const { OPCUAClient, AttributeIds } = require("node-opcua");
const opcua = require("node-opcua");

async function main() {
    const client = OPCUAClient.create({
        endpointMustExist: false,
        securityMode: opcua.MessageSecurityMode.None, // 无安全模式
        securityPolicy: opcua.SecurityPolicy.None // 无安全策略
    });

    try {
        console.log("尝试连接到服务器...");
        await client.connect("opc.tcp://10.71.240.162:12686");
        console.log("已连接到服务器!");

        console.log("正在创建会话...");
   
        const session = await client.createSession({ 
            userName: "administrator", // 替换为实际用户名
            password: "Mxqpj@123!@#" // 替换为实际密码
        });
        
        console.log("会话已创建!");

        // 定义要订阅的多个节点
        const itemsToMonitor = [
            { nodeId: "JD_ZPD_PDJK.D.SMMK01", attributeId: AttributeIds.Value },
        ];

        console.log("正在创建订阅...");
        // 创建订阅
        const subscription = await session.createSubscription2({
            requestedPublishingInterval: 1000,
            requestedLifetimeCount: 10,
            requestedMaxKeepAliveCount: 10,
            publishingEnabled: true,
            priority: 10
        });

        console.log("订阅已创建!");

        console.log("正在添加监控项到订阅...");
        // 添加监控项到订阅
        const monitoredItems = [];
        for (const item of itemsToMonitor) {
            const monitoredItem = await subscription.monitor(
                {
                    nodeId: item.nodeId,
                    attributeId: item.attributeId
                },
                {
                    samplingInterval: 100,
                    discardOldest: true,
                    queueSize: 10
                },
                (dataValue) => {
                    console.log(`项目 ${item.nodeId} 值已更改: `, dataValue.value.value);
                }
            );
            monitoredItems.push(monitoredItem);
        }

        console.log("监控项已添加!");

        console.log("设置定时器以断开连接...");
        // 保持程序运行以接收数据变化通知
        setTimeout(async () => {
            console.log("终止订阅...");
            await subscription.terminate();
            console.log("关闭会话...");
            await session.close();
            console.log("断开与服务器的连接...");
            await client.disconnect();
            console.log("已断开与服务器的连接!");
        }, 30000); // 运行30秒后断开连接
        
    } catch (err) {
        console.error("发生错误: ", err);
    } finally {
        console.log("清理资源...");
        // 这里可以添加任何必要的清理代码，例如关闭连接等
        if (client) {
            await client.disconnect();
        }
    }
}

main();