import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import {
  DEVICE_LOCAL_KEYS,
  SETTINGS_SYNC_VERSION,
  buildSyncedContent,
  isSyncedSettingsContent,
  mergeRemoteSettings,
  pickSyncable,
  shouldApplyRemote,
  syncableEqual,
} from './settingsSync';
import { Settings } from '../state/settings';

// A representative slice of Settings; the helpers are generic over keys so a
// partial object cast is enough to exercise every branch.
const base = {
  settingsSync: true,
  pageZoom: 110,
  isMarkdown: true,
  quietHoursEnabled: false,
  quietHoursStart: '22:00',
  composerToolbarButtons: { showGif: true, order: ['showEmoji', 'showGif'] },
  pttKey: 'KeyV',
  callDenoiseModel: 'rnnoise',
} as unknown as Settings;

describe('pickSyncable', () => {
  it('drops device-local keys and deep-copies objects', () => {
    const picked = pickSyncable(base);
    assert.equal('pageZoom' in picked, false);
    assert.equal('settingsSync' in picked, false);
    assert.equal('callDenoiseModel' in picked, false);
    assert.equal(picked.isMarkdown, true);
    assert.equal(picked.pttKey, 'KeyV');
    assert.notEqual(picked.composerToolbarButtons, base.composerToolbarButtons);
    assert.deepEqual(picked.composerToolbarButtons, base.composerToolbarButtons);
  });

  it('never syncs the sync toggle itself', () => {
    assert.equal(DEVICE_LOCAL_KEYS.has('settingsSync'), true);
  });
});

describe('syncableEqual', () => {
  it('is structural and key-order independent', () => {
    const a = pickSyncable(base);
    const b = Object.fromEntries(Object.entries(a).reverse()) as Partial<Settings>;
    assert.equal(syncableEqual(a, b), true);
    assert.equal(syncableEqual(a, { ...a, isMarkdown: false }), false);
    assert.equal(syncableEqual(a, { ...a, extra: 1 } as Partial<Settings>), false);
  });
});

describe('isSyncedSettingsContent', () => {
  it('accepts a well-formed event and rejects junk', () => {
    assert.equal(isSyncedSettingsContent(buildSyncedContent(base, 5)), true);
    assert.equal(isSyncedSettingsContent({}), false);
    assert.equal(isSyncedSettingsContent(null), false);
    assert.equal(isSyncedSettingsContent({ version: 1, updatedAt: 'x', settings: {} }), false);
    assert.equal(isSyncedSettingsContent({ version: 1, updatedAt: 1, settings: [] }), false);
  });
});

describe('mergeRemoteSettings', () => {
  it('applies syncable keys, ignores device-local and unknown keys and wrong shapes', () => {
    const remote = {
      version: SETTINGS_SYNC_VERSION,
      updatedAt: 10,
      settings: {
        isMarkdown: false,
        pageZoom: 200, // device-local: ignored
        quietHoursStart: 42, // wrong type: ignored
        composerToolbarButtons: 'nope', // wrong type: ignored
        futureKey: true, // unknown: ignored
      } as unknown as Partial<Settings>,
    };
    const merged = mergeRemoteSettings(base, remote);
    assert.equal(merged.isMarkdown, false);
    assert.equal(merged.pageZoom, 110);
    assert.equal(merged.quietHoursStart, '22:00');
    assert.deepEqual(merged.composerToolbarButtons, base.composerToolbarButtons);
    assert.equal('futureKey' in merged, false);
    // Never mutates the input.
    assert.equal(base.isMarkdown, true);
  });
});

describe('shouldApplyRemote', () => {
  it('applies when never synced or strictly newer; ignores echoes', () => {
    const remote = buildSyncedContent(base, 100);
    assert.equal(shouldApplyRemote(remote, null), true);
    assert.equal(shouldApplyRemote(remote, 99), true);
    assert.equal(shouldApplyRemote(remote, 100), false);
    assert.equal(shouldApplyRemote(remote, 101), false);
  });
});

describe('buildSyncedContent', () => {
  it('stamps version and updatedAt around the syncable subset', () => {
    const c = buildSyncedContent(base, 7);
    assert.equal(c.version, SETTINGS_SYNC_VERSION);
    assert.equal(c.updatedAt, 7);
    assert.deepEqual(c.settings, pickSyncable(base));
  });
});