text-[#D7D8ED]" style={{ flex: 1, textAlign: 'left', fontSize: 14, color: '#111827' }}>مبلغ : {formatRial(p.amount_rials)}</span>
              </div>
            ))}
          </div>
        )}
        <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'flex-end', gap: 8, marginTop: 16 }}>
          <span className="dark:text-[#D7D8ED]" style={{ fontSize: 14, fontWeight: 500, color: '#111827' }}>مبلغ باقی‌مانده :</span>
          <span className="dark:text-[#FF5252]" style={{ fontSize: 14, fontWeight: 600, color: '#d32f2f' }}>{formatRial(debt)}</span>
        </div>
      </div>

      {/* ACTIONS */}
      <div style={{ display: 'flex', gap: 8, marginTop: 16, width: '100%', justifyContent: 'flex-end' }}>
        <div style={{ width: '50%', display: 'flex', gap: 4 }}>
          <button type="button" style={{ ...ghostBtn, flex: 1 }} onClick={onCancel}>انصراف</button>
          <button type="button" style={{ ...primaryBtn, flex: 1 }} onClick={onContinue}>ثبت و ادامه</button>
        </div>
      </div>
    </>
  );
}
