"""调制因子派生：从时态快照 + 对话信号派生 [0,1] 因子与关怀类型。

消费 ``TemporalSnapshot``（Plan 1）与 ``ModulationInput``（service 层收集的对话信号），
输出 ``ModulationFactors``（设计 §5.2）。全部纯函数，无副作用。

v1 用即时启发式（参数集中为模块常量，便于调参）；节律曲线 / 窗口函数留 v2。
care_kind 触发规则见设计 §7.3。
"""

from __future__ import annotations

from pydantic import BaseModel

from app.modules.time_sense.snapshot import TemporalSnapshot

# ==================== v1 启发式参数（可调） ====================

# 节日喜悦度权重（设计 §5.2 festival_joy）
_FESTIVAL_JOY_WEIGHTS: dict[str, float] = {
    "春节": 0.9,
    "中秋节": 0.9,
    "元宵节": 0.7,
    "端午节": 0.7,
    "七夕": 0.7,
    "重阳节": 0.7,
    "腊八节": 0.7,
    "元旦": 0.5,
    "劳动节": 0.5,
    "国庆节": 0.5,
    "圣诞节": 0.5,
    "情人节": 0.5,
}
_FESTIVAL_JOY_BASELINE = 0.1  # 无节日
_FESTIVAL_JOY_DEFAULT = 0.5  # 未登记节日

# 季节共振（设计 §5.2 season_resonance；v2 用季节调制函数）
_SEASON_RESONANCE: dict[str, float] = {"春": 0.5, "夏": 0.6, "秋": 0.7, "冬": 0.6}

# 时段共振（设计 §5.2 same_period_resonance；v2 用窗口函数）
_DAY_PERIOD_RESONANCE: dict[str, float] = {
    "凌晨": 0.8,
    "深夜": 0.7,
    "清晨": 0.4,
    "夜晚": 0.4,
    "傍晚": 0.3,
    "上午": 0.2,
    "下午": 0.2,
    "中午": 0.2,
}

# 深夜脆弱度（设计 §5.2 late_night_fragility）
_FRAGILITY_DEEP_NIGHT_BASE = 0.7  # 凌晨基线
_FRAGILITY_LATE_NIGHT_BASE = 0.5  # 深夜基线
_FRAGILITY_DAYTIME = 0.1
_FRAGILITY_PER_TURN_DEEP = 0.05  # 凌晨每轮增量
_FRAGILITY_PER_TURN_LATE = 0.03  # 深夜每轮增量

# 周末放松度
_RELAX_WEEKEND = 0.8
_RELAX_WEEKEND_WITH_FESTIVAL = 0.9
_RELAX_WORKDAY = 0.2

# 关怀
_CARE_SUGGEST_HIT = 0.7  # care_kind 命中时
_CARE_SUGGEST_MISS_FACTOR = 0.5  # 未命中时按脆弱度折半

# 时差关怀阈值（分钟，3 小时）
_JETLAG_DIFF_MINUTES = 180
# 深夜持续聊天阈值（轮数）
_LATE_NIGHT_TURNS = 3


class ModulationInput(BaseModel):
    """compute_modulation 的对话信号输入。

    信号由 Plan 3 service 层收集（轮数统计、内容分类等）；本模块只做纯函数判定。
    关怀阈值（``jetlag_threshold_minutes`` / ``late_night_min_turns``）默认 None，
    由 service 层从 ``settings`` 注入（设计 §7.1/§7.3"阈值可调"）；None 时回退模块常量。
    """

    conversation_turns_today: int = 0
    is_first_message_today: bool = False
    content_work_related: bool = False
    content_lonely: bool = False
    user_birthday_today: bool = False
    # 关怀触发阈值（None → 回退模块常量；service 层从 settings 注入，设计 §7.3）
    jetlag_threshold_minutes: int | None = None
    late_night_min_turns: int | None = None


class ModulationFactors(BaseModel):
    """辰正输出的调制因子（设计 §5.2）。"""

