"""分类器单元测试。"""
from router_system.classifier import RuleClassifier


def test_tie_break_is_deterministic():
    """同分决胜：按领域名字典序，与规则表排列顺序无关。"""
    clf = RuleClassifier()
    clf.rules = {"zeta": [("x", 1.0)], "alpha": [("x", 1.0)]}
    r = clf.classify("x")
    assert r.domain == "alpha"


def test_distinctiveness_penalty():
    """次高分占比高（语义含混）时置信度被压低；单一领域命中不受影响。"""
    clf = RuleClassifier()
    clf.rules = {"a": [("kw", 1.0)], "b": [("kw", 0.9)]}
    r_ambiguous = clf.classify("kw")
    clf_clear = RuleClassifier()
    clf_clear.rules = {"a": [("kw", 1.0)], "b": [("other", 0.1)]}
    r_clear = clf_clear.classify("kw")
    assert r_clear.confidence > r_ambiguous.confidence


def test_code_classification():
    clf = RuleClassifier()
    r = clf.classify("用 Python 写一个快速排序函数")
    assert r.domain == "code"
    assert r.confidence > 0.7


def test_math_classification():
    clf = RuleClassifier()
    r = clf.classify("求解方程 x^2 - 5x + 6 = 0")
    assert r.domain == "math"
    assert r.confidence > 0.7


def test_legal_classification():
    clf = RuleClassifier()
    r = clf.classify("劳动合同到期不续签需要支付经济补偿吗")
    assert r.domain == "legal"


def test_medical_classification():
    clf = RuleClassifier()
    r = clf.classify("高血压患者日常饮食需要注意什么")
    assert r.domain == "medical"


def test_general_low_confidence():
    clf = RuleClassifier()
    r = clf.classify("今天天气怎么样")
    # 未命中任何领域 -> 低置信度，触发 should_fallback
    assert r.domain == "general"
    assert clf.should_fallback(r, 0.6) is True


def test_difficulty_estimation():
    clf = RuleClassifier()
    easy = clf.classify("1 + 1 = ?")
    hard = clf.classify("证明费马大定理并推导其推论，给出详细步骤")
    assert hard.difficulty in ("medium", "hard")
    assert easy.difficulty == "easy"