package com.assu.study.chap05.controller;

import org.springframework.http.ResponseEntity;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.*;

import java.math.BigDecimal;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

@RestController // @Controller 와 @ResponseBody 애너테이션의 기능을 동시에 제공
                // HomeRoomController 가 리턴하는 객체들은 JSON 메시지 형태로 마셜링됨
public class HotelRoomController {

  private static final String HEADER_CREATED_AT = "X-CREATED-AT";
  private final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssXXX");


  @PostMapping(path = "/hotels/{hotelId}/rooms")
  public ResponseEntity<HotelRoomIdResponse> createHotelRoom(
          @PathVariable Long hotelId,
          @RequestBody HotelRoomRequest hotelRoomRequest  // @RequestBody 는 클라이언트에서 전송한 요청 메시지의 body 를 언마셜링하여 자바 객체인 HotelRoomRequest 로 변환
  ) {
    System.out.println(hotelRoomRequest.toString());

    // ResponseEntity 의 HTTP header 는 MultiValueMap 객체를 사용하여 설정
    // add() 메서드를 사용하여 HTTP 헤더 추가 가능
    MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
    headers.add(HEADER_CREATED_AT, DATE_FORMATTER.format(ZonedDateTime.now()));
    HotelRoomIdResponse body = HotelRoomIdResponse.from(1_002_003L);

    return new ResponseEntity<>(body, headers, HttpStatus.OK);
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.domain.HotelRoomType;
import lombok.Getter;
import lombok.ToString;

import java.math.BigDecimal;

// DTO
@Getter
@ToString
public class HotelRoomRequest {
  private String roomNumber;
  private HotelRoomType roomType;
  private BigDecimal originalPrice;
}

package com.assu.study.chap05.controller;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import lombok.Getter;

import java.util.Objects;

@Getter
public class HotelRoomIdResponse {
  @JsonProperty("id") // JSON 객체로 마셜링하는 과정에서 hotelRoomId 속성명 대신 다른 id 가 JSON 객체의 속성명이 됨
  @JsonSerialize(using = ToStringSerializer.class)  // 마셜링 과정에서 hotelRoomId 의 Long 타입을 String 타입으로 변경
  private Long hotelRoomId;

  private HotelRoomIdResponse(Long hotelRoomId) {
    if (Objects.isNull(hotelRoomId)) {
      throw new IllegalArgumentException("hotelRoomId is null.");
    }
    this.hotelRoomId = hotelRoomId;
  }

  public static HotelRoomIdResponse from(Long hotelRoomId) {
    return new HotelRoomIdResponse(hotelRoomId);
  }
}

package com.assu.study.chap05.controller;

import org.springframework.data.domain.Pageable;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.Collections;
import java.util.List;

@RestController
public class ReservationController {
  @GetMapping("/hotels/{hotelId}/rooms/{roomNumber}/reservations")
  public List<Long> getReservationsByPaging(
          @PathVariable Long hotelId,
          @PathVariable String roomNumber,
          Pageable pageable // @RequestParam 이 없어도 Pageable 클래스를 인자로 선언하면 page, size, sort 파라메터값을 매핑한 Pageagle 객체를 주입함
  ) {
    System.out.println("page: " + pageable.getPageNumber());  // page 파라메터값 리턴
    System.out.println("size: " + pageable.getPageSize());  // size 파라메터값 리턴
    
    // Pageable 의 getSort() 는 sort 파라메터값과 대응하는 Sort 객체 리턴하고, sort 파라메터는 하나 이상의 값일 수 있음
    // 따라서 Sort 객체는 inner class 인 Sort.order 객체스트림을 구현함
    // stream() 을 사용하면 클라이언트가 전달한 파라메터 집합 처리 가능
    pageable.getSort().stream().forEach(order -> {
      System.out.println("sort: " + order.getProperty() + ", " + order.getDirection());
    });

    return Collections.emptyList();
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.domain.HotelRoomType;
import jakarta.validation.constraints.Min;
import jakarta.validation.constraints.NotNull;
import lombok.Getter;
import lombok.ToString;

import java.math.BigDecimal;

