feat(ui): add a dashboard with current state of finances

docs/changelog.html

@@ -72,6 +72,10 @@ <h3>Added</h3>
 					Support for PostgreSQL 17 in
 					<a href="https://github.com/VMelnalksnis/Gnomeshade/pull/1394">#1394</a>
 				</li>
+				<li>
+					Dashboard with current state of finances in
+					<a href="https://github.com/VMelnalksnis/Gnomeshade/pull/1395">#1395</a>
+				</li>
 			</ul>
 		</section>
 

source/Gnomeshade.Avalonia.Core/DashboardViewModel.cs

@@ -0,0 +1,375 @@
+// Copyright 2021 Valters Melnalksnis
+// Licensed under the GNU Affero General Public License v3.0 or later.
+// See LICENSE.txt file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Threading.Tasks;
+
+using Gnomeshade.Avalonia.Core.Products;
+using Gnomeshade.Avalonia.Core.Reports;
+using Gnomeshade.Avalonia.Core.Reports.Splits;
+using Gnomeshade.WebApi.Client;
+using Gnomeshade.WebApi.Models.Accounts;
+using Gnomeshade.WebApi.Models.Transactions;
+
+using LiveChartsCore.Defaults;
+using LiveChartsCore.Kernel.Sketches;
+using LiveChartsCore.SkiaSharpView;
+using LiveChartsCore.SkiaSharpView.Painting;
+
+using NodaTime;
+
+using PropertyChanged.SourceGenerator;
+
+using SkiaSharp;
+
+namespace Gnomeshade.Avalonia.Core;
+
+/// <summary>Quick overview of all accounts.</summary>
+public sealed partial class DashboardViewModel : ViewModelBase
+{
+	private readonly IGnomeshadeClient _gnomeshadeClient;
+	private readonly IClock _clock;
+	private readonly IDateTimeZoneProvider _dateTimeZoneProvider;
+
+	/// <summary>Gets the data series of the balance of all user accounts with positive balance.</summary>
+	[Notify(Setter.Private)]
+	private PieSeries<decimal>[] _balanceSeries = [];
+
+	/// <summary>Gets the data series of the balance of all user accounts with negative balance.</summary>
+	[Notify(Setter.Private)]
+	private PieSeries<decimal>[] _liabilitiesBalanceSeries = [];
+
+	/// <summary>Gets the data series of spending by category.</summary>
+	[Notify(Setter.Private)]
+	private PieSeries<decimal>[] _categoriesSeries = [];
+
+	/// <summary>Gets the data series of balance of the users account over time.</summary>
+	[Notify(Setter.Private)]
+	private CandlesticksSeries<FinancialPointI>[] _cashflowSeries = [];
+
+	/// <summary>Gets a collection of all accounts of the current user.</summary>
+	[Notify(Setter.Private)]
+	private List<Account> _userAccounts = [];
+
+	/// <summary>Gets or sets a collection of accounts selected from <see cref="UserAccounts"/>.</summary>
+	[Notify]
+	private ObservableCollection<Account> _selectedAccounts = [];
+
+	/// <summary>Gets a collection of all currencies used in <see cref="UserAccounts"/>.</summary>
+	[Notify(Setter.Private)]
+	private List<Currency> _currencies = [];
+
+	/// <summary>Gets or sets the selected currency from <see cref="Currencies"/>.</summary>
+	[Notify]
+	private Currency? _selectedCurrency;
+
+	/// <summary>Gets the y axes for <see cref="CashflowSeries"/>.</summary>
+	[Notify(Setter.Private)]
+	private ICartesianAxis[] _yAxes = [new Axis()];
+
+	/// <summary>Gets the x axes for <see cref="CashflowSeries"/>.</summary>
+	[Notify(Setter.Private)]
+	private ICartesianAxis[] _xAxes = [new Axis()];
+
+	/// <summary>Gets the collection of account summary rows.</summary>
+	[Notify(Setter.Private)]
+	private AccountRow[] _accountRows = [];
+
+	/// <summary>Gets the collection of rows of various totals of <see cref="AccountRows"/>.</summary>
+	[Notify(Setter.Private)]
+	private AccountRow[] _accountRowsTotals = [];
+
+	/// <summary>Initializes a new instance of the <see cref="DashboardViewModel"/> class.</summary>
+	/// <param name="activityService">Service for indicating the activity of the application to the user.</param>
+	/// <param name="gnomeshadeClient">A strongly typed API client.</param>
