PB-583 : use backend service to get LV03 <> LV95 conversion right

src/api/lv03Reframe.api.js

@@ -0,0 +1,49 @@
+import axios from 'axios'
+import proj4 from 'proj4'
+
+import { LV03, LV95 } from '@/utils/coordinates/coordinateSystems'
+import log from '@/utils/logging'
+
+const REFRAME_BASE_URL = 'https://geodesy.geo.admin.ch/reframe/'
+
+/**
+ * Re-frames LV95 coordinate taking all LV03 -> LV95 deformation into account (they are not stable,
+ * so using "simple" proj4 matrices isn't enough to get a very accurate result)
+ *
+ * @param {[Number, Number]} lv95coordinate LV95 coordinate that we want expressed in LV03
+ * @returns {Promise<[Number, Number]>} Input LV95 coordinate re-framed by the backend service into
+ *   LV03 coordinate
+ * @see https://www.swisstopo.admin.ch/en/rest-api-geoservices-reframe-web
+ * @see https://github.com/geoadmin/mf-geoadmin3/blob/master/src/components/ReframeService.js
+ */
+export default function reframe(lv95coordinate) {
+    return new Promise((resolve, reject) => {
+        if (!Array.isArray(lv95coordinate) || lv95coordinate.length !== 2) {
+            reject(new Error('lv95coordinate must be an array with length of 2'))
+        }
+        axios({
+            method: 'GET',
+            url: `${REFRAME_BASE_URL}lv95tolv03`,
+            params: {
+                easting: lv95coordinate[0],
+                northing: lv95coordinate[1],
+            },
+        })
+            .then((response) => {
+                if (response.data?.coordinates) {
+                    resolve(response.data.coordinates)
+                } else {
+                    log.error(
+                        'Error while re-framing coordinate',
+                        lv95coordinate,
+                        'fallback to proj4'
+                    )
+                    resolve(proj4(LV95.epsg, LV03.epsg, lv95coordinate))
+                }
+            })
+            .catch((error) => {
+                log.error('Error while re-framing coordinate', lv95coordinate, error)
+                reject(error)
+            })
+    })
+}

src/modules/map/components/LocationPopupPosition.vue

@@ -6,6 +6,7 @@ import { computed, onMounted, ref, toRefs, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 import { requestHeight } from '@/api/height.api'
+import reframe from '@/api/lv03Reframe.api'
 import { registerWhat3WordsLocation } from '@/api/what3words.api'
 import CoordinateCopySlot from '@/utils/components/CoordinateCopySlot.vue'
 import {
@@ -15,7 +16,7 @@ import {
     UTMFormat,
     WGS84Format,
 } from '@/utils/coordinates/coordinateFormat'
-import { WGS84 } from '@/utils/coordinates/coordinateSystems'
+import { LV03, LV95, WGS84 } from '@/utils/coordinates/coordinateSystems'
 import log from '@/utils/logging'
 
 const props = defineProps({
@@ -38,6 +39,7 @@ const props = defineProps({
 })
 const { coordinate, clickInfo, projection, currentLang } = toRefs(props)
 
+const lv03Coordinate = ref(null)
 const what3Words = ref(null)
 const height = ref(null)
 
@@ -69,13 +71,15 @@ const heightInMeter = computed(() => {
 
 onMounted(() => {
     if (clickInfo.value) {
+        updateLV03Coordinate()
         updateWhat3Word()
         updateHeight()
     }
 })
 
 watch(clickInfo, (newClickInfo) => {
     if (newClickInfo) {
+        updateLV03Coordinate()
         updateWhat3Word()
         updateHeight()
     }
@@ -84,6 +88,16 @@ watch(currentLang, () => {
     updateWhat3Word()
 })
 
+async function updateLV03Coordinate() {
+    try {
+        const lv95coordinate = proj4(projection.value.epsg, LV95.epsg, coordinate.value)
+        lv03Coordinate.value = await reframe(lv95coordinate)
+    } catch (error) {
+        log.error('Failed to retrieve LV03 coordinate', error)
+        lv03Coordinate.value = null
+    }
+}
+
 async function updateWhat3Word() {
     try {
         what3Words.value = await registerWhat3WordsLocation(
@@ -119,9 +133,11 @@ async function updateHeight() {
                 </a>
             </CoordinateCopySlot>
             <CoordinateCopySlot
+                v-if="lv03Coordinate"
                 identifier="location-popup-lv03"
-                :value="coordinate"
+                :value="lv03Coordinate"
                 :coordinate-format="LV03Format"
+                :coordinate-projection="LV03"
             >
                 <a :href="i18n.t('contextpopup_lv03_url')" target="_blank">
                     {{ LV03Format.label }}

src/utils/components/CoordinateCopySlot.vue

@@ -5,6 +5,7 @@ import { useI18n } from 'vue-i18n'
 import { useStore } from 'vuex'
 
 import { CoordinateFormat } from '@/utils/coordinates/coordinateFormat'
+import CoordinateSystem from '@/utils/coordinates/CoordinateSystem.class'
 import log from '@/utils/logging'
 
 const props = defineProps({
@@ -28,16 +29,21 @@ const props = defineProps({
         type: CoordinateFormat,
         default: null,
     },
+    coordinateProjection: {
+        type: CoordinateSystem,
+        default: null,
+    },
 })
-const { identifier, value, extraValue, resetDelay, coordinateFormat } = toRefs(props)
+const { identifier, value, extraValue, resetDelay, coordinateFormat, coordinateProjection } =
+    toRefs(props)
 
 const copyButton = ref(null)
 const copied = ref(false)
 
 const i18n = useI18n()
 
 const store = useStore()
-const projection = computed(() => store.state.position.projection)
+const projection = computed(() => coordinateProjection.value ?? store.state.position.projection)
 const lang = computed(() => store.state.i18n.lang)
 
 const buttonIcon = computed(() => {

tests/cypress/tests-e2e/mouseposition.cy.js

@@ -119,6 +119,9 @@ describe('Test mouse position and interactions', () => {
         })
         it('shows the LocationPopUp when rightclick occurs on the map', () => {
             let shortUrl = 'https://s.geo.admin.ch/0000000'
+
+            const fakeLV03Coordinate = [1234.56, 7890.12]
+            cy.intercept('**/lv95tolv03**', { coordinates: fakeLV03Coordinate }).as('reframe')
             cy.intercept(/^http[s]?:\/\/(sys-s\.\w+\.bgdi\.ch|s\.geo\.admin\.ch)\//, {
                 body: { shorturl: shortUrl, success: true },
             }).as('shortlink')
@@ -163,10 +166,11 @@ describe('Test mouse position and interactions', () => {
                 .then(checkXY(...centerLV95))
             cy.log('it shows coordinates, correctly re-projected into LV95, in the popup')
 
+            cy.wait('@reframe')
             cy.get('[data-cy="location-popup-lv03"]')
                 .invoke('text')
                 .then(parseLV)
-                .then(checkXY(...centerLV03))
+                .then(checkXY(...fakeLV03Coordinate))
             cy.log('it shows coordinates, correctly re-projected into LV03, in the popup')
 
             cy.get('[data-cy="location-popup-wgs84"]').contains(