refactor(frontend): aligne la vue détail sur le contrat SiteCurrentResponse

`/sites/{site_id}/current` renvoie un objet toujours présent, sans `reading_id`
ni `source`, avec `timestamp` nullable et `null_reasons` non nullable. La vue
s'appuyait sur une réponse nulle pour détecter l'absence de mesure : elle
s'appuie désormais sur `timestamp`, et affiche `data_quality`, que le contrat
précédent ne portait pas.

`getCurrent()` rejoint `SitesService`, l'endpoint appartenant à `/sites`.

apps/frontend/src/app/core/services/readings.service.ts

@@ -7,10 +7,6 @@ import { Reading } from '../../shared/models/reading.model';
 export class ReadingsService {
   private http = inject(HttpClient);
 
-  getLatest(siteId: string) {
-    return this.http.get<Reading | null>(`${environment.apiUrl}/sites/${siteId}/current`);
-  }
-
   getHistory(siteId: string, start?: string, end?: string) {
     let params = new HttpParams().set('site_id', siteId);
     if (start) {

apps/frontend/src/app/core/services/sites.service.ts

@@ -2,6 +2,7 @@ import { Service, inject } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
 import { environment } from '../../../environments/environment';
 import { Site } from '../../shared/models/site.model';
+import { SiteCurrent } from '../../shared/models/site-current.model';
 
 @Service()
 export class SitesService {
@@ -14,4 +15,8 @@ export class SitesService {
   getSite(siteId: string) {
     return this.http.get<Site>(`${environment.apiUrl}/sites/${siteId}`);
   }
+
+  getCurrent(siteId: string) {
+    return this.http.get<SiteCurrent>(`${environment.apiUrl}/sites/${siteId}/current`);
+  }
 }

apps/frontend/src/app/features/sites/site-detail/site-detail.html

@@ -17,9 +17,14 @@
         </p>
       }
     </div>
+    <div class="site-detail__badges">
       @if (site(); as s) {
         <ev-badge [tone]="badgeToneForStatus(s.status)">{{ s.status ?? '-' }}</ev-badge>
       }
+      @if (hasMeasurement() && qualityLabel(); as label) {
+        <ev-badge [tone]="qualityTone()">{{ label }}</ev-badge>
+      }
+    </div>
   </header>
 
   @if (error(); as message) {
@@ -27,15 +32,16 @@
   }
 
   @if (site(); as s) {
+    @if (hasMeasurement()) {
       <section class="overview">
         <ev-card class="card card--gauge">
           <span class="card__label">Consommation vs capacité</span>
           <app-consumption-gauge
-          [consumption]="latestReading()?.consumption_kw ?? 0"
+            [consumption]="current()?.consumption_kw ?? 0"
             [capacity]="s.capacity_kw ?? 0"
           />
           <span class="card__value">
-          {{ latestReading()?.consumption_kw ?? '-' }} / {{ s.capacity_kw ?? '-' }} kW
+            {{ current()?.consumption_kw ?? '-' }} / {{ s.capacity_kw ?? '-' }} kW
           </span>
         </ev-card>
 
@@ -65,6 +71,9 @@
           <app-reading-history-chart [readings]="history()" />
         </section>
       }
+    } @else {
+      <ev-alert severity="warning" class="banner-empty">{{ noMeasurementMessage }}</ev-alert>
+    }
   }
 
