import { test, expect } from "vitest";
import { chmodSync, existsSync, lstatSync, mkdirSync, mkdtempSync, readFileSync, readdirSync, renameSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { dirname, join } from "node:path";
import { execFileSync } from "node:child_process";
import { createHash } from "node:crypto";
import { runBoundedHelper, WorkspaceRuntimeConfigLeaseFactory } from "../src/workspaces/runtime-config-lease.js";
import { parse } from "yaml";
import { parseWorkspaceYaml, serializeWorkspaceYaml } from "../src/workspaces/schema.js";

const workspace = "abc";
const descriptor = `workspace:
  schema_version: 3
  id: ${workspace}
  name: Lease
  language: en
dwh:
  engine: postgres
  database: analytics
  schema: mart
  supported_transports: [postgres_direct]
semantic_index:
  vector_store:
    engine: qdrant
    collection: abc
    dimensions: 1024
    distance: cosine
  embedding:
    provider: ollama_internal
    model: qwen3-embedding:0.6b
    dimensions: 1024
llm_policy:
  allowed: [zai/glm-5.2]
`;

function fixture(extraEnv: Record<string, string> = {}) {
  const root = mkdtempSync(join(tmpdir(), "runtime-config-lease-"));
  const canonicalDescriptor = serializeWorkspaceYaml(parseWorkspaceYaml(descriptor));
  const snapshots = join(root, "snapshots");
  const repo = join(root, "repo");
  mkdirSync(join(repo, "workspaces"), { recursive: true });
  execFileSync("git", ["init", "--initial-branch=main"], { cwd: repo });
  execFileSync("git", ["config", "user.name", "Fixture"], { cwd: repo });
  execFileSync("git", ["config", "user.email", "fixture@example.invalid"], { cwd: repo });
  writeFileSync(join(repo, "workspaces", `${workspace}.yaml`), canonicalDescriptor);
  execFileSync("git", ["add", "."], { cwd: repo });
  execFileSync("git", ["commit", "-m", "fixture"], { cwd: repo });
  const actualCommit = execFileSync("git", ["rev-parse", "HEAD"], { cwd: repo, encoding: "utf8" }).trim();
  const blob = execFileSync("git", ["rev-parse", `HEAD:workspaces/${workspace}.yaml`], { cwd: repo, encoding: "utf8" }).trim();
  const snapshotsDir = join(snapshots, actualCommit);
  const snapshotPath = join(snapshotsDir, `${workspace}.yaml`);
  const dataRoot = join(root, "data");
  const harness = join(root, "harness");
  mkdirSync(snapshotsDir, { recursive: true, mode: 0o700 });
  chmodSync(snapshots, 0o700);
  const publicFiles = {
    [`${workspace}.yaml`]: canonicalDescriptor,
    [`${workspace}.env.example`]: "# fixture\n",
    [`${workspace}.md`]: "# Lease\n",
  };
  for (const [name, contents] of Object.entries(publicFiles)) writeFileSync(join(snapshotsDir, name), contents, { mode: 0o400 });
  writeFileSync(join(snapshotsDir, "snapshot.json"), JSON.stringify({
    head: actualCommit,
    revisions: [{ id: workspace, commit: actualCommit, blob, snapshotPath }],
    files: Object.fromEntries(Object.entries(publicFiles).map(([name, contents]) => [name, createHash("sha256").update(contents).digest("hex")])),
  }), { mode: 0o400 });
  mkdirSync(harness);
  const secret = join(root, "password");
  writeFileSync(secret, "secret", { mode: 0o600 });
  const configPath = join(harness, "config.yaml");
  writeFileSync(configPath, "profile: workstation\n");
  const factoryInput = {
    dataRoot, runtimeSnapshotRoot: snapshots, harnessDir: harness, configPath,
    env: {
      NODE_ENV: "test",
      THT_WS_ABC_DWH_TRANSPORT: "postgres_direct", THT_WS_ABC_DWH_HOST: "dwh",
      THT_WS_ABC_DWH_PORT: "5432", THT_WS_ABC_DWH_USER: "reader",
      THT_WS_ABC_DWH_PASSWORD_FILE: secret, ...extraEnv,
    }, secretRoots: [root], semanticRuntime: {
      internalQdrantUrl: "http://qdrant:6333", internalEmbeddingUrl: "http://embedding:11434",
      internalEmbeddingModel: "qwen3-embedding:0.6b", internalEmbeddingDimensions: 1024,
    },
  };
  const factory = new WorkspaceRuntimeConfigLeaseFactory(factoryInput);
  return { root, repo, snapshotPath, factory, factoryInput, canonicalDescriptor, snapshotManifest: join(snapshotsDir, "snapshot.json") };
}

