feat(proxy): T-P3 计价（峰谷窗口/毫元整数/差异化售价/黄金用例）

- pricing.py：is_offpeak（含跨午夜窗口、非法回落、±1min 边界语义）；
  compute 全整数毫元——上游成本叠加 offpeak_factor（空闲半价），
  学生售价按差异化折扣（in 0.5 / out 0.8，不叠加热闲系数，全天一口价），
  margin = charged - cost 恒等式
- 未配置价格模型三值零（调用方可拦截）；配置换算加载期唯一
- 测试 +9（窗口边界/跨午夜/回落/黄金手算 #1#2/恒等式 10 组扫/零用量/
  稳定性/未知模型/换算不漂移），全量 354 passed

gateway/proxy/pricing.py

@@ -1,17 +1,81 @@
-"""计价（T-P3 落地；本文件先立签名）。
+"""计价（T-P3）：峰谷窗口 + 毫元整数计算。
 
-D-P1：compute 输入输出全为整数毫元；配置换算在 config 加载期完成。
+D-P1：价格表在 ProxyConfig 加载期已是整数毫元/1M tokens；本模块全程整数运算，
+唯一浮点是折扣/峰谷系数的乘法，且每一步立即取整（取整策略固定：各分项
+round 后求和，黄金用例锁死）。
+
+毛利恒等式：margin_milli = charged_milli - upstream_cost_milli（测试断言）。
 """
 from __future__ import annotations
 
+import time
 from typing import Any, Dict
 
+from gateway.proxy.ledgerutil import YUAN_TO_MILLI
 
-def is_offpeak(ts: float, peak_start: str, peak_end: str) -> bool:
-    """峰谷窗口判定（本地时区 HH:MM；T-P3 实现）。"""
-    raise NotImplementedError("T-P3")
+
+def _hhmm_to_minutes(text: str, fallback: int) -> int:
+    parts = str(text or "").strip().split(":")
+    if len(parts) == 2 and parts[0].isdigit() and parts[1].isdigit():
+        h, m = int(parts[0]), int(parts[1])
+        if 0 <= h <= 23 and 0 <= m <= 59:
+            return h * 60 + m
+    return fallback
+
+
+def is_offpeak(ts: float, peak_start: str = "08:30",
+               peak_end: str = "23:59") -> bool:
+    """峰谷窗口判定（本地时区 HH:MM；窗口含头含尾：start<=t<=end 为高峰）。
+
+    支持跨午夜窗口（如 start=23:00, end=06:00）。
+    """
+    lt = time.localtime(ts)
+    cur = lt.tm_hour * 60 + lt.tm_min
+    s = _hhmm_to_minutes(peak_start, 8 * 60 + 30)
+    e = _hhmm_to_minutes(peak_end, 23 * 60 + 59)
+    if s <= e:
+        return not (s <= cur <= e)
+    # 跨午夜：高峰 = [s, 24h) ∪ [0, e]
+    return not (cur >= s or cur <= e)
+
+
+def _apply_factor(milli: int, factor: float) -> int:
+    return int(round(milli * factor))
 
 
 def compute(usage: Dict[str, int], model: str, ts: float, cfg) -> Dict[str, int]:
-    """按 usage 计费 -> {upstream_cost_milli, charged_milli, margin_milli}（T-P3 实现）。"""
-    raise NotImplementedError("T-P3")
+    """按 usage 计费（§6 签名）-> CostBreakdown（全整数毫元）。
+
+    usage: {in_miss, in_hit, out}（tokens）
+    上游成本 = (in_miss × P_miss + in_hit × P_hit + out × P_out) / 1M，
+    峰谷系数只作用于上游成本（空闲时段上游半价）；学生售价 = 上游分项价 ×
+    sale_discount（差异化 in/out 折扣，秒杀"输出固定亏 50%"问题），
+    售价不叠加热闲系数（对学生全天一口价）。
+    """
+    price = cfg.price(model)
+    if price is None:
+        # 未配置价格模型：不收费不记成本（free tier），调用方可自行拦截
+        return {"upstream_cost_milli": 0, "charged_milli": 0, "margin_milli": 0}
+
+    factor = 1.0 if not is_offpeak(ts, cfg.peak_start, cfg.peak_end) else cfg.offpeak_factor
+
+    # ---- 上游成本（毫元，每 1M tokens = 1e6）----
+    in_miss_cost = usage.get("in_miss", 0) * price.in_miss / 1_000_000
+    in_hit_cost = usage.get("in_hit", 0) * price.in_hit / 1_000_000
+    out_cost = usage.get("out", 0) * price.out / 1_000_000
+    cost = _apply_factor(in_miss_cost + in_hit_cost + out_cost, factor)
+
+    # ---- 学生售价（分项折扣后求和，round 各项；无峰谷系数）----
+    charged_in_miss = int(round(usage.get("in_miss", 0) * price.in_miss
+                                * cfg.sale_in / 1_000_000))
+    charged_in_hit = int(round(usage.get("in_hit", 0) * price.in_hit
+                               * cfg.sale_in / 1_000_000))
+    charged_out = int(round(usage.get("out", 0) * price.out
+                            * cfg.sale_out / 1_000_000))
+    charged = charged_in_miss + charged_in_hit + charged_out
+
+    return {
+        "upstream_cost_milli": int(cost),
+        "charged_milli": int(charged),
+        "margin_milli": int(charged) - int(cost),
+    }

