"""回填脚本的「静默缺口」护栏（2026-07-28 生产回填事故的回归）。

背景：`sync_*_for_integration` 遇到 per-scope 超时/驱动错误时**不抛
异常**，而是返回 ``status='partial_failure'``（细节在 ``errors`` /
``per_scope``）。修复前 `backfill_cost_facts.py` 只在 ``except`` 分支
往 ``result.errors`` 写，所以这种返回值只打一行 INFO、`errors` 为空、
脚本**退出码 0** —— 生产上两个最大的 AWS 账号在每个 30 天块都超时，
它们的 `amount_usd_list` 全程留 NULL，最后靠人工 facts-vs-billing_daily
对数才发现。

Pins：
  * ``_collect_chunk_failure``：成功形状返回 None；partial_failure 点名
    出错的 scope（`per_scope` 里非 ok 的行）并带 reason/errors 明细。
  * ``IntegrationResult.status`` 与退出码口径一致：返回值里的
    partial_failure 必须让整轮判失败（而不是只看抛异常）。
  * ``_chunks(chunk_days=N)``：可调块长（重租户用 7 天块避开 300s
    per-scope 闸），且切块完整覆盖窗口、不重不漏。
"""
from __future__ import annotations

import importlib.util
import sys
from datetime import date
from pathlib import Path

_SCRIPT = (
    Path(__file__).resolve().parents[2] / "scripts" / "backfill_cost_facts.py"
)


def _load_script_module():
    spec = importlib.util.spec_from_file_location(
        "backfill_cost_facts_under_test", _SCRIPT,
    )
    assert spec and spec.loader
    module = importlib.util.module_from_spec(spec)
    # 必须先注册进 sys.modules 再 exec:脚本用了 ``from __future__ import
    # annotations`` + @dataclass,dataclass 解析延迟注解时会去
    # ``sys.modules[cls.__module__].__dict__`` 找名字,模块未注册时报
    # ``'NoneType' object has no attribute '__dict__'``。
    sys.modules[spec.name] = module
    spec.loader.exec_module(module)
    return module


_mod = _load_script_module()


# ── _collect_chunk_failure ────────────────────────────────────────


def test_success_shapes_are_not_failures() -> None:
    for status in ("ok", "skipped", "not_supported", "partial_success", "dry_run"):
        assert _mod._collect_chunk_failure(
            surface="cost_facts",
            start=date(2026, 6, 1), end=date(2026, 6, 30),
            payload={"status": status},
        ) is None, status


def test_partial_failure_names_offending_scopes() -> None:
    """生产形状:两个大账号 per-scope 超时,其余 scope ok。"""
    msg = _mod._collect_chunk_failure(
        surface="cost_facts",
        start=date(2026, 6, 1), end=date(2026, 6, 30),
        payload={
            "status": "partial_failure",
            "errors": ["scope 632330501419 exceeded 300.0s timeout; advancing"],
            "per_scope": [
                {"scope": "143458967504", "status": "ok", "facts": 12},
                {"scope": "632330501419", "status": "timeout",
                 "error": "exceeded 300.0s timeout"},
                {"scope": "385595570414", "status": "timeout",
                 "error": "exceeded 300.0s timeout"},
            ],
        },
    )
    assert msg is not None
    assert "status=partial_failure" in msg
    assert "632330501419(timeout)" in msg
    assert "385595570414(timeout)" in msg
    # ok 的 scope 不该被点名
    assert "143458967504" not in msg
    assert "300.0s" in msg  # reason/errors 明细透出


def test_failed_status_without_per_scope_still_reports_reason() -> None:
    msg = _mod._collect_chunk_failure(
        surface="billing_daily",
        start=date(2026, 6, 1), end=date(2026, 6, 30),
        payload={"status": "failed", "reason": "driver load failed: boom"},
    )
    assert msg is not None
    assert "billing_daily" in msg and "driver load failed" in msg


# ── 退出码口径 ────────────────────────────────────────────────────


def test_integration_result_status_flags_returned_partial_failure() -> None:
    result = _mod.IntegrationResult(
        integration_id="i-1", name="AWS", provider="aws",
    )
    result.cost_facts.append({"status": "ok"})
    assert result.status == "ok"
    # 未抛异常、仅返回 partial_failure —— 修复前这里仍算 ok 且 errors 空
    result.cost_facts.append({"status": "partial_failure"})
    assert result.status == "partial_failure"


def test_failure_predicate_matches_status_not_only_exceptions() -> None:
    """退出码口径:status != ok 即判失败(镜像 main_async 的收尾判定)。"""
    ok = _mod.IntegrationResult(
        integration_id="i-ok", name="GCP", provider="gcp",
    )
    ok.cost_facts.append({"status": "ok"})

    partial = _mod.IntegrationResult(
        integration_id="i-partial", name="AWS", provider="aws",
    )
    partial.cost_facts.append({"status": "partial_failure"})

    failed = [r for r in (ok, partial) if r.errors or r.status != "ok"]
    assert [r.name for r in failed] == ["AWS"]


# ── 可调块长 ──────────────────────────────────────────────────────


def test_chunks_respect_chunk_days_and_cover_window() -> None:
    start, end = date(2026, 6, 1), date(2026, 6, 30)
    default_chunks = _mod._chunks(start, end)
    assert default_chunks == [(start, end)]  # 30 天窗口 = 1 块

    seven = _mod._chunks(start, end, chunk_days=7)
    assert len(seven) == 5
    assert seven[0] == (date(2026, 6, 1), date(2026, 6, 7))
    assert seven[-1][1] == end
    # 不重不漏:每块首日 = 上块末日 + 1
    for (prev_s, prev_e), (nxt_s, _nxt_e) in zip(seven, seven[1:], strict=False):
        assert (nxt_s - prev_e).days == 1
        assert prev_s <= prev_e