nexarch/web/dms2-import/lib/api.ts

// Duenner Client fuer die eigenen Backend-for-Frontend-Routen unter
// app/api — kein direkter Zugriff auf die Connect-API vom Client aus,
// gleiches Muster wie web/routing-rules/web/workflow-cases.

export class ApiError extends Error {
  status: number;
  constructor(message: string, status: number) {
    super(message);
    this.status = status;
  }
}

export interface FieldDef {
  nexarch_field: string;
  required: boolean;
}

export interface MappingEntry {
  nexarch_field: string;
  external_field: string;
}

export interface PreviewResult {
  document_count: number;
  available_fields: string[];
  suggested_mapping: MappingEntry[];
  schema: FieldDef[];
}

export interface ImportResult {
  run_id: string;
  document_count: number;
  success_count: number;
  error_count: number;
  errors: string[];
}

async function handle<T>(res: Response): Promise<T> {
  const body = await res.json().catch(() => null);
  if (!res.ok) {
    const message =
      body && typeof body === "object" && "error" in body && typeof (body as { error: unknown }).error === "string"
        ? (body as { error: string }).error
        : "Anfrage fehlgeschlagen";
    throw new ApiError(message, res.status);
  }
  return body as T;
}

export async function previewImport(userId: string, tenant: string, file: File): Promise<PreviewResult> {
  const form = new FormData();
  form.append("file", file);
  const res = await fetch(`/api/dms2-import/preview?userId=${encodeURIComponent(userId)}&tenant=${encodeURIComponent(tenant)}`, {
    method: "POST",
    body: form,
  });
  return handle<PreviewResult>(res);
}

export async function executeImport(userId: string, tenant: string, file: File, mapping: MappingEntry[]): Promise<ImportResult> {
  const form = new FormData();
  form.append("file", file);
  form.append("mapping", JSON.stringify(mapping));
  const res = await fetch(`/api/dms2-import/execute?userId=${encodeURIComponent(userId)}&tenant=${encodeURIComponent(tenant)}`, {
    method: "POST",
    body: form,
  });
  return handle<ImportResult>(res);
}

export async function getRun(userId: string, tenant: string, runId: string): Promise<ImportResult> {
  const res = await fetch(
    `/api/dms2-import/runs/${encodeURIComponent(runId)}?userId=${encodeURIComponent(userId)}&tenant=${encodeURIComponent(tenant)}`,
    { cache: "no-store" }
  );
  return handle<ImportResult>(res);
}