Libation/Source/LibationWinForms/Form1.ScanAuto.cs

using ApplicationServices;
using AudibleUtilities;
using Dinah.Core;
using LibationFileManager;
using LibationUiBase;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace LibationWinForms;

// This is for the auto-scanner. It is unrelated to manual scanning/import
public partial class Form1
{
	private InterruptableTimer? autoScanTimer;
	private AutoScanRunner? autoScanRunner;

	private void Configure_ScanAuto()
	{
        // creating InterruptableTimer inside 'Configure_' is a break from the pattern. As long as no one else needs to access or subscribe to it, this is ok

        autoScanTimer = new InterruptableTimer(TimeSpan.FromMinutes(5));
		autoScanRunner = new AutoScanRunner(
			isAutoScanEnabled: () => Configuration.Instance.AutoScan,
			pauseTimer: () => autoScanTimer?.Stop(),
			resumeTimer: () => autoScanTimer?.PerformNow(),
			notifyAuthRequired: notifyAutoScanAuthRequiredAsync);

		autoScanTimer.Elapsed += async (_, __) => await autoScanRunner.RunAsync();

		Load += updateAutoScanLibraryToolStripMenuItem;
		Shown += startAutoScan;

		AccountsSettingsPersister.Saving += accountsPreSave;
		AccountsSettingsPersister.Saved += accountsPostSave;

		Configuration.Instance.PropertyChanged += Configuration_PropertyChanged;
	}

	private void notifyAutoScanAuthRequired(AuthenticationRequiredException ex)
	{
		MessageBox.Show(
			this,
			AutoScanAuthPrompt.FormatBody(ex),
			AutoScanAuthPrompt.Caption,
			MessageBoxButtons.OK,
			MessageBoxIcon.Warning);
	}

	private Task notifyAutoScanAuthRequiredAsync(AuthenticationRequiredException ex)
	{
		if (InvokeRequired)
		{
			Invoke(() => notifyAutoScanAuthRequired(ex));
			return Task.CompletedTask;
		}

		notifyAutoScanAuthRequired(ex);
		return Task.CompletedTask;
	}

	[PropertyChangeFilter(nameof(Configuration.AutoScan))]
	private void Configuration_PropertyChanged(object? sender, PropertyChangedEventArgsEx e)
    {
        // when autoscan setting is changed, update menu checkbox and run autoscan
        updateAutoScanLibraryToolStripMenuItem(sender, e);
		startAutoScan(sender, e);
	}

	private List<(string AccountId, string LocaleName)>? preSaveDefaultAccounts;
	private List<(string AccountId, string LocaleName)> getDefaultAccounts()
	{
		using var persister = AudibleApiStorage.GetAccountsSettingsPersister();
		return persister.AccountsSettings
			.GetAll()
			.Where(a => a.LibraryScan)
			.Select(a => (a.AccountId, a.Locale?.Name))
			.OfType<(string, string)>()
			.ToList();
	}
	private void accountsPreSave(object? sender = null, EventArgs? e = null)
		=> preSaveDefaultAccounts = getDefaultAccounts();
	private void accountsPostSave(object? sender = null, EventArgs? e = null)
	{
		var postSaveDefaultAccounts = getDefaultAccounts();
		var newDefaultAccounts = postSaveDefaultAccounts.Except(preSaveDefaultAccounts ?? []).ToList();

		if (newDefaultAccounts.Any())
			startAutoScan();
	}

	private void startAutoScan(object? sender = null, EventArgs? e = null)
	{
		autoScanRunner?.OnAutoScanSettingChanged();
		if (Configuration.Instance.AutoScan)
			autoScanTimer?.PerformNow();
		else
			autoScanTimer?.Stop();
	}

	private void updateAutoScanLibraryToolStripMenuItem(object? sender, EventArgs e) => autoScanLibraryToolStripMenuItem.Checked = Configuration.Instance.AutoScan;

	private void autoScanLibraryToolStripMenuItem_Click(object? sender, EventArgs e) => Configuration.Instance.AutoScan = !autoScanLibraryToolStripMenuItem.Checked;
}