package eu.eudat.controllers.controllerhandler;

import eu.eudat.commons.validation.Validator;
import eu.eudat.commons.validation.ValidatorFactory;
import eu.eudat.commons.validation.ValidationFilterAnnotation;
import gr.cite.tools.exception.MyApplicationException;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice;

import java.io.IOException;
import java.lang.reflect.Type;
import java.util.Objects;

@ControllerAdvice
@RestControllerAdvice
public class ValidatorRequestBodyAdvice implements RequestBodyAdvice {
	private final ValidatorFactory validatorFactory;

	public ValidatorRequestBodyAdvice(ValidatorFactory validatorFactory) {
		this.validatorFactory = validatorFactory;
	}

	@Override
	public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType,
	                            Class<? extends HttpMessageConverter<?>> converterType) {
		if (parameter.getMethod() != null) {
			ValidationFilterAnnotation[] annotations = parameter.getMethod().getAnnotationsByType((ValidationFilterAnnotation.class));

			if (annotations == null) return body;
			for (ValidationFilterAnnotation annotation : annotations){
				if (!Objects.equals(parameter.getParameterName(), annotation.argumentName())) continue;

				Validator validator = validatorFactory.validator(annotation.validator());
				if (validator == null) throw new MyApplicationException("validator not provided");

				validator.validateForce(body);
			}
		}
		return body;
	}

	@Override
	public Object handleEmptyBody(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
		return body;
	}

	@Override
	public boolean supports(MethodParameter parameter, Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
		return parameter.getMethod() != null && parameter.getMethod().isAnnotationPresent((ValidationFilterAnnotation.class));
	}

	@Override
	public HttpInputMessage beforeBodyRead(HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class<? extends HttpMessageConverter<?>> converterType) throws IOException {
		return inputMessage;
	}
}