"""题族规格声明单元测试。"""

from __future__ import annotations

import random
from collections import Counter

import pytest
from scipy import stats

from app.question_gen.families import (
    ALL_FAMILIES,
    RETRIEVAL_FAMILY,
    get_family_for_slot,
)

# 12 种任务类型（来自 harness config）
ALL_TASK_TYPES: frozenset[str] = frozenset(
    [
        "Action Recognition",
        "Action Reasoning",
        "Action Prediction",
        "Action Sequence",
        "Object Recognition",
        "Object Reasoning",
        "Object Interaction",
        "Scene Understanding",
        "Event Reasoning",
        "Causal Reasoning",
        "Temporal Reasoning",
        "Spatial Reasoning",
    ]
)


class TestFamilySpec:
    """验证 QuestionFamilySpec 声明的完整性与一致性。"""

    def test_all_families_cover_all_task_types(self) -> None:
        """12 种任务类型在 ALL_FAMILIES 中全覆盖。"""
        covered: set[str] = set()
        for family in ALL_FAMILIES:
            covered.update(family.legal_task_types)
        assert covered == ALL_TASK_TYPES

    def test_skill_targets_unique(self) -> None:
        """每个 family 的 skill_target 不重复。"""
        targets = [f.skill_target for f in ALL_FAMILIES]
        assert len(targets) == len(set(targets))

    def test_all_families_tuple_length(self) -> None:
        """ALL_FAMILIES 包含 5 个家族。"""
        assert len(ALL_FAMILIES) == 5

    def test_family_instances_are_frozen(self) -> None:
        """Family spec 实例不可修改。"""
        with pytest.raises(AttributeError):
            RETRIEVAL_FAMILY.name = "hacked"  # type: ignore[misc]

    def test_legal_task_types_are_frozensets(self) -> None:
        """legal_task_types 是 frozenset，确保不可变。"""
        for family in ALL_FAMILIES:
            assert isinstance(family.legal_task_types, frozenset)

    def test_sampling_constraints_reasonable(self) -> None:
        """采样约束值在合理范围。"""
        for family in ALL_FAMILIES:
            assert family.sampling.min_subtitles >= 0
            assert family.sampling.min_l3_nodes >= 1

    def test_leak_profile_thresholds_valid(self) -> None:
        """泄漏测试阈值在 (0, 1] 范围内。"""
        for family in ALL_FAMILIES:
            assert 0 < family.leak_profile.pass_threshold <= 1.0

    def test_prompt_templates_not_empty(self) -> None:
        """每个 family 的 prompt_template 非空。"""
        for family in ALL_FAMILIES:
            assert family.prompt_template
            assert family.prompt_template.endswith(".md")


class TestGetFamilyForSlot:
    """验证 get_family_for_slot 的核心行为。"""

    def test_respects_legal_task_types(self) -> None:
        """返回的 family 必须包含给定 task_type。"""
        rng = random.Random(42)
        for task_type in ALL_TASK_TYPES:
            for _ in range(50):
                family = get_family_for_slot(
                    task_type=task_type,
                    family_ratios={
                        "RETRIEVAL": 0.30,
                        "REASONING": 0.25,
                        "ENUMERATION": 0.20,
                        "VISUAL": 0.15,
                        "SPATIAL": 0.10,
                    },
                    rng=rng,
                )
                assert task_type in family.legal_task_types

    def test_deterministic_with_seed(self) -> None:
        """相同 seed 产出相同结果。"""
        ratios = {
            "RETRIEVAL": 0.30,
            "REASONING": 0.25,
            "ENUMERATION": 0.20,
            "VISUAL": 0.15,
            "SPATIAL": 0.10,
        }
        results_a = []
        results_b = []
        for seed in range(10):
            rng_a = random.Random(seed)
            rng_b = random.Random(seed)
            results_a.append(get_family_for_slot("Action Reasoning", ratios, rng_a).name)
            results_b.append(get_family_for_slot("Action Reasoning", ratios, rng_b).name)
        assert results_a == results_b

    def test_invalid_task_type_raises(self) -> None:
        """不存在的 task_type 抛 ValueError。"""
        rng = random.Random(0)
        with pytest.raises(ValueError, match="task_type"):
            get_family_for_slot(
                task_type="Nonexistent Type",
                family_ratios={"RETRIEVAL": 1.0},
                rng=rng,
            )

    def test_distribution_approximates_ratios(self) -> None:
        """大样本下分布近似指定比例（chi-square p > 0.01）。

        使用 Action Recognition — 只有 RETRIEVAL 和 VISUAL 合法。
        """
        rng = random.Random(123)
        ratios = {
            "RETRIEVAL": 0.30,
            "REASONING": 0.25,
            "ENUMERATION": 0.20,
            "VISUAL": 0.15,
            "SPATIAL": 0.10,
        }
        n = 5000
        counter: Counter[str] = Counter()
        for _ in range(n):
            family = get_family_for_slot("Action Recognition", ratios, rng)
            counter[family.name] += 1

        # Action Recognition 合法族: RETRIEVAL(0.30), VISUAL(0.15)
        # 归一化后: RETRIEVAL=0.30/0.45≈0.667, VISUAL=0.15/0.45≈0.333
        legal_ratios = {"RETRIEVAL": 0.30, "VISUAL": 0.15}
        total_weight = sum(legal_ratios.values())
        expected_probs = {k: v / total_weight for k, v in legal_ratios.items()}

        observed = [counter.get("RETRIEVAL", 0), counter.get("VISUAL", 0)]
        expected = [expected_probs["RETRIEVAL"] * n, expected_probs["VISUAL"] * n]

        chi2, p_value = stats.chisquare(observed, expected)
        assert p_value > 0.01, f"分布偏离过大: chi2={chi2:.2f}, p={p_value:.4f}"

    def test_no_legal_family_raises(self) -> None:
        """所有 family 权重为 0 时合法族为空，应抛出 ValueError。"""
        rng = random.Random(0)
        # Spatial Reasoning 合法族: RETRIEVAL, REASONING, VISUAL, SPATIAL
        # 如果 ratios 中只含不合法的族名，应抛错
        with pytest.raises(ValueError, match="合法"):
            get_family_for_slot(
                task_type="Spatial Reasoning",
                family_ratios={"ENUMERATION": 1.0},
                rng=rng,
            )