import { cancelPayment } from '@_api/payment/paymentAPI';
import type { PaymentRetrieveResponse } from '@_api/payment/PaymentTypes';
import { cancelReservation, fetchDetailById, fetchSummaryByMember } from '@_api/reservation/reservationAPIV2';
import type { ReservationDetail, ReservationSummaryRetrieveResponse } from '@_api/reservation/reservationTypesV2';
import React, { useEffect, useState } from 'react';
import '../../css/my-reservation-v2.css';

const formatDisplayDateTime = (dateTime: any): string => {
  let date: Date;

  if (typeof dateTime === 'string') {
    // ISO 문자열 형식 처리 (LocalDateTime, OffsetDateTime 모두 포함)
    date = new Date(dateTime);
  } else if (typeof dateTime === 'number') {
    // Unix 타임스탬프(초) 형식 처리
    date = new Date(dateTime * 1000);
  } else if (Array.isArray(dateTime) && dateTime.length >= 6) {
    // 배열 형식 처리: [year, month, day, hour, minute, second, nanosecond?]
    const year = dateTime[0];
    const month = dateTime[1] - 1; // JS Date의 월은 0부터 시작
    const day = dateTime[2];
    const hour = dateTime[3];
    const minute = dateTime[4];
    const second = dateTime[5];
    const millisecond = dateTime.length > 6 ? Math.floor(dateTime[6] / 1000000) : 0;
    date = new Date(year, month, day, hour, minute, second, millisecond);
  } else {
    return '유효하지 않은 날짜 형식';
  }

  if (isNaN(date.getTime())) {
    return '유효하지 않은 날짜';
  }

  const options: Intl.DateTimeFormatOptions = {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
    hour: 'numeric',
    minute: 'numeric',
    hour12: true,
    second: 'numeric'
  };
  return new Intl.DateTimeFormat('ko-KR', options).format(date);
};

const formatCardDateTime = (dateStr: string, timeStr: string): string => {
  const date = new Date(`${dateStr}T${timeStr}`);
  const currentYear = new Date().getFullYear();
  const reservationYear = date.getFullYear();

  const days = ['일', '월', '화', '수', '목', '금', '토'];
  const dayOfWeek = days[date.getDay()];
  const month = date.getMonth() + 1;
  const day = date.getDate();
  let hours = date.getHours();
  const minutes = date.getMinutes();
  const ampm = hours >= 12 ? '오후' : '오전';
  hours = hours % 12;
  hours = hours ? hours : 12;

  let datePart = '';
  if (currentYear === reservationYear) {
    datePart = `${month}월 ${day}일(${dayOfWeek})`;
  } else {
    datePart = `${reservationYear}년 ${month}월 ${day}일(${dayOfWeek})`;
  }

  let timePart = `${ampm} ${hours}시`;
  if (minutes !== 0) {
    timePart += ` ${minutes}분`;
  }

  return `${datePart} ${timePart}`;
};

// --- Cancellation View Component ---
const CancellationView: React.FC<{
  reservation: ReservationDetail;
  onCancelSubmit: (reason: string) => void;
  onBack: () => void;
  isCancelling: boolean;
}> = ({ reservation, onCancelSubmit, onBack, isCancelling }) => {
  const [reason, setReason] = useState('');

  const handleSubmit = () => {
    if (!reason.trim()) {
      alert('취소 사유를 입력해주세요.');
      return;
    }
    onCancelSubmit(reason);
  };

  return (
    <div className="cancellation-view-v2">
      <h3>취소 정보 확인</h3>
      <div className="cancellation-summary-v2">
        <p><strong>테마:</strong> {reservation.themeName}</p>
        <p><strong>신청 일시:</strong> {formatDisplayDateTime(reservation.applicationDateTime)}</p>
        <p><strong>결제 금액:</strong> {reservation.payment.totalAmount.toLocaleString()}원</p>
      </div>
      <textarea
        value={reason}
        onChange={(e) => setReason(e.target.value)}
        placeholder="취소 사유를 입력해주세요."
        className="cancellation-reason-textarea-v2"
        rows={4}
      />
      <div className="modal-actions-v2">
        <button onClick={onBack} className="back-button-v2" disabled={isCancelling}>뒤로가기</button>
        <button onClick={handleSubmit} className="cancel-submit-button-v2" disabled={isCancelling}>
          {isCancelling ? '취소 중...' : '취소 요청'}
        </button>
      </div>
    </div>
  );
};


