Make Ctrl+Plus context aware

src/frontend/utils/circuit-grid-insertion.ts

@@ -0,0 +1,79 @@
+export type GridInsertionRowType =
+  | "circuitCompact"
+  | "circuitSummary"
+  | "deviceRow"
+  | "reserveCircuit"
+  | "placeholder";
+
+export type GridInsertionCellKind = "circuitField" | "deviceField" | "readonly" | "computed";
+
+export interface GridInsertionSelection {
+  rowType: GridInsertionRowType;
+  cellKind: GridInsertionCellKind;
+  sectionId: string;
+  circuitId?: string;
+  deviceId?: string;
+}
+
+export type GridInsertionIntent =
+  | { kind: "circuit"; sectionId: string; afterCircuitId?: string }
+  | { kind: "device"; sectionId: string; circuitId: string; afterDeviceRowId?: string };
+
+export function resolveGridInsertionIntent(
+  selection: GridInsertionSelection | null,
+  fallbackSectionId?: string
+): GridInsertionIntent | null {
+  if (!selection) {
+    return fallbackSectionId ? { kind: "circuit", sectionId: fallbackSectionId } : null;
+  }
+
+  if (selection.rowType === "placeholder") {
+    return { kind: "circuit", sectionId: selection.sectionId };
+  }
+
+  const targetsDevice =
+    selection.rowType === "deviceRow" ||
+    ((selection.rowType === "circuitCompact" || selection.rowType === "reserveCircuit") &&
+      selection.cellKind === "deviceField");
+
+  if (targetsDevice && selection.circuitId) {
+    return {
+      kind: "device",
+      sectionId: selection.sectionId,
+      circuitId: selection.circuitId,
+      afterDeviceRowId: selection.deviceId,
+    };
+  }
+
+  if (selection.circuitId) {
+    return {
+      kind: "circuit",
+      sectionId: selection.sectionId,
+      afterCircuitId: selection.circuitId,
+    };
+  }
+
+  return { kind: "circuit", sectionId: selection.sectionId };
+}
+
+export function getInsertionSortOrder(
+  orderedEntries: Array<{ id: string; sortOrder: number }>,
+  afterId?: string
+): number {
+  if (orderedEntries.length === 0) {
+    return 10;
+  }
+  if (!afterId) {
+    return Math.max(...orderedEntries.map((entry) => entry.sortOrder)) + 10;
+  }
+
+  const entries = [...orderedEntries].sort((left, right) => left.sortOrder - right.sortOrder);
+  const index = entries.findIndex((entry) => entry.id === afterId);
+  if (index < 0) {
+    return entries[entries.length - 1].sortOrder + 10;
+  }
+
+  const current = entries[index].sortOrder;
+  const next = entries[index + 1]?.sortOrder;
+  return next === undefined ? current + 10 : current + (next - current) / 2;
+}