import { mkdtemp, readFile, rm, symlink, writeFile } from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { gzipSync } from "node:zlib";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { clearIdleBackupWakeRequired, idleBackupWakeMarker, markIdleBackupWakeRequired, verifyIdleDatabaseBackup } from "../services/idle-database-backup.js";

let directory: string;
beforeEach(async () => { directory = await mkdtemp(path.join(os.tmpdir(), "idle-backup-")); });
afterEach(async () => { await rm(directory, { recursive: true, force: true }); });

describe("idle database backup persistence", () => {
  it("keeps a restart marker until a fresh valid backup is complete", async () => {
    const archive = path.join(directory, "backup.sql.gz");
    await markIdleBackupWakeRequired(directory);
    await writeFile(archive, gzipSync("CREATE TABLE fixture (id integer);\n"));
    await verifyIdleDatabaseBackup(archive);
    // Verification on the sleep path must not remove the wake obligation.
    expect(await readFile(idleBackupWakeMarker(directory), "utf8")).toContain("restarts");
    await clearIdleBackupWakeRequired(directory);
    await expect(readFile(idleBackupWakeMarker(directory))).rejects.toMatchObject({ code: "ENOENT" });
    expect(await readFile(archive)).toEqual(gzipSync("CREATE TABLE fixture (id integer);\n"));
  });

  it.each([
    ["empty file", Buffer.alloc(0)], ["empty SQL", gzipSync("")],
    ["truncated gzip", gzipSync("SELECT 1;").subarray(0, -4)],
    ["plain text", Buffer.from("SELECT 1;")],
  ])("rejects %s and retains the restart obligation", async (_label, contents) => {
    await markIdleBackupWakeRequired(directory);
    const archive = path.join(directory, "invalid.sql.gz");
    await writeFile(archive, contents);
    await expect(verifyIdleDatabaseBackup(archive)).rejects.toThrow();
    expect(await readFile(idleBackupWakeMarker(directory), "utf8")).toContain("restarts");
  });

  it("rejects a missing archive and symlinked archive or marker", async () => {
    const archive = path.join(directory, "backup.sql.gz");
    await expect(verifyIdleDatabaseBackup(archive)).rejects.toThrow();
    const target = path.join(directory, "target");
    await writeFile(target, gzipSync("SELECT 1;"));
    await symlink(target, archive);
    await expect(verifyIdleDatabaseBackup(archive)).rejects.toThrow();
    await symlink(target, idleBackupWakeMarker(directory));
    await expect(markIdleBackupWakeRequired(directory)).rejects.toThrow();
    expect(await readFile(target)).toEqual(gzipSync("SELECT 1;"));
  });
});