@Getter
@ToString
public class HotelRoomUpdateRequest {
  @NotNull(message = "room Type can't be null")
  private HotelRoomType roomType;

  @NotNull(message = "originalPrice can't be null")
  @Min(value = 0, message = "originalPrice must be larger then 0")  // 0 보다 크거나 같아야 함
  private BigDecimal originalPrice;
}

package com.assu.study.chap05.controller;

import jakarta.validation.Valid;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

@RestController // @Controller 와 @ResponseBody 애너테이션의 기능을 동시에 제공
// HomeRoomController 가 리턴하는 객체들은 JSON 메시지 형태로 마셜링됨
public class HotelRoomController {
  @PutMapping(path = "/hotels/{hotelId}/rooms/{roomNumber}")
  public ResponseEntity<HotelRoomIdResponse> updateHotelRoomByRoomNumber(
          @PathVariable Long hotelId,
          @PathVariable String roomNumber,
          // HotelRoomUpdateRequest 인자 검사, 검사 대상은 대상 클래스 안에 JSR-303 애너테이션이 선언된 속성들
          @Valid @RequestBody HotelRoomUpdateRequest hotelRoomUpdateRequest,
          // HotelRoomUpdateRequest 검증 결과와 결과를 조회할 수 있는 메서드 제공
          BindingResult bindingResult
  ) {

    if (bindingResult.hasErrors()) {
      FieldError fieldError = bindingResult.getFieldError();
      String errorMessage = new StringBuilder("Validation error.")
              .append(" filed: ").append(fieldError.getField()) // 검증에 실패한 속성명 확인
              .append(", code: ").append(fieldError.getCode())  // 어떤 검증을 실패했는지 코드 확인 (=message?)
              .append(", message: ").append(fieldError.getDefaultMessage())
              .toString();

      System.out.println(errorMessage);
      return ResponseEntity.badRequest().build();
    }

    System.out.println(hotelRoomUpdateRequest.toString());
    HotelRoomIdResponse body = HotelRoomIdResponse.from(1_002_003L);
    return ResponseEntity.ok(body);
  }
}

@PostMapping(path = "/hotels/{hotelId}/rooms")
public ResponseEntity<HotelRoomIdResponse> createHotelRoom(
        @PathVariable Long hotelId,
        @Valid @RequestBody List<HotelRoomRequest> hotelRoomRequests,  // @RequestBody 는 클라이언트에서 전송한 요청 메시지의 body 를 언마셜링하여 자바 객체인 HotelRoomRequest 로 변환
        BindingResult bindingResult
) {
        ...
  return new ResponseEntity<>(body, headers, HttpStatus.OK);
}

package org.springframework.validation;

public interface Validator {
  boolean supports(Class<?> clazz);
  void validate(Object target, Errors errors);
}

package com.assu.study.chap05.controller;

import lombok.Getter;
import lombok.ToString;

import java.time.LocalDate;

@Getter
@ToString
public class HotelRoomReserveRequest {
  private LocalDate checkInDate;
  private LocalDate checkOutDate;
  private String name;
}

package com.assu.study.chap05.controller.validator;

import com.assu.study.chap05.controller.HotelRoomReserveRequest;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;

import java.util.Objects;

public class HotelRoomReserveValidator implements Validator {
  @Override
  public boolean supports(Class<?> clazz) {
    // 검증 대상이 HotelRoomReserveRequest 이므로 검증 대상 클래스 타입인 clazz 인자와 HotelRoomReserveRequest 클래스가 같아야 함
    return HotelRoomReserveRequest.class.equals(clazz);
  }

