import { test } from 'node:test';
import assert from 'node:assert/strict';
import { getSettings, setSettings, Settings } from './settings';

// getSettings() reads localStorage; node has none, so install a controllable
// mock per case. (The module already loaded safely with no localStorage thanks
// to the guarded catch — that path is exercised by the "throws" test below.)
const setStored = (value: string | null): void => {
  (globalThis as { localStorage?: unknown }).localStorage = {
    getItem: () => value,
    setItem: () => undefined,
    removeItem: () => undefined,
  };
};
// Map-backed mock (unlike setStored above, get/set actually round-trip)
// for the setSettings merge tests below, which need writes to persist.
const installStorage = (): Map<string, string> => {
  const map = new Map<string, string>();
  (globalThis as { localStorage?: unknown }).localStorage = {
    getItem: (k: string) => (map.has(k) ? map.get(k)! : null),
    setItem: (k: string, v: string) => {
      map.set(k, v);
    },
    removeItem: (k: string) => {
      map.delete(k);
    },
  };
  return map;
};
const setThrowingStorage = (): void => {
  (globalThis as { localStorage?: unknown }).localStorage = {
    getItem: () => {
      throw new Error('storage blocked');
    },
    setItem: () => {
      throw new Error('storage blocked');
    },
    removeItem: () => {
      throw new Error('storage blocked');
    },
  };
};

test('returns defaults when nothing is stored', () => {
  setStored(null);
  assert.equal(getSettings().callNoiseSuppression, 'browser');
});

test('migrates the legacy boolean callNoiseSuppression to the 3-way mode', () => {
  setStored(JSON.stringify({ callNoiseSuppression: true }));
  assert.equal(getSettings().callNoiseSuppression, 'browser');
  setStored(JSON.stringify({ callNoiseSuppression: false }));
  assert.equal(getSettings().callNoiseSuppression, 'off');
  // a new string value passes through untouched
  setStored(JSON.stringify({ callNoiseSuppression: 'ml' }));
  assert.equal(getSettings().callNoiseSuppression, 'ml');
});

test('coerces unknown persisted denoise model / ringtone id back to defaults', () => {
  setStored(null);
  const defaults = getSettings();

  setStored(JSON.stringify({ callDenoiseModel: 'retired-model', ringtoneId: 'bogus' }));
  const coerced = getSettings();
  assert.equal(coerced.callDenoiseModel, defaults.callDenoiseModel);
  assert.equal(coerced.ringtoneId, defaults.ringtoneId);

  setStored(JSON.stringify({ callDenoiseModel: 'rnnoise', ringtoneId: 'chime' }));
  const valid = getSettings();
  assert.equal(valid.callDenoiseModel, 'rnnoise');
  assert.equal(valid.ringtoneId, 'chime');
});

test('coerces unknown persisted seasonalThemeOverride back to auto', () => {
  setStored(null);
  const defaults = getSettings();
  assert.equal(defaults.seasonalThemeOverride, 'auto');

  setStored(JSON.stringify({ seasonalThemeOverride: 'retired-theme' }));
  assert.equal(getSettings().seasonalThemeOverride, 'auto');

  setStored(JSON.stringify({ seasonalThemeOverride: 'earthday' }));
  assert.equal(getSettings().seasonalThemeOverride, 'earthday');
});

test('merges stored values over defaults', () => {
  setStored(JSON.stringify({ callNoiseSuppression: 'off', someUnknownKey: 1 }));
  const s = getSettings();
  assert.equal(s.callNoiseSuppression, 'off');
  // a default field not present in storage is still populated
  assert.notEqual(s.callDenoiseModel, undefined);
});

test('returns defaults without throwing when localStorage access throws', () => {
  setThrowingStorage();
  // regression: the catch used to call localStorage.removeItem(), which re-threw
  // and crashed the app at module load when storage was blocked.
  assert.doesNotThrow(() => getSettings());
  assert.equal(getSettings().callNoiseSuppression, 'browser');
});

test('returns defaults on malformed JSON', () => {
  setStored('{ not valid json');
  assert.doesNotThrow(() => getSettings());
  assert.equal(getSettings().callNoiseSuppression, 'browser');
});

// Gitea #42: two tabs, each holding its own stale snapshot, must not clobber
// a key the *other* tab changed. setSettings() is given `previous` (this
// tab's own pre-update snapshot) and `next` (its whole-object update) and must
// apply only the keys that actually differ, on top of the freshest stored blob
// — not overwrite the blob wholesale with its own stale view.
test('setSettings merges only the changed key onto the freshest stored blob', () => {
  installStorage();
  const original = getSettings();

  // Tab A reads settings, then tab B (concurrently) changes an unrelated key
  // and writes it to the shared storage.
  const tabB = { ...original, gifPickerEnabled: true };
  setSettings(original, tabB);

  // Tab A, still holding its original snapshot, now changes a different key.
  const tabA = { ...original, isMarkdown: !original.isMarkdown };
  setSettings(original, tabA);

  // Both survive: tab B's change was not reverted by tab A's stale write.
  const result = getSettings();
  assert.equal(result.gifPickerEnabled, true);
  assert.equal(result.isMarkdown, !original.isMarkdown);
});

test('setSettings is a no-op for keys unchanged relative to previous', () => {
  const store = installStorage();
  store.set('settings', JSON.stringify({ isMarkdown: false }));
  const current = getSettings();
  assert.equal(current.isMarkdown, false);

  // `next` differs from `current` in object identity/composerToolbarButtons
  // etc. but not in any actual value vs `previous` — nothing should be
  // reapplied, so an out-of-band external change to storage survives.
  const externallyChanged: Settings = { ...current, isMarkdown: true };
  localStorage.setItem('settings', JSON.stringify(externallyChanged));

  const previous = current;
  const next = { ...current }; // identical values to `previous`
  setSettings(previous, next);

  assert.equal(getSettings().isMarkdown, true);
});