Reworked currency service. Some features are missing

src/NadekoBot/Services/Currency/CurrencyService.cs

@@ -0,0 +1,123 @@
+#nullable disable
+using LinqToDB;
+using NadekoBot.Services.Currency;
+using NadekoBot.Services.Database.Models;
+
+namespace NadekoBot.Services;
+
+public class CurrencyService : ICurrencyService, INService
+{
+    private readonly DbService _db;
+
+    public CurrencyService(DbService db)
+        => _db = db;
+
+    public Task<IWallet> GetWalletAsync(ulong userId, CurrencyType type = CurrencyType.Default)
+    {
+        if (type == CurrencyType.Default)
+        {
+            return Task.FromResult<IWallet>(new DefaultWallet(userId, _db.GetDbContext()));
+        }
+
+        throw new ArgumentOutOfRangeException(nameof(type));
+    }
+
+    public async Task AddBulkAsync(
+        IReadOnlyCollection<ulong> userIds,
+        long amount,
+        Extra extra,
+        CurrencyType type = CurrencyType.Default)
+    {
+        if (type == CurrencyType.Default)
+        {
+            await using var ctx = _db.GetDbContext();
+            foreach (var userId in userIds)
+            {
+                var wallet = new DefaultWallet(userId, ctx);
+                await wallet.Add(amount, extra);
+            }
+
+            await ctx.SaveChangesAsync();
+            return;
+        }
+
+        throw new ArgumentOutOfRangeException(nameof(type));
+    }
+
+    public async Task RemoveBulkAsync(
+        IReadOnlyCollection<ulong> userIds,
+        long amount,
+        Extra extra,
+        CurrencyType type = CurrencyType.Default)
+    {
+        if (type == CurrencyType.Default)
+        {
+            await using var ctx = _db.GetDbContext();
+            await ctx.DiscordUser
+                     .Where(x => userIds.Contains(x.UserId))
+                     .UpdateAsync(du => new()
+                     {
+                         CurrencyAmount = du.CurrencyAmount >= amount
+                             ? du.CurrencyAmount - amount
+                             : 0
+                     });
+            return;
+        }
+
+        throw new ArgumentOutOfRangeException(nameof(type));
+    }
+
+    private CurrencyTransaction GetCurrencyTransaction(ulong userId, string reason, long amount)
+        => new() { Amount = amount, UserId = userId, Reason = reason ?? "-" };
+
+    public async Task AddAsync(
+        ulong userId,
+        long amount,
+        Extra extra)
+    {
+        await using var wallet = await GetWalletAsync(userId);
+        await wallet.Add(amount, extra);
+    }
+
+    public async Task AddAsync(
+        IUser user,
+        long amount,
+        Extra extra)
+    {
+        await using var wallet = await GetWalletAsync(user.Id);
+        await wallet.Add(amount, extra);
+    }
+
+    public async Task<bool> RemoveAsync(
+        ulong userId,
+        long amount,
+        Extra extra)
+    {
+        await using var wallet = await GetWalletAsync(userId);
+        return await wallet.Take(amount, extra);
+    }
+
+    public async Task<bool> RemoveAsync(
+        IUser user,
+        long amount,
+        Extra extra)
+    {
+        await using var wallet = await GetWalletAsync(user.Id);
+        return await wallet.Take(amount, extra);
+    }
+
+    public async Task<bool> TransferAsync(
+        ulong from,
+        ulong to,
+        long amount,
+        string note)
+    {
+        await using var fromWallet = await GetWalletAsync(@from);
+        await using var toWallet = await GetWalletAsync(to);
+        
+        var extra = new Extra("transfer", "gift", note);
+        
+        return await fromWallet.Transfer(amount, toWallet, extra);
+    }
+    
+}

src/NadekoBot/Services/Currency/CurrencyType.cs

@@ -0,0 +1,6 @@
+namespace NadekoBot.Services.Currency;
+
+public enum CurrencyType
+{
+    Default,
+}

