Add option in vehicle stats to choose what mileage metric to show

server/common/utils.go

@@ -25,6 +25,33 @@ func RandString(n int) string {
 	return string(b)
 }
 
+// A helper to convert from litres to gallon
+func LitreToGallon(litres float32) float32 {
+	gallonConversionFactor :=  0.21997
+	return litres * float32(gallonConversionFactor);
+}
+
+// A helper to convert from gallon to litres
+func GallonToLitre(gallons float32) float32 {
+	litreConversionFactor :=  3.785412
+	return gallons * float32(litreConversionFactor);
+}
+
+
+// A helper to convert from km to miles
+func KmToMiles(km float32) float32 {
+	kmConversionFactor :=  0.62137119
+	return km * float32(kmConversionFactor);
+}
+
+// A helper to convert from miles to km
+func MilesToKm(miles float32) float32 {
+	milesConversionFactor := 1.609344
+	return miles * float32(milesConversionFactor);
+}
+
+
+
 // A Util function to generate jwt_token which can be used in the request header
 func GenToken(id string, role db.Role) (string, string) {
 	jwt_token := jwt.New(jwt.GetSigningMethod("HS256"))

server/controllers/reports.go

@@ -25,7 +25,7 @@ func getMileageForVehicle(c *gin.Context) {
 			return
 		}
 
-		fillups, err := service.GetMileageByVehicleId(searchByIdQuery.Id, model.Since)
+		fillups, err := service.GetMileageByVehicleId(searchByIdQuery.Id, model.Since, model.MileageOption)
 		if err != nil {
 			c.JSON(http.StatusUnprocessableEntity, common.NewError("getMileageForVehicle", err))
 			return

server/models/report.go

@@ -14,7 +14,7 @@ type MileageModel struct {
 	FuelQuantity float32     `form:"fuelQuantity" json:"fuelQuantity" binding:"required"`
 	PerUnitPrice float32     `form:"perUnitPrice" json:"perUnitPrice" binding:"required"`
 	Currency     string      `json:"currency"`
-
+	DistanceUnit db.DistanceUnit `form:"distanceUnit" json:"distanceUnit"`
 	Mileage     float32 `form:"mileage" json:"mileage" binding:"mileage"`
 	CostPerMile float32 `form:"costPerMile" json:"costPerMile" binding:"costPerMile"`
 	OdoReading  int     `form:"odoReading" json:"odoReading" binding:"odoReading"`
@@ -35,4 +35,5 @@ func (b *MileageModel) MarshalJSON() ([]byte, error) {
 
 type MileageQueryModel struct {
 	Since time.Time `json:"since" query:"since" form:"since"`
+	MileageOption string `json:"mileageOption" query:"mileageOption" form:"mileageOption"`
 }

server/service/reportService.go

@@ -4,11 +4,12 @@ import (
 	"sort"
 	"time"
 
+	"github.com/akhilrex/hammond/common"
 	"github.com/akhilrex/hammond/db"
 	"github.com/akhilrex/hammond/models"
 )
 
-func GetMileageByVehicleId(vehicleId string, since time.Time) (mileage []models.MileageModel, err error) {
+func GetMileageByVehicleId(vehicleId string, since time.Time, mileageOption string) (mileage []models.MileageModel, err error) {
 	data, err := db.GetFillupsByVehicleIdSince(vehicleId, since)
 	if err != nil {
 		return nil, err
@@ -36,14 +37,48 @@ func GetMileageByVehicleId(vehicleId string, since time.Time) (mileage []models.
 			PerUnitPrice: currentFillup.PerUnitPrice,
 			OdoReading:   currentFillup.OdoReading,
 			Currency:     currentFillup.Currency,
+			DistanceUnit: currentFillup.DistanceUnit,
 			Mileage:      0,
 			CostPerMile:  0,
 		}
 