test("session and maintenance share deterministic bytes and path", async () => {
  const f = fixture();
  try {
    const session = await f.factory.acquireSession(f.snapshotPath);
    const maintenance = await f.factory.acquireMaintenance({ snapshotPath: f.snapshotPath });
    expect(session.path).toBe(maintenance.path);
    expect(readFileSync(session.path, "utf8")).toBe(readFileSync(maintenance.path, "utf8"));
    expect(lstatSync(session.path).mode & 0o777).toBe(0o400);
    expect(existsSync(maintenance.manifestPath)).toBe(true);
    const manifest = JSON.parse(readFileSync(maintenance.manifestPath, "utf8"));
    expect(manifest).toMatchObject({ version: 1, descriptor_dev: expect.any(String), descriptor_ino: expect.any(String) });
    expect(existsSync(join(dirname(dirname(maintenance.path)), "runtime-config.lock"))).toBe(false);
    session.release(); maintenance.release();
    expect(existsSync(session.path)).toBe(true);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("same revision changed bytes are refused", async () => {
  const f = fixture();
  try {
    const first = await f.factory.acquireSession(f.snapshotPath);
    chmodSync(first.path, 0o600);
    writeFileSync(first.path, "changed", { mode: 0o600 });
    chmodSync(first.path, 0o400);
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/changed|mismatch|trusted/i);
    first.release();
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("snapshot descriptor must equal the Git canonical descriptor", async () => {
  const f = fixture();
  try {
    const mutated = f.canonicalDescriptor.replace("database: analytics", "database: evil").replace("name: Lease", "name: Lease analytics");
    chmodSync(f.snapshotPath, 0o600);
    writeFileSync(f.snapshotPath, mutated, { mode: 0o600 });
    chmodSync(f.snapshotPath, 0o400);
    const manifestPath = join(dirname(f.snapshotPath), "snapshot.json");
    const manifest = JSON.parse(readFileSync(manifestPath, "utf8"));
    manifest.files[`${workspace}.yaml`] = createHash("sha256").update(mutated).digest("hex");
    chmodSync(manifestPath, 0o600);
    writeFileSync(manifestPath, JSON.stringify(manifest), { mode: 0o600 });
    chmodSync(manifestPath, 0o400);
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/Git descriptor|integrity|identity/i);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("same-byte replacement of the registry descriptor is refused", async () => {
  const f = fixture();
  try {
    const first = await f.factory.acquireSession(f.snapshotPath);
    const replacement = `${f.snapshotPath}.replacement`;
    writeFileSync(replacement, readFileSync(f.snapshotPath), { mode: 0o400 });
    chmodSync(f.snapshotPath, 0o600);
    rmSync(f.snapshotPath);
    writeFileSync(f.snapshotPath, readFileSync(replacement), { mode: 0o400 });
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/identity|changed|mismatch|trusted/i);
    first.release();
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test("manifest binds the complete canonical destination directory chain", async () => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const manifest = JSON.parse(readFileSync(lease.manifestPath, "utf8"));
    expect(manifest.directory_identities.length).toBeGreaterThan(5);
    expect(manifest.directory_identities.map((entry: { path: string }) => entry.path)).toContain(
      `${process.platform === "darwin" ? "/private" : ""}${join(f.root, "data", "sessions", workspace, "preprocessing")}`,
    );
    expect(manifest.directory_identities.every((entry: Record<string, string>) =>
      ["path", "dev", "ino", "mode", "uid"].every((key) => typeof entry[key] === "string"),
    )).toBe(true);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("raw Git identity ignores replacement refs", async () => {
  const f = fixture();
  try {
    const evil = f.canonicalDescriptor.replace("database: analytics", "database: evil");
    chmodSync(join(f.repo, "workspaces", `${workspace}.yaml`), 0o600);
    writeFileSync(join(f.repo, "workspaces", `${workspace}.yaml`), evil);
    execFileSync("git", ["add", "."], { cwd: f.repo });
    execFileSync("git", ["commit", "-m", "evil"], { cwd: f.repo });
    const evilCommit = execFileSync("git", ["rev-parse", "HEAD"], { cwd: f.repo, encoding: "utf8" }).trim();
