import { constants } from "node:fs";
import { mkdir, open, readFile, rename, rm } from "node:fs/promises";
import path from "node:path";
import { accountProfileSchema, type AccountProfile } from "@agent-studio/shared";

export class PersistentAccountProfileStore {
  private profile: AccountProfile | undefined;
  constructor(private readonly persistentPath?: string) {}

  async load(): Promise<void> {
    if (!this.persistentPath) return;
    let raw: string;
    try { raw = await readFile(this.persistentPath, "utf8"); }
    catch (error) { if ((error as NodeJS.ErrnoException).code === "ENOENT") return; throw error; }
    this.profile = accountProfileSchema.parse(JSON.parse(raw));
  }

  get(): AccountProfile | undefined { return this.profile; }

  async save(input: AccountProfile): Promise<AccountProfile> {
    const profile = accountProfileSchema.parse(input);
    if (this.persistentPath) {
      await mkdir(path.dirname(this.persistentPath), { recursive: true, mode: 0o700 });
      const temp = `${this.persistentPath}.${crypto.randomUUID()}.tmp`;
      try {
        const handle = await open(temp, constants.O_CREAT | constants.O_EXCL | constants.O_WRONLY | constants.O_NOFOLLOW, 0o600);
        try { await handle.writeFile(`${JSON.stringify(profile, null, 2)}\n`, "utf8"); await handle.sync(); } finally { await handle.close(); }
        await rename(temp, this.persistentPath);
      } catch (error) { await rm(temp, { force: true }); throw error; }
    }
    this.profile = profile;
    return profile;
  }
}