node-red-contrib-services-mentor/services/receiver.js

Mentor Services

module.exports = function(RED) {
  var log = RED.log;
  function Node(config) {
    
    RED.nodes.createNode(this, config);
    var node = this;
    
    this.mqtt = RED.nodes.getNode(config.mqtt);

    this.broker = config.mqtt;
    this.brokerConn = RED.nodes.getNode(this.broker);


    this.mydb = config.mysql;
    this.mydbConfig = RED.nodes.getNode(this.mydb);

    this.channel = 0;
    this.qos = 2;

  if (this.mydbConfig) {
    this.mydbConfig.connect();
    var busy = false;
    var status = {};
    node.mydbConfig.on("state", function(info) {
        if (info === "connecting") { node.status({fill:"grey",shape:"ring",text:info}); }
        else if (info === "connected") { node.status({fill:"green",shape:"dot",text:info}); }
        else {
            if (info === "ECONNREFUSED") { info = "connection refused"; }
            if (info === "PROTOCOL_CONNECTION_LOST") { info = "connection lost"; }
            node.status({fill:"red",shape:"ring",text:info});
        }
    });

    node.on('close', function () {
        if (node.tout) { clearTimeout(node.tout); }
        node.mydbConfig.removeAllListeners();
        node.status({});
    });
    } else {
      this.error("MySQL database not configured");
    } 

  if (this.brokerConn) { 
      this.status({fill:"red",shape:"ring",text:"node-red:common.status.disconnected"});
      node.brokerConn.register(this);
      this.brokerConn.subscribe('mentor_data',this.qos,function(topic,msg,packet) {
        switch (topic)
        {
          case "mentor_data":
            var obj = JSON.parse(msg.toString());
            var mentor_id = obj.mentor_id;
            node.channel = "mentor_answer_" + mentor_id;
            obj.alarm = obj.alarm || 0;
            node.alarm = obj.alarm;

            existRecord(node, obj, function (exist, err) {
              if (err) { log.error(err);  }      
              else
              {
                if (!exist)
                  { saveRecord(node, obj, mentor_id, function (r, err) {
                    if (err) { log.error(err);  }      
                    else
                      {
                          getAndSendRecord(obj, node);
                      }
                    });
                  }
                else
                    {node.send({payload: {msg:"Record already found ", data: obj}}); getAndSendRecord(obj, node);} 
                }
              }
            );
          break;
          default:
            log.error(topic);
            break;
        }
      }, this.id);
      if (this.brokerConn.connected) {
        node.status({fill:"green",shape:"dot",text:"node-red:common.status.connected"});
      }
      this.on('close', function(done) {
        node.brokerConn.deregister(node,done);
      });
    }
    
 }

  function saveRecord(node, obj, mentor_id, callback)
  {
    if (node.mydbConfig.connected) {
        var sql = "INSERT INTO mqtt_lecturas(time, device, content, status, mentor_id, alarm) VALUES ('"+ obj.time +"','"+obj.device+"','"+obj.content+"', 2, "+mentor_id+",'"+obj.alarm+"');";
        node.mydbConfig.connection.query(sql, [], function(err, rows) {
        if (err) { log.error(err); callback(null, err); }
        else
        {
            node.send({payload: {msg:rows.insertId + " Inserted.", data: obj}});
            callback (true, null);
        }
      });       
    }
    else {
        node.error("Database not connected",msg);
        status = {fill:"red",shape:"ring",text:"not yet connected"};
        callback(null, null);
    }
     
  }

  function existRecord(node,obj,callback)
  {
    if (node.mydbConfig.connected) {
      var sql = "SELECT count(*) as _count FROM mqtt_lecturas WHERE device='"+obj.device+"' AND time*1="+ obj.time;
      node.mydbConfig.connection.query(sql, [], function(err, rows) {
        if (err) { log.error(err); callback(null, err); }
        else
        {
            if (rows[0]._count > 0 )
              callback (true, null);
            else
              callback(false, null);
        }
      });
    }
    else {
        node.error("Database not connected",null);
        status = {fill:"red",shape:"ring",text:"not yet connected"};
        callback(null, null);
    }
  }

  function getAndSendRecord(obj, node)
  {
      var _msg = {};
      _msg.device = obj.device;
      _msg.time = obj.time;
      _msg.status = 2;
      if (node.brokerConn) {
        msg = {};
        msg.qos = 2;
        msg.retain = false;
        msg.payload = JSON.stringify(_msg);
        msg.topic = node.channel;
        msg.alarm = node.alarm;
        node.brokerConn.publish(msg);
        node.status({fill:"red",shape:"ring",text:"node-red:common.status.disconnected"});
        if (node.brokerConn.connected) {
            node.status({fill:"green",shape:"dot",text:"node-red:common.status.connected"});
        }
    }
      
  }
  
  RED.nodes.registerType("Receiver", Node);
};