    const oldCommit = JSON.parse(readFileSync(f.snapshotManifest, "utf8")).head;
    execFileSync("git", ["replace", oldCommit, evilCommit], { cwd: f.repo });
    chmodSync(f.snapshotPath, 0o600);
    writeFileSync(f.snapshotPath, evil);
    chmodSync(f.snapshotPath, 0o400);
    const snapshot = JSON.parse(readFileSync(f.snapshotManifest, "utf8"));
    snapshot.files[`${workspace}.yaml`] = createHash("sha256").update(evil).digest("hex");
    chmodSync(f.snapshotManifest, 0o600);
    writeFileSync(f.snapshotManifest, JSON.stringify(snapshot));
    chmodSync(f.snapshotManifest, 0o400);
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/Git descriptor|integrity|identity/i);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("replacement of canonical destination directories is refused", async () => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const original = join(f.root, "data", "sessions", workspace);
    const moved = `${original}.moved`;
    renameSync(original, moved);
    mkdirSync(join(original, "preprocessing", "runtime-config"), { recursive: true, mode: 0o700 });
    mkdirSync(join(original, "preprocessing", "runtime-config-manifests"), { recursive: true, mode: 0o700 });
    renameSync(join(moved, "preprocessing", "runtime-config", `${lease.workspaceRevision}.yaml`), join(original, "preprocessing", "runtime-config", `${lease.workspaceRevision}.yaml`));
    renameSync(join(moved, "preprocessing", "runtime-config-manifests", `${lease.workspaceRevision}.json`), join(original, "preprocessing", "runtime-config-manifests", `${lease.workspaceRevision}.json`));
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/changed|mismatch|same-revision|identity|trusted/i);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("rename faults fail closed and remove staging files", async () => {
  const f = fixture({ THT_RUNTIME_CONFIG_RENAME_FAIL: "1" });
  try {
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/rename|failed/i);
    const runtime = join(f.root, "data", "sessions", workspace, "preprocessing");
    for (const dir of ["runtime-config", "runtime-config-manifests"]) {
      if (existsSync(join(runtime, dir))) expect(readdirSync(join(runtime, dir)).filter((name) => name.includes("staging")).length).toBe(0);
    }
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test("session and operator outputs retain normalized private-host policy and binding", async () => {
  const f = fixture({ THT_HTTP_PRIVATE_HOST_ALLOWLIST: "internal.example,warehouse.example" });
  try {
    const session = await f.factory.acquireSession(f.snapshotPath);
    const maintenance = await f.factory.acquireMaintenance({ snapshotPath: f.snapshotPath });
    const output = readFileSync(session.path, "utf8");
    expect(output).toContain("http_private_host_allowlist");
    expect(output).toContain("- internal.example");
    expect(output).toContain("- warehouse.example");
    expect(output).toBe(readFileSync(maintenance.path, "utf8"));
    const manifest = JSON.parse(readFileSync(session.manifestPath, "utf8"));
    expect(manifest.config_dwh_binding).toEqual({
      workspace_id: expect.any(String), config_fingerprint: expect.any(String), input_fingerprint: expect.any(String),
    });
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test("unexpected manifest fields are refused before handoff", async () => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const manifest = JSON.parse(readFileSync(lease.manifestPath, "utf8"));
    manifest.unexpected = true;
    chmodSync(lease.manifestPath, 0o600);
    writeFileSync(lease.manifestPath, JSON.stringify(manifest));
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/manifest|invalid|changed/i);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("runtime config symlink replacement is refused", async () => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const replacement = `${lease.path}.real`;
    writeFileSync(replacement, readFileSync(lease.path), { mode: 0o400 });
    chmodSync(lease.path, 0o600);
    rmSync(lease.path);
    // A no-follow handoff must never consume this pathname.
    execFileSync("ln", ["-s", replacement, lease.path]);
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/trusted|changed|configuration|symbolic/i);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


