import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import {
  chmodSync,
  existsSync,
  lstatSync,
  mkdtempSync,
  mkdirSync,
  readdirSync,
  readFileSync,
  rmSync,
  statSync,
  symlinkSync,
  writeFileSync,
} from 'node:fs';
import { createHash } from 'node:crypto';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import {
  buildReseedCommand,
  buildRelaunchCommands,
  readRosterAgentNames,
  runFrameworkReseed,
  refreshActiveFleetUnits,
  readInstalledFrameworkVersion,
  readBundledFrameworkVersion,
  checkFrameworkDrift,
  repairFleetCommsTools,
} from './update-checker.js';

/**
 * F3-m3 / R13: `mosaic update` re-seeds the framework + (opt-in) relaunches
 * durable agents so shipped launcher/runtime changes activate. These cover the
 * pure builders + the missing-installer guard (the exec path is integration).
 */

describe('buildReseedCommand', () => {
  it('invokes the package install.sh in data-safe sync-only keep mode', () => {
    const out = buildReseedCommand('/pkg/framework', '/home/u/.config/mosaic');
    expect(out.installer).toBe('/pkg/framework/install.sh');
    expect(out.command).toBe('bash /pkg/framework/install.sh');
    expect(out.env).toEqual({
      MOSAIC_SYNC_ONLY: '1',
      MOSAIC_INSTALL_MODE: 'keep',
      MOSAIC_HOME: '/home/u/.config/mosaic',
    });
  });
});

describe('buildRelaunchCommands', () => {
  it('builds a systemctl --user restart per agent unit', () => {
    expect(buildRelaunchCommands(['orchestrator', 'coder0'])).toEqual([
      ['systemctl', '--user', 'restart', 'mosaic-agent@orchestrator.service'],
      ['systemctl', '--user', 'restart', 'mosaic-agent@coder0.service'],
    ]);
  });

  it('is empty for an empty roster', () => {
    expect(buildRelaunchCommands([])).toEqual([]);
  });
});

describe('readRosterAgentNames', () => {
  let home: string;

  beforeEach(() => {
    home = mkdtempSync(join(tmpdir(), 'mosaic-roster-'));
  });
  afterEach(() => {
    rmSync(home, { recursive: true, force: true });
  });

  it('returns [] when no roster exists', () => {
    expect(readRosterAgentNames(home)).toEqual([]);
  });

  it('extracts agent names from roster.yaml', () => {
    mkdirSync(join(home, 'fleet'), { recursive: true });
    writeFileSync(
      join(home, 'fleet', 'roster.yaml'),
      [
        'version: 1',
        'transport: tmux',
        'agents:',
        '  - name: orchestrator',
        '    runtime: pi',
        '  - name: coder0',
        '    runtime: claude',
        '  - name: "reviewer-1"',
        '    runtime: codex',
      ].join('\n') + '\n',
    );
    expect(readRosterAgentNames(home)).toEqual(['orchestrator', 'coder0', 'reviewer-1']);
  });

  it('extracts agent names from a JSON-only roster', () => {
    mkdirSync(join(home, 'fleet'), { recursive: true });
    writeFileSync(
      join(home, 'fleet', 'roster.json'),
      JSON.stringify({
        version: 1,
        transport: 'tmux',
        agents: [
          { name: 'orchestrator', runtime: 'pi', class: 'orchestrator' },
          { name: 'coder0', runtime: 'claude', class: 'worker' },
        ],
      }),
    );
    expect(readRosterAgentNames(home)).toEqual(['orchestrator', 'coder0']);
  });
});

describe('repairFleetCommsTools', () => {
  let root: string;
  let framework: string;
  let home: string;
  const toolsContent = '# tools\n<!-- fleet-comms-contract: 1 -->\n';
  const helperContent = '#!/bin/sh\nexit 0\n';

  beforeEach(() => {
    root = mkdtempSync(join(tmpdir(), 'mosaic-tools-repair-'));
    framework = join(root, 'framework');
    home = join(root, 'home');
    mkdirSync(join(framework, 'defaults'), { recursive: true });
    mkdirSync(join(framework, 'tools', 'tmux'), { recursive: true });
    writeFileSync(join(framework, 'defaults', 'TOOLS.md'), toolsContent);
    const helper = join(framework, 'tools', 'tmux', 'agent-send.sh');
    writeFileSync(helper, helperContent);
    chmodSync(helper, 0o755);
  });