+	/// <param name="clock">Clock which can provide the current instant.</param>
+	/// <param name="dateTimeZoneProvider">Time zone provider for localizing instants to local time.</param>
+	public DashboardViewModel(
+		IActivityService activityService,
+		IGnomeshadeClient gnomeshadeClient,
+		IClock clock,
+		IDateTimeZoneProvider dateTimeZoneProvider)
+		: base(activityService)
+	{
+		_gnomeshadeClient = gnomeshadeClient;
+		_clock = clock;
+		_dateTimeZoneProvider = dateTimeZoneProvider;
+	}
+
+	/// <inheritdoc />
+	protected override async Task Refresh()
+	{
+		var (counterparty, allAccounts, currencies) = await
+			(_gnomeshadeClient.GetMyCounterpartyAsync(),
+			_gnomeshadeClient.GetAccountsAsync(),
+			_gnomeshadeClient.GetCurrenciesAsync())
+			.WhenAll();
+
+		var selected = SelectedAccounts.Select(account => account.Id).ToArray();
+		var selectedCurrency = SelectedCurrency?.Id;
+
+		UserAccounts = allAccounts.Where(account => account.CounterpartyId == counterparty.Id).ToList();
+		Currencies = currencies
+			.Where(currency => UserAccounts.SelectMany(account => account.Currencies).Any(aic => aic.CurrencyId == currency.Id))
+			.ToList();
+
+		SelectedAccounts = new(UserAccounts.Where(account => selected.Contains(account.Id)));
+		SelectedCurrency = selectedCurrency is { } id ? Currencies.Single(currency => currency.Id == id) : null;
+
+		IReadOnlyCollection<Account> accounts = SelectedAccounts.Count is not 0 ? SelectedAccounts : UserAccounts;
+
+		var timeZone = _dateTimeZoneProvider.GetSystemDefault();
+		var currentInstant = _clock.GetCurrentInstant();
+		var localTime = currentInstant.InZone(timeZone).LocalDateTime;
+
+		var startTime = localTime.With(DateAdjusters.StartOfMonth).InZoneStrictly(timeZone);
+		var endTime = localTime.With(DateAdjusters.EndOfMonth).InZoneStrictly(timeZone);
+
+		await Task.WhenAll(
+			RefreshCashFlow(accounts, startTime, endTime, timeZone, counterparty),
+			RefreshBalance(),
+			RefreshCategories(accounts, timeZone, startTime));
+	}
+
+	private async Task RefreshCashFlow(
+		IReadOnlyCollection<Account> accounts,
+		ZonedDateTime startTime,
+		ZonedDateTime endTime,
+		DateTimeZone timeZone,
+		Counterparty counterparty)
+	{
+		var inCurrencyIds = accounts
+			.SelectMany(account => account.Currencies.Where(aic => aic.CurrencyId == (SelectedCurrency?.Id ?? account.PreferredCurrencyId)).Select(aic => aic.Id))
+			.ToArray();
+
+		var transfers = (await _gnomeshadeClient.GetTransfersAsync())
+			.Where(transfer =>
+				inCurrencyIds.Contains(transfer.SourceAccountId) ||
+				inCurrencyIds.Contains(transfer.TargetAccountId))
+			.OrderBy(transfer => transfer.ValuedAt ?? transfer.BookedAt)
+			.ThenBy(transfer => transfer.CreatedAt)
+			.ThenBy(transfer => transfer.ModifiedAt)
+			.ToArray();
+		var reportSplit = SplitProvider.DailySplit;
+
+		var values = reportSplit
+			.GetSplits(startTime, endTime)
+			.Select(date =>
+			{
+				var splitZonedDate = date.AtStartOfDayInZone(timeZone);
+				var splitInstant = splitZonedDate.ToInstant();
+
+				var transfersBefore = transfers
+					.Where(transfer => new ZonedDateTime(transfer.ValuedAt ?? transfer.BookedAt!.Value, timeZone).ToInstant() < splitInstant);
+
+				var transfersIn = transfers
+					.Where(transfer => reportSplit.Equals(
+						splitZonedDate,
+						new(transfer.ValuedAt ?? transfer.BookedAt!.Value, timeZone)))
+					.ToArray();
+
+				var sumBefore = transfersBefore.SumForAccounts(inCurrencyIds);
+
+				var sumAfter = sumBefore + transfersIn.SumForAccounts(inCurrencyIds);
+				var sums = transfersIn
+					.Select((_, index) => sumBefore + transfersIn.Where((_, i) => i <= index).SumForAccounts(inCurrencyIds))
+					.ToArray();
+
+				return new FinancialPointI(