function realHarnessBinding(config: string): Record<string, string> {
  const helper = join(process.cwd(), "..", "harness", "tht", "runtime_config_lease_io.py");
  const python = join(process.cwd(), "..", "harness", ".venv", "bin", "python");
  const result = JSON.parse(execFileSync(python, [helper], {
    cwd: join(process.cwd(), "..", "harness"), encoding: "utf8",
    input: JSON.stringify({ protocol_version: 1, action: "binding", config_hex: Buffer.from(config).toString("hex") }),
  }));
  const { protocol_version: _protocol, kind: _kind, ...binding } = result;
  return binding;
}

test("explicit installation overlay is canonical and has one real harness binding", async () => {
  const f = fixture();
  const overlay = {
    profile: "workstation",
    session_storage: { type: "postgres_direct", connection: {
      host: "session-db", port: 5432, database: "sessions", schema: "public",
      user: "runtime", password: "secret", sslmode: "verify-full",
    } },
    egress: { http_private_host_allowlist: ["zeta.example", "alpha.example", "warehouse.example"] },
  };
  const sessionFactory = new WorkspaceRuntimeConfigLeaseFactory({ ...f.factoryInput, installationOverlay: overlay });
  const maintenanceFactory = new WorkspaceRuntimeConfigLeaseFactory({ ...f.factoryInput, installationOverlay: overlay });
  try {
    const session = await sessionFactory.acquireSession(f.snapshotPath);
    const maintenance = await maintenanceFactory.acquireMaintenance({ workspaceConfigPath: f.snapshotPath });
    const sessionYaml = readFileSync(session.path, "utf8");
    const maintenanceYaml = readFileSync(maintenance.path, "utf8");
    expect(session.path).toBe(maintenance.path);
    expect(sessionYaml).toBe(maintenanceYaml);
    expect(parse(sessionYaml)).toMatchObject({
      profile: overlay.profile,
      session_storage: overlay.session_storage,
      egress: { http_private_host_allowlist: ["alpha.example", "warehouse.example", "zeta.example"] },
    });
    const firstBinding = realHarnessBinding(sessionYaml);
    const secondBinding = realHarnessBinding(maintenanceYaml);
    expect(firstBinding).toEqual(secondBinding);
    expect(JSON.parse(readFileSync(session.manifestPath, "utf8")).config_dwh_binding).toEqual(firstBinding);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test.each([
  ["config-file", "config-file"], ["config-parent", "config-parent"],
  ["manifest-file", "manifest-file"], ["manifest-parent", "manifest-parent"],
] as const)("fsync fault at %s fails closed and retries to the same durable pair", async (_label, stage) => {
  const f = fixture({ THT_RUNTIME_CONFIG_FSYNC_FAIL: stage });
  try {
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/fsync|failed/i);
    const runtime = join(f.root, "data", "sessions", workspace, "preprocessing");
    for (const dir of ["runtime-config", "runtime-config-manifests"]) {
      if (existsSync(join(runtime, dir))) {
        expect(readdirSync(join(runtime, dir)).filter((name) => name.includes("staging")).length).toBe(0);
      }
    }
    const recovered = new WorkspaceRuntimeConfigLeaseFactory({ ...f.factoryInput, env: {
      ...f.factoryInput.env, THT_RUNTIME_CONFIG_FSYNC_FAIL: undefined,
    } });
    const lease = await recovered.acquireSession(f.snapshotPath);
    expect(existsSync(lease.path)).toBe(true);
    expect(existsSync(lease.manifestPath)).toBe(true);
    expect(JSON.parse(readFileSync(lease.manifestPath, "utf8")).config_sha256)
      .toBe(createHash("sha256").update(readFileSync(lease.path)).digest("hex"));
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

