"""Tests for _sync.py — reading the alarm the phone pushed, with fallbacks."""

from __future__ import annotations

import json
from typing import TYPE_CHECKING
from unittest.mock import MagicMock, patch
import urllib.error

import pytest

from wake_alarm._constants import FALLBACK_ALARM_HOUR
from wake_alarm._sync import (
    Alarm,
    _fetch_github_alarm,
    _read_cache,
    _write_cache,
    get_alarm,
)

if TYPE_CHECKING:
    from pathlib import Path


def _log(hour: object = 7, minute: object = 30) -> str:
    """Build a crdt_sync log payload shaped like the phone's."""
    return json.dumps(
        {
            "alarm": {
                "fields": {
                    "alarm_hour": [hour, "hlc-1"],
                    "alarm_minute": [minute, "hlc-1"],
                }
            }
        }
    )


@pytest.fixture
def config_file(tmp_path: Path) -> Path:
    """Provide a temporary sync config path."""
    return tmp_path / "sync.json"


@pytest.fixture
def cache_file(tmp_path: Path) -> Path:
    """Provide a temporary alarm cache path."""
    return tmp_path / "cache" / "alarm_cache.json"


@pytest.fixture
def fallback_files(tmp_path: Path) -> tuple[Path, Path]:
    """Provide two temporary sibling-app token paths."""
    return tmp_path / "diet_guard_token", tmp_path / "screen_locker_token"


@pytest.fixture(autouse=True)
def _patch_paths(
    config_file: Path, cache_file: Path, fallback_files: tuple[Path, Path]
) -> None:
    """Redirect every on-disk path into tmp_path for every test."""
    with (
        patch("wake_alarm._sync_transport.SYNC_CONFIG_FILE", config_file),
        patch("wake_alarm._sync.ALARM_CACHE_FILE", cache_file),
        patch("wake_alarm._sync_transport.SYNC_TOKEN_FALLBACK_FILES", fallback_files),
    ):
        yield


class TestAlarm:
    """Tests for the Alarm value object."""

    def test_str_pads_and_names_source(self) -> None:
        """Render zero-padded HH:MM with the source in parentheses."""
        assert str(Alarm(7, 5, "remote")) == "07:05 (remote)"


class TestFetchRemoteAlarm:
    """Tests for the GitHub backend behind fetch_remote_alarm."""

    def test_no_token(self) -> None:
        """Without a token there is nothing to fetch."""
        assert _fetch_github_alarm() is None

    def _with_token(self, config_file: Path) -> None:
        config_file.write_text(json.dumps({"token": "ghp_x"}))

    def test_success(self, config_file: Path) -> None:
        """A 200 with a valid body yields the pair."""
        self._with_token(config_file)
        response = MagicMock()
        response.read.return_value = _log(6, 15).encode()
        response.__enter__.return_value = response
        with patch("urllib.request.urlopen", return_value=response):
            assert _fetch_github_alarm() == (6, 15)

    def test_sends_raw_media_type_and_auth(self, config_file: Path) -> None:
        """The request carries the token and the raw Accept header."""
        self._with_token(config_file)
        response = MagicMock()
        response.read.return_value = _log().encode()
        response.__enter__.return_value = response
        with patch("urllib.request.urlopen", return_value=response) as urlopen:
            _fetch_github_alarm()
        request = urlopen.call_args[0][0]
        assert request.get_header("Authorization") == "token ghp_x"
        assert request.get_header("Accept") == "application/vnd.github.raw"
        assert "kuhyx/syncs" in request.full_url

    def test_refuses_a_non_https_scheme(self, config_file: Path) -> None:
        """The token is never sent over a plaintext or file:// URL."""
        self._with_token(config_file)
        with (
            patch("wake_alarm._sync_transport.SYNC_API_BASE", "http://api.github.com"),
            patch("urllib.request.urlopen") as urlopen,
        ):
            assert _fetch_github_alarm() is None
        urlopen.assert_not_called()

