fix: ensure active spectrum indexes match internal state indexes (#4095)

Spectra loading is asyncronous which can change the order of spectra in the internal state. This have unexpected behavior if you display 2d spectra but you get the active spectrum by index and it returns a 1d spectrum.

Author: tpoisseau

src/component/reducer/actions/LoadAction.ts

@@ -179,6 +179,29 @@ function setData(draft: Draft<State>, input: InputProps | InitiateProps) {
     }),
   );
 
+  // Spectra loading is async, it can cause index reordering
+  // this code section is here to fix the index stored into `activeSpectra`
+  {
+    const mapEntries = draft.data.map((spectrum, index) => {
+      return [spectrum.id, index] as const;
+    });
+    const idToIndex = new Map(mapEntries);
+
+    const nucleusActiveSpectra = Object.values(
+      draft.view.spectra.activeSpectra,
+    );
+    for (const activeSpectra of nucleusActiveSpectra) {
+      if (!activeSpectra) continue;
+
+      for (const activeSpectrum of activeSpectra) {
+        const internalIndex = idToIndex.get(activeSpectrum.id);
+        if (typeof internalIndex !== 'number') continue;
+
+        activeSpectrum.index = internalIndex;
+      }
+    }
+  }
+
   draft.view.spectraContourLevels = initializeContours(draft.data);
 
   setCorrelation(draft, correlations);