Integrate rough estimate balance

src/frontend/utils/api.ts

@@ -38,6 +38,11 @@ import type {
   ExternalInitialImportPlanDto,
   ApplyExternalInitialImportInput,
   ExternalInitialImportResultDto,
+  CreateEstimateBalanceInput,
+  EstimateBalanceCommandResultDto,
+  EstimateBalanceDto,
+  EstimateBalanceUpdateResultDto,
+  EstimateComparisonDto,
 } from "../types";
 import type { ExternalCsvConfiguration } from "../../external-model/csv/external-csv-contracts";
 import type { ProjectDeviceSyncField } from "../../shared/constants/project-device-sync-fields";
@@ -87,6 +92,30 @@ import type {
   CircuitGroupSubtreeSnapshot,
 } from "../../domain/models/circuit-group-subtree-snapshot.model";
 
+/**
+ * Error of a failed API request. The message stays the server's German
+ * error text; status and optional error code allow callers to react to
+ * specific failures such as a revision conflict (409).
+ */
+export class ApiRequestError extends Error {
+  readonly status: number;
+  readonly code: string | null;
+
+  constructor(message: string, status: number, code: string | null = null) {
+    super(message);
+    this.name = "ApiRequestError";
+    this.status = status;
+    this.code = code;
+  }
+}
+
+export function isRevisionConflictError(error: unknown) {
+  return (
+    error instanceof ApiRequestError &&
+    (error.status === 409 || error.code === "PROJECT_REVISION_CONFLICT")
+  );
+}
+
 async function request<T>(url: string, init?: RequestInit): Promise<T> {
   const response = await fetch(url, {
     ...init,
@@ -99,15 +128,23 @@ async function request<T>(url: string, init?: RequestInit): Promise<T> {
 
   if (!response.ok) {
     let details = await response.text();
+    let code: string | null = null;
     try {
-      const parsed = JSON.parse(details) as { error?: unknown };
+      const parsed = JSON.parse(details) as { error?: unknown; code?: unknown };
       if (typeof parsed.error === "string") {
         details = parsed.error;
       }
+      if (typeof parsed.code === "string") {
+        code = parsed.code;
+      }
     } catch {
       // Keep non-JSON error responses unchanged.
     }
-    throw new Error(details || `Anfrage fehlgeschlagen (Status ${response.status})`);
+    throw new ApiRequestError(
+      details || `Anfrage fehlgeschlagen (Status ${response.status})`,
+      response.status,
+      code
+    );
   }
 
   if (response.status === 204) {
@@ -1135,3 +1172,66 @@ export function disconnectProjectDeviceRows(
     }
   );
 }
+
+// ── Grobe Leistungsbilanz (LPH 2/3) ─────────────────────────────────────
+
+function estimateBalancesUrl(projectId: string, balanceId?: string) {
+  const base = `/api/projects/${projectId}/estimate-balances`;
+  return balanceId ? `${base}/${balanceId}` : base;
+}
+
+export function listEstimateBalances(projectId: string) {
+  return request<EstimateBalanceDto[]>(estimateBalancesUrl(projectId));
+}
+
+export function getEstimateBalance(projectId: string, balanceId: string) {
+  return request<EstimateBalanceDto>(estimateBalancesUrl(projectId, balanceId));
+}
+
+export function createEstimateBalance(
+  projectId: string,
+  input: CreateEstimateBalanceInput,
+  expectedRevision: number
+) {
+  return request<EstimateBalanceCommandResultDto>(estimateBalancesUrl(projectId), {
+    method: "POST",
+    body: JSON.stringify({ ...input, expectedRevision }),
+  });
+}
+
+/**
+ * Saves the complete target document. `keepalive` lets the request outlive
+ * the page, e.g. for the last autosave while the tab is being closed.
+ */
+export function updateEstimateBalance(
+  projectId: string,
+  balance: EstimateBalanceDto,
+  expectedRevision: number,
+  options: { keepalive?: boolean } = {}
+) {
+  return request<EstimateBalanceUpdateResultDto>(
+    estimateBalancesUrl(projectId, balance.id),
+    {
+      method: "PUT",
+      body: JSON.stringify({ expectedRevision, balance }),
+      ...(options.keepalive ? { keepalive: true } : {}),
+    }
+  );
+}
+
+export function deleteEstimateBalance(
+  projectId: string,
+  balanceId: string,
+  expectedRevision: number
+) {
+  return request<ProjectCommandResultDto>(estimateBalancesUrl(projectId, balanceId), {
+    method: "DELETE",
+    body: JSON.stringify({ expectedRevision }),
+  });
+}
+
+export function getEstimateComparison(projectId: string, balanceId: string) {
+  return request<EstimateComparisonDto>(
+    `${estimateBalancesUrl(projectId, balanceId)}/comparison`
+  );
+}

src/frontend/utils/project-version-history.ts

@@ -68,6 +68,9 @@ const commandTypeLabels: Record<string, string> = {
   "external-object.unassign-and-delete-created-row":
     "Externes Objekt aus erzeugter Gerätezeile gelöst",
   "external-object.update-row-assignment": "Externe Objektzuordnung geändert",
+  "estimate-balance.insert": "Grobe Leistungsbilanz angelegt",
+  "estimate-balance.update": "Grobe Leistungsbilanz bearbeitet",
+  "estimate-balance.delete": "Grobe Leistungsbilanz entfernt",
 };
 
 export function getProjectRevisionSourceLabel(