import { apiFetch } from '@/lib/csrf'

export async function fetchAgentOutput(commandKey: string, args: string[] = []): Promise<string> {
  const res = await apiFetch('/api/agent/exec', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ command_key: commandKey, args }),
  })

  if (!res.ok) {
    const text = await res.text()
    throw new Error(`agent ${res.status}: ${text}`)
  }

  const reader = res.body?.getReader()
  if (!reader) throw new Error('no response body')

  const decoder = new TextDecoder()
  let buffer = ''
  let output = ''

  while (true) {
    const { done, value } = await reader.read()
    if (done) break
    buffer += decoder.decode(value, { stream: true })
    const lines = buffer.split('\n')
    buffer = lines.pop() ?? ''
    for (const line of lines) {
      if (line.startsWith('data:')) {
        try {
          const parsed = JSON.parse(line.slice(5).trim()) as { data?: string }
          if (parsed.data !== undefined) output += parsed.data
        } catch {
          // ignore malformed SSE
        }
      }
    }
  }

  return output
}