// Shared helpers for the Gemini probes. No secrets here: the key comes from env GOOGLE_GEMINI_API_KEY.
import { GoogleGenAI } from "@google/genai";
import { mkdirSync, writeFileSync } from "node:fs";

export const KEY = process.env.GOOGLE_GEMINI_API_KEY ?? "";
if (!KEY) throw new Error("GOOGLE_GEMINI_API_KEY missing (set -a; . ../../.env; set +a)");

export const ai = new GoogleGenAI({ apiKey: KEY, httpOptions: { timeout: 120_000 } });

// Requested set was 3.8-flash, 3.5-flash, 3.1-pro-preview, 2.5-flash, 2.5-pro, omni — but with this free-tier key
// 2.5-* return 404 "no longer available to new users" and 3.1-pro / omni have free-tier quota 0 (see out/06-availability.json).
// Default probe set = accessible models; override with argv[2] = comma-separated ids.
export const DEFAULT_MODELS = [
  "gemini-3.8-flash",
  "gemini-3.5-flash",
  "gemini-3.5-flash-lite",
  "gemini-3.1-flash-lite",
  "gemini-3-flash-preview",
  "gemma-4-31b-it",
];
export const MODELS = process.argv[2] ? process.argv[2].split(",") : DEFAULT_MODELS;
export const SUFFIX = process.argv[2] ? "-" + process.argv[2].replace(/[^a-z0-9.-]/gi, "_") : "";

mkdirSync("out", { recursive: true });

export function save(name: string, data: unknown) {
  writeFileSync(`out/${name}`, JSON.stringify(data, redact, 2));
}

// Never let a key leak into saved output.
function redact(_k: string, v: unknown) {
  if (typeof v === "string" && KEY && v.includes(KEY)) return v.replaceAll(KEY, "[REDACTED]");
  return v;
}

export function errInfo(e: any) {
  // SDK throws ApiError {name, message, status}. message is usually the JSON error body as string.
  let parsed: any = null;
  const m: string = e?.message ?? String(e);
  try { parsed = JSON.parse(m); } catch { /* not json */ }
  const inner = parsed?.error ?? parsed;
  return {
    name: e?.name,
    httpStatus: e?.status ?? inner?.code ?? null,
    status: inner?.status ?? null,
    message: (inner?.message ?? m).slice(0, 400),
    details: inner?.details ?? null,
  };
}

export const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms));

/** Classify a 429: per-minute quota → retryable; per-day / limit 0 → give up for this model. */
export function quotaKind(e: any): "minute" | "day" | "other" {
  const info = errInfo(e);
  if (info.httpStatus !== 429) return "other";
  const q = (info.details ?? []).find((d: any) => String(d["@type"]).includes("QuotaFailure"));
  const ids: string[] = (q?.violations ?? []).map((v: any) => v.quotaId);
  if (ids.some((i) => /PerDay/.test(i))) return "day";
  if (ids.some((i) => /PerMinute/.test(i))) return "minute";
  return "other";
}

/** Retry on per-minute 429 (honouring RetryInfo.retryDelay) and on 503 high demand; max `tries`. */
export async function withRetry<T>(fn: () => Promise<T>, tries = 4): Promise<T> {
  let last: any;
  for (let i = 0; i < tries; i++) {
    try { return await fn(); } catch (e: any) {
      last = e;
      const info = errInfo(e);
      const kind = quotaKind(e);
      if (kind === "minute" || info.httpStatus === 503) {
        const ri = (info.details ?? []).find((d: any) => String(d["@type"]).includes("RetryInfo"));
        const secs = ri?.retryDelay ? parseInt(String(ri.retryDelay)) + 2 : 20;
        console.log(`   ..${info.httpStatus} (${kind}); waiting ${secs}s then retry ${i + 1}/${tries - 1}`);
        await sleep(secs * 1000);
        continue;
      }
      throw e;
    }
  }
  throw last;
}

/** Pace requests to stay under the free-tier RPM for a given model. */
export const PACE_MS = Number(process.env.PROBE_PACE_MS ?? 7000);

export const shortText = (r: any) =>
  (r?.candidates?.[0]?.content?.parts ?? []).filter((p: any) => p.text && !p.thought).map((p: any) => p.text).join("").slice(0, 120);