token-validator: ip, ping, ...

token-validator/ping.go

@@ -1,14 +1,63 @@
 package main
 
 import (
+	"encoding/json"
+	"errors"
 	"time"
 )
 
+var PongSecret = "felixfixit"
+
 func init() {
+	router.GET("/api/students/:sid/ping", apiHandler(studentHandler(isPinging)))
+	router.GET("/api/students/:sid/pong", apiHandler(studentHandler(func (student Student, body []byte) (interface{}, error) {
+		return student.lastPongs()
+	})))
 	router.POST("/api/students/:sid/pong", apiHandler(studentHandler(stdPong), sslOnly))
 }
 
+func isPinging(student Student, body []byte) (interface{}, error) {
+	if pongs, err := student.lastPongs(); err != nil {
+		return nil, err
+	} else if len(pongs) <= 0 {
+		return false, nil
+	} else {
+		return time.Now().Before(pongs[0].Add(time.Second * 10)), nil
+	}
+}
+
+func (s Student) lastPongs() (pongs []time.Time, err error) {
+	if rows, errr := DBQuery("SELECT time FROM student_pong WHERE id_student = ? ORDER BY time DESC", s.Id); errr != nil {
+		return nil, errr
+	} else {
+		defer rows.Close()
+
+		for rows.Next() {
+			var t time.Time
+			if err = rows.Scan(&t); err != nil {
+				return
+			}
+			pongs = append(pongs, t)
+		}
+		if err = rows.Err(); err != nil {
+			return
+		}
+
+		return
+	}
+}
+
 func stdPong(student Student, body []byte) (interface{}, error) {
+	var gt givenToken
+	if err := json.Unmarshal(body, &gt); err != nil {
+		return nil, err
+	}
+
+	if gt.Token != PongSecret {
+		return nil, errors.New("This is not the expected token.")
+	}
+
+
 	if res, err := DBExec("INSERT INTO student_pong (id_student, time) VALUES (?, ?)", student.Id, time.Now()); err != nil {
 		return false, err
 	} else if _, err := res.LastInsertId(); err != nil {