/** SSE line split + data payload parse (shared by agent-openai + tests). */

/**
 * Parse one SSE `data:` JSON line after the `data: ` prefix.
 * @param {string} dataLine content after `data: ` prefix
 */
function bareAgentParseSseDataPayload(dataLine) {
  const t = String(dataLine).trim()
  if (t === '[DONE]') return { kind: 'done' }
  try {
    const j = JSON.parse(t)
    return { kind: 'json', value: j }
  } catch {
    return { kind: 'raw', value: t }
  }
}

/**
 * Split SSE buffer into lines (keep incomplete tail).
 * @param {string} buf
 * @returns {{ lines: string[], rest: string }}
 */
function bareAgentSplitSseLines(buf) {
  const lines = []
  let start = 0
  for (let i = 0; i < buf.length; i++) {
    if (buf.charCodeAt(i) === 10) {
      lines.push(buf.slice(start, i))
      start = i + 1
    }
  }
  return { lines, rest: buf.slice(start) }
}