Add basic persistent viewership stats

stats.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"math"
+	"os"
+	"time"
+)
+
+type Stats struct {
+	streamConnected       bool      `json:"-"`
+	ViewerCount           int       `json:"viewerCount"`
+	SessionMaxViewerCount int       `json:"sessionMaxViewerCount"`
+	OverallMaxViewerCount int       `json:"overallMaxViewerCount"`
+	LastDisconnectTime    time.Time `json:"lastDisconnectTime"`
+}
+
+func (s *Stats) Setup() {
+	ticker := time.NewTicker(2 * time.Minute)
+	quit := make(chan struct{})
+	go func() {
+		for {
+			select {
+			case <-ticker.C:
+				s.save()
+			case <-quit:
+				ticker.Stop()
+				return
+			}
+		}
+	}()
+}
+
+func (s *Stats) IsStreamConnected() bool {
+	return s.streamConnected
+}
+
+func (s *Stats) SetViewerCount(count int) {
+	s.ViewerCount = count
+	s.SessionMaxViewerCount = int(math.Max(float64(s.ViewerCount), float64(s.SessionMaxViewerCount)))
+	s.OverallMaxViewerCount = int(math.Max(float64(s.SessionMaxViewerCount), float64(s.OverallMaxViewerCount)))
+}
+
+func (s *Stats) GetViewerCount() int {
+	return s.ViewerCount
+}
+
+func (s *Stats) GetSessionMaxViewerCount() int {
+	return s.SessionMaxViewerCount
+}
+
+func (s *Stats) GetOverallMaxViewerCount() int {
+	return s.OverallMaxViewerCount
+}
+
+func (s *Stats) ViewerConnected() {
+}
+
+func (s *Stats) ViewerDisconnected() {
+}
+
+func (s *Stats) StreamConnected() {
+	s.streamConnected = true
+
+	timeSinceDisconnect := time.Since(s.LastDisconnectTime).Minutes()
+	if timeSinceDisconnect > 15 {
+		s.SessionMaxViewerCount = 0
+	}
+}
+
+func (s *Stats) StreamDisconnected() {
+	s.streamConnected = false
+	s.LastDisconnectTime = time.Now()
+}
+
+func (s *Stats) save() {
+	jsonData, err := json.Marshal(&s)
+	verifyError(err)
+
+	f, err := os.Create("config/stats.json")
+	defer f.Close()
+
+	verifyError(err)
+
+	_, err = f.Write(jsonData)
+	verifyError(err)
+}
+
+func getSavedStats() *Stats {
+	filePath := "config/stats.json"
+
+	if !fileExists(filePath) {
+		return &Stats{}
+	}
+
+	jsonFile, err := ioutil.ReadFile(filePath)
+
+	var stats Stats
+	err = json.Unmarshal(jsonFile, &stats)
+	if err != nil {
+		panic(err)
+	}
+
+	return &stats
+}