"""System composition stage, available independently of user canvas resources."""
from sqlmodel import Session, select

from ..models import Agent


DEFAULT_COMPOSER_RULES = """# 组合 Agent 规则
1. 按任务单顺序组合已通过的内容段，跳过用户放弃的段落。
2. 核对五项一致性：跨段矛盾、回指断裂、时间线、情绪曲线和钩子兑现。
3. 特别检查跳过段落后的衔接，下一段必须承接最近一段已通过内容。
4. 结构性问题定位到对应内容段，给出具体修改建议；不能擅自补写事实或改动已确认内容。
5. 保留已有内容的表达风格，不引入任务导图以外的新主题。
"""


def resolve_composer_agent(session: Session) -> Agent:
    # Preserve an existing system configuration, but never pick another user's
    # private Agent as a shared execution stage.
    configured = session.exec(select(Agent).where(
        Agent.role == "composer", Agent.builtin == True,  # noqa: E712
        Agent.status == "active", Agent.owner_user_id == 0,
        Agent.visibility == "global",
    ).order_by(Agent.id)).first()
    if configured:
        return configured
    # This runtime-only Agent follows the global text model.  It is not a
    # canvas/resource record, so deleting a resource cannot remove the stage.
    return Agent(id=0, name="系统组合 Agent", role="composer", builtin=True,
                 organization_id=0, owner_user_id=0, visibility="global",
                 rules=DEFAULT_COMPOSER_RULES)