  afterEach(() => rmSync(root, { recursive: true, force: true }));

  it('restores a partially deleted current-version installation without package updates', () => {
    mkdirSync(join(home, 'tools', 'tmux'), { recursive: true });
    writeFileSync(join(home, 'TOOLS.md'), toolsContent);

    const result = repairFleetCommsTools(framework, home);

    expect(result).toMatchObject({ ok: true, changed: true });
    expect(readFileSync(join(home, 'TOOLS.md'), 'utf8')).toBe(toolsContent);
    expect(readFileSync(join(home, 'tools', 'tmux', 'agent-send.sh'), 'utf8')).toBe(helperContent);
    expect(lstatSync(join(home, 'tools', 'tmux', 'agent-send.sh')).mode & 0o111).not.toBe(0);
  });

  it('creates a digest-qualified no-clobber backup and is idempotent', () => {
    mkdirSync(home, { recursive: true });
    const stale = '# user tools\n';
    writeFileSync(join(home, 'TOOLS.md'), stale);

    const first = repairFleetCommsTools(framework, home);
    expect(first).toMatchObject({ ok: true, changed: true });
    expect(first.backupPath).toMatch(/\.pre-fleet-comms-[a-f0-9]{16}\.bak$/);
    expect(readFileSync(first.backupPath!, 'utf8')).toBe(stale);

    const second = repairFleetCommsTools(framework, home);
    expect(second).toEqual({ ok: true, changed: false, backupPath: undefined });
    expect(readFileSync(first.backupPath!, 'utf8')).toBe(stale);
  });

  it('rejects an installed helper symlink without modifying its target', () => {
    mkdirSync(join(home, 'tools', 'tmux'), { recursive: true });
    writeFileSync(join(home, 'TOOLS.md'), toolsContent);
    const target = join(root, 'external-helper');
    writeFileSync(target, 'do not touch\n');
    symlinkSync(target, join(home, 'tools', 'tmux', 'agent-send.sh'));

    const result = repairFleetCommsTools(framework, home);

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(result.reason).toContain('symbolic link');
    expect(readFileSync(target, 'utf8')).toBe('do not touch\n');
    expect(lstatSync(join(home, 'tools', 'tmux', 'agent-send.sh')).isSymbolicLink()).toBe(true);
  });

  it('refuses a helper directory before replacing stale TOOLS content', () => {
    mkdirSync(join(home, 'tools', 'tmux', 'agent-send.sh'), { recursive: true });
    const stale = '# user tools\n';
    writeFileSync(join(home, 'TOOLS.md'), stale);

    const result = repairFleetCommsTools(framework, home);

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(result.reason).toContain('not a regular file');
    expect(readFileSync(join(home, 'TOOLS.md'), 'utf8')).toBe(stale);
  });

  it('refuses a pre-existing digest backup whose bytes do not match', () => {
    mkdirSync(home, { recursive: true });
    const stale = '# user tools\n';
    writeFileSync(join(home, 'TOOLS.md'), stale);
    const digest = createHash('sha256').update(stale).digest('hex').slice(0, 16);
    writeFileSync(join(home, `TOOLS.md.pre-fleet-comms-${digest}.bak`), 'collision\n');

    const result = repairFleetCommsTools(framework, home);

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(result.reason).toContain('backup collision');
    expect(readFileSync(join(home, 'TOOLS.md'), 'utf8')).toBe(stale);
  });

  it('rejects a symlink in each installed destination ancestor without external writes', () => {
    const cases = [
      { name: 'home', prefix: join(root, 'linked-home'), suffix: '' },
      { name: 'tools', prefix: join(root, 'real-home'), suffix: 'tools' },
      { name: 'tmux', prefix: join(root, 'real-home'), suffix: join('tools', 'tmux') },
    ];
    for (const testCase of cases) {
      const external = join(root, `external-${testCase.name}`);
      mkdirSync(external, { recursive: true });
      const targetHome =
        testCase.name === 'home' ? testCase.prefix : join(root, `installed-${testCase.name}`);
      if (testCase.name === 'home') {
        symlinkSync(external, targetHome);
      } else {
        mkdirSync(targetHome, { recursive: true });
        const linkPath = join(targetHome, testCase.suffix);
        mkdirSync(join(linkPath, '..'), { recursive: true });
        symlinkSync(external, linkPath);
      }

      const result = repairFleetCommsTools(framework, targetHome);

