import { expect, test } from 'bun:test'

const cli = new URL('../src/cli.ts', import.meta.url).pathname

async function run(args: string[], stdin = '') {
  const child = Bun.spawn([process.execPath, cli, ...args], {
    stdin: new Blob([stdin]),
    stdout: 'pipe',
    stderr: 'pipe'
  })
  const [code, stdout, stderr] = await Promise.all([
    child.exited,
    new Response(child.stdout).text(),
    new Response(child.stderr).text()
  ])
  return { code, stdout, stderr }
}

test('CLI help documents file and stdin input without loading a model', async () => {
  const result = await run(['--help'])
  expect(result.code).toBe(0)
  expect(result.stdout).toContain('JSON file path')
  expect(result.stdout).toContain('--device')
  expect(result.stderr).toBe('')
})

test.each([[], ['-', '--device', 'unknown'], ['-', '--dtype', 'unknown'], ['--unknown']])(
  'CLI rejects invalid arguments %j',
  async (...args) => {
    const result = await run(args)
    expect(result.code).toBe(1)
    expect(result.stdout).toBe('')
    expect(result.stderr).toContain('error:')
  }
)

test('CLI reports malformed stdin as JSON on stderr', async () => {
  const result = await run(['-'], '{')
  expect(result.code).toBe(1)
  expect(result.stdout).toBe('')
  expect(JSON.parse(result.stderr).error.type).toBe('invalid-json')
})

test('CLI validates metadata from stdin before inference', async () => {
  const result = await run(['-'], JSON.stringify({ state: null, decisions: [] }))
  expect(result.code).toBe(1)
  expect(result.stdout).toBe('')
  expect(JSON.parse(result.stderr).error).toMatchObject({
    type: 'invalid-input',
    path: 'decisions'
  })
})

test('CLI reports unreadable files', async () => {
  const result = await run([`${cli}/missing.json`])
  expect(result.code).toBe(1)
  expect(result.stdout).toBe('')
  expect(JSON.parse(result.stderr).error.type).toBe('input-read-error')
})