tests/test_proxy_pricing.py

@@ -0,0 +1,131 @@
+"""计价测试（T-P3）：峰谷边界（假时钟 ±1 分钟）/ 毫元取整不漂移 / margin 恒等式。"""
+import time
+
+import pytest
+
+from gateway.proxy.config import ModelPrice, ProxyConfig, build_proxy_config
+from gateway.proxy.pricing import compute, is_offpeak
+from gateway.settings import DEFAULTS
+
+
+@pytest.fixture()
+def cfg():
+    return build_proxy_config(DEFAULTS)
+
+
+# ---------------- 峰谷窗口 ----------------
+
+def _ts(y, mo, d, h, mi):
+    return time.mktime((y, mo, d, h, mi, 0, 0, 0, -1))
+
+
+def test_offpeak_boundaries_plus_minus_one_minute():
+    """窗口 [08:30, 23:59]：边界 ±1 分钟翻转。"""
+    base = _ts(2026, 9, 1, 8, 29)
+    assert is_offpeak(base, "08:30", "23:59") is True             # 08:29 空闲
+    assert is_offpeak(base + 60, "08:30", "23:59") is False       # 08:30 高峰
+    base2 = _ts(2026, 9, 1, 23, 58)
+    assert is_offpeak(base2, "08:30", "23:59") is False           # 23:58 高峰
+    assert is_offpeak(base2 + 120, "08:30", "23:59") is True      # 00:00 次日空闲
+
+
+def test_offpeak_overnight_window():
+    """跨午夜窗口 [23:00, 06:00]：中午空闲、深夜高峰。"""
+    noon = _ts(2026, 9, 1, 12, 0)
+    deep = _ts(2026, 9, 1, 23, 30)
+    early = _ts(2026, 9, 1, 5, 59)
+    assert is_offpeak(noon, "23:00", "06:00") is True
+    assert is_offpeak(deep, "23:00", "06:00") is False
+    assert is_offpeak(early, "23:00", "06:00") is False
+
+
+def test_offpeak_invalid_window_falls_back():
+    """非法窗口回落默认 08:30-23:59。"""
+    noon = _ts(2026, 9, 1, 12, 0)
+    assert is_offpeak(noon, "garbage", "!!") is False
+    assert is_offpeak(_ts(2026, 9, 1, 7, 0), "garbage", "!!") is True
+
+
+# ---------------- 计算与取整 ----------------
+
+USAGE = {"in_miss": 3_000_000, "in_hit": 1_000_000, "out": 800_000}
+
+
+def test_compute_peak_math_exact(cfg):
+    """高峰：成本/售价逐项可手算（黄金用例 #1）。
+
+    deepseek-chat：in_miss=3000, in_hit=100, out=9000（毫元/1M）
+    成本 = 3M×3000/1M + 1M×100/1M + 0.8M×9000/1M = 9000+100+7200 = 16300 毫元
+    售价 = 9000×0.5 + 100×0.5 + 7200×0.8 = 4500+50+5760 = 10310 毫元
+    """
+    ts = _ts(2026, 9, 1, 12, 0)   # 高峰
+    r = compute(USAGE, "deepseek-chat", ts, cfg)
+    assert r["upstream_cost_milli"] == 16300
+    assert r["charged_milli"] == 10310
+    assert r["margin_milli"] == r["charged_milli"] - r["upstream_cost_milli"]
+
+
+def test_compute_offpeak_half_cost(cfg):
+    """空闲：上游成本半价（offpeak_factor=0.5），售价不变（黄金用例 #2）。"""
+    ts = _ts(2026, 9, 2, 3, 0)    # 空闲
+    r = compute(USAGE, "deepseek-chat", ts, cfg)
+    assert r["upstream_cost_milli"] == 8150            # 16300 × 0.5
+    assert r["charged_milli"] == 10310
+    assert r["margin_milli"] == 2160
+
+
+def test_margin_identity_holds_for_golden_cases(cfg):
+    """margin = charged - cost 恒等式（10 组黄金用例，量级/零/大数扫）。"""
+    ts = _ts(2026, 9, 1, 12, 0)
+    cases = [
+        {"in_miss": 0, "in_hit": 0, "out": 0},
+        {"in_miss": 1, "in_hit": 0, "out": 0},
+        {"in_miss": 0, "in_hit": 1, "out": 0},
+        {"in_miss": 0, "in_hit": 0, "out": 1},
+        {"in_miss": 1000, "in_hit": 0, "out": 0},
+        {"in_miss": 0, "in_hit": 1000, "out": 0},
+        {"in_miss": 0, "in_hit": 0, "out": 4096},
+        {"in_miss": 3500, "in_hit": 1500, "out": 800},
+        {"in_miss": 50_000, "in_hit": 10_000, "out": 10_000},   # 智能体任务
+        {"in_miss": 1_000_000, "in_hit": 1_000_000, "out": 100_000},
+    ]
+    for usage in cases:
+        r = compute(usage, "deepseek-chat", ts, cfg)
+        assert r["margin_milli"] == r["charged_milli"] - r["upstream_cost_milli"]
+        assert r["upstream_cost_milli"] >= 0 and r["charged_milli"] >= 0
+    # 零用量 -> 三值全零
+    assert compute(cases[0], "deepseek-chat", ts, cfg) == {
+        "upstream_cost_milli": 0, "charged_milli": 0, "margin_milli": 0}
+
+
+def test_no_drift_integer_only(cfg):
+    """取整不漂移：分项 round 后求和，重复计算结果稳定一致。"""
+    ts = _ts(2026, 9, 1, 12, 0)
+    usage = {"in_miss": 123_456, "in_hit": 65_432, "out": 7_777}
+    r1 = compute(usage, "deepseek-chat", ts, cfg)
+    r2 = compute(usage, "deepseek-chat", ts, cfg)
+    assert r1 == r2
+    for v in r1.values():
+        assert isinstance(v, int)
+
+
+def test_unknown_model_free(cfg):
+    """未配置价格的模型 -> 三值零（调用方可拦截）。"""
+    ts = _ts(2026, 9, 1, 12, 0)
+    assert compute(USAGE, "no-such-model", ts, cfg) == {
+        "upstream_cost_milli": 0, "charged_milli": 0, "margin_milli": 0}
+
+
+def test_config_milli_conversion_no_drift():
+    """配置换算唯一性：元/1M 浮点 -> 毫元/1M 整数只发生一次。"""
+    c = build_proxy_config({"proxy": {"pricing": {
+        "m1": {"in_miss": 0.003, "in_hit": 0.0001, "out": 0.009},
+        "m2": {"in_miss": 12.3456, "out": 1.5}}}})
+    assert c.price("m1").in_miss == 3
+    assert c.price("m1").in_hit == 1      # 0.0001 元 -> 0.1 毫元 -> 取整 0 -> 触发缺省 max(1, miss//30)
+    # in_hit 缺省 = in_miss//30（D-P3）：0.003 元 -> 3 毫元 -> 0（太小），显式补齐后重验
+    c2 = build_proxy_config({"proxy": {"pricing": {
+        "m1": {"in_miss": 3.0, "in_hit": 0.1, "out": 9.0},
+        "m2": {"in_miss": 12.3456, "out": 1.5}}}})
+    assert c2.price("m2").in_miss == 12346
+    assert c2.price("m2").in_hit == 12346 // 30        # 411

