Add configuration type binding and implement database connection, disable NativeAOT.

Add: binding setting file items to `AppSettings` class so to provide DI access as `IOptions<OptixServeSettings>`.

Add: EF Core and DbContext to access database in services. This results in disabling NativeAOT due to poor supports for *pre-compiled query*, however many design are optimized for AOT for later re-adoption.

Add: `DesignTimeDbContextFactory` to support EF Core migrations in NativeAOT. (Kept for re-enabling AOT.)

Add: `DbInitializer` for ensuring database connecting in startup.

Add: `ConfigurationHelper.CreateDefaultBuilder()` to read configuration files in default locations. Note this method is currently ONLY used by `DesignTimeDbContextFactory`. Refactor is expected.

Add: `CommonErrorDto` for simple error message.

Add: `VersionEndpoint` ONLY for debugging and testing purpose. Verylikely to be removed in the future.

Other: many utilities and fixes easy to understand.

Note: EF Core migrations are excluded in the early development. Not expected to be added in version control before v1.0 beta.

OptixServe.Api/Configuration/AppSettings.cs

@@ -0,0 +1,25 @@
+namespace OptixServe.Api.Configuration;
+
+public record OptixServeSettings
+{
+    public ApiSettings? Api { get; set; } = new();
+    public DatabaseSettings? Database { get; set; } = new();
+}
+
+public record ApiSettings
+{
+    public string? Listen { get; set; } = "127.0.0.1";
+    public int? Port { get; set; } = 10086;
+}
+
+public enum DatabaseType
+{
+    Sqlite,
+    MySQL
+}
+
+public record DatabaseSettings
+{
+    public DatabaseType Type { get; set; } = DatabaseType.Sqlite;
+    public string? Host { get; set; }
+}

OptixServe.Api/Configuration/ConfigurationHelper.cs

@@ -0,0 +1,27 @@
+using System;
+
+namespace OptixServe.Api.Configuration;
+
+public static class ConfigurationHelper
+{
+    public static IConfigurationBuilder CreateDefaultBuilder()
+    {
+        var aspEnv = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
+        var netEnv = Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT");
+        // Console.WriteLine($"ASPNETCORE_ENVIRONMENT: {aspEnv}, DOTNET_ENVIRONMENT: {netEnv}");
+        var env = aspEnv ?? netEnv ?? null;
+
+        var builder = new ConfigurationBuilder()
+            .SetBasePath(Directory.GetCurrentDirectory())
+            .AddJsonFile("appsettings.json", optional: true)
+            .AddJsonFile("config.json", optional: true);
+        
+        if (env != null)
+        {
+            builder.AddJsonFile($"appsettings.{env}.json", optional: true)
+                .AddJsonFile($"config.{env}.json", optional: true);
+        }
+
+        return builder;
+    }
+}

OptixServe.Api/Dtos/Error.cs

@@ -0,0 +1,6 @@
+namespace OptixServe.Api.Dtos;
+
+public record CommonErrorDto
+{
+    public string? Message { get; set; }
+}

OptixServe.Api/Endpoints/VersionEndpoint.cs

@@ -0,0 +1,35 @@
+using System.Text.Json.Serialization;
+using Microsoft.Extensions.Options;
+using OptixServe.Api.Configuration;
+using OptixServe.Api.Dtos;
+
+namespace OptixServe.Api.Endpoints;
+
+
+[JsonSerializable(typeof(string))]
+[JsonSerializable(typeof(CommonErrorDto))]
+public partial class VersionJsonContext : JsonSerializerContext { }
+
+
+/// <summary>
+/// This is a endpoint ONLY FOR TEST!
+/// Should not expect ANY stable behavior on it!
+/// </summary>
+public static class VersionEndpoint
+{
+    public static void Register(RouteGroupBuilder parentGroup)
+    {
+        var group = parentGroup.MapGroup("/version");
+
+        group.MapGet("/", () => "v1");
+        group.MapGet("/test/dbconfig", (IOptions<OptixServeSettings> appSettings) =>
+        {
+            var dbType = appSettings.Value.Database?.Type;
+            var dbHost = appSettings.Value.Database?.Host;
+            return Results.Ok(new CommonErrorDto
+            {
+                Message = $"Set up {dbType} database on {dbHost}"
+            });
+        });
+    }
+}

OptixServe.Api/OptixServe.Api.csproj

@@ -1,11 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
-  <ItemGroup>
-    <ProjectReference Include="..\OptixServe.Core\OptixServe.Core.csproj" />
+  <ItemGroup>
+    <ProjectReference Include="..\OptixServe.Core\OptixServe.Core.csproj" />
   </ItemGroup>
 