  @Override
  public void validate(Object target, Errors errors) {
    // target 인수를 HotelRoomReserveRequest 객체로 캐스팅
    // support() 로 확인한 객체만 validate() 의 target 인수로 넘어옴
    HotelRoomReserveRequest request = HotelRoomReserveRequest.class.cast(target);

    if (Objects.isNull(request.getCheckInDate())) {
      errors.rejectValue("checkInDate", "NotNull", "checkInDate is null");
      return;
    }
    if (Objects.isNull(request.getCheckOutDate())) {
      errors.rejectValue("checkOutDate", "NotNull", "checkOutDate is null");
      return;
    }
    // checkInDate 가 checkOutDate 보다 크면 검증 실패 입력
    if (request.getCheckInDate().compareTo(request.getCheckOutDate()) >= 0) {
      errors.rejectValue("checkOutDate", "Constraint Error", "checkOutDate is earlier than checkInDate");
      return;
    }
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.controller.validator.HotelRoomReserveValidator;
import com.assu.study.chap05.domain.reservation.ReserveService;
import jakarta.validation.Valid;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.*;

@RestController
public class HotelRoomReserveController {
  private final ReserveService reserveService;

  public HotelRoomReserveController(ReserveService reserveService) {
    this.reserveService = reserveService;
  }

  @InitBinder // initBinder() 초기화 함수에 선언
  void initBinder(WebDataBinder binder) {
    // 개발자가 Validator 를 확장한 클래스 추가
    binder.addValidators(new HotelRoomReserveValidator());
  }

  @PostMapping(path = "/hotels/{hotelId}/rooms/{roomNumber}/reserve")
  public ResponseEntity<HotelRoomIdResponse> reserveHotelRoomByRoomNumber(
          @PathVariable Long hotelId,
          @PathVariable String roomNumber,
          @Valid @RequestBody HotelRoomReserveRequest reserveRequest,
          BindingResult bindingResult
  ) {
    // 예외 처리
    if (bindingResult.hasErrors()) {
      FieldError fieldError = bindingResult.getFieldError();
      String errorMessage = new StringBuilder(bindingResult.getFieldError().getCode())
              .append(" [").append(fieldError.getField()).append("] ")
              .append(fieldError.getDefaultMessage())
              .toString();

      System.out.println("error  : " + errorMessage);
      return ResponseEntity.badRequest().build();
    }

    System.out.println(reserveRequest.toString());

    Long reservationId = reserveService.reserveHotelRoom(
            hotelId,
            roomNumber,
            reserveRequest.getCheckInDate(),
            reserveRequest.getCheckOutDate()
    );

    HotelRoomIdResponse body = HotelRoomIdResponse.from(reservationId);

    return ResponseEntity.ok(body);
  }
}

package com.assu.study.chap05.domain.reservation;

import org.springframework.stereotype.Service;

import java.time.LocalDate;

@Service
public class ReserveService {
  public Long reserveHotelRoom(Long hotelId, String roomNumber, LocalDate checkInDate, LocalDate checkOutDate) {
    if (1==1) {
      // 해당 메서드를 호출하는 곳에 @ExceptionHandler 가 선언된 예외 처리 메서드가 있으면 
      // BadRequestException 예외 객체를 예외 처리 메서드로 전달
      // 임시 코드
      Optional.empty().orElseThrow(() -> {
        return new BadRequestException("BadRequestException!!!");
      });

    }
    return 1_002_003L;
  }
}

package com.assu.study.chap05.domain;

// RuntimeException 을 상속하여 Unchecked Exception 으로 설계
// 따라서 불필요한 예외 처리 구문을 사용하지 않음
public class BadRequestException extends RuntimeException {
  // 클라이언트에 전달할 목적
  private String errorMessage;

  public BadRequestException(String errorMessage) {
    super();
    this.errorMessage = errorMessage;
  }

  public String getErrorMessage() {
    return errorMessage;
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.domain.BadRequestException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@RestControllerAdvice // @ExceptionHandler 가 정의된 메서드를 포함하는 Spring bean 애너테이션
public class ApiExceptionHandler {