for (const [label, mutate] of [
  ["wrong commit", (f: ReturnType<typeof fixture>) => f.snapshotPath.replace(/\/[0-9a-f]{40}\//, "/" + "0".repeat(40) + "/")],
  ["outside path", (f: ReturnType<typeof fixture>) => join(f.root, "outside.yaml")],
  ["wrong workspace id", (f: ReturnType<typeof fixture>) => f.snapshotPath.replace("abc.yaml", "abd.yaml")],
] as const) {
  test(`rejects ${label} before publication`, async () => {
    const f = fixture();
    try {
      await expect(f.factory.acquireSession(mutate(f))).rejects.toThrow(/trusted|snapshot|identity|path|Git|unavailable|ENOENT|No such/i);
    } finally { rmSync(f.root, { recursive: true, force: true }); }
  });
}

for (const [label, replace] of [
  ["descriptor symlink", (path: string, root: string) => { const target = `${path}.target`; writeFileSync(target, readFileSync(path), { mode: 0o400 }); rmSync(path); execFileSync("ln", ["-s", target, path]); }],
  ["descriptor hardlink", (path: string, root: string) => { const target = `${path}.target`; execFileSync("ln", [path, target]); rmSync(path); execFileSync("ln", [target, path]); }],
] as const) {
  test(`rejects ${label}`, async () => {
    const f = fixture();
    try {
      replace(f.snapshotPath, f.root);
      await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/trusted|integrity|identity|link/i);
    } finally { rmSync(f.root, { recursive: true, force: true }); }
  });
}

for (const [label, target] of [
  ["config symlink", "config"], ["config hardlink", "config"],
  ["manifest symlink", "manifest"], ["manifest hardlink", "manifest"],
] as const) {
  test(`rejects destination ${label} and recovers safely`, async () => {
    const f = fixture();
    try {
      const first = await f.factory.acquireSession(f.snapshotPath);
      const path = target === "config" ? first.path : first.manifestPath;
      const backup = `${path}.target`;
      writeFileSync(backup, readFileSync(path), { mode: target === "config" ? 0o400 : 0o600 });
      rmSync(path);
      if (label.includes("symlink")) execFileSync("ln", ["-s", backup, path]);
      else execFileSync("ln", [backup, path]);
      await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/trusted|configuration|manifest|link|changed/i);
      rmSync(path);
      // A replaced inode can never be trusted again. Remove the paired durable
      // publication and let a fresh no-replace publication recover the layout.
      rmSync(first.path, { force: true });
      rmSync(first.manifestPath, { force: true });
      const recovered = await f.factory.acquireSession(f.snapshotPath);
      expect(recovered.path).toBe(first.path);
    } finally { rmSync(f.root, { recursive: true, force: true }); }
  });
}

for (const [label, target, mode] of [
  ["config", "config", 0o600], ["manifest", "manifest", 0o400],
] as const) {
  test(`refuses wrong ${label} mode then recovers after restoring mode`, async () => {
    const f = fixture();
    try {
      const first = await f.factory.acquireSession(f.snapshotPath);
      const path = target === "config" ? first.path : first.manifestPath;
      chmodSync(path, mode);
      await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/trusted|mode|configuration|manifest/i);
      chmodSync(path, target === "config" ? 0o400 : 0o600);
      await expect(f.factory.acquireSession(f.snapshotPath)).resolves.toBeDefined();
    } finally { rmSync(f.root, { recursive: true, force: true }); }
  });
}

