import { mkdirSync, mkdtempSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';

import { Command } from 'commander';
import { afterEach, describe, expect, it } from 'vitest';

import { exitStatusFor, registerWatchCommand, resolveAgentWatchTool } from './watch.js';

// The dispatch command execs a real process with inherited stdio; the spec
// covers the pure resolution and exit-mapping surfaces plus the absent-tool
// path (which exits without spawning). Live pass-through is exercised by the
// fleet smoke test against the real brain tool.

describe('resolveAgentWatchTool', () => {
  const saved = process.env['MOSAIC_BRAIN_HOME'];
  afterEach(() => {
    if (saved === undefined) delete process.env['MOSAIC_BRAIN_HOME'];
    else process.env['MOSAIC_BRAIN_HOME'] = saved;
  });

  it('honors MOSAIC_BRAIN_HOME over the canonical brain', () => {
    const tmp = mkdtempSync(join(tmpdir(), 'watch-resolve-'));
    process.env['MOSAIC_BRAIN_HOME'] = tmp;
    expect(resolveAgentWatchTool('/nonexistent/mosaic-home')).toBe(
      join(tmp, 'tools', 'agent-watch', 'agent-watch.sh'),
    );
  });

  it('resolves inside the brain tools tree', () => {
    const tmp = mkdtempSync(join(tmpdir(), 'watch-resolve-'));
    process.env['MOSAIC_BRAIN_HOME'] = tmp;
    const tool = resolveAgentWatchTool(tmp);
    expect(tool.endsWith(join('tools', 'agent-watch', 'agent-watch.sh'))).toBe(true);
  });
});

describe('exitStatusFor', () => {
  it('maps absent tool to 127', () => {
    expect(exitStatusFor({ status: 0 }, false)).toBe(127);
  });

  it('passes the tool exit status through', () => {
    expect(exitStatusFor({ status: 2 }, true)).toBe(2);
    expect(exitStatusFor({ status: 78 }, true)).toBe(78);
  });

  it('maps signal death / null status to 125', () => {
    expect(exitStatusFor({ status: null }, true)).toBe(125);
  });
});

describe('registerWatchCommand absent-tool path', () => {
  const saved = process.env['MOSAIC_BRAIN_HOME'];
  afterEach(() => {
    if (saved === undefined) delete process.env['MOSAIC_BRAIN_HOME'];
    else process.env['MOSAIC_BRAIN_HOME'] = saved;
    process.exitCode = undefined;
  });

  it('sets exitCode 127 with the resolved path when the tool is missing', async () => {
    const tmp = mkdtempSync(join(tmpdir(), 'watch-missing-'));
    // The suite directory exists but the tool file does not.
    mkdirSync(join(tmp, 'tools', 'agent-watch'), { recursive: true });
    process.env['MOSAIC_BRAIN_HOME'] = tmp;

    const program = new Command();
    registerWatchCommand(program);
    await program.parseAsync(['watch', 'list'], { from: 'user' });
    expect(process.exitCode).toBe(127);
  });
});