From 169cf49c13f9c8145d293d3f5a2855f1a262a129 Mon Sep 17 00:00:00 2001
From: rkfg <rkfg@rkfg.me>
Date: Mon, 29 Mar 2021 14:20:50 +0300
Subject: [PATCH] Add downtime detection&reporting

---
 config.go          |  3 +++
 config_sample.json |  1 +
 query.go           | 20 ++++++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/config.go b/config.go
index d98a682..2581d34 100644
--- a/config.go
+++ b/config.go
@@ -30,6 +30,8 @@ type ns2server struct {
 	currentMap         string
 	avgSkill           int
 	restartChan        chan bool
+	failures           int
+	downSince          *time.Time
 }
 
 func (s *ns2server) playersString() string {
@@ -72,6 +74,7 @@ var config struct {
 	LevelDBPath   string        `json:"ldb_database_path"`
 	BoltDBPath    string        `json:"bdb_database_path"`
 	QueryInterval time.Duration `json:"query_interval"`
+	FailureLimit  int           `json:"failure_limit"`
 	Servers       []*ns2server
 	Seeding       seeding
 }
diff --git a/config_sample.json b/config_sample.json
index 1a38909..6139498 100644
--- a/config_sample.json
+++ b/config_sample.json
@@ -4,6 +4,7 @@
     "steam_key": "get your key at https://steamcommunity.com/dev/apikey",
     "bdb_database_path": "/path/to/botdb/",
     "query_interval": 60,
+    "failure_limit": 10,
     "servers": [
         {
             "name": "Server 1",
diff --git a/query.go b/query.go
index c64f692..8825a5b 100644
--- a/query.go
+++ b/query.go
@@ -11,6 +11,10 @@ import (
 	"github.com/rumblefrog/go-a2s"
 )
 
+const (
+	timeFormat = "2 Jan 2006 15:04:05 -0700"
+)
+
 type queryError struct {
 	description string
 	err         error
@@ -52,6 +56,9 @@ func serverStatus(srv *ns2server) *discordgo.MessageSend {
 		Footer: &discordgo.MessageEmbedFooter{Text: fmt.Sprintf("Skill: %d", srv.avgSkill)},
 	},
 	}
+	if srv.failures > config.FailureLimit && srv.downSince != nil {
+		msg.Embed.Title = fmt.Sprintf("%s [%s] currently DOWN since %s", srv.Name, srv.currentMap, srv.downSince.Format(timeFormat))
+	}
 	playersCount := len(srv.players)
 	if playersCount < config.Seeding.AlmostFull {
 		msg.Embed.Color = 0x009900
@@ -155,6 +162,19 @@ func query(srv *ns2server) {
 		err = queryServer(client, srv)
 		if err != nil {
 			log.Printf("Error: %s", err)
+			srv.failures++
+			if srv.failures > config.FailureLimit && srv.downSince == nil {
+				now := time.Now()
+				srv.downSince = &now
+				sendChan <- message{MessageSend: &discordgo.MessageSend{Content: fmt.Sprintf("Server %s is down!", srv.Name)}}
+			}
+		} else {
+			if srv.failures > config.FailureLimit && srv.downSince != nil {
+				sendChan <- message{MessageSend: &discordgo.MessageSend{Content: fmt.Sprintf("Server %s is back up! Was down since: %s",
+					srv.Name, srv.downSince.Format(timeFormat))}}
+				srv.downSince = nil
+			}
+			srv.failures = 0
 		}
 		if err, ok := err.(queryError); ok {
 			if err, ok := err.err.(*net.OpError); ok && err.Op == "write" {