import { describe, it, expect, afterEach } from 'vitest';
import { Command } from 'commander';
import { existsSync, mkdirSync, rmSync, writeFileSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import {
  LEASE_ACTIVATION_CAPABILITY,
  LEASE_CAPABILITY_PROBE_COMMAND,
  defaultCapabilityProbe,
  defaultSupervisorProbe,
  leaseEnforcementActivatable,
  registerLeaseCapabilityProbe,
  type LeaseActivationCapability,
  type SupervisorProbeResult,
} from './lease-activation-probe.js';

/**
 * Red-first tests for issue #869 Point-1 C1 — leaseEnforcementActivatable().
 *
 * Root cause under test: #828 shipped the lease broker's ENFORCEMENT half
 * (hooks) and ACTIVATION half (execLeaseGatedRuntime + a running daemon.py
 * broker) on different channels, and they drifted — the published CLI
 * tarball lacked the activation half even though it existed in source. The
 * predicate here must say NO when either half of activation is unavailable,
 * and only YES when both are genuinely present — never based on "does the
 * source file exist", but on a real capability signal + real supervisor
 * detection.
 */

const compatibleCapability: LeaseActivationCapability = { ...LEASE_ACTIVATION_CAPABILITY };
const presentSupervisor: SupervisorProbeResult = {
  supervisorPresent: true,
  socketPath: '/run/user/1000/mosaic-lease/broker.sock',
};

describe('leaseEnforcementActivatable', () => {
  it('is false when the activation capability is absent (null)', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => null,
      probeSupervisor: () => presentSupervisor,
    });
    expect(result).toBe(false);
  });

  it('is false when the activation capability name does not match', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => ({
        name: 'some-other-capability',
        version: LEASE_ACTIVATION_CAPABILITY.version,
      }),
      probeSupervisor: () => presentSupervisor,
    });
    expect(result).toBe(false);
  });

  it('is false when the activation capability version is incompatible (stale/newer build)', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => ({
        name: LEASE_ACTIVATION_CAPABILITY.name,
        version: LEASE_ACTIVATION_CAPABILITY.version + 1,
      }),
      probeSupervisor: () => presentSupervisor,
    });
    expect(result).toBe(false);
  });

  it('is false when the supervisor artifacts (launcher/daemon) are not present', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => compatibleCapability,
      probeSupervisor: () => ({
        supervisorPresent: false,
        socketPath: presentSupervisor.socketPath,
      }),
    });
    expect(result).toBe(false);
  });

  it('is false when the supervisor socket path is not resolvable', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => compatibleCapability,
      probeSupervisor: () => ({ supervisorPresent: true, socketPath: null }),
    });
    expect(result).toBe(false);
  });

  it('is false when BOTH capability and supervisor are absent', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => null,
      probeSupervisor: () => ({ supervisorPresent: false, socketPath: null }),
    });
    expect(result).toBe(false);
  });

  it('is true when a compatible capability AND a resolvable supervisor are both present', () => {
    const result = leaseEnforcementActivatable({
      getCapability: () => compatibleCapability,
      probeSupervisor: () => presentSupervisor,
    });
    expect(result).toBe(true);
  });

  it('uses the real default probes when no deps are injected (does not throw)', () => {
    // No live broker / built CLI is guaranteed in a test environment, so this
    // only asserts the predicate degrades to a safe boolean rather than
    // throwing — the fail-closed behavior itself is covered by the injected
    // cases above.
    expect(() => leaseEnforcementActivatable()).not.toThrow();
    expect(typeof leaseEnforcementActivatable()).toBe('boolean');
  });
});

describe('defaultCapabilityProbe', () => {
  it('returns null (fail-closed) when no built CLI artifact is resolvable', () => {
    // This source checkout has no dist/cli.js built for @mosaicstack/mosaic,
    // so the probe must report "no capability" rather than fabricate one
    // from source-tree presence — this is the exact distinction #828's
    // version skew needed: source existing is not the same as the published
    // artifact advertising the capability.
    expect(defaultCapabilityProbe()).toBeNull();
  });

