From 5d60bb05ab98c4ed31a9e5a189c4a6dfeb62d817 Mon Sep 17 00:00:00 2001
From: Simon Zolin <s.zolin@adguard.com>
Date: Tue, 25 Jun 2019 15:55:09 +0300
Subject: [PATCH] * /control/version.json: add "recheck_now" parameter

---
 AGHTechDoc.md          |  6 +++++-
 home/control_update.go | 34 ++++++++++++++++++++++++----------
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/AGHTechDoc.md b/AGHTechDoc.md
index e4462ad9..cfe0304f 100644
--- a/AGHTechDoc.md
+++ b/AGHTechDoc.md
@@ -257,7 +257,11 @@ Server can only auto-update if the current version is equal or higher than `self
 
 Request:
 
-	GET /control/version.json
+	POST /control/version.json
+
+	{
+		"recheck_now": true | false // if false, server will check for a new version data only once in several hours
+	}
 
 Response:
 
diff --git a/home/control_update.go b/home/control_update.go
index f910b055..763a0b48 100644
--- a/home/control_update.go
+++ b/home/control_update.go
@@ -51,6 +51,10 @@ func getVersionResp(data []byte) []byte {
 	return d
 }
 
+type getVersionJSONRequest struct {
+	RecheckNow bool `json:"recheck_now"`
+}
+
 // Get the latest available version from the Internet
 func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 	log.Tracef("%s %v", r.Method, r.URL)
@@ -60,19 +64,29 @@ func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	now := time.Now()
-	controlLock.Lock()
-	cached := now.Sub(versionCheckLastTime) <= versionCheckPeriod && len(versionCheckJSON) != 0
-	data := versionCheckJSON
-	controlLock.Unlock()
-
-	if cached {
-		// return cached copy
-		w.Header().Set("Content-Type", "application/json")
-		w.Write(getVersionResp(data))
+	req := getVersionJSONRequest{}
+	err := json.NewDecoder(r.Body).Decode(&req)
+	if err != nil {
+		httpError(w, http.StatusBadRequest, "JSON parse: %s", err)
 		return
 	}
 
+	now := time.Now()
+	if !req.RecheckNow {
+		controlLock.Lock()
+		cached := now.Sub(versionCheckLastTime) <= versionCheckPeriod && len(versionCheckJSON) != 0
+		data := versionCheckJSON
+		controlLock.Unlock()
+
+		if cached {
+			log.Tracef("Returning cached data")
+			w.Header().Set("Content-Type", "application/json")
+			w.Write(getVersionResp(data))
+			return
+		}
+	}
+
+	log.Tracef("Downloading data from %s", versionCheckURL)
 	resp, err := client.Get(versionCheckURL)
 	if err != nil {
 		httpError(w, http.StatusBadGateway, "Couldn't get version check json from %s: %T %s\n", versionCheckURL, err, err)