import json
import os
import tempfile
from pathlib import Path

import pytest

from spectra.trigger import (
    _trigger_path,
    cache_dir,
    clear_trigger,
    read_and_clear_trigger,
    read_trigger,
    write_trigger,
)


@pytest.fixture(autouse=True)
def isolate_cache(monkeypatch, tmp_path):
    cache = tmp_path / "cache"
    cache.mkdir()
    monkeypatch.setenv("SPECTRA_CACHE_DIR", str(cache))
    yield
    monkeypatch.delenv("SPECTRA_CACHE_DIR", raising=False)


class TestWriteRead:
    def test_write_then_read(self):
        write_trigger({"action": "refresh"})
        data = read_trigger()
        assert data == {"action": "refresh"}

    def test_read_empty(self):
        assert read_trigger() is None

    def test_write_overwrites(self):
        write_trigger({"action": "refresh"})
        write_trigger({"action": "clear"})
        data = read_trigger()
        assert data == {"action": "clear"}

    def test_write_complex_data(self):
        write_trigger({"action": "show_upload", "path": "/tmp/test.png", "image_id": 42})
        data = read_trigger()
        assert data["action"] == "show_upload"
        assert data["path"] == "/tmp/test.png"
        assert data["image_id"] == 42


class TestClear:
    def test_clear_trigger(self):
        write_trigger({"action": "refresh"})
        clear_trigger()
        assert read_trigger() is None

    def test_clear_missing_trigger(self):
        clear_trigger()

    def test_clear_then_read(self):
        write_trigger({"action": "refresh"})
        clear_trigger()
        assert read_trigger() is None


class TestReadAndClear:
    def test_read_and_clear_returns_data(self):
        write_trigger({"action": "refresh"})
        data = read_and_clear_trigger()
        assert data == {"action": "refresh"}

    def test_read_and_clear_removes_file(self):
        write_trigger({"action": "refresh"})
        read_and_clear_trigger()
        assert read_trigger() is None

    def test_read_and_clear_nonexistent(self):
        assert read_and_clear_trigger() is None

    def test_read_and_clear_is_atomic(self):
        write_trigger({"action": "refresh"})
        data = read_and_clear_trigger()
        assert data == {"action": "refresh"}
        assert read_trigger() is None


class TestCacheDir:
    def test_cache_dir_uses_env(self, monkeypatch):
        monkeypatch.setenv("SPECTRA_CACHE_DIR", "/tmp/spectra-test-cache")
        d = cache_dir()
        assert d == "/tmp/spectra-test-cache"

    def test_trigger_path_uses_cache_dir(self):
        d = cache_dir()
        path = _trigger_path()
        assert path.startswith(d)
        assert path.endswith("trigger.json")


class TestCorruptFile:
    def test_corrupt_json_returns_none(self):
        path = _trigger_path()
        os.makedirs(os.path.dirname(path), exist_ok=True)
        with open(path, "w") as f:
            f.write("{invalid json")
        assert read_trigger() is None
        assert read_and_clear_trigger() is None