fix: canonicalize persisted geometry

Issue: #224
User-Visible: yes

src/coordinate-canonicalization.ts

@@ -0,0 +1,135 @@
+/**
+ * Stable, allow-listed persisted geometry.
+ *
+ * Mirrored by custom_components/houseplan/coordinate_canonicalization.py.
+ * Keep the precision, scalar formula and field allow-list in lockstep.
+ */
+
+export const COORDINATE_DECIMALS = 9;
+export const COORDINATE_FACTOR = 10 ** COORDINATE_DECIMALS;
+
+type JsonRecord = Record<string, any>;
+
+function cloneJson<T>(value: T): T {
+  if (Array.isArray(value)) return value.map((item) => cloneJson(item)) as T;
+  if (value !== null && typeof value === 'object') {
+    const out: JsonRecord = {};
+    for (const [key, item] of Object.entries(value as JsonRecord)) out[key] = cloneJson(item);
+    return out as T;
+  }
+  return value;
+}
+
+export function canonicalizeNumber(value: unknown): unknown {
+  if (typeof value !== 'number' || !Number.isFinite(value)) return value;
+  const sign = value < 0 || Object.is(value, -0) ? -1 : 1;
+  const result = sign
+    * (Math.floor(Math.abs(value) * COORDINATE_FACTOR + 0.5) / COORDINATE_FACTOR);
+  return result === 0 ? 0 : result;
+}
+
+function record(value: unknown): JsonRecord | null {
+  return value !== null && typeof value === 'object' && !Array.isArray(value)
+    ? value as JsonRecord : null;
+}
+
+function records(value: unknown): JsonRecord[] {
+  return Array.isArray(value)
+    ? value.filter((item): item is JsonRecord => record(item) !== null)
+    : [];
+}
+
+function fields(item: JsonRecord, names: readonly string[]): void {
+  for (const name of names) {
+    if (Object.prototype.hasOwnProperty.call(item, name)) {
+      item[name] = canonicalizeNumber(item[name]);
+    }
+  }
+}
+
+function point(value: unknown): void {
+  if (!Array.isArray(value)) return;
+  for (let index = 0; index < Math.min(2, value.length); index++) {
+    value[index] = canonicalizeNumber(value[index]);
+  }
+}
+
+function points(value: unknown): void {
+  if (!Array.isArray(value)) return;
+  for (const item of value) point(item);
+}
+
+export function canonicalizePosition<T>(position: T): T {
+  const result = cloneJson(position);
+  const item = record(result);
+  if (item) fields(item, ['x', 'y']);
+  return result;
+}
+
+export function canonicalizeLayoutGeometry<T>(layout: T): T {
+  const result = cloneJson(layout);
+  const root = record(result);
+  if (!root) return result;
+  for (const value of Object.values(root)) {
+    const item = record(value);
+    if (item) fields(item, ['x', 'y']);
+  }
+  return result;
+}
+
+export function canonicalizeConfigGeometry<T>(config: T): T {
+  const result = cloneJson(config);
+  const root = record(result);
+  if (!root) return result;
+
+  for (const space of records(root.spaces)) {
+    fields(space, [
+      'plan_x', 'plan_y', 'plan_scale', 'plan_scale_x', 'plan_scale_y', 'plan_angle',
+    ]);
+
+    for (const room of records(space.rooms)) {
+      fields(room, ['x', 'y', 'w', 'h']);
+      points(room.poly);
+    }
+
+    for (const wall of records(space.walls)) {
+      point(wall.a);
+      point(wall.b);
+    }
+
+    for (const opening of records(space.openings)) {
+      fields(opening, ['x', 'y', 'angle', 'length']);
+      const host = record(opening.host);
+      if (host) fields(host, ['t']);
+    }
+
+    for (const decor of records(space.decor)) {
+      if (decor.kind === 'line') fields(decor, ['x1', 'y1', 'x2', 'y2']);
+      else if (decor.kind === 'rect' || decor.kind === 'ellipse' || decor.kind === 'furniture') {
+        fields(decor, ['x', 'y', 'w', 'h', 'angle']);
+      } else if (decor.kind === 'text') {
+        fields(decor, ['x', 'y', 'scale', 'angle']);
+      }
+    }
+
+    for (const draft of records(space.room_drafts)) points(draft.points);
+
+    for (const partition of records(space.partitions)) {
+      point(partition.a);
+      point(partition.b);
+    }
+
+    for (const column of records(space.wall_columns)) {
+      point(column.center);
+      if (column.shape === 'square') fields(column, ['angle']);
+    }
+
+    for (const span of records(space.open_spans)) {
+      point(span.a);
+      point(span.b);
+    }
+  }
+
+  for (const marker of records(root.markers)) fields(marker, ['angle']);
+  return result;
+}

src/houseplan-card.ts

@@ -187,6 +187,11 @@ import {
   clampCanvasR, clampCanvasN, type ContentItem, type Rect,
 } from './space-geometry';
 import { optimizePlans, type OptimizeReport } from './plan-optimizer';
+import {
+  canonicalizeConfigGeometry,
+  canonicalizeLayoutGeometry,
+  canonicalizePosition,
+} from './coordinate-canonicalization';
 import { hasTranslation, langOf, t, type I18nKey } from './i18n';
 import { CommandStack } from './command-stack';
 import { resolvedSvgScreenBlend, svgScreenBlendSupported } from './glow-blend';
@@ -4416,8 +4421,9 @@ class HouseplanCard extends LitElement {
       const ids = [...this._dirtyPos];
       this._dirtyPos.clear();
       for (const id of ids) {
-        const pos = this._layout[id];
+        const pos = canonicalizePosition(this._layout[id]);
         if (!pos) continue;
+        this._layout = { ...this._layout, [id]: pos };
         // in flight until the server answers: a layout reload triggered in the
         // meantime must keep this position, not the one the server still has
         this._sentPos.set(id, pos);
@@ -4429,6 +4435,7 @@ class HouseplanCard extends LitElement {
       }
       this._cacheSnapshot();
     } else {
+      this._layout = canonicalizeLayoutGeometry(this._layout);
       localStorage.setItem(LS_KEY, JSON.stringify(this._layout));
     }
   }, 600);
@@ -6945,8 +6952,13 @@ class HouseplanCard extends LitElement {
       .then(async () => {
         if (!this._serverCfg) return;
         this._dropLegacySegments();
+        const candidate = canonicalizeConfigGeometry(this._serverCfg);
+        const candidateFingerprint = contentFingerprint(candidate);
+        if (candidateFingerprint !== contentFingerprint(this._serverCfg)) this._cfgEpoch++;
+        this._serverCfg = candidate;
+        this._cfgContentFingerprint = candidateFingerprint;
         const r = await this.hass.callWS({
-          type: 'houseplan/config/set', config: this._serverCfg, expected_rev: this._cfgRev,
+          type: 'houseplan/config/set', config: candidate, expected_rev: this._cfgRev,
         });
         this._cfgRev = r?.rev ?? this._cfgRev + 1;
       });