 test("release retains durable state while changed binding is refused by a new factory", async () => {
  const f = fixture();
  try {
    const first = await f.factory.acquireSession(f.snapshotPath);
    first.release();
    const changed = new WorkspaceRuntimeConfigLeaseFactory({ ...f.factoryInput, env: {
      ...f.factoryInput.env, THT_WS_ABC_DWH_HOST: "other-dwh",
    } });
    await expect(changed.acquireSession(f.snapshotPath)).rejects.toThrow(/changed|mismatch|configuration/i);
    expect(existsSync(first.path)).toBe(true);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("strict manifest rejects an extra field and recovery preserves exact bytes", async () => {
  const f = fixture();
  try {
    const first = await f.factory.acquireSession(f.snapshotPath);
    const original = readFileSync(first.manifestPath, "utf8");
    const manifest = JSON.parse(original);
    manifest.extra = "reject";
    chmodSync(first.manifestPath, 0o600);
    writeFileSync(first.manifestPath, JSON.stringify(manifest), { mode: 0o600 });
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/manifest|invalid|changed/i);
    writeFileSync(first.manifestPath, original, { mode: 0o600 });
    await expect(f.factory.acquireSession(f.snapshotPath)).resolves.toBeDefined();
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test.each([
  ["duplicate", "alpha.example,alpha.example"],
  ["uppercase", "Alpha.example"],
  ["ip address", "127.0.0.1"],
] as const)("rejects %s private-host policy", async (_label, allowlist) => {
  expect(() => fixture({ THT_HTTP_PRIVATE_HOST_ALLOWLIST: allowlist }))
    .toThrow(/allowlist|hostname|duplicate|invalid/i);
});

test.each([
  ["runtime-config", "config"], ["runtime-config-manifests", "manifest"],
] as const)("rejects a replaced %s destination ancestor", async (directory, _kind) => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const parent = join(f.root, "data", "sessions", workspace, "preprocessing", directory);
    const moved = `${parent}.moved`;
    renameSync(parent, moved);
    execFileSync("ln", ["-s", moved, parent]);
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/trusted|symbolic|changed|directory/i);
    rmSync(parent);
    renameSync(moved, parent);
    await expect(f.factory.acquireSession(f.snapshotPath)).resolves.toBeDefined();
    lease.release();
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("release is idempotent and does not remove either durable publication", async () => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    lease.release(); lease.release();
    expect(existsSync(lease.path)).toBe(true);
    expect(existsSync(lease.manifestPath)).toBe(true);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("partial os.write calls are completed by the real Python publication helper", async () => {
  const python = join(process.cwd(), "..", "harness", ".venv", "bin", "python");
  const helper = join(process.cwd(), "..", "harness", "tht", "runtime_config_lease_io.py");
  const code = `import os, sys; sys.path.insert(0, ${JSON.stringify(dirname(helper))}); import runtime_config_lease_io as m; real=os.write; os.write=lambda fd,b: real(fd,b[:3]); m.write_all(1, b'partial-write-ok\\n')`;
  const output = execFileSync(python, ["-c", code], { encoding: "utf8" });
  expect(output).toBe("partial-write-ok\n");
});

test("a clean existing equal publication is reconciled by a new factory", async () => {
  const f = fixture();
  try {
    const first = await f.factory.acquireSession(f.snapshotPath);
    const second = await new WorkspaceRuntimeConfigLeaseFactory(f.factoryInput).acquireMaintenance({ snapshotPath: f.snapshotPath });
    expect(readFileSync(second.path)).toEqual(readFileSync(first.path));
    expect(readFileSync(second.manifestPath)).toEqual(readFileSync(first.manifestPath));
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test.each([["config"], ["manifest"]] as const)("rename failure is scoped to the %s branch and leaves no staging", async (kind) => {
  const f = fixture({ THT_RUNTIME_CONFIG_RENAME_FAIL: kind });
  try {
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/rename|failed/i);
    const runtime = join(f.root, "data", "sessions", workspace, "preprocessing");
    for (const dir of ["runtime-config", "runtime-config-manifests"]) {
      if (existsSync(join(runtime, dir))) expect(readdirSync(join(runtime, dir)).some((name) => name.includes("staging"))).toBe(false);
    }
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});

