package ru.dxunvrs.todo.exception;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(TaskNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleTaskNotFound(TaskNotFoundException ex) {
        ErrorResponse error = new ErrorResponse(
                HttpStatus.NOT_FOUND.value(),
                ex.getMessage(),
                LocalDateTime.now()
        );
        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);
    }

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<ValidationErrorResponse> handleValidation(MethodArgumentNotValidException ex) {
        Map<String, String> errors = new HashMap<>();
        ex.getBindingResult().getAllErrors().forEach(error -> {
            String fieldName = ((FieldError) error).getField();
            String message = error.getDefaultMessage();
            errors.put(fieldName, message);
        });
        
        ValidationErrorResponse response = new ValidationErrorResponse(
                HttpStatus.BAD_REQUEST.value(),
                "Validation failed",
                LocalDateTime.now(),
                errors
        );
        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(response);
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<ErrorResponse> handleGeneral(Exception ex) {
        ErrorResponse error = new ErrorResponse(
                HttpStatus.INTERNAL_SERVER_ERROR.value(),
                "Internal server error",
                LocalDateTime.now()
        );
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(error);
    }

    record ErrorResponse(int status, String message, LocalDateTime timestamp) {}
    
    record ValidationErrorResponse(int status, String message, LocalDateTime timestamp, Map<String, String> errors) {}
}