"""纯域求值引擎：排序、硬约束拦截、用户禁忌压过专业推荐、性能基准（T-P2-02）。"""

from __future__ import annotations

import time
from typing import Any

from packages.rules import dsl, engine


def _rule(
    rule_key: str,
    priority: int,
    *,
    category: str = "test",
    confidence: float = 0.9,
    is_hard: bool = False,
    conditions: dict[str, Any] | None = None,
    recommend: tuple[dict[str, Any], ...] = (),
    avoid: tuple[dict[str, Any], ...] = (),
    explanation: str | None = None,
) -> dsl.Rule:
    effects: dict[str, Any] = {}
    if recommend:
        effects["recommend"] = list(recommend)
    if avoid:
        effects["avoid"] = list(avoid)
    if explanation:
        effects["explanation"] = explanation
    if not effects:
        effects["explanation"] = "测试规则"  # 空效果本身非法，测试助手兜底
    return dsl.Rule.model_validate(
        {
            "rule_key": rule_key,
            "category": category,
            "priority": priority,
            "conditions": conditions or {},
            "effects": effects,
            "is_hard": is_hard,
            "confidence": confidence,
        }
    )


# ── 排序与命中链 ───────────────────────────────────────────────────────────


def test_hits_sorted_by_priority_then_confidence_then_key() -> None:
    rules = [
        _rule("R-LOW", 50),
        _rule("R-TIE-B", 90, confidence=0.9),
        _rule("R-TOP", 95, confidence=0.5),
        _rule("R-TIE-A", 90, confidence=0.9),
        _rule("R-TIE-C", 90, confidence=0.8),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert [h.rule_key for h in verdict.rule_hits] == [
        "R-TOP",
        "R-TIE-A",
        "R-TIE-B",
        "R-TIE-C",
        "R-LOW",
    ]
    assert [h.priority for h in verdict.rule_hits] == [95, 90, 90, 90, 50]


def test_rule_hit_carries_metadata_and_explanations_in_priority_order() -> None:
    rules = [
        _rule("R-LOW", 50, explanation="趋势解释", category="trend", confidence=0.7),
        _rule("R-HIGH", 90, explanation="体型解释", category="body_shape", confidence=0.95),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    top = verdict.rule_hits[0]
    assert (top.rule_key, top.priority, top.category, top.confidence) == (
        "R-HIGH",
        90,
        "body_shape",
        0.95,
    )
    assert top.is_hard is False
    assert verdict.explanations == ("体型解释", "趋势解释")
    assert verdict.explanation == "体型解释；趋势解释"


def test_no_rules_or_no_hits_yield_empty_verdict() -> None:
    assert engine.evaluate([], dsl.RuleContext()).recommend == ()
    verdict = engine.evaluate(
        [_rule("R-X", 90, conditions={"body_shape": "A型"})],
        dsl.RuleContext(body_shape="H型"),
    )
    assert verdict.rule_hits == ()
    assert verdict.blocked is False


# ── 硬约束 ─────────────────────────────────────────────────────────────────


def test_hard_rule_with_avoid_populates_hard_blocks() -> None:
    avoid = {"slot": "shoes", "attrs": {"material": ["真皮"]}}
    rules = [_rule("R-HARD", 100, is_hard=True, avoid=(avoid,), explanation="合规红线")]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert verdict.blocked is True
    assert len(verdict.hard_blocks) == 1
    block = verdict.hard_blocks[0]
    assert block.rule_key == "R-HARD"
    assert block.avoid[0].slot == "shoes"
    assert block.avoid[0].attrs["material"] == ("真皮",)
    assert block.explanation == "合规红线"


def test_hard_rule_without_avoid_does_not_block() -> None:
    # 拦截语义只由 avoid 表达：is_hard 规则只写 recommend 就无物可拦
    rules = [
        _rule(
            "R-HARD-REC",
            100,
            is_hard=True,
            recommend=({"slot": "top", "attrs": {"collar": ["衬衫领"]}},),
        )
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert verdict.hard_blocks == ()
    assert verdict.blocked is False


def test_hard_rule_not_fired_does_not_block() -> None:
    rules = [
        _rule(
            "R-HARD",
            100,
            is_hard=True,
            conditions={"occasion": "面试"},
            avoid=({"slot": "top", "attrs": {"neckline": ["深V"]}},),
        )
    ]
    assert engine.evaluate(rules, dsl.RuleContext(occasion="通勤")).blocked is False
    assert engine.evaluate(rules, dsl.RuleContext(occasion="面试")).blocked is True


def test_soft_rule_with_avoid_never_blocks() -> None:
    rules = [_rule("R-SOFT", 90, avoid=({"slot": "top", "attrs": {"silhouette": ["修身"]}},))]
    assert engine.evaluate(rules, dsl.RuleContext()).hard_blocks == ()


# ── 冲突仲裁：高优先级 avoid 剔除严格低优先级的冲突 recommend ────────────────


def test_user_taboo_overrides_professional_recommend() -> None:
    # 用户禁忌（95）与专业推荐（90）同 slot 同维度取值相交 → 推荐被剔除
    rules = [
        _rule(
            "R-PRO",
            dsl.PRIORITY_BODY_SHAPE,
            recommend=({"slot": "top", "attrs": {"shoulder": ["落肩"]}},),
        ),
        _rule(
            "R-TABOO",
            dsl.PRIORITY_USER_TABOO,
            conditions={"user_taboos": {"include": ["oversize"]}},
            avoid=({"slot": "top", "attrs": {"shoulder": ["落肩"]}},),
        ),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext(user_taboos=("oversize",)))
    assert verdict.recommend == ()
    assert verdict.avoid != ()  # 禁忌约束保留在 avoid 里供下游过滤
    assert [h.rule_key for h in verdict.rule_hits] == ["R-TABOO", "R-PRO"]