      expect(result, testCase.name).toMatchObject({ ok: false, changed: false });
      expect(result.reason, testCase.name).toContain('symbolic link');
      expect(readdirSync(external), testCase.name).toEqual([]);
    }
  });

  it('rolls back the backup and exact TOOLS bytes/mode when helper commit fails', () => {
    mkdirSync(join(home, 'tools', 'tmux'), { recursive: true });
    const staleTools = '# user tools\n';
    const staleHelper = '#!/bin/sh\nexit 17\n';
    writeFileSync(join(home, 'TOOLS.md'), staleTools, { mode: 0o640 });
    writeFileSync(join(home, 'tools', 'tmux', 'agent-send.sh'), staleHelper, { mode: 0o710 });

    const result = repairFleetCommsTools(framework, home, {
      beforeCommit(which) {
        if (which === 'helper') throw new Error('injected helper commit failure');
      },
    });

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(result.backupPath).toBeUndefined();
    expect(result.reason).toContain('injected helper commit failure');
    expect(readFileSync(join(home, 'TOOLS.md'), 'utf8')).toBe(staleTools);
    expect(statSync(join(home, 'TOOLS.md')).mode & 0o777).toBe(0o640);
    expect(readFileSync(join(home, 'tools', 'tmux', 'agent-send.sh'), 'utf8')).toBe(staleHelper);
    expect(statSync(join(home, 'tools', 'tmux', 'agent-send.sh')).mode & 0o777).toBe(0o710);
    expect(readdirSync(home).filter((name) => name.includes('pre-fleet-comms'))).toEqual([]);
    expect(
      readdirSync(home).some((name) => name.includes('.repair-')) ||
        readdirSync(join(home, 'tools', 'tmux')).some((name) => name.includes('.repair-')),
    ).toBe(false);
  });

  it('rolls back initially absent destinations and created directories on commit failure', () => {
    const result = repairFleetCommsTools(framework, home, {
      beforeCommit(which) {
        if (which === 'helper') throw new Error('injected absent helper failure');
      },
    });

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(result.reason).toContain('injected absent helper failure');
    expect(existsSync(home)).toBe(false);
  });

  it('does not persist a backup or replacement when backup commit fails', () => {
    mkdirSync(home, { recursive: true });
    const stale = '# user tools\n';
    writeFileSync(join(home, 'TOOLS.md'), stale, { mode: 0o640 });

    const result = repairFleetCommsTools(framework, home, {
      beforeCommit(which) {
        if (which === 'backup') throw new Error('injected backup commit failure');
      },
    });

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(readFileSync(join(home, 'TOOLS.md'), 'utf8')).toBe(stale);
    expect(statSync(join(home, 'TOOLS.md')).mode & 0o777).toBe(0o640);
    expect(readdirSync(home).filter((name) => name.includes('pre-fleet-comms'))).toEqual([]);
  });

  it('fails before writes when bundled source paths traverse a symlink ancestor', () => {
    const external = join(root, 'external-source');
    mkdirSync(join(external, 'defaults'), { recursive: true });
    mkdirSync(join(external, 'tools', 'tmux'), { recursive: true });
    writeFileSync(join(external, 'defaults', 'TOOLS.md'), toolsContent);
    writeFileSync(join(external, 'tools', 'tmux', 'agent-send.sh'), helperContent, { mode: 0o755 });
    const linkedFramework = join(root, 'linked-framework');
    symlinkSync(external, linkedFramework);

    const result = repairFleetCommsTools(linkedFramework, home);

    expect(result).toMatchObject({ ok: false, changed: false });
    expect(result.reason).toContain('symbolic link');
    expect(existsSync(home)).toBe(false);
  });
});

describe('runFrameworkReseed', () => {
  it('reports not-ok (not throw) when the installer is absent', () => {
    const missing = mkdtempSync(join(tmpdir(), 'mosaic-noinstaller-'));
    const res = runFrameworkReseed(missing, join(missing, 'home'));
    expect(res.ok).toBe(false);
    expect(res.reason).toContain('installer not found');
    rmSync(missing, { recursive: true, force: true });
  });
});

describe('refreshActiveFleetUnits', () => {
  let root: string;
  let mosaicHome: string;
  let configHome: string;

