LANCommander/LANCommander.Launcher.Data/DatabaseContext.cs

using LANCommander.Launcher.Data.Interceptors;
using LANCommander.Launcher.Data.Models;
using LANCommander.SDK;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

namespace LANCommander.Launcher.Data
{
    public class DatabaseContext : DbContext
    {
        private readonly ILoggerFactory LoggerFactory;

        public DatabaseContext() { }

        public DatabaseContext(ILoggerFactory loggerFactory, DbContextOptions options)
            : base(options)
        {
            LoggerFactory = loggerFactory;
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            // Skip the SQLite default when the caller has already chosen a provider
            // (e.g. tests using EF InMemory) — EF errors out if two providers are registered.
            if (optionsBuilder.IsConfigured)
                return;

            var dbPath = AppPaths.GetConfigPath("LANCommander.db");

            var connectionString = new SqliteConnectionStringBuilder
            {
                DataSource = dbPath,
                Cache = SqliteCacheMode.Shared,
            }.ToString();

            optionsBuilder.AddInterceptors(new AuditingInterceptor());
            optionsBuilder.UseLoggerFactory(LoggerFactory);
            optionsBuilder.UseSqlite(connectionString, options =>
            {
                options.CommandTimeout(30);
            });
        }

        /// <summary>
        /// Enables WAL mode for concurrent reads during background writes.
        /// Should be called once after the database is created/migrated.
        /// </summary>
        public async Task EnableWalModeAsync()
        {
            await Database.ExecuteSqlRawAsync("PRAGMA journal_mode=WAL;");
        }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            base.OnModelCreating(builder);

            builder.Entity<Genre>()
                .HasMany(g => g.Games)
                .WithMany(g => g.Genres);

            builder.Entity<Category>()
                .HasMany(c => c.Games)
                .WithMany(g => g.Categories);

            builder.Entity<Category>()
                .HasMany(c => c.Children)
                .WithOne(c => c.Parent)
                .IsRequired(false);

            builder.Entity<Tag>()
                .HasMany(t => t.Games)
                .WithMany(g => g.Tags);

            builder.Entity<Platform>()
                .HasMany(p => p.Games)
                .WithMany(g => g.Platforms);
            
            builder.Entity<Library>()
                .HasOne(l => l.User)
                .WithOne(u => u.Library)
                .OnDelete(DeleteBehavior.Cascade);

            builder.Entity<Library>()
                .HasMany(l => l.Games)
                .WithMany(l => l.Libraries)
                .UsingEntity<Dictionary<string, object>>(
                    "LibraryGame",
                    lg => lg.HasOne<Game>().WithMany().HasForeignKey("GameId").OnDelete(DeleteBehavior.Cascade),
                    lg => lg.HasOne<Library>().WithMany().HasForeignKey("LibraryId").OnDelete(DeleteBehavior.Cascade)
                );
            
            builder.Entity<User>()
                .HasOne(u => u.Avatar)
                .WithOne(a => a.User)
                .OnDelete(DeleteBehavior.Cascade);

            #region Game Relationships
            builder.Entity<Game>()
                .Property(g => g.BaseGameId)
                .HasConversion(new GuidToNullConverter());

            builder.Entity<Game>()
                .HasMany(g => g.MultiplayerModes)
                .WithOne(m => m.Game)
                .IsRequired(false)
                .OnDelete(DeleteBehavior.Cascade);

            builder.Entity<Game>()
                .HasMany(g => g.Media)
                .WithOne(m => m.Game)
                .IsRequired(false)
                .OnDelete(DeleteBehavior.Cascade);

            builder.Entity<Game>()
                .HasMany(g => g.Developers)
                .WithMany(c => c.DevelopedGames)
                .UsingEntity<Dictionary<string, object>>(
                    "GameDeveloper",
                    g => g.HasOne<Company>().WithMany().HasForeignKey("DeveloperId"),
                    g => g.HasOne<Game>().WithMany().HasForeignKey("GameId")
                );

            builder.Entity<Game>()
                .HasMany(g => g.Publishers)
                .WithMany(c => c.PublishedGames)
                .UsingEntity<Dictionary<string, object>>(
                    "GamePublisher",
                    g => g.HasOne<Company>().WithMany().HasForeignKey("PublisherId"),
                    g => g.HasOne<Game>().WithMany().HasForeignKey("GameId")
                );

            builder.Entity<Game>()
                .HasMany(g => g.Redistributables)
                .WithMany(r => r.Games)
                .UsingEntity<Dictionary<string, object>>(
                    "GameRedistributable",
                    gr => gr.HasOne<Redistributable>().WithMany().HasForeignKey("RedistributableId"),
                    gr => gr.HasOne<Game>().WithMany().HasForeignKey("GameId")
                );

            builder.Entity<Game>()
                .HasMany(g => g.DependentGames)
                .WithOne(g => g.BaseGame)
                .IsRequired(false)
                .OnDelete(DeleteBehavior.SetNull);

            builder.Entity<Game>()
                .HasOne(g => g.Engine)
                .WithMany(e => e.Games)
                .IsRequired(false)
                .OnDelete(DeleteBehavior.SetNull);

            builder.Entity<Game>()
                .HasMany(g => g.ExternalIds)
                .WithOne(e => e.Game)
                .IsRequired(false)
                .OnDelete(DeleteBehavior.Cascade);
            #endregion

            #region Collection Relationships
            builder.Entity<Collection>()
                .HasMany(c => c.Games)
                .WithMany(g => g.Collections)
                .UsingEntity<Dictionary<string, object>>(
                    "CollectionGame",
                    cg => cg.HasOne<Game>().WithMany().HasForeignKey("GameId"),
                    cg => cg.HasOne<Collection>().WithMany().HasForeignKey("CollectionId")
                );
            #endregion
        }

        public DbSet<Engine>? Engines { get; set; }
        public DbSet<Game>? Games { get; set; }

        public DbSet<Genre>? Genres { get; set; }

        public DbSet<Category>? Categories { get; set; }

        public DbSet<Tag>? Tags { get; set; }

        public DbSet<Company>? Companies { get; set; }

        public DbSet<Redistributable>? Redistributables { get; set; }

        public DbSet<Media>? Media { get; set; }
        public DbSet<Library>? Libraries { get; set; }
        public DbSet<User>? Users { get; set; }
    }
}