"""连续并发 gate 的前缀消费纯逻辑测试。"""

from __future__ import annotations

from app.harness.validate import GateSpec, _advance_prefix, _GateRun
from core.evolution import GateParams
from core.types import GeneratedQuestion, QuestionUnit


def _mk_question(qid: str, task_type: str = "Action Reasoning") -> GeneratedQuestion:
    """构造最小可用的 single 题（字段以 core.types 真实定义为准，缺省值从简）。"""
    return GeneratedQuestion(
        question_id=qid,
        video_id="v1",
        task_type=task_type,
        question=f"q-{qid}",
        options=("A. x", "B. y"),
        answer="A",
        source_nodes=(),
        difficulty="easy",
    )


def _mk_unit(qid: str, task_type: str = "Action Reasoning") -> QuestionUnit:
    """由单条题目构造 single 单元（unit_id 回填为 question_id）。"""
    return QuestionUnit.from_single(_mk_question(qid, task_type))


def _mk_run(n_units: int) -> _GateRun:
    """构造含 n_units 个 single 单元的初始 gate 运行时状态。"""
    spec = GateSpec(
        task_type="Action Reasoning",
        target_file="action-reasoning.md",
        candidate_content="cand",
        base_skill_content="base",
        units=tuple(_mk_unit(f"q{i}") for i in range(n_units)),
        gate_run_prefix="r_e1_s0_gate_action-reasoning",
    )
    return _GateRun.from_spec(spec)


_PARAMS = GateParams(
    e_confirm=20.0,
    e_provisional=3.0,
    w_net_min=2,
    delta_min=0.02,
    lambda_dir=-0.642,
    e_rollback=10.0,
)


def test_prefix_blocks_on_unresolved_head() -> None:
    """阶梯头部单元未配齐时,即使尾部全部配齐也一个都不消费。"""
    run = _mk_run(4)
    for i in (1, 2, 3):  # 尾部三个先到
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.n_used == 0 and run.w == 0 and run.verdict is None


def test_prefix_consumes_in_ladder_order_after_head_arrives() -> None:
    """头部补齐后一次性顺序消费到最长已配齐前缀。"""
    run = _mk_run(4)
    for i in (0, 1, 2):
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.n_used == 3 and run.w == 3 and run.l == 0
    assert [r["ladder_rank"] for r in run.evidence_rows] == [0, 1, 2]


def test_freeze_on_terminal_verdict_stops_consumption() -> None:
    """过线即冻结,后续已配齐单元不再消费。

    数值:W 连胜 L=0 时 E=(2^(W+1)-1)/(W+1),W=6→18.14<20,W=7→31.875≥20,
    故 7 连胜恰好 confirmed 过线(Codex 复核)。
    """
    run = _mk_run(12)
    for i in range(12):
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.frozen and run.verdict is not None
    assert run.verdict.decision == "accept_confirmed"
    assert run.n_used == 7  # 第 7 个净胜恰好过线,早停不吃满


def test_tail_infra_reaches_terminal_not_continue() -> None:
    """尾部全 INFRA:剔除后须重判(n_remaining 归 0 → 题尽第四出口),
    verdict 不得停留在 continue(Codex plan 审 C1 回归锁)。"""
    run = _mk_run(4)
    run.slots[0].base = False
    run.slots[0].cand_per_q = {"q0": True}
    run.slots[1].base = True
    run.slots[1].cand_per_q = {"q1": True}
    for i in (2, 3):
        run.slots[i].base_infra = True
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.verdict is not None and run.verdict.decision != "continue"
    assert run.frozen


def test_infra_unit_skipped_not_counted() -> None:
    """INFRA 单元(任一臂)剔除:不入 (W,L)、计入 n_excluded、前缀继续推进。

    注意 futility 出口在小 n_remaining 下很敏感,用 6 单元(首个 INFRA、其余 5 个
    W 翻转)保证消费全程不提前触发 futility:题尽走 accept_provisional 终态。
    """
    run = _mk_run(6)
    run.slots[0].base_infra = True
    run.slots[0].cand_per_q = {"q0": True}
    for i in range(1, 6):
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.n_excluded == 1 and run.n_used == 5 and run.w == 5 and run.l == 0
    assert run.verdict is not None and run.verdict.decision == "accept_provisional"


def test_all_infra_leaves_verdict_none() -> None:
    """全部单元被剔除:verdict 保持 None、frozen 保持 False——终态由调度编排层
    (Task 3 的 validate_skills_concurrent)检测 verdict None 并 raise,本函数不管。"""
    run = _mk_run(3)
    for i in range(3):
        run.slots[i].base_infra = True
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.verdict is None and not run.frozen and run.n_excluded == 3 and run.prefix_ptr == 3


def test_repeated_calls_are_idempotent() -> None:
    """部分前缀消费后重复调用不改变状态;补齐剩余单元后再调用正常推进。"""
    run = _mk_run(4)
    for i in (0, 1):
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    snapshot = (run.n_used, run.w, run.l, run.prefix_ptr, len(run.evidence_rows))
    _advance_prefix(run, _PARAMS)
    _advance_prefix(run, _PARAMS)
    assert (run.n_used, run.w, run.l, run.prefix_ptr, len(run.evidence_rows)) == snapshot
    for i in (2, 3):
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.n_used > snapshot[0] and run.prefix_ptr > snapshot[3]


def test_frozen_run_call_is_noop() -> None:
    """frozen 后再调用是 no-op:不再消费已配齐单元、证据不再追加。"""
    run = _mk_run(12)
    for i in range(12):
        run.slots[i].base = False
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.frozen and run.n_used == 7
    n_evidence = len(run.evidence_rows)
    _advance_prefix(run, _PARAMS)
    assert run.n_used == 7 and len(run.evidence_rows) == n_evidence


def test_ties_hit_futility_early_and_freeze() -> None:
    """全打平(无翻转对)时 futility 出口尽早触发并冻结——早停语义(数值:W=L=0
    时乐观 E = E(n_remaining, 0),n 小易 <e_provisional=3)。"""
    run = _mk_run(3)
    for i in range(3):
        run.slots[i].base = True
        run.slots[i].cand_per_q = {f"q{i}": True}
    _advance_prefix(run, _PARAMS)
    assert run.frozen
    # 精确锁定 futility 出口:首个消费后 W=L=0,n_remaining=2,
    # 乐观 E=E(2,0)=(2^3-1)/3=2.33<3 → 立即 reject_futility(Codex 复核)
    assert run.verdict is not None and run.verdict.decision == "reject_futility"
    assert run.n_used == 1 and run.w == 0 and run.l == 0