import { existsSync } from "node:fs";
import { mkdir, mkdtemp, rm, unlink, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { afterEach, describe, expect, it, vi } from "vitest";
import { env } from "../../../apps/api/src/config.js";
import {
  assertLocalCapacity,
  computeWorkspaceUsedBytes,
  isOverWorkspaceCap,
} from "../../../apps/api/src/lib/object-storage.js";

describe("isOverWorkspaceCap", () => {
  it("is disabled (never over) when maxGb is 0", () => {
    expect(isOverWorkspaceCap(999 * 1024 ** 3, 0)).toBe(false);
  });

  it("is false when usage is under the cap", () => {
    expect(isOverWorkspaceCap(5 * 1024 ** 3, 10)).toBe(false);
  });

  it("is true when usage exceeds the cap", () => {
    expect(isOverWorkspaceCap(11 * 1024 ** 3, 10)).toBe(true);
  });
});

describe("computeWorkspaceUsedBytes", () => {
  let root = "";
  afterEach(async () => {
    if (root) await rm(root, { recursive: true, force: true });
    root = "";
  });

  it("sums file sizes across uploads/ and outputs/ job dirs", async () => {
    root = await mkdtemp(join(tmpdir(), "snapotter-wscap-"));
    await mkdir(join(root, "uploads", "job1"), { recursive: true });
    await mkdir(join(root, "outputs", "job2"), { recursive: true });
    await writeFile(join(root, "uploads", "job1", "a.bin"), Buffer.alloc(1000));
    await writeFile(join(root, "outputs", "job2", "b.bin"), Buffer.alloc(2000));
    expect(await computeWorkspaceUsedBytes(root)).toBe(3000);
  });

  it("returns 0 for an empty or missing workspace", async () => {
    root = await mkdtemp(join(tmpdir(), "snapotter-wscap-"));
    expect(await computeWorkspaceUsedBytes(root)).toBe(0);
    expect(await computeWorkspaceUsedBytes(join(root, "nope"))).toBe(0);
  });
});

// assertLocalCapacity wires the aggregate size cap and the free-space floor to
// the real WORKSPACE_PATH. This file never calls putObject, so the module's
// 30s workspace-size cache starts empty; each test picks a base timestamp far
// past any prior one so its first check recomputes rather than reusing a stale
// cached total.
describe("assertLocalCapacity capacity guard", () => {
  const originalWorkspace = env.WORKSPACE_PATH;
  const originalMaxGb = env.MAX_WORKSPACE_SIZE_GB;
  let root = "";
  let nowBase = 1_000_000_000_000;

  afterEach(async () => {
    vi.restoreAllMocks();
    (env as { WORKSPACE_PATH: string }).WORKSPACE_PATH = originalWorkspace;
    (env as { MAX_WORKSPACE_SIZE_GB: number }).MAX_WORKSPACE_SIZE_GB = originalMaxGb;
    if (root) await rm(root, { recursive: true, force: true });
    root = "";
    // Advance the base well past the 30s cache window for the next test.
    nowBase += 10 * 60_000;
  });

  it("returns without error when the workspace root does not exist yet", async () => {
    (env as { WORKSPACE_PATH: string }).WORKSPACE_PATH = join(
      tmpdir(),
      `snapotter-absent-${process.pid}-${Date.now()}`,
    );
    (env as { MAX_WORKSPACE_SIZE_GB: number }).MAX_WORKSPACE_SIZE_GB = 0.000001;
    await expect(assertLocalCapacity()).resolves.toBeUndefined();
  });

  it("passes when usage is under the configured aggregate cap", async () => {
    root = await mkdtemp(join(tmpdir(), "snapotter-cap-under-"));
    await mkdir(join(root, "uploads", "job1"), { recursive: true });
    await writeFile(join(root, "uploads", "job1", "a.bin"), Buffer.alloc(4096));
    (env as { WORKSPACE_PATH: string }).WORKSPACE_PATH = root;
    (env as { MAX_WORKSPACE_SIZE_GB: number }).MAX_WORKSPACE_SIZE_GB = 10;
    vi.spyOn(Date, "now").mockReturnValue(nowBase);

    await expect(assertLocalCapacity()).resolves.toBeUndefined();
  });

  it("does not enforce the aggregate cap when MAX_WORKSPACE_SIZE_GB is 0", async () => {
    root = await mkdtemp(join(tmpdir(), "snapotter-cap-off-"));
    await mkdir(join(root, "outputs", "job1"), { recursive: true });
    await writeFile(join(root, "outputs", "job1", "big.bin"), Buffer.alloc(2 * 1024 * 1024));
    (env as { WORKSPACE_PATH: string }).WORKSPACE_PATH = root;
    (env as { MAX_WORKSPACE_SIZE_GB: number }).MAX_WORKSPACE_SIZE_GB = 0;
    vi.spyOn(Date, "now").mockReturnValue(nowBase);

    // Cap disabled: even a tiny disk must not 503 on the cap path. statfs on a
    // real temp dir reports the (ample) host free space, so the floor passes too.
    await expect(assertLocalCapacity()).resolves.toBeUndefined();
  });

  it("throws a 503 when aggregate usage exceeds the cap", async () => {
    root = await mkdtemp(join(tmpdir(), "snapotter-cap-over-"));
    await mkdir(join(root, "outputs", "job1"), { recursive: true });
    // 2 MiB of files; cap of 0.001 GB (~1 MiB) is exceeded.
    await writeFile(join(root, "outputs", "job1", "big.bin"), Buffer.alloc(2 * 1024 * 1024));
    (env as { WORKSPACE_PATH: string }).WORKSPACE_PATH = root;
    (env as { MAX_WORKSPACE_SIZE_GB: number }).MAX_WORKSPACE_SIZE_GB = 0.001;
    vi.spyOn(Date, "now").mockReturnValue(nowBase);

    await expect(assertLocalCapacity()).rejects.toMatchObject({
      statusCode: 503,
      message: expect.stringMatching(/storage limit/i),
    });
  });

  it("reuses the cached workspace total within the cache window", async () => {
    root = await mkdtemp(join(tmpdir(), "snapotter-cap-cache-"));
    await mkdir(join(root, "outputs", "job1"), { recursive: true });
    const big = join(root, "outputs", "job1", "big.bin");
    await writeFile(big, Buffer.alloc(2 * 1024 * 1024));
    (env as { WORKSPACE_PATH: string }).WORKSPACE_PATH = root;
    (env as { MAX_WORKSPACE_SIZE_GB: number }).MAX_WORKSPACE_SIZE_GB = 0.001;
    // Freeze time so both calls fall inside the 30s window.
    vi.spyOn(Date, "now").mockReturnValue(nowBase);

    // First call computes the real total (2 MiB) and trips the cap.
    await expect(assertLocalCapacity()).rejects.toMatchObject({ statusCode: 503 });

    // Delete every file so a fresh recompute would report 0 bytes and pass. The
    // second call still trips the cap, proving it read the cached total, not disk.
    await unlink(big);
    expect(existsSync(big)).toBe(false);
    await expect(assertLocalCapacity()).rejects.toMatchObject({ statusCode: 503 });
  });
});