+					(double)sums.Concat([sumBefore, sumAfter]).Max(),
+					(double)sumBefore,
+					(double)sumAfter,
+					(double)sums.Append(sumBefore).Min());
+			});
+
+		CashflowSeries = [new() { Values = values.ToArray(), Name = counterparty.Name }];
+		XAxes = [reportSplit.GetXAxis(startTime, endTime)];
+	}
+
+	private async Task RefreshBalance()
+	{
+		var accountRowTasks = UserAccounts
+			.Select(async account =>
+			{
+				var balances = await _gnomeshadeClient.GetAccountBalanceAsync(account.Id);
+				var preferredAccountInCurrency = account
+					.Currencies
+					.Single(currency => currency.CurrencyId == account.PreferredCurrencyId);
+
+				var balance =
+					balances.Single(balance => balance.AccountInCurrencyId == preferredAccountInCurrency.Id);
+
+				return new AccountRow(account.Name, balance.TargetAmount - balance.SourceAmount);
+			});
+
+		var rows = await Task.WhenAll(accountRowTasks);
+		AccountRows = rows.OrderByDescending(row => row.Balance).ToArray();
+		AccountRowsTotals =
+		[
+			new("Balance", AccountRows.Where(row => row.Balance > 0).Sum(row => row.Balance)),
+			new("Liabilities", AccountRows.Where(row => row.Balance < 0).Sum(row => row.Balance)),
+			new("Total", AccountRows.Sum(row => row.Balance)),
+		];
+
+		var balanceSeries = AccountRows
+			.Select(row => new PieSeries<decimal>
+			{
+				Name = row.Name,
+				Values = [row.Balance],
+				DataLabelsPaint = new SolidColorPaint(SKColors.Black),
+				DataLabelsFormatter = point => point.Model.ToString("N2"),
+			})
+			.ToArray();
+
+		BalanceSeries = balanceSeries.Where(series => series.Values?.Sum() > 0).ToArray();
+		LiabilitiesBalanceSeries = balanceSeries
+			.Where(series => series.Values?.Sum() < 0)
+			.Select(series =>
+			{
+				series.Values = series.Values?.Select(x => -x) ?? [];
+				return series;
+			})
+			.ToArray();
+	}
+
+	private async Task RefreshCategories(IReadOnlyCollection<Account> accounts, DateTimeZone timeZone, ZonedDateTime startTime)
+	{
+		var accountsInCurrency = accounts.SelectMany(account => account.Currencies).ToArray();
+		var (allTransactions, categories, products) = await (
+			_gnomeshadeClient.GetDetailedTransactionsAsync(new(Instant.MinValue, Instant.MaxValue)),
+			_gnomeshadeClient.GetCategoriesAsync(),
+			_gnomeshadeClient.GetProductsAsync())
+			.WhenAll();
+		var displayableTransactions = allTransactions
+			.Select(transaction => transaction with { TransferBalance = -transaction.TransferBalance })
+			.Where(transaction => transaction.TransferBalance > 0)
+			.ToArray();
+
+		var transactions = new CategoryReportViewModel.TransactionData[displayableTransactions.Length];
+		for (var i = 0; i < displayableTransactions.Length; i++)
+		{
+			var transaction = displayableTransactions[i];
+			var date = new ZonedDateTime(transaction.ValuedAt ?? transaction.BookedAt!.Value, timeZone);
+
+			var transactionTransfers = transaction.Transfers;
+			var transferAccounts = transactionTransfers
+				.Select(transfer => transfer.SourceAccountId)
+				.Concat(transactionTransfers.Select(transfer => transfer.TargetAccountId))
+				.ToArray();
+
+			var sourceCurrencyIds = accountsInCurrency
+				.IntersectBy(transferAccounts, currency => currency.Id)
+				.Select(currency => currency.CurrencyId)
+				.Distinct()
+				.ToArray();
+
+			var targetCurrencyIds = accountsInCurrency
+				.IntersectBy(transferAccounts, currency => currency.Id)
+				.Select(account => account.CurrencyId)
+				.Distinct()
+				.ToArray();
+
+			transactions[i] = new(transaction, date, sourceCurrencyIds, targetCurrencyIds);
+		}
+
+		var nodes = categories
+			.Where(category => category.CategoryId == null)
+			.Select(category => CategoryNode.FromCategory(category, categories))
+			.ToList();
+
