def _escape(value):
    if value is None:
        return None
    return str(value).replace("'", "''")


async def chat_session_messages(ns={}):
    """获取某次会话的全部消息"""
    session_id = ns.get('session_id')
    if not session_id:
        return {'status': False, 'msg': 'session_id is required'}

    userid = ns.get('userid') or await get_user()
    if not userid:
        return {'status': False, 'msg': '未找到用户'}

    db = DBPools()
    async with db.sqlorContext('kboss') as sor:
        try:
            sessions = await sor.R('chat_session', {'id': session_id, 'userid': userid})
            if not sessions:
                return {'status': False, 'msg': '会话不存在'}

            sql = """
                SELECT id, role, content, content_type, created_at
                FROM chat_message
                WHERE session_id = '%s'
                ORDER BY created_at ASC;
            """ % _escape(session_id)
            rows = await sor.sqlExe(sql, {})

            messages = []
            for row in rows:
                content = row.get('content') or ''
                if row.get('content_type') == 'mixed':
                    import json
                    try:
                        content = json.loads(content)
                    except Exception:
                        pass
                if isinstance(content, list):
                    text_parts = [p.get('text', '') for p in content if p.get('type') == 'text']
                    display = '\n'.join([t for t in text_parts if t]) or '[多媒体消息]'
                else:
                    display = content
                messages.append({
                    'id': row['id'],
                    'role': row['role'],
                    'content': display,
                    'created_at': row.get('created_at'),
                })

            return {
                'status': True,
                'msg': 'get messages success',
                'data': {
                    'session': sessions[0],
                    'messages': messages,
                },
            }
        except Exception as e:
            return {'status': False, 'msg': 'get messages failed, %s' % str(e)}


ret = await chat_session_messages(params_kw)
return ret