// Thin fetch client for the cable-sizing module, kept separate from
// ../utils/api.ts so the module stays self-contained (see
// docs/cable-sizing-module.md).
import type {
  CableSizingAlert,
  CableSizingInput,
  CableSizingResult,
} from "../../cable-sizing/domain/cable-sizing-calculation";
import {
  WRITE_REQUEST_HEADER_NAME,
  WRITE_REQUEST_HEADER_VALUE,
} from "../../shared/constants/request-security";

export interface CalculateCableSizingResponse {
  result: CableSizingResult;
  alerts: CableSizingAlert[];
}

export async function calculateCableSizing(
  input: CableSizingInput
): Promise<CalculateCableSizingResponse> {
  const response = await fetch("/api/cable-sizing/calculate", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      [WRITE_REQUEST_HEADER_NAME]: WRITE_REQUEST_HEADER_VALUE,
    },
    body: JSON.stringify(input),
    cache: "no-store",
  });
  if (!response.ok) {
    let details = await response.text();
    try {
      const parsed = JSON.parse(details) as { error?: unknown };
      if (typeof parsed.error === "string") {
        details = parsed.error;
      }
    } catch {
      // keep raw text
    }
    throw new Error(details || `Anfrage fehlgeschlagen (Status ${response.status})`);
  }
  return response.json() as Promise<CalculateCableSizingResponse>;
}