   <a routerLink="/sites" class="ev-link">Retour aux sites</a>

apps/frontend/src/app/features/sites/site-detail/site-detail.ts

@@ -1,11 +1,12 @@
 import { Component, DestroyRef, computed, inject, signal } from '@angular/core';
 import { takeUntilDestroyed, toObservable, toSignal } from '@angular/core/rxjs-interop';
 import { ActivatedRoute, RouterLink } from '@angular/router';
-import { catchError, EMPTY, filter, map, Observable, switchMap } from 'rxjs';
+import { catchError, EMPTY, filter, map, Observable, of, switchMap } from 'rxjs';
 import { SitesService } from '../../../core/services/sites.service';
 import { ReadingsService } from '../../../core/services/readings.service';
 import { Site } from '../../../shared/models/site.model';
-import { Reading } from '../../../shared/models/reading.model';
+import { Reading, ReadingDataQuality } from '../../../shared/models/reading.model';
+import { SiteCurrent } from '../../../shared/models/site-current.model';
 import { Card } from '../../../shared/components/ui/card/card';
 import { Alert } from '../../../shared/components/ui/alert/alert';
 import { Badge, BadgeTone } from '../../../shared/components/ui/badge/badge';
@@ -14,6 +15,7 @@ import { ConsumptionGauge } from '../../../shared/components/consumption-gauge/c
 import { ReadingHistoryChart } from '../../../shared/components/reading-history-chart/reading-history-chart';
 
 const UNAVAILABLE_MESSAGE = 'Détail du site indisponible, réessayez plus tard.';
+const NO_MEASUREMENT_MESSAGE = 'Aucune mesure remontée pour ce site.';
 const HISTORY_WINDOW_MS = 24 * 60 * 60 * 1000;
 
 const TON_PAR_STATUT: Record<string, BadgeTone> = {
@@ -22,6 +24,20 @@ const TON_PAR_STATUT: Record<string, BadgeTone> = {
   hors_service: 'danger',
 };
 
+const TON_PAR_QUALITE: Record<ReadingDataQuality, BadgeTone> = {
+  good: 'success',
+  partial: 'warning',
+  degraded: 'danger',
+  critical: 'critical',
+};
+
+const LIBELLE_PAR_QUALITE: Record<ReadingDataQuality, string> = {
+  good: 'Données complètes',
+  partial: 'Données partielles',
+  degraded: 'Données dégradées',
+  critical: 'Données critiques',
+};
+
 type MetricKey =
   | 'consumption_kw'
   | 'voltage_v'
@@ -45,9 +61,8 @@ const METRIC_DEFS: MetricDef[] = [
   { key: 'humidity_percent', label: 'Humidité', format: (v) => `${v.toFixed(0)} %` },
 ];
 
-// Contrainte : miroir de `RAISON_VERS_CAPTEUR`/`CHAMPS_PAR_CAPTEUR` côté backend
+// Contrainte : miroir de RAISON_VERS_CAPTEUR et CHAMPS_PAR_CAPTEUR (backend, services/sensor.py) ;
-// (apps/backend/app/services/sensor.py) - `null_reasons` porte le code de panne du capteur,
+// `null_reasons` porte le code de panne du capteur, jamais le nom du champ resté vide.
-// jamais le nom du champ.
 const RAISONS_PAR_CHAMP: Record<MetricKey, string[]> = {
   consumption_kw: ['consumption_sensor_failure', 'network_loss'],
   voltage_v: ['electrical_sensor_failure', 'network_loss'],
@@ -85,22 +100,36 @@ export class SiteDetail {
   private readingsService = inject(ReadingsService);
   private destroyRef = inject(DestroyRef);
 
+  readonly noMeasurementMessage = NO_MEASUREMENT_MESSAGE;
+
   siteId = toSignal(this.route.paramMap.pipe(map((params) => params.get('siteId') ?? '')));
 
   site = signal<Site | null>(null);
-  latestReading = signal<Reading | null>(null);
+  current = signal<SiteCurrent | null>(null);
   history = signal<Reading[]>([]);
   error = signal<string | null>(null);
 
