package com.starry.common.utils;

/**
 * @author admin
 * @since 2024/7/25 下午3:15
 **/

import java.io.File;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.Objects;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.FileUtils;
import org.lionsoul.ip2region.DataBlock;
import org.lionsoul.ip2region.DbConfig;
import org.lionsoul.ip2region.DbSearcher;
import org.lionsoul.ip2region.Util;
import org.springframework.core.io.ClassPathResource;

/**
 * 根据ip离线查询地址
 *
 * @author admin
 */
@Slf4j
public class RegionUtils {

    private static final String JAVA_TEMP_DIR = "java.io.tmpdir";

    static DbConfig config = null;
    static DbSearcher searcher = null;

    /**
     * 初始化IP库
     */
    static {
        try {
            // 因为jar无法读取文件,复制创建临时文件
            String dbPath = Objects.requireNonNull(RegionUtils.class.getResource("/ip2region/ip2region.db")).getPath();
            File file = new File(dbPath);
            if (!file.exists()) {
                String tmpDir = System.getProperties().getProperty(JAVA_TEMP_DIR);
                dbPath = tmpDir + "ip2region.db";
                file = new File(dbPath);
                ClassPathResource cpr = new ClassPathResource("ip2region" + File.separator + "ip2region.db");
                InputStream resourceAsStream = cpr.getInputStream();
                FileUtils.copyInputStreamToFile(resourceAsStream, file);
            }
            config = new DbConfig();
            searcher = new DbSearcher(config, dbPath);
            log.info("bean [{}]", config);
            log.info("bean [{}]", searcher);
        } catch (Exception e) {
            log.error("init ip region error:", e);
        }
    }

    /**
     * 解析IP
     *
     * @param ip
     * @return
     */
    public static String getRegion(String ip) {
        try {
            // db
            if (searcher == null || StringUtils.isEmpty(ip)) {
                log.error("DbSearcher is null");
                return StringUtils.EMPTY;
            }
            long startTime = System.currentTimeMillis();
            // 查询算法
            int algorithm = DbSearcher.MEMORY_ALGORITYM;
            Method method = null;
            switch (algorithm) {
                case DbSearcher.BTREE_ALGORITHM :
                    method = searcher.getClass().getMethod("btreeSearch", String.class);
                    break;
                case DbSearcher.BINARY_ALGORITHM :
                    method = searcher.getClass().getMethod("binarySearch", String.class);
                    break;
                case DbSearcher.MEMORY_ALGORITYM :
                    method = searcher.getClass().getMethod("memorySearch", String.class);
                    break;
                default :
                    return StringUtils.EMPTY;
            }

            DataBlock dataBlock = null;
            if (!Util.isIpAddress(ip)) {
                log.warn("warning: Invalid ip address");
            }
            dataBlock = (DataBlock) method.invoke(searcher, ip);
            String result = dataBlock.getRegion();
            long endTime = System.currentTimeMillis();
            log.debug("region use time[{}] result[{}]", endTime - startTime, result);
            return result;

        } catch (Exception e) {
            log.error("error:", e);
        }
        return StringUtils.EMPTY;
    }

}
