From d0898c86500e40f19ce9881b32c6fa77adc3dade Mon Sep 17 00:00:00 2001
From: Kevin Lutzer <kevinlutzer@proton.me>
Date: Sun, 17 Sep 2023 11:48:40 -0400
Subject: [PATCH] Expose total subscribers and topics in the /v1/stats api

---
 server/server.go      | 19 +++++++++++++++++--
 server/server_test.go | 13 +++++++------
 server/types.go       |  6 ++++--
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/server/server.go b/server/server.go
index 0ab36524..69fbc55f 100644
--- a/server/server.go
+++ b/server/server.go
@@ -631,14 +631,29 @@ func (s *Server) handleDocs(w http.ResponseWriter, r *http.Request, _ *visitor)
 // handleStats returns the publicly available server stats
 func (s *Server) handleStats(w http.ResponseWriter, _ *http.Request, _ *visitor) error {
 	s.mu.RLock()
+
+	var totalTopics, totalSubscriptions int64
+	for _, t := range s.topics {
+		if t.Stale() {
+			continue
+		}
+
+		totalTopics += 1
+		subscribers, _ := t.Stats()
+		totalSubscriptions += int64(subscribers)
+	}
+
 	messages, n, rate := s.messages, len(s.messagesHistory), float64(0)
 	if n > 1 {
 		rate = float64(s.messagesHistory[n-1]-s.messagesHistory[0]) / (float64(n-1) * s.config.ManagerInterval.Seconds())
 	}
+
 	s.mu.RUnlock()
 	response := &apiStatsResponse{
-		Messages:     messages,
-		MessagesRate: rate,
+		Messages:           messages,
+		MessagesRate:       rate,
+		TotalTopics:        totalTopics,
+		TotalSubscriptions: totalSubscriptions,
 	}
 	return s.writeJSON(w, response)
 }
diff --git a/server/server_test.go b/server/server_test.go
index 647268fb..2633a12c 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -6,8 +6,6 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"golang.org/x/crypto/bcrypt"
-	"heckel.io/ntfy/user"
 	"io"
 	"math/rand"
 	"net/http"
@@ -22,6 +20,9 @@ import (
 	"testing"
 	"time"
 
+	"golang.org/x/crypto/bcrypt"
+	"heckel.io/ntfy/user"
+
 	"github.com/SherClockHolmes/webpush-go"
 	"github.com/stretchr/testify/require"
 	"heckel.io/ntfy/log"
@@ -2501,7 +2502,7 @@ func TestServer_MessageHistoryAndStatsEndpoint(t *testing.T) {
 
 	response := request(t, s, "GET", "/v1/stats", "", nil)
 	require.Equal(t, 200, response.Code)
-	require.Equal(t, `{"messages":5,"messages_rate":0}`+"\n", response.Body.String())
+	require.Equal(t, `{"messages":5,"messages_rate":0,"total_topics":1,"total_subscriptions":0}`+"\n", response.Body.String())
 
 	// Run manager and see message history update
 	s.execManager()
@@ -2509,7 +2510,7 @@ func TestServer_MessageHistoryAndStatsEndpoint(t *testing.T) {
 
 	response = request(t, s, "GET", "/v1/stats", "", nil)
 	require.Equal(t, 200, response.Code)
-	require.Equal(t, `{"messages":5,"messages_rate":2.5}`+"\n", response.Body.String()) // 5 messages in 2 seconds = 2.5 messages per second
+	require.Equal(t, `{"messages":5,"messages_rate":2.5,"total_topics":1,"total_subscriptions":0}`+"\n", response.Body.String()) // 5 messages in 2 seconds = 2.5 messages per second
 
 	// Publish some more messages
 	for i := 0; i < 10; i++ {
@@ -2521,7 +2522,7 @@ func TestServer_MessageHistoryAndStatsEndpoint(t *testing.T) {
 
 	response = request(t, s, "GET", "/v1/stats", "", nil)
 	require.Equal(t, 200, response.Code)
-	require.Equal(t, `{"messages":15,"messages_rate":2.5}`+"\n", response.Body.String()) // Rate did not update yet
+	require.Equal(t, `{"messages":15,"messages_rate":2.5,"total_topics":1,"total_subscriptions":0}`+"\n", response.Body.String()) // Rate did not update yet
 
 	// Run manager and see message history update
 	s.execManager()
@@ -2529,7 +2530,7 @@ func TestServer_MessageHistoryAndStatsEndpoint(t *testing.T) {
 
 	response = request(t, s, "GET", "/v1/stats", "", nil)
 	require.Equal(t, 200, response.Code)
-	require.Equal(t, `{"messages":15,"messages_rate":3.75}`+"\n", response.Body.String()) // 15 messages in 4 seconds = 3.75 messages per second
+	require.Equal(t, `{"messages":15,"messages_rate":3.75,"total_topics":1,"total_subscriptions":0}`+"\n", response.Body.String()) // 15 messages in 4 seconds = 3.75 messages per second
 }
 
 func TestServer_MessageHistoryMaxSize(t *testing.T) {
diff --git a/server/types.go b/server/types.go
index eeb566fc..d10a1399 100644
--- a/server/types.go
+++ b/server/types.go
@@ -244,8 +244,10 @@ type apiHealthResponse struct {
 }
 
 type apiStatsResponse struct {
-	Messages     int64   `json:"messages"`
-	MessagesRate float64 `json:"messages_rate"` // Average number of messages per second
+	Messages           int64   `json:"messages"`
+	MessagesRate       float64 `json:"messages_rate"` // Average number of messages per second
+	TotalTopics        int64   `json:"total_topics"`
+	TotalSubscriptions int64   `json:"total_subscriptions"`
 }
 
 type apiUserAddRequest struct {