"""Unit tests for the in-memory per-session classification cache (session_cache.py).

Offline, no network. Drive the pure get/put/TTL logic directly. time.time is
monkeypatched so expiry tests are deterministic (no wall-clock dependence).
"""

from __future__ import annotations

import pytest

import session_cache


@pytest.fixture(autouse=True)
def _clean_cache():
    session_cache.clear()
    yield
    session_cache.clear()


def _freeze(monkeypatch, t: float):
    """Freeze session_cache.time.time at ``t`` seconds."""
    monkeypatch.setattr(session_cache.time, "time", lambda: t)


def test_get_miss_returns_none():
    assert session_cache.get("sess-none", staleness_seconds=60) is None


def test_get_hit_returns_fresh_entry(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    session_cache.put("sess-1", "coding_general", 2)
    got = session_cache.get("sess-1", staleness_seconds=60)
    assert got is not None
    assert got.task_category == "coding_general"
    assert got.task_tier == 2
    assert got.cached_at == 1000.0


def test_get_expired_returns_none(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    session_cache.put("sess-2", "debugging", 3)
    # Advance past the 60s staleness window.
    _freeze(monkeypatch, 1000.0 + 60.0 + 0.001)
    assert session_cache.get("sess-2", staleness_seconds=60) is None


def test_get_on_staleness_boundary_is_fresh(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    session_cache.put("sess-3", "coding_refactor", 1)
    # Exactly 60s later: not strictly greater than staleness_seconds, so fresh.
    _freeze(monkeypatch, 1000.0 + 60.0)
    got = session_cache.get("sess-3", staleness_seconds=60)
    assert got is not None
    assert got.task_category == "coding_refactor"


def test_put_overwrites_existing_entry(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    session_cache.put("sess-4", "coding_general", 1)
    _freeze(monkeypatch, 1100.0)
    session_cache.put("sess-4", "summarization", 2)
    got = session_cache.get("sess-4", staleness_seconds=60)
    assert got is not None
    assert got.task_category == "summarization"
    assert got.task_tier == 2
    assert got.cached_at == 1100.0


def test_get_staleness_is_per_session(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    session_cache.put("sess-a", "coding_general", 2)
    session_cache.put("sess-b", "debugging", 3)
    _freeze(monkeypatch, 1000.0 + 61.0)
    # sess-a is now stale, sess-b was written at the same time so also stale;
    # write sess-b fresh to isolate per-session expiry.
    _freeze(monkeypatch, 1000.0 + 62.0)
    session_cache.put("sess-b", "debugging", 3)
    assert session_cache.get("sess-a", staleness_seconds=60) is None
    assert session_cache.get("sess-b", staleness_seconds=60) is not None