"""视频级切分科研旋钮单元测试：诊断指纹 + val_wrong_min 功效护栏。

覆盖：
    - diag_fingerprint 对 (prompt 版本 / 模型 / 代码版本) 三元组确定且敏感；
    - split_by_video_assignment 的 val_wrong_min 门控 fail loud（验证信号不足即报错）；
    - val_wrong_min 默认 0 时行为与 Task 11 现有调用完全一致（不回归）。

注：结果驱动视频级切分不复用 PoolConfig——它有独立的 VideoSplitConfig /
SplitBuildConfig / SelectConfig，故 PoolConfig 不承载视频级切分旋钮（无死配置面）。
"""

from __future__ import annotations

import pytest

from app.harness.pools import InsufficientValSignal, split_by_video_assignment
from app.harness.split_selection import diag_fingerprint
from core.types import GeneratedQuestion


def _q(qid: str, vid: str, tt: str = "Counting Problem") -> GeneratedQuestion:
    """构造最小可用题目（补齐 GeneratedQuestion 的必填 source_nodes/difficulty）。"""
    return GeneratedQuestion(
        question_id=qid,
        video_id=vid,
        task_type=tt,
        question="",
        options=("A", "B", "C", "D"),
        answer="A",
        source_nodes=(),
        difficulty="easy",
    )


def test_diag_fingerprint_deterministic_and_sensitive():
    """诊断指纹对相同三元组稳定，对任一分量变化敏感。"""
    a = diag_fingerprint("p1", "deepseek-v4", "abc123")
    assert a == diag_fingerprint("p1", "deepseek-v4", "abc123")  # 确定性
    assert a != diag_fingerprint("p2", "deepseek-v4", "abc123")  # prompt 变则变
    assert a != diag_fingerprint("p1", "kimi", "abc123")  # model 变则变
    assert a != diag_fingerprint("p1", "deepseek-v4", "def456")  # 代码版本变则变
    assert len(a) == 16  # sha256 截断 16 位十六进制


def test_val_wrong_min_enforced():
    """val 错题数 < val_wrong_min 时 fail loud（InsufficientValSignal），不静默兜底。"""
    qs = [_q("v1-1", "v1"), _q("v1-2", "v1"), _q("v1-3", "v1")]
    correctness = {q.question_id: True for q in qs}  # 全对 → val 无错题
    with pytest.raises(InsufficientValSignal):  # val 错题 < val_wrong_min
        split_by_video_assignment(
            qs,
            {"v1": "trainval"},
            correctness=correctness,
            val_ratio=0.5,
            seed=0,
            val_wrong_min=5,
        )


def test_val_wrong_min_default_zero_no_regression():
    """val_wrong_min 默认 0 时不检查错题数，保持 Task 11 现有调用契约不破。"""
    qs = [_q("v1-1", "v1"), _q("v2-1", "v2")]
    assignment = {"v1": "trainval", "v2": "trainval"}
    correctness = {"v1-1": True, "v2-1": True}  # 全对但默认不触发护栏
    pools = split_by_video_assignment(
        qs, assignment, correctness=correctness, val_ratio=1.0, seed=0
    )
    assert len(pools.validation) == 2  # 未抛异常，正常返回