from typing import List, Dict
from config import DEFAULT_SYSTEM_PROMPT

def build_messages(frames_b64: List[str], edit_instruction: str) -> list[dict]:
    """
    多帧图像 + 文本，OpenAI Chat Completions 标准格式：
      - 每张图一个 {"type":"image_url","image_url":{"url":"data:image/jpeg;base64,..."}}
      - 文本 {"type":"text","text": "..."}
      - 放在同一条 user 消息的 content 数组中
    """
    content_parts = [
        {"type": "image_url", "image_url": {"url": f"data:image/jpeg;base64,{b64}"}}
        for b64 in frames_b64
    ]
    content_parts.append({"type": "text", "text": edit_instruction})

    return [
        {"role": "system", "content": [{"type": "text", "text": DEFAULT_SYSTEM_PROMPT}]},
        {"role": "user", "content": content_parts}
    ]