-  <ItemGroup>
-    <PackageReference Include="System.CommandLine" Version="2.0.0-beta5.25306.1" />
+  <ItemGroup>
+    <PackageReference Include="System.CommandLine" Version="2.0.0-beta5.25306.1" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.6">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="9.0.6" />
   </ItemGroup>
 
   <PropertyGroup>
@@ -13,7 +18,7 @@
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <InvariantGlobalization>true</InvariantGlobalization>
-    <PublishAot>true</PublishAot>
+    <PublishAot>false</PublishAot>
   </PropertyGroup>
 
 </Project>

OptixServe.Api/Program.cs

@@ -1,6 +1,9 @@
 using System.CommandLine;
+using OptixServe.Api.Configuration;
 using OptixServe.Api.Endpoints;
+using OptixServe.Core.Data;
 using OptixServe.Core.Services;
+using OptixServe.Api.Utilites;
 
 class Program
 {
@@ -46,8 +49,15 @@ class Program
             builder.RegiserJsonContext();
 
             var app = builder.Build();
+
+            using (var scope = app.Services.CreateScope())
+            {
+                var initializer = scope.ServiceProvider.GetRequiredService<DbInitializer>();
+                initializer.Initialize();
+            }
+
             var apiGroup = app.MapGroup("api/v1");
-            ExtensionMethods.RegisterEndpoints(apiGroup);
+            StartupHelper.RegisterEndpoints(apiGroup);
 
             app.Run();
         });
@@ -62,7 +72,7 @@ class Program
 /// <summary>
 /// Contains extension methods for WebApplicationBuilder and WebApplication
 /// </summary>
-static class ExtensionMethods
+static class StartupHelper
 {
     /// <summary>
     /// Adds configuration sources to the application builder
@@ -88,6 +98,37 @@ static class ExtensionMethods
         builder.Configuration.AddConfiguration(configurationBuilder.Build());
     }
 
+    /// <summary>
+    /// Configures DbContext services
+    /// </summary>
+    /// <param name="services"></param>
+    /// <param name="configuration"></param>
+    /// <returns></returns>
+    public static IServiceCollection AddAppDatabase(this IServiceCollection services, DatabaseSettings dbSettings)
+    {
+        services.AddDbContext<AppDbContext>(options => DatabaseHelper.ConfigureDbContext(options, dbSettings));
+        return services;
+    }
+
+    /// <summary>
+    /// Configures services for DI
+    /// </summary>
+    /// <param name="builder">WebApplicationBuilder instance</param>
+    public static void RegisterServices(this WebApplicationBuilder builder)
+    {
+        // Add configuration class
+        var optixSettigns = builder.Configuration.GetSection("OptixServe");
+        var onConfigSettings = optixSettigns.Get<OptixServeSettings>();
+        builder.Services.Configure<OptixServeSettings>(optixSettigns);
+
+        // Add DBContext class
+        builder.Services.AddAppDatabase(onConfigSettings?.Database!);
+        builder.Services.AddScoped<DbInitializer>();
+
+        // Application services
+        builder.Services.AddScoped<IUserService, UserService>();
+    }
+
     /// <summary>
     /// Configures JSON serialization options with custom context
     /// </summary>
@@ -97,26 +138,18 @@ static class ExtensionMethods
         builder.Services.ConfigureHttpJsonOptions(options =>
         {
             options.SerializerOptions.TypeInfoResolverChain.Add(UserJsonContext.Default);
+            options.SerializerOptions.TypeInfoResolverChain.Add(VersionJsonContext.Default);
         });
     }
 
-    /// <summary>
-    /// Configures services for DI
-    /// </summary>
-    /// <param name="builder"></param>
-    public static void RegisterServices(this WebApplicationBuilder builder)
-    {
-        // Application services
-        builder.Services.AddScoped<IUserService, UserService>();
-    }
-
     /// <summary>
     /// Registers all API endpoints
     /// </summary>
-    /// <param name="app">WebApplication instance</param>
+    /// <param name="rootGroup">Root RouteGroupBuilder instance</param>
     public static void RegisterEndpoints(RouteGroupBuilder rootGroup)
     {
         UserEndpoint.Register(rootGroup);
+        VersionEndpoint.Register(rootGroup);
     }
 
 }

OptixServe.Api/Utilites/DatabaseHelper.cs

@@ -0,0 +1,34 @@
+using Microsoft.EntityFrameworkCore;
+using OptixServe.Api.Configuration;
+using OptixServe.Core.Data;
+
+namespace OptixServe.Api.Utilites;
+
+public static class DatabaseHelper
+{
+    public static string BuildConnectionString(DatabaseSettings dbSettings)
+    {
+        return dbSettings.Type switch
+        {
+            DatabaseType.Sqlite => $"Data Source={dbSettings.Host ?? "optixserve.db"}",
+            DatabaseType.MySQL => throw new NotSupportedException("MySQL connection is not yet implemented"),
+            _ => throw new NotSupportedException($"Database type {dbSettings.Type} is not supported")
+        };
+    }
+
+    public static void ConfigureDbContext(DbContextOptionsBuilder options, DatabaseSettings dbSettings)
+    {
+        if (dbSettings?.Type == DatabaseType.Sqlite)
+        {
+            var dbPath = dbSettings.Host ?? "optixserve.db";
+            var connectionString = $"Data Source={dbPath}";
+
+            options.UseSqlite(connectionString, b => b.MigrationsAssembly("OptixServe.Api"));
+
+        }
+        else
+        {
+            throw new NotImplementedException("Only SQLite database is currently supported");
+        }
+    }
+}