+  hasMeasurement = computed(() => this.current()?.timestamp != null);
+
+  qualityLabel = computed(() => {
+    const quality = this.current()?.data_quality;
+    return quality ? LIBELLE_PAR_QUALITE[quality] : null;
+  });
+
+  qualityTone = computed<BadgeTone>(() => {
+    const quality = this.current()?.data_quality;
+    return quality ? TON_PAR_QUALITE[quality] : 'neutral';
+  });
+
   metrics = computed<MetricView[]>(() => {
-    const reading = this.latestReading();
+    const current = this.current();
     return METRIC_DEFS.map((def) => {
-      const valeur = reading ? reading[def.key] : null;
+      const valeur = current ? current[def.key] : null;
       return {
         key: def.key,
         label: def.label,
         value: valeur != null ? def.format(valeur) : null,
-        reason: valeur == null ? this.reasonFor(def.key, reading) : '',
+        reason: valeur == null ? this.reasonFor(def.key, current) : '',
       };
     });
   });
@@ -117,7 +146,7 @@ export class SiteDetail {
       .subscribe((result) => {
         this.error.set(null);
         this.site.set(result.site);
-        this.latestReading.set(result.latest);
+        this.current.set(result.current);
         this.history.set(result.history);
       });
   }
@@ -129,27 +158,29 @@ export class SiteDetail {
   private load(siteId: string) {
     return this.sitesService.getSite(siteId).pipe(
       switchMap((site) =>
-        this.readingsService.getLatest(siteId).pipe(map((latest) => ({ site, latest }))),
+        this.sitesService.getCurrent(siteId).pipe(map((current) => ({ site, current }))),
+      ),
+      switchMap(({ site, current }) =>
+        this.loadHistory(siteId, current).pipe(map((history) => ({ site, current, history }))),
       ),
-      switchMap(({ site, latest }) => {
-        // Piège : le dataset historique se termine bien avant « maintenant ». Ancrer la
-        // fenêtre sur la dernière mesure connue plutôt que sur l'horloge évite un historique
-        // vide dès que le jeu de données n'est plus récent.
-        const end = latest?.timestamp;
-        const start = end
-          ? new Date(new Date(end).getTime() - HISTORY_WINDOW_MS).toISOString()
-          : undefined;
-        return this.readingsService
-          .getHistory(siteId, start, end)
-          .pipe(map((history) => ({ site, latest, history })));
-      }),
       catchError(() => this.reportUnavailable()),
     );
   }
 
-  private reasonFor(field: MetricKey, reading: Reading | null): string {
+  private loadHistory(siteId: string, current: SiteCurrent): Observable<Reading[]> {
+    // Piège : le jeu de données s'arrête bien avant « maintenant » ; ancrer la fenêtre sur la
+    // dernière mesure connue plutôt que sur l'horloge évite un historique systématiquement vide.
+    const end = current.timestamp;
+    if (end === null) {
+      return of([]);
+    }
+    const start = new Date(new Date(end).getTime() - HISTORY_WINDOW_MS).toISOString();
+    return this.readingsService.getHistory(siteId, start, end);
+  }
+
+  private reasonFor(field: MetricKey, current: SiteCurrent | null): string {
     const raisons = RAISONS_PAR_CHAMP[field];
-    const trouvees = (reading?.null_reasons ?? [])
+    const trouvees = (current?.null_reasons ?? [])
       .filter((raison) => raisons.includes(raison))
       .map((raison) => LIBELLE_PAR_RAISON[raison] ?? raison);
     return trouvees.length > 0 ? trouvees.join(', ') : 'cause inconnue';

apps/frontend/src/app/shared/models/site-current.model.ts

@@ -0,0 +1,16 @@
+import { ReadingDataQuality } from './reading.model';
+
+export interface SiteCurrent {
+  timestamp: string | null;
+  site_id: string;
+  site_type: string;
+  consumption_kw: number | null;
+  consumption_kwh: number | null;
+  voltage_v: number | null;
+  current_a: number | null;
+  power_factor: number | null;
+  temperature_celsius: number | null;
+  humidity_percent: number | null;
+  null_reasons: string[];
+  data_quality: ReadingDataQuality;
+}