  @ExceptionHandler(BadRequestException.class)  // BadRequestException 이 발생하면 처리할 메서드 지정
  public ResponseEntity<ErrorResponse> handleBadRequestException(BadRequestException ex) {  //
    System.out.println("Error Message: " + ex.getErrorMessage());

    // 클라이언트에 응답 메시지를 전달
    return new ResponseEntity<>(
            new ErrorResponse(ex.getErrorMessage()),
            HttpStatus.BAD_REQUEST
    );
  }

  @ExceptionHandler(Exception.class)
  public ResponseEntity<ErrorResponse> handleException(Exception ex) {
    return new ResponseEntity<>(
            new ErrorResponse("System Error"),
            HttpStatus.INTERNAL_SERVER_ERROR
    );
  }
}

package com.assu.study.chap05.controller;

import lombok.Getter;
import lombok.ToString;

@Getter
@ToString
public class ErrorResponse {
  private String errorMessage;

  public ErrorResponse(String errorMessage) {
    this.errorMessage = errorMessage;
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.domain.FileDownloadException;
import org.springframework.core.io.ClassPathResource;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.util.StreamUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.io.InputStream;

@RestController
public class ReservationController {
  
  ...

  // pdf byte 정보 조회
  @GetMapping(value = "/hotels/pdf/getByte")
  public ResponseEntity<byte[]> getInvoice() {
    String filePath = "pdf/hotel_invoice.pdf";  // resources/pdf/hotel_invoice.pdf
    
    try (InputStream inputStream = new ClassPathResource(filePath).getInputStream()) {
      // inputStream 객체를 byte[] 로 변환 후 리턴
      byte[] bytes = StreamUtils.copyToByteArray(inputStream);
      return new ResponseEntity<>(bytes, HttpStatus.OK);
    } catch (Throwable th) {
      th.printStackTrace();
      throw new FileDownloadException("file read Error~");
    }
  }
}

package com.assu.study.chap05.domain;

public class FileDownloadException extends RuntimeException {
  public FileDownloadException() {
    super();
  }

  public FileDownloadException(String message) {
    super(message);
  }

  public FileDownloadException(String message, Throwable cause) {
    super(message, cause);
  }

  public FileDownloadException(Throwable cause) {
    super(cause);
  }

  protected FileDownloadException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
    super(message, cause, enableSuppression, writableStackTrace);
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.domain.FileDownloadException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@RestControllerAdvice // @ExceptionHandler 가 정의된 메서드를 포함하는 Spring bean 애너테이션
public class ApiExceptionHandler {

  ...
  
  @ExceptionHandler(FileDownloadException.class)
  public ResponseEntity handleFileDownloadException(FileDownloadException e) {
    return new ResponseEntity(HttpStatus.INTERNAL_SERVER_ERROR);
  }
}

package com.assu.study.chap05.controller;

import com.assu.study.chap05.domain.FileDownloadException;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.core.io.ClassPathResource;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.util.StreamUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.InputStream;
import java.io.OutputStream;

@RestController
public class ReservationController {

  // pdf download
  @GetMapping(value = "/hotels/pdf/download", produces = "application/pdf")
  public void downloadInvoice(
          HttpServletResponse response
  ) {
    String filePath = "pdf/hotel_invoice.pdf";  // resources/pdf/hotel_invoice.pdf

    try (InputStream inputStream = new ClassPathResource(filePath).getInputStream()) {
      OutputStream outputStream = response.getOutputStream();

      // HttpServletResponse 객체의 메서드를 사용하여 HTTP status code, header 설정
      response.setStatus(HttpStatus.OK.value());
      response.setContentType(MediaType.APPLICATION_PDF_VALUE);
      response.setHeader("Content-Disposition", "filename=invoice.pdf");

      // 파일을 읽어오는 InputStream 객체에서 데이터를 읽고, HttpServletResponse 의 OutputStream 객체에 데이터를 씀
      StreamUtils.copy(inputStream, outputStream);
    } catch (Throwable th) {
      th.printStackTrace();
      throw new FileDownloadException("file download error~");
    }
  }
}