  describe('positive path — a real built dist/cli.js advertises the capability', () => {
    // Resolve the ACTUAL @mosaicstack/mosaic package root on disk (two levels
    // up from src/commands/), so this test exercises the exact same
    // require.resolve('@mosaicstack/mosaic') self-reference codepath
    // defaultCapabilityProbe() itself uses — no mocking of the resolver.
    // This is the regression proof for the reviewer-found bug: the previous
    // implementation resolved via the NOT-exported './package.json' subpath
    // (ERR_PACKAGE_PATH_NOT_EXPORTED on every real install), which the
    // catch-all silently turned into an always-null probe. That bug returns
    // null here regardless of a built dist/cli.js being present — so this
    // test fails red against it and only passes once resolution goes through
    // the package's already-exported "." entry.
    const mosaicRoot = join(dirname(fileURLToPath(import.meta.url)), '..', '..');
    const distDir = join(mosaicRoot, 'dist');
    const distIndexPath = join(distDir, 'index.js');
    const distCliPath = join(distDir, 'cli.js');

    // dist/ is gitignored and unbuilt in a fresh checkout; only remove what
    // THIS test created, never a real build that predates it.
    const distDirPreexisted = existsSync(distDir);
    const indexPreexisted = existsSync(distIndexPath);
    const cliPreexisted = existsSync(distCliPath);

    afterEach(() => {
      if (!cliPreexisted) rmSync(distCliPath, { force: true });
      if (!indexPreexisted) rmSync(distIndexPath, { force: true });
      if (!distDirPreexisted) rmSync(distDir, { recursive: true, force: true });
    });

    it('returns the real {name, version} capability object', () => {
      mkdirSync(distDir, { recursive: true });
      // Minimal stand-in for the built "." export target — only needs to
      // exist for require.resolve('@mosaicstack/mosaic') to succeed; its
      // content is never loaded by defaultCapabilityProbe().
      writeFileSync(distIndexPath, 'export {};\n');
      // Minimal stand-in for the built CLI's hidden __lease-capability
      // subcommand — prints exactly what registerLeaseCapabilityProbe()
      // wires the real `mosaic __lease-capability` command to print.
      writeFileSync(
        distCliPath,
        `process.stdout.write(JSON.stringify(${JSON.stringify(LEASE_ACTIVATION_CAPABILITY)}));\n`,
      );

      const result = defaultCapabilityProbe();
      expect(result).toEqual(LEASE_ACTIVATION_CAPABILITY);
    });
  });
});

describe('defaultSupervisorProbe', () => {
  it('returns a well-shaped result without starting or connecting to anything', () => {
    const result = defaultSupervisorProbe({});
    expect(typeof result.supervisorPresent).toBe('boolean');
    expect(result.socketPath === null || typeof result.socketPath === 'string').toBe(true);
  });

  it('resolves a socket path from an explicit MOSAIC_LEASE_BROKER_SOCKET override', () => {
    const result = defaultSupervisorProbe({ MOSAIC_LEASE_BROKER_SOCKET: '/tmp/explicit.sock' });
    expect(result.socketPath).toBe('/tmp/explicit.sock');
  });
});

describe('registerLeaseCapabilityProbe', () => {
  it('registers a hidden subcommand named __lease-capability', () => {
    const program = new Command();
    program.exitOverride();
    registerLeaseCapabilityProbe(program);

    const registered = program.commands.find((c) => c.name() === LEASE_CAPABILITY_PROBE_COMMAND);
    expect(registered).toBeDefined();
    // Commander exposes "hidden" only as help-output suppression (no public
    // getter) — assert the observable behavior instead of a private field.
    expect(program.helpInformation()).not.toContain(LEASE_CAPABILITY_PROBE_COMMAND);
  });

  it('prints the capability constant as JSON when invoked', () => {
    const program = new Command();
    program.exitOverride();
    registerLeaseCapabilityProbe(program);

    let written = '';
    const originalWrite = process.stdout.write.bind(process.stdout);
    process.stdout.write = ((chunk: string) => {
      written += chunk;
      return true;
    }) as typeof process.stdout.write;

    try {
      program.parse(['node', 'mosaic', LEASE_CAPABILITY_PROBE_COMMAND]);
    } finally {
      process.stdout.write = originalWrite;
    }

    expect(JSON.parse(written)).toEqual(LEASE_ACTIVATION_CAPABILITY);
  });
});