import { access, readFile } from "node:fs/promises";
import { join } from "node:path";
import type { Mode, PrivacyProfile } from "../types.js";

export const FREE_UNAVAILABLE_MARKER = "ultrapi-free-unavailable";
export const PROFILE_MARKER = "ultrapi-profile.json";

export interface ProfileMarkerStatus { valid: boolean; profile?: PrivacyProfile; reason: "ok" | "missing" | "invalid" | "free-unavailable" }

function object(value: unknown): Record<string, unknown> | undefined {
  return value && typeof value === "object" && !Array.isArray(value) ? value as Record<string, unknown> : undefined;
}

export async function inspectProfileMarker(agentDir: string): Promise<ProfileMarkerStatus> {
  let value: unknown;
  try { value = JSON.parse(await readFile(join(agentDir, PROFILE_MARKER), "utf8")); }
  catch (error) {
    if ((error as NodeJS.ErrnoException).code === "ENOENT") return { valid: false, reason: "missing" };
    if (error instanceof SyntaxError) return { valid: false, reason: "invalid" };
    throw error;
  }
  const profile = object(value)?.profile;
  if (profile !== "private" && profile !== "free") return { valid: false, reason: "invalid" };
  if (profile === "free") {
    try { await access(join(agentDir, FREE_UNAVAILABLE_MARKER)); return { valid: false, profile, reason: "free-unavailable" }; }
    catch (error) { if ((error as NodeJS.ErrnoException).code !== "ENOENT") throw error; }
  }
  return { valid: true, profile, reason: "ok" };
}

export async function assertAutoModeProfile(agentDir: string, mode: Mode): Promise<void> {
  if (mode !== "auto") return;
  const marker = await inspectProfileMarker(agentDir);
  if (!marker.valid) throw new Error(`UltraPi auto mode requires a valid profile marker for ${agentDir} (${marker.reason})`);
}