Init

Prefab/Data/Seeder/Extensions.cs

@@ -0,0 +1,29 @@
+using Microsoft.Extensions.DependencyInjection;
+using System.Threading.Channels;
+
+namespace Prefab.Data.Seeder;
+
+public static class Extensions
+{
+    /// <summary>
+    /// Registers a seeder and its options so it can participate in environment-aware execution.
+    /// </summary>
+    /// <typeparam name="TSeeder">Seeder implementation.</typeparam>
+    /// <param name="services">The host service collection.</param>
+    /// <param name="runMode">Determines when the seeder is allowed to run.</param>
+    /// <returns>The provided service collection.</returns>
+    public static IServiceCollection AddSeeder<TSeeder>(this IServiceCollection services, RunMode runMode = RunMode.RunOnFirstLoadOnly) where TSeeder : class, ISeeder
+    {
+        services.AddScoped<ISeeder, TSeeder>();
+        services.AddScoped<TSeeder>();
+        services.Configure<SeederOptions<TSeeder>>(opts => opts.RunMode = runMode);
+
+        return services;
+    }
+
+    /// <summary>
+    /// Gets the channel used to queue seeder operations for background execution.
+    /// </summary>
+    public static Channel<Func<IServiceProvider, CancellationToken, Task>> Channel { get; }
+        = System.Threading.Channels.Channel.CreateUnbounded<Func<IServiceProvider, CancellationToken, Task>>();
+}

Prefab/Data/Seeder/ISeeder.cs

@@ -0,0 +1,12 @@
+namespace Prefab.Data.Seeder;
+
+/// <summary>
+/// Represents a seeder that can be used to seed the database with data.
+/// </summary>
+public interface ISeeder
+{
+    /// <summary>
+    /// Executes the seed task.
+    /// </summary>
+    Task Execute(IServiceProvider serviceProvider, CancellationToken cancellationToken);
+}

Prefab/Data/Seeder/Options.cs

@@ -0,0 +1,13 @@
+namespace Prefab.Data.Seeder;
+
+/// <summary>
+/// Options for a specific <see cref="ISeeder"/> implementation.
+/// </summary>
+/// <typeparam name="TSeeder">The seeder type these options apply to.</typeparam>
+public class SeederOptions<TSeeder>
+{
+    /// <summary>
+    /// Gets or sets when the seeder should execute.
+    /// </summary>
+    public RunMode RunMode { get; set; } = RunMode.RunOnFirstLoadOnly;
+}