const ReservationDetailView: React.FC<{
  reservation: ReservationDetail;
  onGoToCancel: () => void;
}> = ({ reservation, onGoToCancel }) => {

  const renderPaymentDetails = (payment: PaymentRetrieveResponse) => {
    const { detail } = payment;

    switch (detail.type) {
      case 'CARD':
        return (
          <>
            <p><strong>주문 ID:</strong> {payment.orderId}</p>
            {payment.totalAmount === detail.amount ? (
              <p><strong>결제 금액:</strong> {payment.totalAmount.toLocaleString()}원</p>
            ) : (
              <>
                <p><strong>전체 금액:</strong> {payment.totalAmount.toLocaleString()}원</p>
                <p><strong>승인 금액:</strong> {detail.amount.toLocaleString()}원</p>
                {detail.easypayDiscountAmount && (
                  <p><strong>할인 금액:</strong> {detail.easypayDiscountAmount.toLocaleString()}원</p>
                )}
              </>
            )}
            <p><strong>결제 수단:</strong> {detail.easypayProviderName ? `간편결제 / ${detail.easypayProviderName}` : '카드'}</p>
            <p><strong>카드사 / 구분:</strong> {detail.issuerCode}({detail.ownerType}) / {detail.cardType}</p>
            <p><strong>카드 번호:</strong> {detail.cardNumber}</p>
            <p><strong>할부 방식:</strong> {detail.installmentPlanMonths === 0 ? '일시불' : `${detail.installmentPlanMonths}개월`}</p>
            <p><strong>승인 번호:</strong> {detail.approvalNumber}</p>
          </>
        );
      case 'BANK_TRANSFER':
        return (
          <>
            <p><strong>결제 수단:</strong> 계좌이체</p>
            <p><strong>은행:</strong> {detail.bankName}</p>
          </>
        );
      case 'EASYPAY_PREPAID':
        return (
          <>
            <p><strong>결제 수단:</strong> 간편결제 / {detail.providerName}</p>
            <p><strong>총 금액 :</strong> {payment.totalAmount.toLocaleString()}원</p>
            <p><strong>결제 금액:</strong> {detail.amount.toLocaleString()}원</p>
            {detail.discountAmount > 0 && <p><strong>포인트:</strong> {detail.discountAmount.toLocaleString()}원</p>}
          </>
        );
      default:
        return <p><strong>결제 수단:</strong> {payment.method}</p>;
    }
  };

  return (
    <>
      <div className="modal-section-v2">
        <h3>예약 정보</h3>
        <p><strong>예약 테마:</strong> {reservation.themeName}</p>
        <p><strong>이용 예정일:</strong> {formatCardDateTime(reservation.date, reservation.startAt)}</p>
        <p><strong>예약자 이름:</strong> {reservation.member.name}</p>
        <p><strong>예약자 이메일:</strong> {reservation.member.email}</p>
        <p><strong>예약 신청 일시:</strong> {formatDisplayDateTime(reservation.applicationDateTime)}</p>
      </div>
      <div className="modal-section-v2">
        <h3>결제 정보</h3>
        {/* <p><strong>결제금액:</strong> {reservation.payment.totalAmount.toLocaleString()}원</p> */}
        {renderPaymentDetails(reservation.payment)}
        <p><strong>결제 승인 일시:</strong> {formatDisplayDateTime(reservation.payment.approvedAt)}</p>
      </div>
      {reservation.payment.cancellation && (
        <div className="modal-section-v2 cancellation-section-v2">
          <h3>취소 정보</h3>
          <p><strong>취소 요청 일시:</strong> {formatDisplayDateTime(reservation.payment.cancellation.cancellationRequestedAt)}</p>
          <p><strong>환불 완료 일시:</strong> {formatDisplayDateTime(reservation.payment.cancellation.cancellationApprovedAt)}</p>
          <p><strong>취소 사유:</strong> {reservation.payment.cancellation.cancelReason}</p>
          <p><strong>취소 요청자:</strong> {reservation.payment.cancellation.canceledBy == reservation.member.id ? '회원 본인' : '관리자'}</p>
        </div>
      )}
      {reservation.payment.status !== 'CANCELED' && (
        <div className="modal-actions-v2">
          <button onClick={onGoToCancel} className="cancel-button-v2">예약 취소하기</button>
        </div>
      )}
    </>
  );
};