 		if currentFillup.IsTankFull != nil && *currentFillup.IsTankFull && (currentFillup.HasMissedFillup == nil || !(*currentFillup.HasMissedFillup)) {
-			distance := float32(currentFillup.OdoReading - lastFillup.OdoReading)
-			mileage.Mileage = distance / currentFillup.FuelQuantity
-			mileage.CostPerMile = distance / currentFillup.TotalAmount
+			currentOdoReading := float32(currentFillup.OdoReading);
+			lastFillupOdoReading := float32(lastFillup.OdoReading);
+			currentFuelQuantity := float32(currentFillup.FuelQuantity);
+			// If miles per gallon option and distanceUnit is km, convert from km to miles 
+			// 	then check if fuel unit is litres. If it is, convert to gallons
+			if (mileageOption == "mpg" && mileage.DistanceUnit == db.KILOMETERS) {
+				currentOdoReading = common.KmToMiles(currentOdoReading);
+				lastFillupOdoReading = common.KmToMiles(lastFillupOdoReading);
+				if (mileage.FuelUnit == db.LITRE) {
+					currentFuelQuantity = common.LitreToGallon(currentFuelQuantity);
+				}
+			}
+
+			// If km_litre option or litre per 100km and distanceUnit is miles, convert from miles to km 
+			// 	then check if fuel unit is not litres. If it isn't, convert to litres
+
+			if ((mileageOption == "km_litre" || mileageOption == "litre_100km") && mileage.DistanceUnit == db.MILES) {
+				currentOdoReading = common.MilesToKm(currentOdoReading);
+				lastFillupOdoReading = common.MilesToKm(lastFillupOdoReading);
+
+				if (mileage.FuelUnit == db.US_GALLON) {
+					currentFuelQuantity = common.GallonToLitre(currentFuelQuantity);
+				}
+			} 
+
+
+
+
+			distance := float32(currentOdoReading - lastFillupOdoReading);
+			if (mileageOption == "litre_100km") {
+				mileage.Mileage = currentFuelQuantity / distance * 100;
+			} else {
+				mileage.Mileage = distance / currentFuelQuantity;
+			}
+
+			mileage.CostPerMile = distance / currentFillup.TotalAmount;
 
 		}
 

ui/src/components/mileageChart.vue

@@ -3,9 +3,20 @@ import { Line } from 'vue-chartjs'
 
 import axios from 'axios'
 import { mapState } from 'vuex'
+import { string } from 'yargs'
 export default {
   extends: Line,
-  props: { vehicle: { type: Object, required: true }, since: { type: Date, default: '' }, user: { type: Object, required: true } },
+  props: {
+    vehicle: { type: Object, required: true },
+    since: { type: Date, default: '' },
+    user: { type: Object, required: true },
+    mileageOption: { type: string, default: 'litre_100km' },
+  },
+  data: function() {
+    return {
+      chartData: [],
+    }
+  },
   computed: {
     ...mapState('utils', ['isMobile']),
   },
@@ -17,20 +28,28 @@ export default {
       this.fetchMileage()
     },
   },
-  data: function() {
-    return {
-      chartData: [],
-    }
-  },
   mounted() {
     this.fetchMileage()
   },
   methods: {
     showChart() {
+      let mileageLabel = ''
+      switch (this.mileageOption) {
+        case 'litre_100km':
+          mileageLabel = 'L/100km'
+          break
+        case 'km_litre':
+          mileageLabel = 'km/L'
+          break
+        case 'mpg':
+          mileageLabel = 'mpg'
+          break
+      }
+
       var labels = this.chartData.map((x) => x.date.substr(0, 10))
       var dataset = {
         steppedLine: true,
-        label: `Mileage (${this.user.distanceUnitDetail.short}/${this.vehicle.fuelUnitDetail.short})`,
+        label: `Mileage (${mileageLabel})`,
         fill: true,
         data: this.chartData.map((x) => x.mileage),
       }
@@ -41,6 +60,7 @@ export default {
         .get(`/api/vehicles/${this.vehicle.id}/mileage`, {
           params: {
             since: this.since,
+            mileageOption: this.mileageOption,
           },
         })
         .then((response) => {

ui/src/router/views/vehicle.vue

@@ -48,6 +48,12 @@ export default {
         { label: 'All Time', value: 'all_time' },
       ],
       dateRangeOption: 'past_30_days',
+      mileageOptions: [
+        { label: 'L/100km', value: 'litre_100km' },
+        { label: 'km/L', value: 'km_litre' },
+        { label: 'mpg', value: 'mpg' },
+      ],
+      mileageOption: 'litre_100km',
     }
   },
   computed: {
@@ -529,14 +535,25 @@ export default {
       <div class="columns">
         <div class="column" :class="isMobile ? 'has-text-centered' : ''"> <h1 class="title">Stats</h1></div>
         <div class="column">
-          <b-select v-model="dateRangeOption" class="is-pulled-right is-medium">
-            <option v-for="option in dateRangeOptions" :key="option.value" :value="option.value">
-              {{ option.label }}
-            </option>
-          </b-select></div
-        >
+          <div class="columns is-pulled-right is-medium">
+            <div class="column">
+              <b-select v-model="mileageOption">
+                <option v-for="option in mileageOptions" :key="option.value" :value="option.value">
+                  {{ option.label }}
+                </option>
+              </b-select>
+            </div>
+            <div class="column">
+              <b-select v-model="dateRangeOption">
+                <option v-for="option in dateRangeOptions" :key="option.value" :value="option.value">
+                  {{ option.label }}
+                </option>
+              </b-select>
+            </div>
+          </div>
+        </div>
       </div>
-      <MileageChart :vehicle="vehicle" :since="getStartDate()" :user="me" :height="300" />
+      <MileageChart :vehicle="vehicle" :since="getStartDate()" :user="me" :height="300" :mileage-option="mileageOption" />
     </div>
   </Layout>
 </template>