Prefab/Data/Seeder/PrefabDbSeeder.cs

@@ -0,0 +1,199 @@
+using System.Reflection;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+using Prefab.Base;
+using Prefab.Data.Entities;
+
+namespace Prefab.Data.Seeder;
+
+/// <summary>
+/// Base infrastructure for executing database seeders with lookup synchronization support.
+/// </summary>
+/// <typeparam name="TSeeder">The concrete seeder implementation.</typeparam>
+/// <typeparam name="TDb">The database abstraction used by the seeder.</typeparam>
+public abstract class PrefabDbSeeder<TSeeder, TDb> : ISeeder where TDb : IPrefabDb
+{
+    /// <inheritdoc />
+    public async Task Execute(IServiceProvider serviceProvider, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var db = serviceProvider.GetRequiredService<TDb>();
+            var options = serviceProvider.GetService<IOptions<SeederOptions<TSeeder>>>()?.Value ?? new SeederOptions<TSeeder>();
+            var seederName = typeof(TSeeder).FullName ?? typeof(TSeeder).Name;
+            var runMode = options.RunMode;
+            var shouldSeedData = false;
+
+            await SeedLookups(db, cancellationToken);
+            await ApplyViews(db, serviceProvider, cancellationToken);
+
+            switch (runMode)
+            {
+                case RunMode.RunAlways:
+                    shouldSeedData = true;
+                    break;
+                case RunMode.SingleRun:
+                case RunMode.RunOnFirstLoadOnly:
+                    shouldSeedData = !db.SeederLogs.Any(x => x.SeederName == seederName);
+                    break;
+            }
+
+            if (!shouldSeedData)
+            {
+                return;
+            }
+
+            await SeedData(db, serviceProvider, cancellationToken);
+
+            db.SeederLogs.Add(new SeederLog
+            {
+                SeederName = seederName,
+                RunMode = runMode.ToString(),
+                RunAt = DateTime.UtcNow
+            });
+
+            await db.SaveChangesAsync(cancellationToken);
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine(ex);
+            throw;
+        }
+    }
+
+    /// <summary>
+    /// Applies database views, ensuring dependent queries exist before data seeding runs.
+    /// </summary>
+    protected abstract Task ApplyViews(TDb db, IServiceProvider serviceProvider, CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Seeds data specific to the derived context.
+    /// </summary>
+    protected abstract Task SeedData(TDb db, IServiceProvider serviceProvider, CancellationToken cancellationToken);
+
+    private static async Task SeedLookups(TDb dbContext, CancellationToken cancellationToken)
+    {
+        var processedTypes = new HashSet<Type>();
+        var dbContextType = dbContext.GetType();
+        var dbSetProperties = dbContextType.GetProperties(BindingFlags.Public | BindingFlags.Instance)
+            .Where(prop => prop.PropertyType.IsGenericType &&
+                           prop.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>));
+
+        foreach (var prop in dbSetProperties)
+        {
+            var entityType = prop.PropertyType.GetGenericArguments()[0];
+            if (!processedTypes.Add(entityType))
+            {
+                continue;
+            }
+
+            if (!IsSubclassOfGeneric(entityType, typeof(LookupEntity<>)))
+            {
+                continue;
+            }
+
+            var baseType = entityType.BaseType;
+            if (baseType is not { IsGenericType: true } ||
+                baseType.GetGenericTypeDefinition() != typeof(LookupEntity<>))
+            {
+                continue;
+            }
+
+            var enumType = baseType.GetGenericArguments()[0];
+            var method = typeof(PrefabDbSeeder<TSeeder, TDb>).GetMethod(nameof(SeedLookupAsync), BindingFlags.NonPublic | BindingFlags.Static);
+            if (method is null)
+            {
+                continue;
+            }
+
+            var genericMethod = method.MakeGenericMethod(entityType, enumType);
+            await (Task)genericMethod.Invoke(null, new object[] { dbContext, cancellationToken })!;
+        }
+
+        return;
+
+        static bool IsSubclassOfGeneric(Type type, Type generic)
+        {
+            while (type is not null && type != typeof(object))
+            {
+                var current = type.IsGenericType ? type.GetGenericTypeDefinition() : type;
+                if (current == generic)
+                {
+                    return true;
+                }
+
+                type = type.BaseType!;
+            }
+
+            return false;
+        }
+    }
+
+    private static async Task SeedLookupAsync<TLookup, TEnum>(DbContext dbContext, CancellationToken cancellationToken)
+        where TLookup : LookupEntity<TEnum>, new()
+        where TEnum : PrefabEnum<TEnum>
+    {
+        var dbSet = dbContext.Set<TLookup>();
+
+        var enumMembers = PrefabEnum<TEnum>.List
+            .Select(e => new
+            {
+                Value = e.Value,
+                Name = e.Name,
+                ShortName = GetOptionalString(e, "ShortName"),
+                Description = GetOptionalString(e, "Description"),
+                SortOrder = e.Value
+            })
+            .ToList();
+
+        var existingRows = await dbSet.ToListAsync(cancellationToken);
+
+        foreach (var member in enumMembers)
+        {
+            var lookupRow = existingRows.FirstOrDefault(r => r.Id == member.Value);
+            if (lookupRow is null)
+            {
+                lookupRow = new TLookup
+                {
+                    Id = member.Value,
+                    Name = member.Name,
+                    ShortName = member.ShortName,
+                    Description = member.Description,
+                    SortOrder = member.SortOrder
+                };
+                dbSet.Add(lookupRow);
+            }
+            else if (lookupRow.Name != member.Name ||
+                     lookupRow.ShortName != member.ShortName ||
+                     lookupRow.Description != member.Description ||
+                     lookupRow.SortOrder != member.SortOrder)
+            {
+                lookupRow.Name = member.Name;
+                lookupRow.ShortName = member.ShortName;
+                lookupRow.Description = member.Description;
+                lookupRow.SortOrder = member.SortOrder;
+                dbSet.Update(lookupRow);
+            }
+        }
+
+        var validValues = enumMembers.Select(m => m.Value).ToHashSet();
+        foreach (var row in existingRows.Where(row => !validValues.Contains(row.Id)))
+        {
+            dbSet.Remove(row);
+        }
+
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        static string? GetOptionalString(PrefabEnum<TEnum> value, string propertyName)
+        {
+            var property = value.GetType().GetProperty(propertyName, BindingFlags.Instance | BindingFlags.Public | BindingFlags.FlattenHierarchy);
+            if (property is null || property.PropertyType != typeof(string))
+            {
+                return null;
+            }
+
+            return property.GetValue(value) as string;
+        }
+    }
+}

Prefab/Data/Seeder/RunMode.cs

@@ -0,0 +1,21 @@
+namespace Prefab.Data.Seeder;
+
+/// <summary>
+/// Indicates when a data loader should be run.
+/// </summary>
+public enum RunMode
+{
+    /// <summary>
+    /// Data loader will be run only for a newly-initialized database
+    /// </summary>
+    RunOnFirstLoadOnly,
+    /// <summary>
+    /// Data loader will be run once only in a given database
+    /// </summary>
+    SingleRun,
+    /// <summary>
+    /// Data loader will run every time the app starts up
+    /// </summary>
+    RunAlways
+}
+