import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import fs from "fs";
import os from "os";
import path from "path";

const tempDirs: string[] = [];
const originalEnv = { ...process.env };

function makeTempDir(): string {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "termix-db-guard-"));
  tempDirs.push(dir);
  return dir;
}

beforeEach(() => {
  vi.resetModules();
});

afterEach(() => {
  process.env = { ...originalEnv };
  for (const dir of tempDirs.splice(0)) {
    fs.rmSync(dir, { recursive: true, force: true });
  }
});

describe("unreadable encrypted database guard", () => {
  it("refuses to start and leaves the file untouched", async () => {
    const dataDir = makeTempDir();
    const encryptedDbPath = path.join(dataDir, "db.sqlite.encrypted");
    // A truncated write: the file exists but its header cannot be parsed.
    const damaged = Buffer.from("not-a-valid-encrypted-database-header");
    fs.writeFileSync(encryptedDbPath, damaged);

    process.env.DATA_DIR = dataDir;
    process.env.DB_FILE_ENCRYPTION = "true";
    process.env.DATABASE_KEY = "a".repeat(64);
    delete process.env.ALLOW_UNREADABLE_DB_RESET;

    const { initializeDatabase } = await import("../../database/db/index.js");

    await expect(initializeDatabase()).rejects.toThrow(
      /not a valid encrypted database/,
    );

    // the damaged file must survive for recovery
    expect(fs.readFileSync(encryptedDbPath)).toEqual(damaged);
  });

  it("names the opt-out environment variable in the error", async () => {
    const dataDir = makeTempDir();
    fs.writeFileSync(path.join(dataDir, "db.sqlite.encrypted"), "damaged");

    process.env.DATA_DIR = dataDir;
    process.env.DB_FILE_ENCRYPTION = "true";
    process.env.DATABASE_KEY = "a".repeat(64);
    delete process.env.ALLOW_UNREADABLE_DB_RESET;

    const { initializeDatabase, ALLOW_UNREADABLE_DB_RESET_ENV } =
      await import("../../database/db/index.js");

    await expect(initializeDatabase()).rejects.toThrow(
      new RegExp(ALLOW_UNREADABLE_DB_RESET_ENV),
    );
  });
});