import 'server-only'

const AGENT_URL = process.env.OPS_AGENT_URL ?? 'http://127.0.0.1:3099'
const AGENT_SECRET = process.env.OPS_AGENT_SECRET ?? ''

export async function execAgent(
  commandKey: string,
  args: string[] = [],
  onChunk?: (chunk: string) => void,
): Promise<string> {
  const response = await fetch(`${AGENT_URL}/agent/v1/exec`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      Authorization: `Bearer ${AGENT_SECRET}`,
    },
    body: JSON.stringify({ command_key: commandKey, args }),
    cache: 'no-store',
  })

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

  const reader = response.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:')) {
        const jsonStr = line.slice(5).trim()
        try {
          const parsed = JSON.parse(jsonStr) as { data?: string }
          if (parsed.data !== undefined) {
            output += parsed.data
            onChunk?.(parsed.data)
          }
        } catch {
          // skip malformed SSE data
        }
      }
    }
  }

  return output
}