    festival_joy: float
    late_night_fragility: float
    reunion_intensity: float
    weekend_relax: float
    season_resonance: float
    same_period_resonance: float
    care_suggest: float
    care_kind: str | None = None


def _festival_joy(snapshot: TemporalSnapshot) -> float:
    if not snapshot.festivals:
        return _FESTIVAL_JOY_BASELINE
    return max(_FESTIVAL_JOY_WEIGHTS.get(f.name, _FESTIVAL_JOY_DEFAULT) for f in snapshot.festivals)


def _late_night_fragility(snapshot: TemporalSnapshot, turns: int) -> float:
    period = snapshot.day_period
    if period == "凌晨":
        return min(1.0, _FRAGILITY_DEEP_NIGHT_BASE + turns * _FRAGILITY_PER_TURN_DEEP)
    if period == "深夜":
        return min(1.0, _FRAGILITY_LATE_NIGHT_BASE + turns * _FRAGILITY_PER_TURN_LATE)
    return _FRAGILITY_DAYTIME


def _weekend_relax(snapshot: TemporalSnapshot) -> float:
    if not snapshot.is_weekend:
        return _RELAX_WORKDAY
    if snapshot.festivals:
        return _RELAX_WEEKEND_WITH_FESTIVAL
    return _RELAX_WEEKEND


def _care_kind(snapshot: TemporalSnapshot, signals: ModulationInput) -> str | None:
    """设计 §7.3 关怀触发判定（按优先级）。

    阈值读 ``signals``（None 回退模块常量），由 service 层从 settings 注入（§7.3 可调）。
    """
    deep = snapshot.day_period in {"凌晨", "深夜"}
    jetlag_threshold = signals.jetlag_threshold_minutes or _JETLAG_DIFF_MINUTES
    late_night_turns = signals.late_night_min_turns or _LATE_NIGHT_TURNS
    # 1. 时差关怀：深夜/凌晨 + 家时差显著
    if deep and abs(snapshot.home_tz_diff_minutes) >= jetlag_threshold:
        return "jetlag"
    # 2. 用户生日
    if signals.user_birthday_today:
        return "birthday"
    # 3. 清晨异常：清晨时段 + 本地 4-6 点 + 今日首条
    if signals.is_first_message_today and snapshot.day_period == "清晨" and snapshot.local_hour < 6:
        return "early_morning"
    # 4. 深夜工作话题
    if deep and signals.content_work_related:
        return "overwork"
    # 5. 节日孤独
    if bool(snapshot.festivals) and signals.content_lonely:
        return "festival_lonely"
    # 6. 深夜持续聊天：深夜/凌晨 + 连续 ≥ N 轮
    if deep and signals.conversation_turns_today >= late_night_turns:
        return "late_night"
    return None


def _care_suggest(fragility: float, care_kind_value: str | None) -> float:
    if care_kind_value is not None:
        return _CARE_SUGGEST_HIT
    return round(fragility * _CARE_SUGGEST_MISS_FACTOR, 3)


def compute_modulation(snapshot: TemporalSnapshot, signals: ModulationInput) -> ModulationFactors:
    """从时态快照 + 对话信号派生调制因子。纯函数。"""
    fragility = _late_night_fragility(snapshot, signals.conversation_turns_today)
    care_kind_value = _care_kind(snapshot, signals)
    return ModulationFactors(
        festival_joy=round(_festival_joy(snapshot), 3),
        late_night_fragility=round(fragility, 3),
        reunion_intensity=round(snapshot.offline.reunion_intensity, 3),
        weekend_relax=_weekend_relax(snapshot),
        season_resonance=_SEASON_RESONANCE.get(snapshot.season, 0.5),
        same_period_resonance=_DAY_PERIOD_RESONANCE.get(snapshot.day_period, 0.3),
        care_suggest=_care_suggest(fragility, care_kind_value),
        care_kind=care_kind_value,
    )