    @pytest.mark.parametrize(
        "exc",
        [
            urllib.error.URLError("down"),
            OSError("timeout"),
            UnicodeDecodeError("utf-8", b"\xff", 0, 1, "bad"),
        ],
    )
    def test_network_failures_yield_none(
        self, config_file: Path, exc: Exception
    ) -> None:
        """Every transport failure degrades to None, never raises."""
        self._with_token(config_file)
        with patch("urllib.request.urlopen", side_effect=exc):
            assert _fetch_github_alarm() is None


class TestCache:
    """Tests for the on-disk cache helpers."""

    def test_roundtrip(self, cache_file: Path) -> None:
        """A written cache reads back with the same values."""
        _write_cache(6, 45)
        cached = _read_cache()
        assert cached is not None
        assert cached[0] == 6
        assert cached[1] == 45

    def test_write_creates_parent_dir(self, cache_file: Path) -> None:
        """The cache directory is created on demand."""
        _write_cache(6, 45)
        assert cache_file.exists()

    def test_write_failure_is_swallowed(self) -> None:
        """An unwritable cache logs but does not raise."""
        with patch("pathlib.Path.mkdir", side_effect=OSError("read-only")):
            _write_cache(6, 45)

    def test_missing_file(self) -> None:
        """No cache file yields None."""
        assert _read_cache() is None

    @pytest.mark.parametrize(
        "content",
        [
            "{not json",
            "[]",
            json.dumps({"hour": "6", "minute": 45, "fetched_at": 1.0}),
            json.dumps({"hour": 6, "minute": "45", "fetched_at": 1.0}),
            json.dumps({"hour": 6, "minute": 45, "fetched_at": "soon"}),
            json.dumps({"hour": 24, "minute": 45, "fetched_at": 1.0}),
            json.dumps({"hour": 6, "minute": 60, "fetched_at": 1.0}),
        ],
    )
    def test_malformed_cache_yields_none(self, cache_file: Path, content: str) -> None:
        """Any unexpected cache shape is treated as no cache."""
        cache_file.parent.mkdir(parents=True, exist_ok=True)
        cache_file.write_text(content)
        assert _read_cache() is None


class TestGetAlarm:
    """Tests for the get_alarm resolution chain."""

    def test_fresh_cache_skips_network(self, cache_file: Path) -> None:
        """A young cache entry is served without any fetch."""
        _write_cache(6, 45)
        with patch("wake_alarm._sync.fetch_remote_alarm") as fetch:
            alarm = get_alarm()
        fetch.assert_not_called()
        assert (alarm.hour, alarm.minute, alarm.source) == (6, 45, "cache")

    def test_stale_cache_triggers_fetch(self, cache_file: Path) -> None:
        """An old cache entry is refreshed from the network."""
        _write_cache(6, 45)
        with patch("wake_alarm._sync.fetch_remote_alarm", return_value=(7, 0)):
            alarm = get_alarm(max_cache_age_seconds=0)
        assert (alarm.hour, alarm.minute, alarm.source) == (7, 0, "remote")

    def test_fetch_result_is_cached(self, cache_file: Path) -> None:
        """A successful fetch is written to the cache for next time."""
        with patch("wake_alarm._sync.fetch_remote_alarm", return_value=(7, 0)):
            get_alarm()
        assert json.loads(cache_file.read_text())["hour"] == 7

    def test_falls_back_to_stale_cache(self, cache_file: Path) -> None:
        """When the fetch fails, an old cache entry is still used."""
        _write_cache(6, 45)
        with patch("wake_alarm._sync.fetch_remote_alarm", return_value=None):
            alarm = get_alarm(max_cache_age_seconds=0)
        assert (alarm.hour, alarm.minute, alarm.source) == (
            6,
            45,
            "stale-cache",
        )

    def test_falls_back_to_constant(self) -> None:
        """With no cache and no network, the fixed fallback hour is used."""
        with patch("wake_alarm._sync.fetch_remote_alarm", return_value=None):
            alarm = get_alarm()
        assert (alarm.minute, alarm.source) == (0, "fallback")
        # Bound to the constant, not a literal: the fallback deliberately
        # matches the phone's baked-in baseline, so hardcoding the number here
        # would fail every time that shared value moves.
        assert alarm.hour == FALLBACK_ALARM_HOUR