  beforeEach(() => {
    root = mkdtempSync(join(tmpdir(), 'mosaic-units-'));
    mosaicHome = join(root, 'mosaic');
    configHome = join(root, 'config');
    mkdirSync(join(mosaicHome, 'systemd', 'user'), { recursive: true });
    mkdirSync(join(configHome, 'systemd', 'user'), { recursive: true });
    // Freshly re-seeded units (new content).
    writeFileSync(join(mosaicHome, 'systemd', 'user', 'mosaic-agent@.service'), 'NEW\n');
    writeFileSync(join(mosaicHome, 'systemd', 'user', 'mosaic-tmux-holder.service'), 'NEW\n');
  });
  afterEach(() => rmSync(root, { recursive: true, force: true }));

  it('refreshes active units when a fleet is already installed', () => {
    // Active dir already carries mosaic units (stale) → fleet is installed.
    writeFileSync(join(configHome, 'systemd', 'user', 'mosaic-agent@.service'), 'OLD\n');
    const res = refreshActiveFleetUnits(mosaicHome, {
      XDG_CONFIG_HOME: configHome,
    } as NodeJS.ProcessEnv);
    expect(res.refreshed).toContain('mosaic-agent@.service');
    expect(
      readFileSync(join(configHome, 'systemd', 'user', 'mosaic-agent@.service'), 'utf-8'),
    ).toBe('NEW\n');
  });

  it('is a no-op when no fleet is installed (active dir has no mosaic units)', () => {
    const res = refreshActiveFleetUnits(mosaicHome, {
      XDG_CONFIG_HOME: configHome,
    } as NodeJS.ProcessEnv);
    expect(res.refreshed).toEqual([]);
    expect(existsSync(join(configHome, 'systemd', 'user', 'mosaic-agent@.service'))).toBe(false);
  });
});

/**
 * #642: re-seed when the on-disk framework is older than the bundled one even
 * if no package is reported outdated (CLI upgraded outside `mosaic update`).
 */
describe('framework drift detection', () => {
  let home: string; // stand-in for ~/.config/mosaic
  let fw: string; // stand-in for the bundled framework root

  beforeEach(() => {
    const root = mkdtempSync(join(tmpdir(), 'mosaic-drift-'));
    home = join(root, 'mosaic');
    fw = join(root, 'framework');
    mkdirSync(home, { recursive: true });
    mkdirSync(fw, { recursive: true });
  });
  afterEach(() => {
    rmSync(join(home, '..'), { recursive: true, force: true });
  });

  const writeInstalled = (v: string) => writeFileSync(join(home, '.framework-version'), v);
  const writeBundled = (v: string) =>
    writeFileSync(join(fw, 'install.sh'), `#!/usr/bin/env bash\nFRAMEWORK_VERSION=${v}\n`);

  describe('readInstalledFrameworkVersion', () => {
    it('returns undefined when the version file is absent', () => {
      expect(readInstalledFrameworkVersion(home)).toBeUndefined();
    });
    it('parses the integer (tolerating surrounding whitespace)', () => {
      writeInstalled('  3\n');
      expect(readInstalledFrameworkVersion(home)).toBe(3);
    });
    it('returns undefined for non-numeric content', () => {
      writeInstalled('not-a-number\n');
      expect(readInstalledFrameworkVersion(home)).toBeUndefined();
    });
  });

  describe('readBundledFrameworkVersion', () => {
    it('returns undefined when install.sh is absent', () => {
      expect(readBundledFrameworkVersion(fw)).toBeUndefined();
    });
    it('parses FRAMEWORK_VERSION=<n> from install.sh', () => {
      writeBundled('4');
      expect(readBundledFrameworkVersion(fw)).toBe(4);
    });
  });

  describe('checkFrameworkDrift', () => {
    it('reports drift when on-disk is older than bundled', () => {
      writeInstalled('3');
      writeBundled('4');
      expect(checkFrameworkDrift(home, fw)).toEqual({ drifted: true, installed: 3, bundled: 4 });
    });
    it('no drift when versions match', () => {
      writeInstalled('4');
      writeBundled('4');
      expect(checkFrameworkDrift(home, fw)).toMatchObject({ drifted: false });
    });
    it('no drift when on-disk is newer than bundled', () => {
      writeInstalled('5');
      writeBundled('4');
      expect(checkFrameworkDrift(home, fw)).toMatchObject({ drifted: false });
    });
    it('no drift (conservative) when a version cannot be read', () => {
      writeBundled('4'); // installed version file missing
      expect(checkFrameworkDrift(home, fw)).toMatchObject({ drifted: false, bundled: 4 });
    });
  });
});