"""TDD — push_mpack_put timeout scaling (issue #40).

Large mpack PUT uploads were timing out at the global 300s ceiling on slow
uplinks.  The fix: push_mpack_put uses its own timeout derived from the
payload size and a minimum throughput floor, with an env-var escape hatch.

PT-1  Small mpack (100 B) → timeout is at least _PUT_TIMEOUT_FLOOR.
PT-2  Large mpack (50 MB) → timeout > _PUT_TIMEOUT_FLOOR (scales with size).
PT-3  Timeout never exceeds _PUT_TIMEOUT_MAX.
PT-4  push_mpack_put passes the computed timeout to _urllib_do (not the
      global _TIMEOUT_SECONDS).
PT-5  MUSE_PUSH_TIMEOUT_SECONDS env var overrides the computed value.
PT-6  MUSE_PUSH_TIMEOUT_SECONDS=0 (or missing) keeps the computed default.
PT-7  push_mpack_put timeout is independent of the global _TIMEOUT_SECONDS —
      changing the global does not affect the PUT timeout.
"""
from __future__ import annotations

import os
from unittest.mock import patch

import pytest

from muse.core.transport import (
    HttpTransport,
    TransportError,
    _mpack_put_timeout,
)

_UPLOAD_URL = "https://r2.example.com/mpacks/sha256:abc?X-Amz-Signature=fake"


def _mock_urllib_do(captured: list[dict]) -> object:
    def _side(method: str, url: str, headers: dict, data: bytes | None = None, **kw: object) -> bytes:
        captured.append({"method": method, "url": url, "timeout": kw.get("timeout")})
        return b""
    return _side


# ── PT-1 ─────────────────────────────────────────────────────────────────────

def test_pt1_small_payload_gets_floor_timeout() -> None:
    small = b"x" * 100
    t = _mpack_put_timeout(len(small))
    from muse.core.transport import _PUT_TIMEOUT_FLOOR
    assert t >= _PUT_TIMEOUT_FLOOR


# ── PT-2 ─────────────────────────────────────────────────────────────────────

def test_pt2_large_payload_exceeds_floor() -> None:
    # 100 MB / 50_000 bytes/sec = 2000s > _PUT_TIMEOUT_FLOOR (1800s)
    large = 100 * 1024 * 1024  # 100 MB
    from muse.core.transport import _PUT_TIMEOUT_FLOOR
    assert _mpack_put_timeout(large) > _PUT_TIMEOUT_FLOOR


# ── PT-3 ─────────────────────────────────────────────────────────────────────

def test_pt3_timeout_never_exceeds_max() -> None:
    enormous = 100 * 1024 * 1024 * 1024  # 100 GB (absurd)
    from muse.core.transport import _PUT_TIMEOUT_MAX
    assert _mpack_put_timeout(enormous) <= _PUT_TIMEOUT_MAX


# ── PT-4 ─────────────────────────────────────────────────────────────────────

def test_pt4_computed_timeout_passed_to_urllib_do() -> None:
    mpack = b"m" * (40 * 1024 * 1024)  # 40 MB
    expected_timeout = _mpack_put_timeout(len(mpack))
    calls: list[dict] = []

    with patch("muse.core.transport._urllib_do", side_effect=_mock_urllib_do(calls)):
        HttpTransport().push_mpack_put(_UPLOAD_URL, mpack)

    assert calls, "no _urllib_do call recorded"
    assert calls[0]["timeout"] == expected_timeout


# ── PT-5 ─────────────────────────────────────────────────────────────────────

def test_pt5_env_var_overrides_computed_timeout() -> None:
    mpack = b"m" * (40 * 1024 * 1024)
    calls: list[dict] = []

    with patch.dict(os.environ, {"MUSE_PUSH_TIMEOUT_SECONDS": "9999"}):
        with patch("muse.core.transport._urllib_do", side_effect=_mock_urllib_do(calls)):
            HttpTransport().push_mpack_put(_UPLOAD_URL, mpack)

    assert calls[0]["timeout"] == 9999


# ── PT-6 ─────────────────────────────────────────────────────────────────────

def test_pt6_env_var_absent_uses_computed_default() -> None:
    mpack = b"m" * (40 * 1024 * 1024)
    expected_timeout = _mpack_put_timeout(len(mpack))
    calls: list[dict] = []

    env = {k: v for k, v in os.environ.items() if k != "MUSE_PUSH_TIMEOUT_SECONDS"}
    with patch.dict(os.environ, env, clear=True):
        with patch("muse.core.transport._urllib_do", side_effect=_mock_urllib_do(calls)):
            HttpTransport().push_mpack_put(_UPLOAD_URL, mpack)

    assert calls[0]["timeout"] == expected_timeout


# ── PT-7 ─────────────────────────────────────────────────────────────────────

def test_pt7_global_timeout_does_not_affect_put_timeout() -> None:
    import muse.core.transport as _t
    mpack = b"m" * (40 * 1024 * 1024)
    expected_timeout = _mpack_put_timeout(len(mpack))
    calls: list[dict] = []

    original = _t._TIMEOUT_SECONDS
    try:
        _t._TIMEOUT_SECONDS = 1  # change global to something tiny
        with patch("muse.core.transport._urllib_do", side_effect=_mock_urllib_do(calls)):
            HttpTransport().push_mpack_put(_UPLOAD_URL, mpack)
    finally:
        _t._TIMEOUT_SECONDS = original

    assert calls[0]["timeout"] == expected_timeout