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

Database.go

@@ -26,17 +26,23 @@ func CloseDb() {
 	}
 }
 
-func writeSnapshotToDb(snapshotSub *SnapshotSubmission) error {
+func writeSnapshotToDb(snapshotSub *SnapshotSubmission) (int64, error) {
-	query := fmt.Sprintf("INSERT INTO `snapshots` (`temp`, `humidity`, `co2`, `time`, `id`) VALUES (%v, %v, %v, '%v', NULL);",
+	queryStr := "INSERT INTO `snapshots` (`temp`, `humidity`, `co2`, `time`, `id`) VALUES (%v, %v, %v, '%v', NULL);"
+	query, err := ClimateDb.Prepare(queryStr)
+	if err != nil {
+		return -1, fmt.Errorf("couldn't prepare snapshot query: %w", err)
+	}
+	result, err := query.Exec(
 		snapshotSub.Temp,
 		snapshotSub.Humidity,
 		snapshotSub.Co2,
-		snapshotSub.Timestamp)
+		snapshotSub.Timestamp,
-	_, err := ClimateDb.Query(query)
+	)
 	if err != nil {
-		return err
+		return -1, fmt.Errorf("couldn't execute query to write snapshot to db: %w", err)
 	}
-	return nil
+	id, _ := result.LastInsertId()
+	return id, nil
 }
 
 func getLastSnapshotRecordFromDb() (*SnapshotRecord, error) {
@@ -55,7 +61,7 @@ func getLastSnapshotRecordFromDb() (*SnapshotRecord, error) {
 		&snapshotRecord.Timestamp,
 	)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("couldn't read last snapshot from the database: %w", err)
 	}
 	return &snapshotRecord, nil
 }
@@ -67,7 +73,7 @@ func getSnapshotRecordsFromDb(minuteAgo int) ([]*SnapshotRecord, error) {
 	if err != nil {
 		return nil, err
 	}
-	for i := 0; rows.Next(); i++ {
+	for rows.Next() {
 		var snapshotRecord SnapshotRecord
 		err = rows.Scan(
 			&snapshotRecord.Id,
@@ -77,7 +83,7 @@ func getSnapshotRecordsFromDb(minuteAgo int) ([]*SnapshotRecord, error) {
 			&snapshotRecord.Timestamp,
 		)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("couldn't read rows from the database: %w", err)
 		}
 		snapshots = append(snapshots, &snapshotRecord)
 	}

HandlerHelpers.go

@@ -71,7 +71,7 @@ func getPatternHandler(pattern string) http.HandlerFunc {
 			err = cb(w, r)
 		}
 		if err != nil {
-			sendInternalError(err, w, r)
+			internalErrorOnErr(err, w, r)
 		}
 	}
 }

Snapshot.go

@@ -43,7 +43,7 @@ func createSnapshotSubFromJsonBodyStream(jsonBodyStream io.ReadCloser) (*Snapsho
 func createJsonFromSnapshotRecords(records []*SnapshotRecord) ([]byte, error) {
 	jsonResult, err := json.Marshal(SnapshotPayload{records})
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("couldn't marshal json: %w", err)
 	}
 	return jsonResult, nil
 }

climate-server.go

@@ -66,61 +66,43 @@ func sendData(w http.ResponseWriter, r *http.Request) {
 		count = newCount
 	}
 	records, err := getSnapshotRecordsFromDb(int(count))
-	if err != nil {
+	if internalErrorOnErr(fmt.Errorf("couldn't get snapshots from db: %w", err), w, r) { return }
-		sendInternalError(fmt.Errorf("couldn't read rows from the database: %w", err), w, r)
-		return
-	}
 	json, err := createJsonFromSnapshotRecords(records)
-	if err != nil {
+	if internalErrorOnErr(fmt.Errorf("couldn't create json from snapshots: %w", err), w, r) { return }
-		sendInternalError(fmt.Errorf("couldn't create a json from the records: %w", err), w, r)
-		return
-	}
 	w.Header().Set("Content-Type", "application/json")
-	_, err = fmt.Fprintf(w, string(json))
+	fmt.Fprintf(w, string(json))
-	if err != nil {
-		sendInternalError(err, w, r)
-		return
-	}
 }
 
 func sendLastSnapshot(w http.ResponseWriter, r *http.Request) {
 	record, err := getLastSnapshotRecordFromDb()
-	if err != nil {
+	if internalErrorOnErr(fmt.Errorf("couldn't get last snapshot from db: %w", err), w, r) { return }
-		sendInternalError(fmt.Errorf("couldn't read last snapshot from the database: %w", err), w, r)
-		return
-	}
 	json, err := createJsonFromSnapshotRecords([]*SnapshotRecord{record})
-	if err != nil {
+	if internalErrorOnErr(fmt.Errorf("couldn't create json from last snapshots: %w", err), w, r) { return }
-		sendInternalError(fmt.Errorf("couldn't create a json from the last record: %w", err), w, r)
-		return
-	}
 	w.Header().Set("Content-Type", "application/json")
-	_, err = fmt.Fprintf(w, string(json))
+	fmt.Fprintf(w, string(json))
-	if err != nil {
-		sendInternalError(err, w, r)
-		return
-	}
 }
 
 func saveSnapshot(w http.ResponseWriter, r *http.Request) {
 	snapshotSub, err := createSnapshotSubFromJsonBodyStream(r.Body)
-	if err != nil {
+	if internalErrorOnErr(fmt.Errorf("couldn't create snapshot from JSON: %w", err), w, r) { return }
-		sendInternalError(fmt.Errorf("couldn't create snapshot from JSON: %w", err), w, r)
+	newId, err := writeSnapshotToDb(snapshotSub)
-	}
+	if internalErrorOnErr(fmt.Errorf("couldn't submit snapshot into the database: %w", err), w, r) { return }
-	err = writeSnapshotToDb(snapshotSub)
+	fmt.Fprintf(w, "{id: %v}", newId)
-	if err != nil {
-		sendInternalError(fmt.Errorf("couldn't submit snapshot into the database: %w", err), w, r)
-	}
 }
 
-func sendInternalError(err error, w http.ResponseWriter, r *http.Request) {
+func internalErrorOnErr(err error, w http.ResponseWriter, r *http.Request) bool {
-	errorMessage := "Internal Server Error!"
+	if err != nil {
-	if DEBUG {
+		errorMessage := "Internal Server Error!"
-		errorMessage += fmt.Sprintf(" Happened during %s request for pattern '%s': %s",
+		if DEBUG {
-			r.Method,
+			errorMessage += fmt.Sprintf(" Happened during %s request for pattern '%s': %s",
-			r.URL,
+				r.Method,
-			err.Error())
+				r.URL,
+				err.Error())
+		}
+		fmt.Println(errorMessage)
+		http.Error(w, errorMessage, 500)
+		return true
 	}
-	fmt.Println(errorMessage)
+	return false
-	http.Error(w, errorMessage, 500)
 }
+