package org.jeecg.config;


import com.github.xiaoymin.knife4j.spring.annotations.EnableKnife4j;
import io.swagger.annotations.ApiOperation;
import org.jeecg.common.constant.CommonConstant;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping;
import springfox.bean.validators.configuration.BeanValidatorPluginsConfiguration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.ParameterBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.schema.ModelRef;
import springfox.documentation.service.*;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @Author scott
 */
@Configuration
@EnableSwagger2    //开启 Swagger2
@EnableKnife4j     //开启 knife4j，可以不写
@Import(BeanValidatorPluginsConfiguration.class)
public class Swagger2Config implements WebMvcConfigurer {

    /**
     * 显示swagger-ui.html文档展示页，还必须注入swagger资源：
     *
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("swagger-ui.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("doc.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
    }

    /**
     * swagger2的配置文件，这里可以配置swagger2的一些基本的内容，比如扫描的包等等
     *
     * @return Docket
     */
    @Bean(value = "defaultApi2")
    public Docket defaultApi2() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                .select()
                //此包路径下的类，才生成接口文档
                .apis(RequestHandlerSelectors.basePackage("org.jeecg"))
                //加了ApiOperation注解的类，才生成接口文档
                .apis(RequestHandlerSelectors.withClassAnnotation(RestController.class))
                .apis(RequestHandlerSelectors.withMethodAnnotation(ApiOperation.class))
                .paths(PathSelectors.any())
                .build()
                .securitySchemes(Collections.singletonList(securityScheme()))
                .securityContexts(securityContexts())
                .globalOperationParameters(setHeaderToken());
    }

    /***
     * oauth2配置
     * 需要增加swagger授权回调地址
     * http://localhost:8888/webjars/springfox-swagger-ui/o2c.html
     * @return
     */
    @Bean
    SecurityScheme securityScheme() {
        return new ApiKey(CommonConstant.X_ACCESS_TOKEN, CommonConstant.X_ACCESS_TOKEN, "header");
    }

    /**
     * JWT token
     *
     * @return
     */
    private List<Parameter> setHeaderToken() {
        ParameterBuilder tokenPar = new ParameterBuilder();
        List<Parameter> pars = new ArrayList<>();
        tokenPar.name(CommonConstant.X_ACCESS_TOKEN).description("token").modelRef(new ModelRef("string")).parameterType("header").required(false).build();
        pars.add(tokenPar.build());
        return pars;
    }

    /**
     * api文档的详细信息函数,注意这里的注解引用的是哪个
     *
     * @return
     */
    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                // //大标题
                .title("JeecgBoot 后台服务API接口文档")
                // 版本号
                .version("1.0")
                // 描述
                .description("后台API接口")
                // 作者
                .contact(new Contact(" ", " ", " "))
                .license("The Apache License, Version 2.0")
                .licenseUrl("http://www.apache.org/licenses/LICENSE-2.0.html")
                .build();
    }

    /**
     * 新增 securityContexts 保持登录状态
     */
    private List<SecurityContext> securityContexts() {
        return new ArrayList(
                Collections.singleton(SecurityContext.builder()
                        .securityReferences(defaultAuth())
                        .forPaths(PathSelectors.regex("^(?!auth).*$"))
                        .build())
        );
    }

    private List<SecurityReference> defaultAuth() {
        AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];
        authorizationScopes[0] = authorizationScope;
        return new ArrayList(
                Collections.singleton(new SecurityReference(CommonConstant.X_ACCESS_TOKEN, authorizationScopes)));
    }

    /**
     * 解决springboot2.6 和springfox不兼容问题
     *
     * @return
     */
    @Bean
    public static BeanPostProcessor springfoxHandlerProviderBeanPostProcessor() {
        return new BeanPostProcessor() {

            @Override
            public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
                if (bean instanceof WebMvcRequestHandlerProvider) {
                    customizeSpringfoxHandlerMappings(getHandlerMappings(bean));
                }
                return bean;
            }

            private <T extends RequestMappingInfoHandlerMapping> void customizeSpringfoxHandlerMappings(List<T> mappings) {
                List<T> copy = mappings.stream()
                        .filter(mapping -> mapping.getPatternParser() == null)
                        .collect(Collectors.toList());
                mappings.clear();
                mappings.addAll(copy);
            }

            @SuppressWarnings("unchecked")
            private List<RequestMappingInfoHandlerMapping> getHandlerMappings(Object bean) {
                try {
                    Field field = ReflectionUtils.findField(bean.getClass(), "handlerMappings");
                    field.setAccessible(true);
                    return (List<RequestMappingInfoHandlerMapping>) field.get(bean);
                } catch (IllegalArgumentException | IllegalAccessException e) {
                    throw new IllegalStateException(e);
                }
            }
        };
    }


}
