import hashlib
import json

import pytest

from lintunes.lastfm import sign, LastFm
from lintunes.player import make_shuffle_order
from lintunes.preferences import Preferences


class TestLastFmSignature:
    def test_signature_matches_hand_computed(self):
        params = {
            "method": "auth.getMobileSession",
            "api_key": "KEY",
            "username": "trav",
            "password": "hunter2",
            "format": "json",       # must be excluded from the signature
        }
        expected = hashlib.md5(
            ("api_keyKEY"
             "methodauth.getMobileSession"
             "passwordhunter2"
             "usernametrav"
             "SECRET").encode()).hexdigest()
        assert sign(params, "SECRET") == expected

    def test_format_and_callback_excluded(self):
        base = {"method": "x", "api_key": "k"}
        with_extras = dict(base, format="json", callback="cb")
        assert sign(base, "s") == sign(with_extras, "s")


class TestScrobbleQueue:
    def test_queue_round_trip(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        lastfm = LastFm(prefs, tmp_path)
        entry = {"artist": "A", "track": "T", "album": "L",
                 "timestamp": 123, "duration": 180}
        lastfm._enqueue(entry)
        assert lastfm._load_queue() == [entry]
        lastfm._save_queue([])
        assert lastfm._load_queue() == []
        assert not (tmp_path / "scrobble_queue.json").exists()

    def test_queue_capped(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        lastfm = LastFm(prefs, tmp_path)
        for i in range(600):
            lastfm._enqueue({"artist": "A", "track": str(i), "timestamp": i})
        queue = lastfm._load_queue()
        assert len(queue) == 500
        assert queue[-1]["track"] == "599"


class TestShuffleOrder:
    def test_permutation_starts_at_current(self):
        order = make_shuffle_order(10, 4)
        assert order[0] == 4
        assert sorted(order) == list(range(10))

    def test_single_track(self):
        assert make_shuffle_order(1, 0) == [0]

    def test_empty(self):
        assert make_shuffle_order(0, 0) == []

    def test_is_randomized(self):
        # With 20 tracks, two consecutive shuffles colliding entirely is
        # vanishingly unlikely (1/19!)
        orders = {tuple(make_shuffle_order(20, 0)) for _ in range(5)}
        assert len(orders) > 1


class TestPreferences:
    def test_defaults(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        assert prefs.get("ui_scale") == "medium"
        assert prefs.get("highlight") == "blue"
        assert prefs.lastfm["scrobble_enabled"] is False

    def test_round_trip(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        prefs.set("ui_scale", "large")
        prefs.update_lastfm(username="trav", session_key="abc")

        reloaded = Preferences(tmp_path)
        assert reloaded.get("ui_scale") == "large"
        assert reloaded.lastfm["username"] == "trav"
        assert reloaded.lastfm["session_key"] == "abc"
        # Unknown/missing keys fall back to defaults
        assert reloaded.get("highlight") == "blue"

    def test_changed_signal(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        fired = []
        prefs.changed.connect(lambda: fired.append(1))
        prefs.set("highlight", "seafoam")
        prefs.set("highlight", "seafoam")  # no-op, shouldn't fire again
        assert len(fired) == 1

    def test_corrupt_file_falls_back(self, qapp, tmp_path):
        (tmp_path / "preferences.json").write_text("{not json")
        prefs = Preferences(tmp_path)
        assert prefs.get("ui_scale") == "medium"