import { selectKeyStore } from "../lib/key-store.js";
import { PropertyDataError } from "../lib/propertydata-api.js";

const BASE_URL = "https://api.propertydata.co.uk";
const REQUEST_TIMEOUT_MS = 15_000;

// Validate the key against PropertyData's /valuation-sale endpoint with no
// inputs — a valid key returns HTTP 400 + body code 701 "Missing input:
// property_type" (proof the key was accepted), without consuming a credit.
// An invalid key returns auth failure (401/403) or a different upstream code.
// Evidence: probing `/national-hpi` returns code X01 "Invalid API endpoint"
// — that path does not exist on PropertyData; `/valuation-sale` does.

async function validateApiKey(apiKey: string): Promise<void> {
  // Probe /valuation-sale with one input. Evidence-backed envelopes:
  //   invalid key → {code:"X03", message:"Invalid input: key"}
  //   valid key   → {code:"701", message:"Missing input: property_type"} (no credit)
  // PropertyData does not charge for missing-input errors, so this is a free probe.
  const url = `${BASE_URL}/valuation-sale?key=${encodeURIComponent(apiKey)}&postcode=SW1A1AA`;
  const response = await fetch(url, {
    headers: { Accept: "application/json" },
    signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
  });
  const body = await response.text().catch(() => "");
  if (response.status === 401 || response.status === 403) {
    throw new Error(`PropertyData rejected the API key (HTTP ${response.status}).`);
  }
  let parsed: { status?: string; code?: string; message?: string } = {};
  try { parsed = JSON.parse(body); } catch { /* fall through */ }
  if (parsed.code === "X03") {
    throw new Error(`PropertyData rejected the API key (code=X03 ${parsed.message ?? "Invalid input: key"}).`);
  }
  // 701 (missing-input) or status:"success" both prove the key was authenticated.
  // Any other envelope: surface raw so the operator sees the upstream error.
  if (parsed.status === "success" || parsed.code === "701") return;
  if (parsed.status === "error") {
    throw new Error(
      `PropertyData validate probe returned unexpected envelope (code=${parsed.code ?? "?"} message=${parsed.message ?? "?"}).`,
    );
  }
  if (!response.ok) {
    throw new PropertyDataError(response.status, "valuation-sale", body.slice(0, 200));
  }
}

export async function keyRegister(params: {
  apiKey: string;
  accountId: string;
}): Promise<void> {
  const { apiKey, accountId } = params;
  await validateApiKey(apiKey);
  await selectKeyStore().save(accountId, apiKey);
  console.error(`[property-data] key-op op=register account=${accountId}`);
}