From 0f07cd612c42c309c34aff404e349dbcf387afdd Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Mon, 23 Jan 2023 18:48:34 +0100
Subject: [PATCH] InfluxDB: write slice of structs (#5873)

---
 server/influxdb.go | 93 +++++++++++++++++++++++++---------------------
 1 file changed, 50 insertions(+), 43 deletions(-)

diff --git a/server/influxdb.go b/server/influxdb.go
index 938ed6482..ba5f69e52 100644
--- a/server/influxdb.go
+++ b/server/influxdb.go
@@ -2,12 +2,16 @@ package server
 
 import (
 	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
 	"sync"
 	"time"
 
 	"github.com/evcc-io/evcc/core/loadpoint"
 	"github.com/evcc-io/evcc/util"
 	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
+	"github.com/influxdata/influxdb-client-go/v2/api"
 	influxlog "github.com/influxdata/influxdb-client-go/v2/log"
 )
 
@@ -54,22 +58,10 @@ func NewInfluxClient(url, token, org, user, password, database string) *Influx {
 	}
 }
 
-// supportedType checks if type can be written as influx value
-func (m *Influx) supportedType(p util.Param) bool {
-	if p.Val == nil {
-		return true
-	}
-
-	switch val := p.Val.(type) {
-	case int, int64, float64:
-		return true
-	case [3]float64:
-		return true
-	case []float64:
-		return len(val) == 3
-	default:
-		return false
-	}
+// writePoint asynchronously writes a point to influx
+func (m *Influx) writePoint(writer api.WriteAPI, key string, fields map[string]any, tags map[string]string) {
+	m.log.TRACE.Printf("write %s=%v (%v)", key, fields, tags)
+	writer.WritePoint(influxdb2.NewPoint(key, tags, fields, time.Now()))
 }
 
 // Run Influx publisher
@@ -90,49 +82,64 @@ func (m *Influx) Run(loadPoints []loadpoint.API, in <-chan util.Param) {
 	// add points to batch for async writing
 	for param := range in {
 		// vehicle name
-		if param.Loadpoint != nil {
-			if name, ok := param.Val.(string); ok && param.Key == "vehicleTitle" {
-				vehicles[*param.Loadpoint] = name
+		if param.Loadpoint != nil && param.Key == "vehicleTitle" {
+			if vehicle, ok := param.Val.(string); ok {
+				vehicles[*param.Loadpoint] = vehicle
 				continue
 			}
 		}
 
-		if !m.supportedType(param) {
-			continue
-		}
+		fields := make(map[string]any)
 
-		tags := map[string]string{}
+		tags := make(map[string]string)
 		if param.Loadpoint != nil {
 			tags["loadpoint"] = loadPoints[*param.Loadpoint].Name()
 			tags["vehicle"] = vehicles[*param.Loadpoint]
 		}
 
-		fields := map[string]interface{}{}
+		switch val := param.Val.(type) {
+		case int, int64, float64:
+			fields["value"] = param.Val
 
-		// array to slice
-		val := param.Val
-		if v, ok := val.([3]float64); ok {
-			val = v[:]
-		}
-
-		// add slice as phase values
-		if phases, ok := val.([]float64); ok {
-			var total float64
-			for i, v := range phases {
-				total += v
+		case [3]float64:
+			// add array as phase values
+			for i, v := range val {
 				fields[fmt.Sprintf("l%d", i+1)] = v
 			}
 
-			// add total as "value"
-			val = total
+		default:
+			// allow writing nil values
+			if param.Val == nil {
+				break
+			}
+
+			// slice of structs
+			if typ := reflect.TypeOf(param.Val); typ.Kind() == reflect.Slice && typ.Elem().Kind() == reflect.Struct {
+				val := reflect.ValueOf(param.Val)
+
+				// loop slice
+				for i := 0; i < val.Len(); i++ {
+					val := val.Index(i)
+					typ := val.Type()
+
+					// loop struct
+					for j := 0; j < typ.NumField(); j++ {
+						n := typ.Field(j).Name
+						v := val.Field(j).Interface()
+
+						key := param.Key + strings.ToUpper(n[:1]) + n[1:]
+						fields["value"] = v
+						tags["id"] = strconv.Itoa(i + 1)
+
+						m.writePoint(writer, key, fields, tags)
+					}
+				}
+			}
+
+			continue
 		}
 
-		fields["value"] = val
-
-		// write asynchronously
-		m.log.TRACE.Printf("write %s=%v (%v)", param.Key, param.Val, tags)
-		p := influxdb2.NewPoint(param.Key, tags, fields, time.Now())
-		writer.WritePoint(p)
+		m.writePoint(writer, param.Key, fields, tags)
 	}
 
 	m.client.Close()