"""决策缓存测试（T-X3）：LRU+TTL 单元契约 + Grader live 模式接线（embed 去重）。"""
import asyncio

import pytest

from gateway.sense.config import build_sense_config
from gateway.sense.decision_cache import DecisionCache
from gateway.sense.grader import Grader
from gateway.sense.store import SenseStore


# ---------------- DecisionCache 单元 ----------------

class _Clock:
    def __init__(self):
        self.t = 100.0

    def __call__(self):
        return self.t


def test_key_scope_and_text_sensitive():
    assert DecisionCache.key("proxy", "abc") == DecisionCache.key("proxy", "abc")
    assert DecisionCache.key("proxy", "abc") != DecisionCache.key("pipeline", "abc")
    assert DecisionCache.key("proxy", "abc") != DecisionCache.key("proxy", "abd")


def test_put_get_hit_miss_counters():
    c = DecisionCache()
    assert c.get("s", "q") is None
    c.put("s", "q", {"tier": "T1"})
    assert c.get("s", "q") == {"tier": "T1"}
    st = c.stats()
    assert st["hits"] == 1 and st["misses"] == 1 and st["entries"] == 1


def test_ttl_expiry_with_fake_clock():
    clock = _Clock()
    c = DecisionCache(ttl_s=60.0, now=clock)
    c.put("s", "q", {"v": 1})
    assert c.get("s", "q") == {"v": 1}
    clock.t += 61.0                    # 超时
    assert c.get("s", "q") is None
    assert c.stats()["entries"] == 0   # 过期条目被清除


def test_lru_eviction_at_maxsize():
    c = DecisionCache(maxsize=2)
    c.put("s", "a", 1)
    c.put("s", "b", 2)
    c.get("s", "a")                    # a 变为最近使用
    c.put("s", "c", 3)                 # 淘汰 b
    assert c.get("s", "a") == 1
    assert c.get("s", "b") is None
    assert c.get("s", "c") == 3


def test_clear_keeps_counters_but_drops_entries():
    c = DecisionCache()
    c.put("s", "q", 1)
    c.get("s", "q")
    c.clear()
    assert c.get("s", "q") is None
    assert c.stats()["hits"] == 1      # 计数保留（审计口径不回退）


# ---------------- Grader live 模式接线 ----------------

class _CountingObserver:
    def __init__(self):
        self.logs = []

    def log(self, obs):
        self.logs.append(obs)


class _FakeHead:
    version = "test-head"

    def predict(self, vec):
        return {"t1": 0.95, "t2": 0.03, "t3": 0.02}


def _make_grader(tmp_path, mode, counter, observer=None):
    """构造测试 Grader：embed 打点计数 + FakeHead 注入。"""
    import gateway.sense.grader as gr

    cfg = build_sense_config({"sense": {
        "enabled": True, "mode": mode,
        "db_path": str(tmp_path / "s.sqlite3"),
        "models_dir": str(tmp_path / "models")}})
    store = SenseStore.init_db(cfg.db_path)
    g = Grader(cfg, store, observer or _CountingObserver())
    g._load_head = lambda: _FakeHead()

    async def fake_embed(text, c):
        counter["n"] += 1
        return [1, 2, 3]

    orig = gr.embed
    gr.embed = fake_embed
    return g, orig


def test_grader_live_mode_dedupes_embed(tmp_path):
    """live 模式：同文本第二次 decide 命中缓存，embed 只跑一次；观察仍写两条。"""
    import gateway.sense.grader as gr
    counter = {"n": 0}
    observer = _CountingObserver()
    g, orig = _make_grader(tmp_path, "live", counter, observer)
    try:
        async def run():
            d1 = await g.decide("什么是递归", "proxy")
            d2 = await g.decide("什么是递归", "proxy")
            d3 = await g.decide("换一个问题", "proxy")
            return d1, d2, d3

        d1, d2, d3 = asyncio.run(run())
    finally:
        gr.embed = orig
    assert d1.tier == "T1" and d2.tier == "T1" and d3.tier == "T1"
    assert counter["n"] == 2                       # 同文本去重：2 个不同文本各 1 次
    assert d2.head_version == d1.head_version
    assert len(observer.logs) == 3                 # 观察不因缓存命中而跳过


def test_grader_collect_mode_no_cache(tmp_path):
    """collect/shadow：校准数据必须全量产出，不走缓存。"""
    import gateway.sense.grader as gr
    counter = {"n": 0}
    g, orig = _make_grader(tmp_path, "collect", counter)
    try:
        async def run():
            await g.decide("同一个问题", "proxy")
            await g.decide("同一个问题", "proxy")

        asyncio.run(run())
    finally:
        gr.embed = orig
    assert counter["n"] == 2


def test_grader_invalidate_clears_cache(tmp_path):
    """invalidate（工件切换）后缓存清空：同文本重新 embed。"""
    import gateway.sense.grader as gr
    counter = {"n": 0}
    g, orig = _make_grader(tmp_path, "live", counter)
    try:
        async def run():
            await g.decide("什么是递归", "proxy")
            g.invalidate()
            await g.decide("什么是递归", "proxy")

        asyncio.run(run())
    finally:
        gr.embed = orig
    assert counter["n"] == 2