test("snapshot manifest rejects an undeclared extra immutable file", async () => {
  const f = fixture();
  try {
    const snapshot = JSON.parse(readFileSync(f.snapshotManifest, "utf8"));
    writeFileSync(join(dirname(f.snapshotPath), "smuggled.txt"), "smuggled", { mode: 0o400 });
    snapshot.files["smuggled.txt"] = createHash("sha256").update("smuggled").digest("hex");
    chmodSync(f.snapshotManifest, 0o600);
    writeFileSync(f.snapshotManifest, JSON.stringify(snapshot), { mode: 0o400 });
    await expect(f.factory.acquireSession(f.snapshotPath)).rejects.toThrow(/integrity|snapshot|trusted/i);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test("independent OS publishers converge when equal and elect one winner when unequal", async () => {
  const f = fixture();
  try {
    const seed = await f.factory.acquireSession(f.snapshotPath);
    const full = JSON.parse(readFileSync(seed.manifestPath, "utf8"));
    const base = Object.fromEntries(["workspace_id", "workspace_revision", "descriptor_git_blob",
      "descriptor_sha256", "descriptor_dev", "descriptor_ino", "config_dwh_binding"]
      .map((key) => [key, full[key]]));
    const python = join(process.cwd(), "..", "harness", ".venv", "bin", "python");
    const helper = join(process.cwd(), "..", "harness", "tht", "runtime_config_lease_io.py");
    const configBytes = readFileSync(seed.path);
    // Leave the workspace-owned destination directories in place, but remove
    // both durable leaves: the following OS processes race on a clean layout.
    rmSync(seed.path); rmSync(seed.manifestPath);
    const payload = JSON.stringify({ protocol_version: 1, action: "publish", data_root: f.factoryInput.dataRoot,
      workspace_id: workspace, workspace_revision: full.workspace_revision,
      config_hex: Buffer.from(configBytes).toString("hex"), manifest_base: base });
    const code = `import json,multiprocessing,sys
multiprocessing.set_start_method("fork")
sys.path.insert(0, ${JSON.stringify(dirname(helper))})
import runtime_config_lease_io as m
import contextlib,os
def run(x):
  try:
    with open(os.devnull,"w") as error, contextlib.redirect_stderr(error): m.publish(x)
  except Exception: raise SystemExit(1)
x=json.loads(sys.argv[1]); y=json.loads(sys.argv[1])
if len(sys.argv)>2: y["config_hex"]="646966666572656e742d72756e74696d652d636f6e666967"
p=[multiprocessing.Process(target=run,args=(x,)),multiprocessing.Process(target=run,args=(y,))]
[q.start() for q in p]; [q.join() for q in p]
print(json.dumps([q.exitcode for q in p]))`
    const equal = JSON.parse(execFileSync(python, ["-c", code, payload], { encoding: "utf8" }).trim());
    expect(equal.sort()).toEqual([0, 0]);
    rmSync(join(f.factoryInput.dataRoot, "sessions", workspace, "preprocessing", "runtime-config", `${full.workspace_revision}.yaml`));
    rmSync(join(f.factoryInput.dataRoot, "sessions", workspace, "preprocessing", "runtime-config-manifests", `${full.workspace_revision}.json`));
    const unequalPayload = JSON.stringify({ ...JSON.parse(payload), config_hex: Buffer.from("different-runtime-config").toString("hex") });
    const unequal = JSON.parse(execFileSync(python, ["-c", code, payload, "unequal"], { encoding: "utf8" }).trim());
    expect(unequal.filter((exit: number) => exit === 0)).toHaveLength(1);
    expect(unequal.filter((exit: number) => exit !== 0)).toHaveLength(1);
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test.each(["leaf", "ancestor"] as const)("actual harness rejects canonical %s swap", async (kind) => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const harnessBin = join(process.cwd(), "..", "harness", ".venv", "bin", "tht");
    const harnessCwd = join(process.cwd(), "..", "harness");
    const env = { ...process.env, THT_RUNTIME_CONFIG_MANIFEST_SHA256: lease.manifestSha256 };
    if (kind === "leaf") {
      const moved = `${lease.path}.moved`;
      renameSync(lease.path, moved);
      execFileSync("ln", ["-s", moved, lease.path]);
    } else {
      const parent = dirname(lease.path);
      const moved = `${parent}.moved`;
      renameSync(parent, moved);
      execFileSync("ln", ["-s", moved, parent]);
    }
    expect(() => execFileSync(harnessBin, ["config", "check", "-c", lease.path], {
      cwd: harnessCwd, env, stdio: "pipe",
    })).toThrow();
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test("actual harness rejects a workspace chain swap between config and manifest traversal", async () => {
  const f = fixture();
  try {
    const lease = await f.factory.acquireSession(f.snapshotPath);
    const python = join(process.cwd(), "..", "harness", ".venv", "bin", "python");
    const helper = join(process.cwd(), "..", "harness", "tht");
    const workspaceRoot = join(f.factoryInput.dataRoot, "sessions", workspace);
    const code = `import os,sys
from pathlib import Path
sys.path.insert(0, sys.argv[3])
from tht.config import ConfigError, _read_runtime_config_source
config_path = Path(sys.argv[1])
workspace = Path(sys.argv[2])
revision = config_path.stem