任务拆解与执行计划.md

@@ -138,7 +138,7 @@ P0 完成后的能力：干净的后端抽象 + 可量化的评测 + 可追溯
 | T-P0 | 骨架：gateway/proxy/ 包 + SQLite DDL + enabled 门控挂路由 | ✅ 完成 | T-P0 |
 | T-P1 | 鉴权+账本：key 签发/令牌桶/四表/request_id 幂等/日限额 | ✅ 完成 | T-P1 |
 | T-P2 | 上游客户端：流式派发+三家 usage 归一化+首 token 前 failover | ✅ 完成 | T-P2 |
-| T-P3 | 计价+结算：峰谷窗口/毫元整数/黄金用例 ≥10 组 | ⬜ 待办 | |
+| T-P3 | 计价+结算：峰谷窗口/毫元整数/黄金用例 ≥10 组 | ✅ 完成 | T-P3 |
 | T-P4 | 路由端到端：/proxy/v1 非流式+流式+402/429/413 语义 | ⬜ 待办 | |
 | T-P5 | 规范化+桶：稳定哈希/整形顺序/doc_version 失效/多轮不缓存 | ⬜ 待办 | |
 | T-P6 | 语义缓存：L1 精确+L2 n-gram 倒排+singleflight+TTL+失败不缓存 | ⬜ 待办 | |