package com.codeway.gateway.config;

import com.codeway.gateway.execption.GlobalExceptionHandler;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.boot.web.reactive.error.ErrorWebExceptionHandler;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.result.view.ViewResolver;

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

/**
 * 覆盖默认的异常处理
 *
 * @author GuoGuang
 *
 */
@Configuration
@EnableConfigurationProperties({ServerProperties.class, ResourceProperties.class})
public class ErrorHandlerConfiguration {

	private final ServerProperties serverProperties;

	private final ApplicationContext applicationContext;

	private final ResourceProperties resourceProperties;

	private final List<ViewResolver> viewResolvers;

	private final ServerCodecConfigurer serverCodecConfigurer;

	public ErrorHandlerConfiguration(ServerProperties serverProperties,
	                                 ResourceProperties resourceProperties,
	                                 ObjectProvider<List<ViewResolver>> viewResolversProvider,
	                                 ServerCodecConfigurer serverCodecConfigurer,
	                                 ApplicationContext applicationContext) {
		this.serverProperties = serverProperties;
		this.applicationContext = applicationContext;
		this.resourceProperties = resourceProperties;
		this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
		this.serverCodecConfigurer = serverCodecConfigurer;
	}

	@Bean
	@Order(Ordered.HIGHEST_PRECEDENCE)
	public ErrorWebExceptionHandler errorWebExceptionHandler(ErrorAttributes errorAttributes) {
		GlobalExceptionHandler exceptionHandler = new GlobalExceptionHandler(
				errorAttributes,
				this.resourceProperties,
				this.serverProperties.getError(),
				this.applicationContext);
		exceptionHandler.setViewResolvers(this.viewResolvers);
		exceptionHandler.setMessageWriters(this.serverCodecConfigurer.getWriters());
		exceptionHandler.setMessageReaders(this.serverCodecConfigurer.getReaders());
		return exceptionHandler;
	}

}