"""Usage-log smoke tests — make sure JSONL records land on disk."""

from __future__ import annotations

import importlib
import json
import os
import sys
from pathlib import Path

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))


def test_track_writes_jsonl_record(monkeypatch, tmp_path):
    monkeypatch.setenv("USAGE_LOG_DIR", str(tmp_path))
    monkeypatch.setenv("USAGE_LOG_KEEP_DAYS", "90")
    from ag_bids_mcp import usage
    importlib.reload(usage)

    with usage.track("best_local_bid", commodity="corn"):
        pass

    files = list(tmp_path.glob("usage-*.jsonl"))
    assert len(files) == 1
    line = files[0].read_text().strip().splitlines()[-1]
    rec = json.loads(line)
    assert rec["tool"] == "best_local_bid"
    assert rec["commodity"] == "corn"
    assert rec["ok"] is True
    assert "elapsed_ms" in rec


def test_track_records_failure(monkeypatch, tmp_path):
    monkeypatch.setenv("USAGE_LOG_DIR", str(tmp_path))
    from ag_bids_mcp import usage
    importlib.reload(usage)

    import pytest
    with pytest.raises(RuntimeError):
        with usage.track("price_history", commodity="corn"):
            raise RuntimeError("boom")

    files = list(tmp_path.glob("usage-*.jsonl"))
    rec = json.loads(files[0].read_text().splitlines()[-1])
    assert rec["ok"] is False
    assert rec["error_class"] == "RuntimeError"
    assert "boom" in rec["error_msg"]


def test_track_no_log_dir_is_silent(monkeypatch):
    monkeypatch.delenv("USAGE_LOG_DIR", raising=False)
    from ag_bids_mcp import usage
    importlib.reload(usage)

    # Should not raise even though no log dir is set
    with usage.track("noop"):
        pass


def test_prune_removes_old_files(monkeypatch, tmp_path):
    from datetime import datetime, timedelta, timezone
    monkeypatch.setenv("USAGE_LOG_DIR", str(tmp_path))
    monkeypatch.setenv("USAGE_LOG_KEEP_DAYS", "1")
    from ag_bids_mcp import usage
    importlib.reload(usage)

    # Create a fake old log file
    old_date = (datetime.now(timezone.utc) - timedelta(days=5)).date().isoformat()
    old_file = tmp_path / f"usage-{old_date}.jsonl"
    old_file.write_text('{"old": true}\n')
    assert old_file.exists()

    # Writing a new record triggers prune
    with usage.track("ping"):
        pass

    assert not old_file.exists(), "expected old log file to be pruned"