ServiceCollectionRegistrations.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Ploch.Data.EFCore;
using Ploch.Data.EFCore.SqLite;

// The namespace intentionally omits the ".SqLite" suffix so that it matches the SqlServer
// variant exactly. Consumers switch databases by changing the package reference — no code
// changes needed. Both packages expose the same class name and method in this shared namespace.
#pragma warning disable IDE0130 // Namespace does not match folder structure
namespace Ploch.Data.GenericRepository.EFCore.DependencyInjection;
#pragma warning restore IDE0130

/// <summary>
///     Provides extension methods for registering a <see cref="DbContext" /> with the
///     SQLite provider, the <see cref="SqLiteDbContextCreationLifecycle" />, and
///     generic repository and Unit of Work services in a single call.
/// </summary>
/// <remarks>
///     <para>
///         This class and <c>Ploch.Data.GenericRepository.EFCore.DependencyInjection.SqlServer</c>
///         share the same namespace and method signature. Switching the database provider
///         requires only changing the package reference — no code changes are needed.
///     </para>
///     <example>
///         <code>
///         // In Program.cs — identical regardless of which DI package is referenced:
///         builder.Services.AddDbContextWithRepositories&lt;MyDbContext&gt;();
///         </code>
///     </example>
/// </remarks>
public static class ServiceCollectionRegistrations
{
    /// <summary>
    ///     Registers a <typeparamref name="TDbContext" /> using the SQLite provider,
    ///     the <see cref="SqLiteDbContextCreationLifecycle" />, and the generic
    ///     repository and Unit of Work services.
    /// </summary>
    /// <remarks>
    ///     <para>
    ///         If <paramref name="connectionString" /> is <c>null</c>, the connection
    ///         string is loaded from <c>appsettings.json</c> using the
    ///         <c>DefaultConnection</c> key via <c>ConnectionString.FromJsonFile()</c>.
    ///     </para>
    /// </remarks>
    /// <typeparam name="TDbContext">The type of <see cref="DbContext" /> to register.</typeparam>
    /// <param name="services">The service collection to add the registrations to.</param>
    /// <param name="connectionString">
    ///     A function that returns the SQLite connection string, or <c>null</c> to load
    ///     from <c>appsettings.json</c>.
    /// </param>
    /// <returns>The same <see cref="IServiceCollection" /> for chaining.</returns>
    /// <exception cref="InvalidOperationException">
    ///     Thrown if the connection string function returns <c>null</c>.
    /// </exception>
    public static IServiceCollection AddDbContextWithRepositories<TDbContext>(this IServiceCollection services, Func<string?>? connectionString = null) where TDbContext : DbContext
    {
        connectionString ??= ConnectionString.FromJsonFile();

        return services.AddDbContextWithRepositories<TDbContext, SqLiteDbContextCreationLifecycle>(options => options.UseSqlite(connectionString() ??
                                                                                                                                throw new
                                                                                                                                    InvalidOperationException($"SQLite connection string for {typeof(TDbContext).Name} not found. " +
                                                                                                                                                              "Provide a connection string or ensure it is present in appsettings.json under 'ConnectionStrings:DefaultConnection'.")));
    }

    /// <summary>
    ///     Registers a <typeparamref name="TDbContext" /> using the provided
    ///     <paramref name="configurator" />, the <see cref="SqLiteDbContextCreationLifecycle" />,
    ///     and the generic repository and Unit of Work services.
    /// </summary>
    /// <typeparam name="TDbContext">The type of <see cref="DbContext" /> to register.</typeparam>
    /// <param name="services">The service collection to add the registrations to.</param>
    /// <param name="configurator">
    ///     The <see cref="SqLiteDbContextConfigurator" /> used to configure the
    ///     <typeparamref name="TDbContext" /> with SQLite.
    /// </param>
    /// <param name="configuration">
    ///     Optional application configuration used for configuring the generic repositories.
    /// </param>
    /// <returns>The same <see cref="IServiceCollection" /> for chaining.</returns>
    public static IServiceCollection AddDbContextWithRepositories<TDbContext>(this IServiceCollection services,
                                                                              SqLiteDbContextConfigurator configurator,
                                                                              IConfiguration? configuration) where TDbContext : DbContext =>
        services.AddDbContextWithRepositories<TDbContext, SqLiteDbContextCreationLifecycle>(configurator, configuration);
}