OptixServe.Api/Utilites/DesignTimeDbContextFactory.cs

@@ -0,0 +1,20 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Design;
+using OptixServe.Api.Configuration;
+using OptixServe.Core.Data;
+
+namespace OptixServe.Api.Utilites;
+
+public class DesignTimeDbContextFactory : IDesignTimeDbContextFactory<AppDbContext>
+{
+    public AppDbContext CreateDbContext(string[] args)
+    {
+        var configuration = ConfigurationHelper.CreateDefaultBuilder().Build();
+
+        var dbSettings = configuration.GetSection("OptixServe:Database").Get<DatabaseSettings>()!;
+        var optionsBuilder = new DbContextOptionsBuilder<AppDbContext>();
+        DatabaseHelper.ConfigureDbContext(optionsBuilder, dbSettings);
+
+        return new AppDbContext(optionsBuilder.Options);
+    }
+}

OptixServe.Api/appsettings.json

@@ -5,5 +5,15 @@
       "Microsoft.AspNetCore": "Warning"
     }
   },
-  "AllowedHosts": "*"
+  "AllowedHosts": "*",
+  "OptixServe": {
+    "Api": {
+      "Listen": "0.0.0.0",
+      "Port": "54321"
+    },
+    "Database": {
+      "Type": "Sqlite",
+      "Host": "optixserve.db"
+    }
+  }
 }

OptixServe.Core/Data/AppDbContext.cs

@@ -0,0 +1,21 @@
+using Microsoft.EntityFrameworkCore;
+using OptixServe.Core.Models;
+
+namespace OptixServe.Core.Data;
+
+public class AppDbContext(DbContextOptions options) : DbContext(options)
+{
+    public DbSet<User> Users { get; set; } = null!;
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        modelBuilder.Entity<User>(user =>
+        {
+            user.HasKey(u => u.Id);
+        });
+
+        modelBuilder.Entity<User>().HasData([
+            new() {Id = "1", UserName = "admin", Password = "admin12345"}
+        ]);
+    }
+}

OptixServe.Core/Data/DbInitializer.cs

@@ -0,0 +1,11 @@
+namespace OptixServe.Core.Data;
+
+public class DbInitializer(AppDbContext dbContext)
+{
+    private readonly AppDbContext _context = dbContext;
+
+    public void Initialize()
+    {
+        _context.Database.EnsureCreated();
+    }
+}

OptixServe.Core/Models/User.cs

@@ -1,8 +1,15 @@
 namespace OptixServe.Core.Models;
 
+public enum PrivilegeGroup
+{
+    Admin,
+    User,
+}
+
 public record User
 {
     public required string Id { get; set; }
     public required string UserName { get; set; }
-    public required string Password { get; set; }
+    public string? Password { get; set; }
+    public PrivilegeGroup PrivilegeGroup { get; set; } = PrivilegeGroup.User;
 }

OptixServe.Core/OptixServe.Core.csproj

@@ -6,4 +6,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.6" />
+  </ItemGroup>
+
 </Project>

OptixServe.Core/Services/UserService.cs

@@ -1,3 +1,4 @@
+using OptixServe.Core.Data;
 using OptixServe.Core.Models;
 
 namespace OptixServe.Core.Services;
@@ -5,21 +6,20 @@ namespace OptixServe.Core.Services;
 public interface IUserService
 {
     IEnumerable<User> GetUsers();
-    User? GetUserById(string Id);
+    User? GetUserById(string id);
 }
 
-public class UserService : IUserService
+public class UserService(AppDbContext dbContext) : IUserService
 {
-    public User? GetUserById(string Id)
+    private readonly AppDbContext _dbContext = dbContext;
+
+    public User? GetUserById(string id)
     {
-        throw new NotImplementedException();
+        return _dbContext.Users.FirstOrDefault(u => u.Id == id);
     }
 
     public IEnumerable<User> GetUsers()
     {
-        return [
-            new() { Id = "1234", UserName = "xxx", Password = "pass1" },
-            new() { Id = "5678", UserName = "yyy", Password = "pass2" }
-        ];
+        return _dbContext.Users.AsEnumerable();
     }
 }