def swap_workspace_chain():
    moved = Path(str(workspace) + ".moved")
    os.rename(workspace, moved)
    (workspace / "preprocessing").mkdir(parents=True, mode=0o700)
    for name, leaf in (("runtime-config", revision + ".yaml"),
                       ("runtime-config-manifests", revision + ".json")):
        source = moved / "preprocessing" / name
        destination = workspace / "preprocessing" / name
        original_inode = os.stat(source).st_ino
        original_leaf_inode = os.stat(source / leaf).st_ino
        os.rename(source, destination)
        assert os.stat(destination).st_ino == original_inode
        assert os.stat(destination / leaf).st_ino == original_leaf_inode

try:
    _read_runtime_config_source(
        config_path,
        between_config_and_manifest_traversal=swap_workspace_chain,
    )
except ConfigError:
    print("rejected")
else:
    raise SystemExit("secure reader accepted a replaced workspace chain")
`;
    const output = execFileSync(python, ["-c", code, lease.path, workspaceRoot, helper], {
      cwd: join(process.cwd(), "..", "harness"),
      env: { ...process.env, THT_RUNTIME_CONFIG_MANIFEST_SHA256: lease.manifestSha256 },
      encoding: "utf8",
    });
    expect(output.trim()).toBe("rejected");
  } finally { rmSync(f.root, { recursive: true, force: true }); }
});


test("bounded helper settles early stdin close and a never-reading child without crashing", async () => {
  const options = (action: string, payload: string, timeoutMs = 200) => ({
    cwd: tmpdir(), env: process.env, action, payload, timeoutMs,
  });
  await expect(runBoundedHelper(process.execPath, ["-e", "process.stdin.destroy(); setTimeout(() => {}, 1000)"],
    options("early-close", "x".repeat(16 * 1024 * 1024)))).rejects.toThrow();
  const started = Date.now();
  const timer = new Promise<void>((resolve) => setTimeout(resolve, 20));
  await expect(runBoundedHelper(process.execPath, ["-e", "setTimeout(() => {}, 10000)"],
    options("never-read", "x".repeat(16 * 1024 * 1024), 80))).rejects.toThrow(/timed out|pipe|closed/i);
  await timer;
  expect(Date.now() - started).toBeLessThan(2_000);
});