"""SDK version guard (C2.5, closes C-N3) — LOAD-BEARING (§11).

The seam this file keeps alive: every SDK attribute premise in
``sdk_client.py`` was verified against a CONCRETE version range
(0.2.110 read at source level, release notes through 0.2.120; sdk-review
2026-07-16). The pin ``claude-agent-sdk>=0.2.111,<0.3`` freezes that range —
this guard makes an upgrade outside it a RED test naming exactly which
premises must be re-verified, instead of a silent behaviour drift.

Offline-safe: reads installed package metadata only — no key, no network.
"""

from __future__ import annotations

import importlib.metadata
from pathlib import Path

import pytest

_PYPROJECT = Path(__file__).resolve().parents[1] / "pyproject.toml"

# The verified range — MUST match the pyproject pin (bound below).
_VERIFIED_FLOOR = (0, 2, 111)
_VERIFIED_CEILING = (0, 3)
_PIN = "claude-agent-sdk>=0.2.111,<0.3"

# The sdk_client.py attribute premises the verified range vouches for
# (sdk-review 2026-07-16, verified against package source through 0.2.120).
_SDK_PREMISES = (
    "AssistantMessage.error/.model/.content",
    "ResultMessage.usage/.total_cost_usd/.is_error/.subtype/.errors",
    "ClaudeAgentOptions.max_budget_usd/.setting_sources/.system_prompt/.max_turns/.model/.tools",
    "TextBlock.text",
    "query() yields AssistantMessage then a closing ResultMessage",
)


def _parse(raw: str) -> tuple[int, ...]:
    return tuple(int(part) for part in raw.split(".")[:3])


def check_sdk_version() -> str:
    """Fail if the installed SDK is outside the verified range — naming the premises."""
    raw = importlib.metadata.version("claude-agent-sdk")
    if not (_VERIFIED_FLOOR <= _parse(raw) < _VERIFIED_CEILING):
        raise AssertionError(
            f"claude-agent-sdk {raw} is OUTSIDE the verified range >=0.2.111,<0.3. "
            "Re-verify the sdk_client.py attribute premises against the new version "
            "BEFORE widening the pin (pyproject.toml + this guard together): "
            + "; ".join(_SDK_PREMISES)
        )
    return raw


class TestSdkVersionGuard:
    def test_the_installed_sdk_is_within_the_verified_range(self) -> None:
        assert check_sdk_version() == importlib.metadata.version("claude-agent-sdk")

    def test_a_version_above_the_ceiling_trips_the_guard(
        self, monkeypatch: pytest.MonkeyPatch
    ) -> None:
        monkeypatch.setattr(importlib.metadata, "version", lambda name: "0.3.0")
        with pytest.raises(AssertionError) as err:
            check_sdk_version()
        message = str(err.value)
        assert "sdk_client.py" in message
        for premise in _SDK_PREMISES:
            assert premise in message

    def test_a_version_below_the_floor_trips_the_guard(
        self, monkeypatch: pytest.MonkeyPatch
    ) -> None:
        # 0.2.110 works but misses the 0.2.111 read-loop fixes (NDJSON
        # whitespace on >64 KiB lines, plain-string content TypeError,
        # zombie subprocess on cancellation) — below the floor is unverified.
        monkeypatch.setattr(importlib.metadata, "version", lambda name: "0.2.110")
        with pytest.raises(AssertionError):
            check_sdk_version()

    def test_the_pyproject_pin_matches_the_verified_range(self) -> None:
        # Detach-proof: the pin and this guard cannot drift apart silently.
        assert _PIN in _PYPROJECT.read_text(encoding="utf-8")