first try of implementing sms alerts

alert.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+        "fmt"
+        "io/ioutil"
+        "log"
+        "time"
+        "net/http"
+        "net/url"
+)
+
+func sendSMS(phonenumber string, alertMessage string) {
+        myurl := fmt.Sprintf("https://api.smsapi.com/sms.do?to=%s&message=%s&format=json",phonenumber,url.QueryEscape(alertMessage))
+
+	req, err := http.NewRequest("GET", myurl, nil)
+	if err != nil {
+		log.Fatal("Error reading request. ", err)
+	}
+ 
+	req.Header.Set("Authorization", "Bearer IQ4vRG2JvNOmYmrYz6RuSwAanYZgd2hHGwtN62kq")
+ 
+	client := &http.Client{Timeout: time.Second * 10}
+ 
+	resp, err := client.Do(req)
+	if err != nil {
+		log.Fatal("Error reading response. ", err)
+	}
+	defer resp.Body.Close()
+ 
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		log.Fatal("Error reading body. ", err)
+	}
+ 
+	fmt.Printf("%s\n", body)
+}
+
+func sendAlert(deveui string, alertMessage string) {
+  fmt.Printf("sendAlert: deveui=%s, message=%s\n", deveui, alertMessage)
+  sendSMS("41765006123",alertMessage)
+}

lorahandler.go

@@ -86,6 +86,7 @@ type payload_1 struct {
 // Global variables
 var file *os.File
 
+var alertMap map[string]string
 
 func DecodePayload(s string, deveui string, devaddr string, lrrlat float32, lrrlon float32, write2file bool) {
   var ba []byte
@@ -159,7 +160,11 @@ func DecodePayload(s string, deveui string, devaddr string, lrrlat float32, lrrl
        WriteDatapoint(tfp,deveui,devaddr,pl_128.Vbat,pl_128.H,pl_128.P,pl_128.W,pl_128.W1,pl_128.W2,pl_128.T,lrrlat,lrrlon)
     }
   }
-
+  // Send alert if necessary
+  if val, ok := alertMap[deveui]; ok {
+    sendAlert(deveui,val)
+    delete(alertMap,deveui)
+  }
 }
 
 func WriteDatapoint(mytime int64, deveui string, devaddr string, v uint8, h uint8, p uint8, w uint16, w1 int32, w2 int32, t int16, lrrlat float32, lrrlon float32) {
@@ -182,6 +187,18 @@ func WriteDatapoint(mytime int64, deveui string, devaddr string, v uint8, h uint
          }
 
          WriteStringToFile(s)
+
+         w_gram := w*5
+         addValue(deveui,w_gram)
+         w_loss := getMaxValue(deveui) - w_gram;
+         if (w_loss > 500) { 
+           // Schwarmalarm!
+           s = fmt.Sprintf("alert,deveui=%s reason=\"swarmalarm\",w=%di,w_loss=%di %d\n",deveui,w_gram,w_loss,mytime*60*1000*1000*1000)
+           location, _ := time.LoadLocation("Europe/Zurich")
+           alertMap[deveui] = fmt.Sprintf("*** Schwarmalarm ***\n%s\n%s\nGewichtsverlust: %d g",getDevAlias(deveui),time.Unix(mytime*60,0).In(location).Format("02.01.2006 15:04"),w_loss)
+           WriteStringToFile(s)
+           
+         }
      }
 }
 
@@ -198,6 +215,11 @@ func WriteStringToFile(s string) {
 }
 
 func main() {
+        // Init Redis
+        initDB()
+
+        // Init alertMap
+        alertMap = make(map[string]string)
 
         // Open Output File
 	f, err := os.OpenFile(outputfile,os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)

persistence.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+        "fmt"
+        "time"
+        "github.com/gomodule/redigo/redis"
+)
+
+var globalPool *redis.Pool
+
+const lastvaluesPrefix string = "lastvalues:"
+const devPrefix string = "dev:"
+
+func newPool() *redis.Pool {
+	return &redis.Pool{
+		// Maximum number of idle connections in the pool.
+		MaxIdle: 80,
+		// max number of connections
+		MaxActive: 12000,
+		// Dial is an application supplied function for creating and
+		// configuring a connection.
+		Dial: func() (redis.Conn, error) {
+			c, err := redis.Dial("tcp", ":6379")
+			if err != nil {
+				panic(err.Error())
+			}
+			return c, err
+		},
+	}
+}
+
+// ping tests connectivity for redis (PONG should be returned)
+func ping(c redis.Conn) error {
+	// Send PING command to Redis
+	// PING command returns a Redis "Simple String"
+	// Use redis.String to convert the interface type to string
+	_, err := redis.String(c.Do("PING"))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func initDB() {
+
+	// newPool returns a pointer to a redis.Pool
+	pool := newPool()
+	// get a connection from the globalPool (redis.Conn)
+	conn := pool.Get()
+        defer conn.Close()
+
+        globalPool = pool
+
+        // wir machen einen Connection Test
+        ping(conn)
+
+        addValue("0000000000000000",uint16(time.Now().Unix()));
+}
+
+func closeDB() {
+	globalPool.Close()
+}
+
+func checkDevAvailable(deveui string) bool {
+        conn := globalPool.Get()
+        defer conn.Close()
+
+        _, err := redis.String(conn.Do("GET", lastvaluesPrefix + deveui))
+	if (err == redis.ErrNil) {
+                return true
+        } else if err != nil {
+                return false
+	}
+	return false
+}
+
+func getMaxValue(deveui string) uint16 {
+        var res uint16 = 0
+        var myvalues []uint16
+        conn := globalPool.Get()
+        defer conn.Close()
+
+	values, _ := redis.Values(conn.Do("LRANGE", lastvaluesPrefix + deveui, 0, -1))
+
+        if err := redis.ScanSlice(values, &myvalues); err != nil {
+           fmt.Println(err)
+           return 0
+        }
+        
+        for _, value := range myvalues {
+           if (uint16(value) > res) {
+              res = uint16(value)
+           }
+        }
+
+        return res
+}
+
+func addValue(deveui string, value uint16) {
+        conn := globalPool.Get()
+        defer conn.Close()
+
+	_, err := conn.Do("LPUSH", lastvaluesPrefix + deveui, value)
+
+	if err != nil {
+		return
+        }
+
+	_, err2 := conn.Do("LTRIM", lastvaluesPrefix + deveui, 0, 4)
+
+	if err2 != nil {
+		return
+        }
+
+        // we set an expiration time of one hour
+	_, err3 := conn.Do("EXPIRE", lastvaluesPrefix + deveui, 3600)
+
+	if err3 != nil {
+		return
+        }
+}
+
+func getDevAlias(deveui string) string {
+        res := deveui
+
+        if deveui == "" {
+           return res
+        }
+
+
+        conn := globalPool.Get()
+        defer conn.Close()
+
+	alias, err := redis.String(conn.Do("HGET", devPrefix+deveui, "alias"))
+        if err == nil {
+          res = alias
+        } else {
+          res = deveui
+        }
+
+        return res
+}