def test_taboo_keeps_non_conflicting_recommend() -> None:
    # 不同维度（length vs shoulder）不构成冲突：专业推荐保留
    rules = [
        _rule(
            "R-PRO",
            90,
            recommend=({"slot": "top", "attrs": {"shoulder": ["垫肩"]}},),
        ),
        _rule(
            "R-TABOO",
            95,
            avoid=({"slot": "top", "attrs": {"length": ["短款"]}},),
        ),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert [item.slot for item in verdict.recommend] == ["top"]
    assert verdict.recommend[0].attrs["shoulder"] == ("垫肩",)


def test_taboo_does_not_override_higher_priority_recommend() -> None:
    # 合规（100）> 用户禁忌（95）：只有"严格更低"优先级的推荐才会被剔除
    rules = [
        _rule(
            "R-COMPLIANCE",
            dsl.PRIORITY_COMPLIANCE,
            recommend=({"slot": "top", "attrs": {"shoulder": ["落肩"]}},),
        ),
        _rule(
            "R-TABOO",
            dsl.PRIORITY_USER_TABOO,
            avoid=({"slot": "top", "attrs": {"shoulder": ["落肩"]}},),
        ),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert len(verdict.recommend) == 1


def test_lower_priority_recommend_vetoed_by_higher_soft_avoid() -> None:
    # 通用优先级语义：体型 avoid（90）同样压过趋势 recommend（50）
    rules = [
        _rule(
            "R-TREND",
            dsl.PRIORITY_TREND,
            recommend=({"slot": "top", "attrs": {"silhouette": ["修身"]}},),
        ),
        _rule(
            "R-BODY",
            dsl.PRIORITY_BODY_SHAPE,
            avoid=({"slot": "top", "attrs": {"silhouette": ["修身"]}},),
        ),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert verdict.recommend == ()


def test_same_priority_avoid_does_not_veto_recommend() -> None:
    # 同优先级不仲裁：推荐与回避并存，由下游按场景取舍
    rules = [
        _rule(
            "R-A",
            90,
            recommend=({"slot": "top", "attrs": {"sleeve": ["泡泡袖"]}},),
        ),
        _rule(
            "R-B",
            90,
            avoid=({"slot": "top", "attrs": {"sleeve": ["泡泡袖"]}},),
        ),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert len(verdict.recommend) == 1


def test_different_slot_never_conflicts() -> None:
    rules = [
        _rule(
            "R-REC",
            50,
            recommend=({"slot": "bottom", "attrs": {"silhouette": ["紧身"]}},),
        ),
        _rule(
            "R-AVOID",
            100,
            is_hard=True,
            avoid=({"slot": "top", "attrs": {"silhouette": ["紧身"]}},),
        ),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert len(verdict.recommend) == 1
    assert verdict.blocked is True  # 拦截归拦截，推荐归推荐


# ── 汇总与去重 ─────────────────────────────────────────────────────────────


def test_identical_recommend_deduped_and_order_follows_priority() -> None:
    item = {"slot": "top", "attrs": {"collar": ["衬衫领"]}}
    rules = [
        _rule("R-STYLE", 70, recommend=(item,)),
        _rule("R-OCCASION", 80, recommend=(item,)),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert len(verdict.recommend) == 1
    assert len(verdict.avoid) == 0


def test_identical_avoid_deduped() -> None:
    avoid = {"slot": "top", "attrs": {"silhouette": ["修身"]}}
    rules = [
        _rule("R-A", 90, avoid=(avoid,)),
        _rule("R-B", 60, avoid=(avoid,)),
    ]
    verdict = engine.evaluate(rules, dsl.RuleContext())
    assert len(verdict.avoid) == 1


# ── 性能基准（T-P2-02：p95 < 50ms @ 400 条规则）─────────────────────────────


def test_benchmark_400_rules_well_under_50ms_budget() -> None:
    """400 条规则 × 1000 次求值。

    断言均值 < 5ms/次（对 50ms 预算留 10 倍裕量，CI 机器差异不至于 flaky），
    并直接断言 p95 < 50ms 对应验收指标。求值是纯内存操作，规则从缓存来，
    不含任何 I/O。
    """
    shapes = ("A型", "H型", "X型", "O型")
    rules = [
        _rule(
            f"R-BENCH-{i:03d}",
            50 + (i % 6) * 10,
            category="bench",
            confidence=0.5 + (i % 10) / 20,
            conditions={"body_shape": shapes[i % 4], "season": {"exclude": ["夏"]}},
            recommend=({"slot": "top", "attrs": {"collar": [f"领型{i % 5}"]}},),
            avoid=({"slot": "bottom", "attrs": {"silhouette": ["紧身"]}},),
            explanation=f"基准规则 {i}",
        )
        for i in range(400)
    ]
    assert len(rules) == 400
    ctx = dsl.RuleContext(body_shape="A型", season="冬", temperature=18.0)

    engine.evaluate(rules, ctx)  # 预热：首次调用的函数定位等开销不摊给被测对象
    timings: list[float] = []
    for _ in range(1000):
        start = time.perf_counter()
        engine.evaluate(rules, ctx)
        timings.append(time.perf_counter() - start)

    mean = sum(timings) / len(timings)
    p95 = sorted(timings)[int(len(timings) * 0.95) - 1]
    assert mean < 0.005, f"平均单次求值 {mean * 1000:.2f}ms，超出 5ms 基线"
    assert p95 < 0.05, f"p95 单次求值 {p95 * 1000:.2f}ms，超出 50ms 预算"