// --- Main Page Component ---
const MyReservationPageV2: React.FC = () => {
  const [reservations, setReservations] = useState<ReservationSummaryRetrieveResponse[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const [selectedReservation, setSelectedReservation] = useState<ReservationDetail | null>(null);
  const [isModalOpen, setIsModalOpen] = useState(false);
  const [isDetailLoading, setIsDetailLoading] = useState(false);
  const [detailError, setDetailError] = useState<string | null>(null);

  const [modalView, setModalView] = useState<'detail' | 'cancel'>('detail');
  const [isCancelling, setIsCancelling] = useState(false);

  const loadReservations = async () => {
    try {
      setIsLoading(true);
      const data = await fetchSummaryByMember();
      setReservations(data.reservations);
      setError(null);
    } catch (err) {
      setError('예약 목록을 불러오는 데 실패했습니다.');
    } finally {
      setIsLoading(false);
    }
  };

  useEffect(() => {
    loadReservations();
  }, []);

  const handleShowDetail = async (id: string, themeName: string, date: string, time: string) => {
    try {
      setIsDetailLoading(true);
      setDetailError(null);
      setModalView('detail');
      const detailData = await fetchDetailById(id);
      setSelectedReservation({
        id: detailData.id,
        themeName: themeName,
        date: date,
        startAt: time,
        member: detailData.member,
        applicationDateTime: detailData.applicationDateTime,
        payment: detailData.payment
      });
      setIsModalOpen(true);
    } catch (err) {
      setDetailError('예약 상세 정보를 불러오는 데 실패했습니다.');
    } finally {
      setIsDetailLoading(false);
    }
  };

  const handleCloseModal = () => {
    setIsModalOpen(false);
    setSelectedReservation(null);
  };

  const handleCancelSubmit = async (reason: string) => {
    if (!selectedReservation) return;

    if (!window.confirm('정말 취소하시겠어요?')) {
      return;
    }

    try {
      setIsCancelling(true);
      setDetailError(null);
      await cancelReservation(selectedReservation.id, reason);
      cancelPayment({ reservationId: selectedReservation.id, cancelReason: reason });
      alert('예약을 취소했어요. 결제 취소까지는 3-5일 정도 소요될 수 있어요.');
      handleCloseModal();
      await loadReservations(); // Refresh the list
    } catch (err) {
      setDetailError(err instanceof Error ? err.message : '예약 취소에 실패했습니다.');
    } finally {
      setIsCancelling(true);
    }
  };
  console.log("reservations=", reservations);

  return (
    <div className="my-reservation-container-v2">
      <h1>내 예약 V2</h1>

      {isLoading && <p>목록 로딩 중...</p>}
      {error && <p className="error-message-v2">{error}</p>}

      {!isLoading && !error && (
        <div className="reservation-list-v2">
          {reservations.map((res) => (
            <div key={res.id} className={`reservation-summary-card-v2 status-${res.status.toString().toLowerCase()}`}>
              <div className="summary-details-v2">
                <h3 className="summary-theme-name-v2">{res.themeName}</h3>
                <p className="summary-datetime-v2">{formatCardDateTime(res.date, res.startAt)}</p>
              </div>
              <button
                onClick={() => handleShowDetail(res.id, res.themeName, res.date, res.startAt)}
                disabled={isDetailLoading}
                className="detail-button-v2"
              >
                {isDetailLoading && selectedReservation?.id === res.id ? '로딩중...' : '상세보기'}
              </button>
            </div>
          ))}
        </div>
      )}

      {isModalOpen && selectedReservation && (
        <div className="modal-overlay-v2" onClick={handleCloseModal}>
          <div className="modal-content-v2" onClick={(e) => e.stopPropagation()}>
            <button className="modal-close-button-v2" onClick={handleCloseModal}>×</button>
            <h2>{modalView === 'detail' ? '예약 상세 정보' : '예약 취소'}</h2>
            {detailError && <p className="error-message-v2">{detailError}</p>}

            {modalView === 'detail' ? (
              <ReservationDetailView
                reservation={selectedReservation}
                onGoToCancel={() => setModalView('cancel')}
              />
            ) : (
              <CancellationView
                reservation={selectedReservation}
                onCancelSubmit={handleCancelSubmit}
                onBack={() => setModalView('detail')}
                isCancelling={isCancelling}
              />
            )}
          </div>
        </div>
      )}
    </div>
  );
};

export default MyReservationPageV2;