+		var uncategorizedTransfers = transactions
+			.Where(data => data.Transaction.TransferBalance > data.Transaction.PurchaseTotal)
+			.Select(data =>
+			{
+				var purchase = new Purchase { Price = data.Transaction.TransferBalance - data.Transaction.PurchaseTotal };
+				return new CategoryReportViewModel.PurchaseData(purchase, null, data);
+			})
+			.ToList();
+
+		var groupings = transactions
+			.SelectMany(data => data.Transaction.Purchases.Select(purchase =>
+			{
+				var product = products.SingleOrDefault(product => product.Id == purchase.ProductId);
+				var node = product?.CategoryId is not { } categoryId
+					? null
+					: nodes.SingleOrDefault(node => node.Contains(categoryId));
+
+				return new CategoryReportViewModel.PurchaseData(purchase, node, data);
+			}))
+			.Concat(uncategorizedTransfers)
+			.GroupBy(data => data.Node)
+			.ToArray();
+
+		CategoriesSeries = groupings
+			.Select(grouping =>
+			{
+				var zonedSplit = startTime;
+
+				var purchasesToSum = grouping
+					.Where(purchase => SplitProvider.MonthlySplit.Equals(zonedSplit, purchase.Date))
+					.ToArray();
+
+				var sum = 0m;
+				for (var purchaseIndex = 0; purchaseIndex < purchasesToSum.Length; purchaseIndex++)
+				{
+					var purchase = purchasesToSum[purchaseIndex];
+					var sourceCurrencyIds = purchase.SourceCurrencyIds;
+					var targetCurrencyIds = purchase.TargetCurrencyIds;
+
+					if (sourceCurrencyIds.Length is not 1 || targetCurrencyIds.Length is not 1)
+					{
+						// todo cannot handle multiple currencies (#686)
+						sum += purchase.Purchase.Price;
+						continue;
+					}
+
+					var sourceCurrency = sourceCurrencyIds.Single();
+					var targetCurrency = targetCurrencyIds.Single();
+
+					if (sourceCurrency == targetCurrency)
+					{
+						sum += purchase.Purchase.Price;
+						continue;
+					}
+
+					var transfer = purchase.Transfers.Single();
+					var ratio = transfer.SourceAmount / transfer.TargetAmount;
+					sum += Math.Round(purchase.Purchase.Price * ratio, 2);
+				}
+
+				return new PieSeries<decimal>
+				{
+					Name = grouping.Key?.Name ?? "Uncategorized",
+					Values = [sum],
+					DataLabelsPaint = new SolidColorPaint(SKColors.Black),
+					DataLabelsFormatter = point => point.Model.ToString("N2"),
+				};
+			})
+			.Where(series => series.Values?.Sum() > 0)
+			.OrderByDescending(series => series.Values?.Sum())
+			.ToArray();
+	}
+
+	/// <summary>Minimal overview of a single <see cref="Account"/>.</summary>
+	public sealed class AccountRow : PropertyChangedBase
+	{
+		/// <summary>Initializes a new instance of the <see cref="AccountRow"/> class.</summary>
+		/// <param name="name">The name of the account.</param>
+		/// <param name="balance">The balance of the account in the preferred currency.</param>
+		public AccountRow(string name, decimal balance)
+		{
+			Name = name;
+			Balance = balance;
+		}
+
+		/// <summary>Gets the name of the account.</summary>
+		public string Name { get; }
+
+		/// <summary>Gets the account balance in the preferred currency.</summary>
+		public decimal Balance { get; }
+	}
+}

source/Gnomeshade.Avalonia.Core/DesignTime/DesignTimeData.cs

@@ -236,6 +236,10 @@ public static class DesignTimeData
 	public static ProjectViewModel ProjectViewModel { get; } =
 		InitializeViewModel<ProjectViewModel>(new(ActivityService, GnomeshadeClient, DateTimeZoneProvider));
 
+	/// <summary>Gets an instance of <see cref="DashboardViewModel"/> for use during design time.</summary>
+	public static DashboardViewModel DashboardViewModel { get; } =
+		InitializeViewModel<DashboardViewModel>(new(ActivityService, GnomeshadeClient, Clock, DateTimeZoneProvider));
+
 	[UnconditionalSuppressMessage(
 		"Trimming",
 		"IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code",