"""表达层：渐进式通知体系"""

from enum import Enum
from dataclasses import dataclass
from typing import Optional


class NotificationLevel(Enum):
    BREATHING = 1     # 呼吸光效 — 暗示有想法但不打扰
    TITLE = 2         # 标题预览 — "关于你明天的会议..."
    FULL = 3          # 完整消息 — 用户点击后展开


@dataclass
class ExpressionOutput:
    """表达层输出"""
    level: NotificationLevel
    title: str
    body: str
    reason: Optional[str] = None
    animation: str = "fade_in"


class ExpressionLayer:
    """
    表达层：将决策转化为用户可感知的交互
    
    三级通知体系:
    1. 呼吸光效：仅暗示，不占用注意力
    2. 标题预览：一行文字，表明意向
    3. 完整消息：用户决定查看后才展开
    """

    def __init__(self):
        self._dismissed: set = set()  # 已关闭的消息ID

    def render(self, message: str, decision_confidence: float,
               should_show_reason: bool = True) -> ExpressionOutput:
        """根据决策置信度决定通知等级"""
        # 高置信度 → 直接完整消息
        if decision_confidence > 0.85:
            level = NotificationLevel.FULL
            title = self._extract_title(message)
            reason = None if not should_show_reason else "我有把握你会需要这个"

        # 中等置信度 → 标题预览
        elif decision_confidence > 0.70:
            level = NotificationLevel.TITLE
            title = message[:40] + ("..." if len(message) > 40 else "")
            reason = "不太确定是否合适，你先看看标题？"

        # 低置信度 → 仅呼吸光效
        else:
            level = NotificationLevel.BREATHING
            title = ""
            reason = None

        return ExpressionOutput(
            level=level,
            title=title,
            body=message if level == NotificationLevel.FULL else title,
            reason=reason,
        )

    def dismiss(self, message_id: str):
        self._dismissed.add(message_id)

    def is_dismissed(self, message_id: str) -> bool:
        return message_id in self._dismissed

    @staticmethod
    def _extract_title(text: str, max_len: int = 30) -> str:
        """提取消息的第一句作为标题"""
        first = text.split("。")[0].split("!")[0].split("?")[0]
        return first[:max_len] + ("..." if len(first) > max_len else "")