// Saves the Anthropic API key the user pastes into the side menu. The key is
// written to the project's .env (gitignored, owner-only permissions) so it
// survives restarts, and applied to process.env right away. It is never sent
// back to the browser — only a masked hint is.

import { chmodSync, existsSync, readFileSync, writeFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const here = path.dirname(fileURLToPath(import.meta.url));
export const ENV_PATH = path.resolve(here, "../.env");

const KEY_LINE = /^\s*ANTHROPIC_API_KEY\s*=.*$/m;

export function currentKey(): string | undefined {
  return process.env.ANTHROPIC_API_KEY?.trim() || undefined;
}

export function keyHint(key = currentKey()): string | null {
  if (!key) return null;
  return `${key.slice(0, 7)}…${key.slice(-4)}`;
}

/** Writes (or with `null`, clears) ANTHROPIC_API_KEY in .env and process.env. */
export function storeKey(key: string | null) {
  const existing = existsSync(ENV_PATH) ? readFileSync(ENV_PATH, "utf8") : "";
  const line = `ANTHROPIC_API_KEY=${key ?? ""}`;
  let next = KEY_LINE.test(existing) ? existing.replace(KEY_LINE, line) : `${line}\n${existing}`;
  if (!next.endsWith("\n")) next += "\n";
  writeFileSync(ENV_PATH, next, { mode: 0o600 });
  chmodSync(ENV_PATH, 0o600);
  if (key) process.env.ANTHROPIC_API_KEY = key;
  else delete process.env.ANTHROPIC_API_KEY;
}

/** Rough shape check so obvious paste mistakes get a friendly error. */
export function looksLikeKey(key: string) {
  return /^sk-ant-[A-Za-z0-9_-]{20,}$/.test(key);
}