src/NadekoBot/Services/Currency/DefaultWallet.cs

@@ -0,0 +1,104 @@
+using LinqToDB;
+using LinqToDB.EntityFrameworkCore;
+using NadekoBot.Services.Database;
+using NadekoBot.Services.Database.Models;
+
+namespace NadekoBot.Services.Currency;
+
+public class DefaultWallet : IWallet
+{
+    public ulong UserId { get; }
+
+    private readonly NadekoContext _ctx;
+
+    public DefaultWallet(ulong userId, NadekoContext ctx)
+    {
+        UserId = userId;
+        _ctx = ctx;
+    }
+
+    public Task<long> GetBalance()
+        => _ctx.DiscordUser
+               .ToLinqToDBTable()
+               .Where(x => x.UserId == UserId)
+               .Select(x => x.CurrencyAmount)
+               .FirstOrDefaultAsync();
+
+    public async Task<bool> Take(long amount, Extra extra)
+    {
+        if (amount < 0)
+            throw new ArgumentOutOfRangeException(nameof(amount), "Amount to take must be non negative.");
+
+        var changed = await _ctx.DiscordUser
+                                .Where(x => x.UserId == UserId && x.CurrencyAmount >= amount)
+                                .UpdateAsync(x => new()
+                                {
+                                    CurrencyAmount = x.CurrencyAmount - amount
+                                });
+
+        if (changed == 0)
+            return false;
+
+        // todo type, subtype
+        // todo from? by?
+        await _ctx.CreateLinqToDbContext()
+                  .InsertAsync(new CurrencyTransaction()
+                  {
+                      Amount = -amount,
+                      Reason = extra.Note,
+                      UserId = UserId,
+                  });
+
+        return true;
+    }
+
+    public async Task Add(long amount, Extra extra)
+    {
+        if (amount <= 0)
+            throw new ArgumentOutOfRangeException(nameof(amount), "Amount must be greater than 0.");
+
+        await using (var tran = await _ctx.Database.BeginTransactionAsync())
+        {
+            var changed = await _ctx.DiscordUser
+                                    .UpdateAsync(x => new()
+                                    {
+                                        CurrencyAmount = x.CurrencyAmount + amount
+                                    });
+            
+            if (changed == 0)
+            {
+                await _ctx.DiscordUser
+                          .ToLinqToDBTable()
+                          .Value(x => x.UserId, UserId)
+                          .Value(x => x.Username, "Unknown")
+                          .Value(x => x.Discriminator, "????")
+                          .Value(x => x.CurrencyAmount, amount)
+                          .InsertAsync();
+            }
+
+            await tran.CommitAsync();
+        }
+
+        var ct = new CurrencyTransaction()
+        {
+            Amount = amount,
+            Reason = extra.Note,
+            UserId = UserId,
+        };
+
+        await _ctx.CreateLinqToDbContext()
+                  .InsertAsync(ct);
+    }
+
+    public void Dispose()
+    {
+        _ctx.SaveChanges();
+        _ctx.Dispose();
+    }
+    
+    public async ValueTask DisposeAsync()
+    {
+        await _ctx.SaveChangesAsync();
+        await _ctx.DisposeAsync();
+    }
+}

src/NadekoBot/Services/Currency/Extra.cs

@@ -0,0 +1,3 @@
+namespace NadekoBot.Services.Currency;
+
+public record class Extra(string Type, string Subtype, string Note = "", ulong OtherId = 0);

src/NadekoBot/Services/Currency/ICurrencyService.cs

@@ -0,0 +1,47 @@
+using NadekoBot.Services.Currency;
+
+#nullable disable
+namespace NadekoBot.Services;
+
+public interface ICurrencyService
+{
+    Task<IWallet> GetWalletAsync(ulong userId, CurrencyType type = CurrencyType.Default);
+
+    Task AddBulkAsync(
+        IReadOnlyCollection<ulong> userIds,
+        long amount,
+        Extra extra,
+        CurrencyType type = CurrencyType.Default);
+
+    Task RemoveBulkAsync(
+        IReadOnlyCollection<ulong> userIds,
+        long amount,
+        Extra extra,
+        CurrencyType type = CurrencyType.Default);
+
+    Task AddAsync(
+        ulong userId,
+        long amount,
+        Extra extra);
+
+    Task AddAsync(
+        IUser user,
+        long amount,
+        Extra extra);
+
+    Task<bool> RemoveAsync(
+        ulong userId,
+        long amount,
+        Extra extra);
+
+    Task<bool> RemoveAsync(
+        IUser user,
+        long amount,
+        Extra extra);
+
+    Task<bool> TransferAsync(
+        ulong from,
+        ulong to,
+        long amount,
+        string note);
+}

src/NadekoBot/Services/Currency/IWallet.cs

@@ -0,0 +1,36 @@
+namespace NadekoBot.Services.Currency;
+
+public interface IWallet : IDisposable, IAsyncDisposable
+{
+    public ulong UserId { get; }
+    
+    public Task<long> GetBalance();
+    public Task<bool> Take(long amount, Extra extra);
+    public Task Add(long amount, Extra extra);
+    
+    public async Task<bool> Transfer(
+        long amount,
+        IWallet to,
+        Extra extra)
+    {
+        if (amount <= 0)
+            throw new ArgumentOutOfRangeException(nameof(amount), "Amount must be greater than 0.");
+
+        var succ = await Take(amount,
+            extra with
+            {
+                OtherId = to.UserId
+            });
+
+        if (!succ)
+            return false;
+
+        await to.Add(amount,
+            extra with
+            {
+                OtherId = UserId
+            });
+
+        return true;
+    }
+}