/**
 * 将 /v1/responses API 结果转换为 /v1/chat/completions 兼容格式
 * 适用于非流式响应
 * @param {Object} resp - 原始响应对象
 * @returns {Object} OpenAI 兼容的聊天补全格式
 */
export function convertResponseToChatCompletion(resp) {
  if (!resp || typeof resp !== 'object') {
    throw new Error('Invalid response object')
  }

  const outputMsg = (resp.output || []).find(o => o.type === 'message')
  const textBlocks = outputMsg?.content?.filter(c => c.type === 'output_text') || []
  const content = textBlocks.map(c => c.text).join('')

  const chatCompletion = {
    id: resp.id ? resp.id.replace(/^resp_/, 'chatcmpl-') : `chatcmpl-${Date.now()}`,
    object: 'chat.completion',
    created: resp.created_at || Math.floor(Date.now() / 1000),
    model: resp.model || 'unknown-model',
    choices: [
      {
        index: 0,
        message: {
          role: outputMsg?.role || 'assistant',
          content: content || ''
        },
        finish_reason: resp.status === 'completed' ? 'stop' : 'unknown'
      }
    ],
    usage: {
      prompt_tokens: resp.usage?.input_tokens ?? 0,
      completion_tokens: resp.usage?.output_tokens ?? 0,
      total_tokens: resp.usage?.total_tokens ?? 0
    }
  }

  return chatCompletion
}