package com.sunyard.snmp;

import org.snmp4j.*;
import org.snmp4j.mp.*;
import org.snmp4j.security.*;
import org.snmp4j.smi.*;
import org.snmp4j.transport.DefaultUdpTransportMapping;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import java.util.Properties;
import java.util.Vector;

public class SnmpTrapSender {
    private static volatile SnmpTrapSender instance;
    private Snmp snmp;
    private Properties config;

    // 配置参数
    private String ip;
    private int port;
    private String enterpriseOid;
    private String community;
    private int version;


    private SnmpTrapSender() throws IOException {
//        loadConfig();
        ip = "172.16.18.113";
        port = 162;
        enterpriseOid = "1.3.6.1.4.1.2021.251.1";
        community = "public";
        version = 1;
        initializeSNMP();
    }

    public static SnmpTrapSender getInstance() throws IOException {
        if (instance == null) {
            synchronized (SnmpTrapSender.class) {
                if (instance == null) {
                    instance = new SnmpTrapSender();
                }
            }
        }
        return instance;
    }

    private void loadConfig() {
        try (InputStream input = getClass().getClassLoader().getResourceAsStream("test.properties")) {
            config = new Properties();
            config.load(input);

            ip = config.getProperty("snmp.target.ip");
            port = Integer.parseInt(config.getProperty("snmp.target.port"));
            enterpriseOid = config.getProperty("enterprise.oid");
            community = config.getProperty("snmp.community");
            version = Integer.parseInt(config.getProperty("snmp.version"));

        } catch (IOException | NumberFormatException e) {
            throw new RuntimeException("加载配置文件失败", e);
        }
    }

    public void loadConfig(Map<String, String> map) {
        ip = map.getOrDefault("snmp.target.ip", null);
//        port = Integer.parseInt(map.getOrDefault("snmp.target.port", "0"));
        enterpriseOid = map.getOrDefault("enterprise.oid", null);
        community = map.getOrDefault("snmp.community", null);
//        version = Integer.parseInt(map.getOrDefault("snmp.version", "1"));
    }

    private void initializeSNMP() throws IOException {
        TransportMapping<?> transport = new DefaultUdpTransportMapping();
        snmp = new Snmp(transport);
        snmp.listen();
    }

    public void sendTrap(String message, int severity) throws IOException {
        switch (version) {
            case SnmpConstants.version1:
                sendV1Trap(message, severity);
                break;
            case SnmpConstants.version2c:
                sendV2Trap(message, severity);
                break;
            default:
                throw new IllegalArgumentException("不支持的SNMP版本");
        }
    }

    private void sendV1Trap(String message, int severity) throws IOException {
        CommunityTarget target = createCommunityTarget(SnmpConstants.version1);
        PDUv1 pdu = new PDUv1();
        configureCommonTrap(pdu, message, severity);
        pdu.setGenericTrap(PDUv1.ENTERPRISE_SPECIFIC);
        snmp.send(pdu, target);
    }

    private void sendV2Trap(String message, int severity) throws IOException {
        CommunityTarget target = createCommunityTarget(SnmpConstants.version2c);
        PDU pdu = new PDU();
        configureCommonTrap(pdu, message, severity);
        pdu.setType(PDU.TRAP);
        snmp.send(pdu, target);
    }


    private void configureCommonTrap(PDU pdu, String message, int severity) {
        pdu.add(new VariableBinding(SnmpConstants.sysUpTime,
                new TimeTicks(System.currentTimeMillis()/1000)));
        pdu.add(new VariableBinding(SnmpConstants.snmpTrapOID,
                new OID(enterpriseOid + ".0.1")));
        pdu.add(new VariableBinding(new OID(enterpriseOid + ".1.1"),
                new OctetString(message)));
        pdu.add(new VariableBinding(new OID(enterpriseOid + ".1.2"),
                new Integer32(severity)));
    }

    private CommunityTarget createCommunityTarget(int version) {
        CommunityTarget target = new CommunityTarget();
        target.setCommunity(new OctetString(community));
        target.setAddress(GenericAddress.parse("udp:"+ip+"/"+port));
        target.setVersion(version);
        target.setTimeout(5000);
        target.setRetries(3);
        return target;
    }

    public void close() throws IOException {
        if (snmp != null) {
            snmp.close();
        }
    }
}