Foxchat.NET/Foxchat.Chat/Database/ChatContext.cs

using Foxchat.Chat.Database.Models;
using Foxchat.Core;
using Foxchat.Core.Database;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Design;
using Npgsql;

namespace Foxchat.Chat.Database;

public class ChatContext : IDatabaseContext
{
    private readonly NpgsqlDataSource _dataSource;

    public override DbSet<Instance> Instance { get; set; }
    public DbSet<IdentityInstance> IdentityInstances { get; set; }
    public DbSet<User> Users { get; set; }
    public DbSet<Guild> Guilds { get; set; }
    public DbSet<Channel> Channels { get; set; }
    public DbSet<Message> Messages { get; set; }

    public ChatContext(InstanceConfig config)
    {
        var connString = new NpgsqlConnectionStringBuilder(config.Database.Url)
        {
            Timeout = config.Database.Timeout ?? 5,
            MaxPoolSize = config.Database.MaxPoolSize ?? 50,
        }.ConnectionString;

        var dataSourceBuilder = new NpgsqlDataSourceBuilder(connString);
        dataSourceBuilder.UseNodaTime();
        _dataSource = dataSourceBuilder.Build();
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseNpgsql(_dataSource, o => o.UseNodaTime())
            .UseSnakeCaseNamingConvention();

    protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
    {
        // ULIDs are stored as UUIDs in the database
        configurationBuilder.Properties<Ulid>().HaveConversion<UlidConverter>();
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<IdentityInstance>().HasIndex(i => i.Domain).IsUnique();

        modelBuilder.Entity<User>().HasIndex(u => new { u.RemoteUserId, u.InstanceId }).IsUnique();
        modelBuilder.Entity<User>().HasIndex(u => new { u.Username, u.InstanceId }).IsUnique();

        modelBuilder.Entity<Guild>()
            .HasOne(e => e.Owner)
            .WithMany(e => e.OwnedGuilds)
            .HasForeignKey(e => e.OwnerId)
            .IsRequired();

        modelBuilder.Entity<User>()
            .HasMany(e => e.Guilds)
            .WithMany(e => e.Users);
    }
}

// ReSharper disable once UnusedType.Global
public class DesignTimeIdentityContextFactory : IDesignTimeDbContextFactory<ChatContext>
{
    public ChatContext CreateDbContext(string[] args)
    {
        // Read the configuration file
        var config = new ConfigurationBuilder()
            .AddConfiguration("chat.ini")
            .Build()
            // Get the configuration as our config class
            .Get<InstanceConfig>() ?? new();

        return new ChatContext(config);
    }
}