package com.bjtds.brichat.config;

import org.apache.http.client.config.RequestConfig;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
import org.springframework.beans.factory.annotation.Value;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.annotation.PreDestroy;
import java.util.concurrent.TimeUnit;

@Configuration
public class RestTemplateConfig {
    
    private static final Logger logger = LoggerFactory.getLogger(RestTemplateConfig.class);

    private PoolingHttpClientConnectionManager connectionManager;
    private CloseableHttpClient httpClient;
    
    // RestTemplate连接池配置参数
    @Value("${rest-template.pool.max-total:300}")
    private int maxTotal;
    
    @Value("${rest-template.pool.max-per-route:100}")
    private int maxPerRoute;
    
    @Value("${rest-template.timeout.connect:15000}")
    private int connectTimeout;
    
    @Value("${rest-template.timeout.socket:60000}")
    private int socketTimeout;
    
    @Value("${rest-template.timeout.request:10000}")
    private int connectionRequestTimeout;

    @Bean
    public RestTemplate restTemplate() {
        // 创建连接池管理器
        connectionManager = new PoolingHttpClientConnectionManager();
        
        // 设置最大连接数
        connectionManager.setMaxTotal(maxTotal);
        
        // 设置每个路由的最大连接数
        connectionManager.setDefaultMaxPerRoute(maxPerRoute);
        
        // 设置连接验证间隔
        connectionManager.setValidateAfterInactivity(30000);
        
        // 设置连接超时、读取超时等配置
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(connectTimeout)        // 连接超时
                .setSocketTimeout(socketTimeout)         // 读取超时
                .setConnectionRequestTimeout(connectionRequestTimeout) // 从连接池获取连接超时
                .build();
        
        // 创建HttpClient
        httpClient = HttpClients.custom()
                .setConnectionManager(connectionManager)
                .setDefaultRequestConfig(requestConfig)
                .setConnectionManagerShared(false)
                .evictExpiredConnections() // 自动清理过期连接
                .evictIdleConnections(60, TimeUnit.SECONDS) // 清理60秒空闲连接
                .build();
        
        // 创建HttpComponentsClientHttpRequestFactory
        HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient);
        
        // 创建RestTemplate
        RestTemplate restTemplate = new RestTemplate(factory);
        
        logger.info("RestTemplate连接池配置完成 - 最大连接数: {}, 每路由最大连接数: {}, 连接超时: {}ms, 读取超时: {}ms", 
                   maxTotal, maxPerRoute, connectTimeout, socketTimeout);
        
        return restTemplate;
    }
    
    /**
     * 获取RestTemplate连接池状态
     */
    public String getRestTemplateConnectionPoolStatus() {
        if (connectionManager != null) {
            return String.format("RestTemplate连接池 - 总连接数: %d, 可用: %d, 已使用: %d, 等待: %d",
                    connectionManager.getTotalStats().getAvailable() + connectionManager.getTotalStats().getLeased(),
                    connectionManager.getTotalStats().getAvailable(),
                    connectionManager.getTotalStats().getLeased(),
                    connectionManager.getTotalStats().getPending());
        }
        return "RestTemplate连接池未初始化";
    }
    
    /**
     * 应用关闭时清理资源
     */
    @PreDestroy
    public void destroy() {
        try {
            if (httpClient != null) {
                logger.info("正在关闭RestTemplate连接池...");
                httpClient.close();
                logger.info("RestTemplate连接池已关闭");
            }
            if (connectionManager != null) {
                connectionManager.close();
                logger.info("RestTemplate连接管理器已关闭");
            }
        } catch (Exception e) {
            logger.error("关闭RestTemplate连接池时发生异常", e);
        }
    }
}