@Service
public class TicketChangeService {

    @Autowired
    private TicketRepository ticketRepository;
    
    @Autowired
    private PaymentService paymentService;

    /**
     * 處理退票操作
     * @param ticketId 票據(jù)ID
     */
    public void processRefund(Long ticketId) {
        Ticket ticket = ticketRepository.findById(ticketId)
                .orElseThrow(() -> new IllegalArgumentException("無效的票據(jù)ID"));
        
        if (ticket.canBeRefunded()) {
            // 計算退款金額，可能包括手續(xù)費等邏輯
            BigDecimal refundAmount = calculateRefundAmount(ticket);
            // 執(zhí)行退款操作
            paymentService.refund(ticket.getUserId(), refundAmount);
            // 更新票據(jù)狀態(tài)為已退票
            ticket.setStatus(TicketStatus.REFUNDED);
            ticketRepository.save(ticket);
        } else {
            throw new IllegalStateException("該票據(jù)不能退票");
        }
    }

    /**
     * 處理改簽操作
     * @param ticketId 票據(jù)ID
     * @param newTripDetails 新的行程詳情
     */
    public void processChange(Long ticketId, String newTripDetails) {
        Ticket ticket = ticketRepository.findById(ticketId)
                .orElseThrow(() -> new IllegalArgumentException("無效的票據(jù)ID"));
        
        // 檢查新的行程信息是否有效
        if (isValidTrip(newTripDetails)) {
            // 執(zhí)行改簽邏輯，可能包含差價計算等
            BigDecimal extraCost = calculateChangeCost(newTripDetails);
            if (extraCost.compareTo(BigDecimal.ZERO) > 0) {
                // 如果有額外成本，執(zhí)行額外支付
                paymentService.payExtra(ticket.getUserId(), extraCost);
            }
            // 更新票據(jù)信息
            ticket.setTripDetails(newTripDetails);
            ticketRepository.save(ticket);
        } else {
            throw new IllegalArgumentException("無效的新行程信息");
        }
    }
    
    private BigDecimal calculateRefundAmount(Ticket ticket) {
        long daysBeforeDeparture = ChronoUnit.DAYS.between(LocalDate.now(), ticket.getDepartureDate());
        BigDecimal basePrice = ticket.getPrice();
        BigDecimal refundAmount;

        if (daysBeforeDeparture > 30) {
            refundAmount = basePrice.multiply(new BigDecimal("0.90")); // 退還90%
        } else if (daysBeforeDeparture > 7) {
            refundAmount = basePrice.multiply(new BigDecimal("0.50")); // 退還50%
        } else {
            refundAmount = basePrice.multiply(new BigDecimal("0.20")); // 退還20%
        }

        return refundAmount;
    }
    
    // 驗證新行程信息的有效性
 private boolean isValidTrip(String tripDetails) {
    // 假設(shè) tripDetails 的格式為 "Train123-2023-07-20"
    String[] parts = tripDetails.split("-");
    if (parts.length != 3) {
        return false;
    }

    String trainNumber = parts[0];
    LocalDate date;
    try {
        date = LocalDate.parse(parts[1] + "-" + parts[2]);
    } catch (DateTimeParseException e) {
        return false;
    }

    // 假設(shè)存在一個方法來檢查列車編號和日期的有效性
    return checkTrainAndDate(trainNumber, date);
}

  private boolean checkTrainAndDate(String trainNumber, LocalDate date) {
      // 此方法實現(xiàn)依賴于具體的業(yè)務(wù)邏輯，例如檢查數(shù)據(jù)庫中是否存在對應(yīng)的列車安排
      // 為了示例，這里簡單地返回 true
      return true;
  }  

  private boolean isValidTrip(String tripDetails) {
        String[] parts = tripDetails.split("-");
        if (parts.length != 2) {
            return false;
        }

        String trainNumber = parts[0];
        LocalDate date;
        try {
            // 假設(shè)日期格式為 YYYY-MM-DD
            date = LocalDate.parse(parts[1], DateTimeFormatter.ISO_LOCAL_DATE);
        } catch (DateTimeParseException e) {
            return false;
        }

        // 檢查列車編號的有效性
        if (!isTrainNumberValid(trainNumber)) {
            return false;
        }

        // 確保日期不在過去
        if (date.isBefore(LocalDate.now())) {
            return false;
        }

        // 如果有額外的日期條件，如只允許預(yù)訂未來60天內(nèi)的票
        if (date.isAfter(LocalDate.now().plusDays(60))) {
            return false;
        }

        return true;
    }
    
    // 計算改簽差價的示意方法
    private BigDecimal calculateChangeCost(String newTripDetails) {
        // 新旅程價格可能根據(jù)日期等因素有所不同
        // 假設(shè) checkNewTripPrice 方法會根據(jù)新行程信息返回新的價格
        BigDecimal newPrice = checkNewTripPrice(newTripDetails);

        // 假設(shè)原票價為固定價，實際場景中應(yīng)從 Ticket 對象中獲取
        BigDecimal originalPrice = new BigDecimal("500.00");

        // 如果新價格高于原價格，計算差價
        if (newPrice.compareTo(originalPrice) > 0) {
            return newPrice.subtract(originalPrice);
        } else {
            return BigDecimal.ZERO; // 沒有額外成本
        }
    }

    private BigDecimal checkNewTripPrice(String tripDetails) {
        // 這個方法應(yīng)根據(jù)實際業(yè)務(wù)邏輯來實現(xiàn)，此處簡單返回示例新價格
        return new BigDecimal("550.00");
    }
}

@RestController
@RequestMapping("/ticket")
public class TicketController {

    private final TicketChangeService ticketChangeService;

    // 構(gòu)造器注入TicketChangeService
    public TicketController(TicketChangeService ticketChangeService) {
        this.ticketChangeService = ticketChangeService;
    }

    /**
     * 退票接口
     * @param ticketId 票據(jù)ID
     * @return 響應(yīng)實體
     */
    @PostMapping("/refund/{ticketId}")
    public ResponseEntity<?> refundTicket(@PathVariable Long ticketId) {
        ticketChangeService.processRefund(ticketId);
        // 返回簡單的成功響應(yīng)
        return ResponseEntity.ok().body("退票成功");
    }

    /**
     * 改簽接口
     * @param ticketId 票據(jù)ID
     * @param newTripDetails 新的行程信息
     * @return 響應(yīng)實體
     */
    @PostMapping("/change")
    public ResponseEntity<?> changeTicket(@RequestParam Long ticketId, @RequestParam String newTripDetails) {
        ticketChangeService.processChange(ticketId, newTripDetails);
        // 返回簡單的成功響應(yīng)
        return ResponseEntity.ok().body("改簽成功");
    }
}