"""FileStore tests.

On the Space this same store writes into a mounted bucket, so the properties
that matter are the filesystem ones: sharding, atomic replacement, and a clean
NotFound for anything absent.
"""

import json

import pytest

import storage


@pytest.fixture
def store(tmp_path):
    return storage.FileStore(str(tmp_path / "traces"))


def test_roundtrip(store):
    record = {"id": "abc", "payload": {"messages": []}}
    store.put("abc", record)
    assert store.get("abc") == record


def test_sharded_layout(store, tmp_path):
    store.put("abcdef", {"id": "abcdef"})
    assert (tmp_path / "traces" / "ab" / "abcdef.json").is_file()


def test_missing_raises_notfound(store):
    with pytest.raises(storage.NotFound):
        store.get("nope")


def test_unicode_survives(store):
    store.put("abc", {"title": "hé ✓", "payload": "日本語"})
    assert store.get("abc")["title"] == "hé ✓"


def test_no_temp_files_left_behind(store, tmp_path):
    store.put("abc", {"id": "abc"})
    assert not list((tmp_path / "traces").rglob("*.tmp"))


def test_write_is_atomic(store, tmp_path, monkeypatch):
    """A failed write must leave no partial file for a reader to find."""
    real_replace = storage.os.replace

    def boom(src, dst):
        raise OSError("disk full")

    monkeypatch.setattr(storage.os, "replace", boom)
    with pytest.raises(OSError):
        store.put("abc", {"id": "abc"})
    monkeypatch.setattr(storage.os, "replace", real_replace)

    with pytest.raises(storage.NotFound):
        store.get("abc")
    assert not list((tmp_path / "traces").rglob("*.tmp"))


def test_build_store_creates_dir(monkeypatch, tmp_path):
    target = tmp_path / "mounted" / "traces"
    monkeypatch.setenv("TRACE_DIR", str(target))
    store = storage.build_store()
    assert target.is_dir()
    assert store.root == target


def test_build_store_rejects_readonly_dir(monkeypatch, tmp_path):
    """A bucket accidentally mounted read-only should fail at boot, not on the
    first upload."""
    target = tmp_path / "ro"
    target.mkdir()
    target.chmod(0o500)
    monkeypatch.setenv("TRACE_DIR", str(target))
    try:
        with pytest.raises(RuntimeError, match="not writable"):
            storage.build_store()
    finally:
        target.chmod(0o700)


def test_record_is_plain_json_on_disk(store, tmp_path):
    store.put("abcdef", {"id": "abcdef", "title": "t"})
    body = json.loads((tmp_path / "traces" / "ab" / "abcdef.json").read_text())
    assert body["title"] == "t"