Timescaledb (#2)

Added TimescaleDB support

metric.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"regexp"
+	"strings"
+	"unicode"
+)
+
+// generateMetricName takes a rawMetric string (for example "pd.wireUsedTime") received from Ecoflow Rest API.
+// the function returns two values: metricName and deviceMetric name.
+// metricName is used as a metric name in prometheus
+// deviceMetricName is used as unique key from all metrics (device serial number + metric name). It's required to store all metrics in a map.
+// The function converts rawMetric to prometheus compatible value (pd_wire_used_time)
+// As a result it returns two values:
+// metricName: prefix + prometheus compatible value (ecoflow_pd_wire_used_time)
+// deviceMetricName: device serial number + metricName (R13124123123213_ecoflow_pd_wire_used_time)
+// Example:
+// rawMetric: pd.wireUsedTime
+// prefix: ecoflow
+// deviceSn: R13124123123213
+//
+// return values:
+// metricName: ecoflow_pd_wire_used_time
+// deviceMetricName: R13124123123213_ecoflow_pd_wire_used_time
+
+func generateMetricName(rawMetric string, prefix string, deviceSn string) (string, string, error) {
+	prometheusName, err := ecoflowParamToPrometheusMetric(rawMetric)
+	if err != nil {
+		return "", "", err
+	}
+	metricName := prefix + "_" + prometheusName
+	deviceMetricName := deviceSn + "_" + metricName
+	return metricName, deviceMetricName, nil
+}
+
+// ecoflowParamToPrometheusMetric takes a metricKey string and converts it to a Prometheus compatible name.
+// It replaces the dot "." with an underscore "_" and converts any uppercase letters to lowercase,
+// adding an underscore before each uppercase letter except when it's preceded by an underscore.
+// The converted metricKey string must adhere to the Prometheus data model pattern [a-zA-Z_:][a-zA-Z0-9_:]*.
+// If the conversion fails, an error is returned.
+//
+// Example:
+//
+//	metricKey: "pd.wireUsedTime"
+//	converted: "pd_wire_used_time"
+//
+// Args:
+//
+//	metricKey: The original metric key string.
+//
+// Returns:
+//
+//	The converted metric key string, nil if successful.
+//	Returns an error if the conversion fails.
+func ecoflowParamToPrometheusMetric(metricKey string) (string, error) {
+	key := strings.Replace(metricKey, ".", "_", -1)
+	runes := []rune(key)
+	var newKey bytes.Buffer
+
+	newKey.WriteString(strings.ToLower(string(runes[0])))
+
+	for _, character := range runes[1:] {
+		if unicode.IsUpper(character) && !strings.HasSuffix(newKey.String(), "_") {
+			newKey.WriteString("_")
+		}
+		newKey.WriteString(strings.ToLower(string(character)))
+	}
+
+	matches, err := regexp.MatchString("[a-zA-Z_:][a-zA-Z0-9_:]*", newKey.String())
+	if err != nil {
+		return "", err
+	}
+
+	if !matches {
+		return "", fmt.Errorf("ecoflow parameter `%s` can't be converted to prometheus name", metricKey)
+	}
+
+	return newKey.String(), nil
+}