Changed endpoints and db queries, chart now shows suggested mins and maxes

Database.go

@@ -39,17 +39,10 @@ func writeSnapshotToDb(snapshotSub *SnapshotSubmission) error {
 	return nil
 }
 
-func getSnapshotRecordsFromDb(rowCount int) ([]*SnapshotRecord, error) {
-	snapshots := make([]*SnapshotRecord, rowCount)
-	query := fmt.Sprintf("SELECT `%s`, `%s`, `%s`, `%s`, `%s` FROM `snapshots` ORDER BY `id` DESC LIMIT %v;",
-		"id",
-		"temp",
-		"humidity",
-		"co2",
-		"time",
-		rowCount,
-	)
-	rows, err := ClimateDb.Query(query)
+func getSnapshotRecordsFromDb(minuteAgo int) ([]*SnapshotRecord, error) {
+	snapshots := make([]*SnapshotRecord, minuteAgo)
+	query := "SELECT `%s`, `%s`, `%s`, `%s`, `%s` FROM `snapshots` ORDER BY `id` DESC WHERE %s > date_sub(now(), interval %v minute);"
+	rows, err := ClimateDb.Query(fmt.Sprintf(query, "id", "temp", "humidity", "co2", "time", "time", minuteAgo))
 	if err != nil {
 		return nil, err
 	}

charts.html

@@ -15,11 +15,18 @@
     const tempColor = 'rgb(0,134,222)';
     const co2Color = 'rgb(194,30,30)';
 
+    async function getData() {
+        let urlEndpoint = "data/";
+        if (window.location.includes("since")) {
+            urlEndpoint += "since/" + window.location.slice(window.location.lastIndexOf("/") + 1);
+        }
+        const data = await fetch(urlEndpoint);
+        return transformData(await data.json());
+    }
+
     async function initChart() {
         const ctx = document.getElementById('myChart').getContext('2d');
-        const data = await fetch("data/");
-        console.log(data);
-        const {humidity, temp, co2} = transformData(await data.json());
+        const {humidity, temp, co2} = getData();
         const myChart = Chart.Line(ctx, {
             data: {
                 datasets: [{
@@ -65,8 +72,8 @@
                         id: 'y-axis-1',
                         ticks: {
                             fontColor: co2Color,
-                            min: 400,
-                            max: 1100,
+                            suggestedMin: 400,
+                            suggestedMax: 1100,
                         },
                     }, {
                         type: 'linear',
@@ -75,8 +82,8 @@
                         id: 'y-axis-2',
                         ticks: {
                             fontColor: tempColor,
-                            min: 10,
-                            max: 35,
+                            suggestedMin: 10,
+                            suggestedMax: 35,
                         },
                         gridLines: {
                             drawOnChartArea: false,
@@ -88,8 +95,8 @@
                         id: 'y-axis-3',
                         ticks: {
                             fontColor: humidityColor,
-                            min: 15,
-                            max: 85,
+                            suggestedMin: 15,
+                            suggestedMax: 85,
                         },
                         gridLines: {
                             drawOnChartArea: false,
@@ -117,9 +124,9 @@
         setInterval(async () => {
             const newDatum = await fetch("data/1");
             const snapshot = (await newDatum.json()).snapshots[0];
-            chart.data.datasets[0].data.push({x: snapshot.time, y: snapshot.humidity});
-            chart.data.datasets[1].data.push({x: snapshot.time, y: snapshot.temp});
-            chart.data.datasets[2].data.push({x: snapshot.time, y: snapshot.co2});
+            chart.data.datasets[0].data.splice(0, 1, {x: snapshot.time, y: snapshot.humidity});
+            chart.data.datasets[1].data.splice(0, 1, {x: snapshot.time, y: snapshot.temp});
+            chart.data.datasets[2].data.splice(0, 1, {x: snapshot.time, y: snapshot.co2});
             chart.update(0);
         }, 10 * 1000);
     }

climate-server.go

@@ -36,8 +36,9 @@ func startServer() {
 	port := "8001"
 	r := mux.NewRouter()
 	r.HandleFunc("/", showCharts).Methods("GET")
+	r.HandleFunc("/since/{mins}", showCharts).Methods("GET")
 	r.HandleFunc("/data/", sendData).Methods("GET")
-	r.HandleFunc("/data/{count}", sendData).Methods("GET")
+	r.HandleFunc("/data/since/{mins}", sendData).Methods("GET")
 	r.HandleFunc("/", saveSnapshot).Methods("POST")
 	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("static/"))))
 	http.Handle("/", r)
@@ -46,13 +47,19 @@ func startServer() {
 }
 
 func showCharts(w http.ResponseWriter, r *http.Request) {
-	http.ServeFile(w, r, "charts.html")
+	if countStr := mux.Vars(r)["mins"]; countStr != "" {
+		if _, err := strconv.ParseInt(countStr, 10, 0); err != nil {
+			http.Redirect(w, r, "/", 303)
+		}
+	} else {
+		http.ServeFile(w, r, "charts.html")
+	}
 }
 
 func sendData(w http.ResponseWriter, r *http.Request) {
-	var count int64 = 180
-	if vars := mux.Vars(r); vars["count"] != "" {
-		newCount, err := strconv.ParseInt(vars["count"], 10, 0)
+	var count int64 = 60
+	if vars := mux.Vars(r); vars["mins"] != "" {
+		newCount, err := strconv.ParseInt(vars["mins"], 10, 0)
 		if err != nil {
 			sendInternalError(errors.New("bad snapshot count request"), w, r)
 			return