feat: initial config command implementation

src/AltGen.Console/Common/HostBuilderExtensions.cs

@@ -6,6 +6,9 @@ static class HostBuilderExtensions
   {
     var registrar = new TypeRegistrar(builder);
     var app = new CommandApp<GenerateCommand>(registrar);
+
+    app.Configure(static c => c.AddCommand<ConfigCommand>("config"));
+
     return app;
   }
 }

src/AltGen.Console/Config/ConfigCommand.cs

@@ -0,0 +1,109 @@
+
+using Microsoft.Extensions.Configuration;
+
+namespace AltGen.Console.Config;
+
+// TODO: We should refactor this so that
+// we have a config add and a config remove command
+// the config add will have basically the same code
+// as below but the config remove will just
+// accept a provider identifier and remove it
+
+sealed class ConfigCommand(
+  IAnsiConsole console,
+  IFileSystem fileSystem,
+  IConfiguration config
+) : AsyncCommand<ConfigCommand.Settings>
+{
+  static readonly JsonSerializerOptions JsonOptions = new()
+  {
+    PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+    PropertyNameCaseInsensitive = true,
+    WriteIndented = true
+  };
+  readonly IAnsiConsole _console = console;
+  readonly IFileSystem _fileSystem = fileSystem;
+  readonly IConfiguration _config = config;
+
+  public class Settings(IFileSystem filesystem) : CommandSettings
+  {
+    readonly IFileSystem _fileSystem = filesystem;
+
+    [CommandArgument(1, "<provider>")]
+    [Description("The provider to configure.")]
+    public string Provider { get; init; } = string.Empty;
+
+    [CommandArgument(2, "<key>")]
+    [Description("The key for the provider.")]
+    public string Key { get; init; } = string.Empty;
+
+    [CommandOption("-d|--default")]
+    [Description("Set the provider as the default.")]
+    public bool Default { get; init; }
+
+    public string SettingsPath => _fileSystem.Path.Combine(AppContext.BaseDirectory, "appsettings.json");
+  }
+
+  public override async Task<int> ExecuteAsync(CommandContext context, Settings settings)
+  {
+    var settingsExist = _fileSystem.File.Exists(settings.SettingsPath);
+
+    if (settingsExist is false)
+    {
+      var appSettings = new AppSettings([
+        new(settings.Provider, settings.Key, settings.Default)
+      ]);
+
+      var json = JsonSerializer.Serialize(appSettings, JsonOptions);
+      await _fileSystem.File.WriteAllTextAsync(settings.SettingsPath, json);
+      _console.MarkupLine($"[bold]{settings.Provider}[/] has been configured.");
+      return 0;
+    }
+
+    var existingJson = await _fileSystem.File.ReadAllTextAsync(settings.SettingsPath);
+    var existingAppSettings = JsonSerializer.Deserialize<AppSettings>(existingJson, JsonOptions)
+      ?? throw new ConfigException("Failed to deserialize settings.");
+    var updatedAppSettings = existingAppSettings.Update(settings);
+    var udpatedJson = JsonSerializer.Serialize(updatedAppSettings, JsonOptions);
+    await _fileSystem.File.WriteAllTextAsync(settings.SettingsPath, udpatedJson);
+    _console.MarkupLine($"[bold]{settings.Provider}[/] has been configured.");
+    return 0;
+  }
+}
+
+record AppSettings(ProviderSettings[] Providers)
+{
+  public AppSettings Update(ConfigCommand.Settings settings)
+  {
+    var updatedProviders = Providers.Select(p =>
+    {
+      if (p.Provider == settings.Provider)
+      {
+        return p with { Key = settings.Key, Default = settings.Default };
+      }
+
+      if (p.Provider != settings.Provider && settings.Default)
+      {
+        return p with { Default = false };
+      }
+
+      return p;
+    });
+
+    var provider = Providers.FirstOrDefault(p => p.Provider == settings.Provider);
+
+    if (provider is null)
+    {
+      var newProvider = new ProviderSettings(settings.Provider, settings.Key, settings.Default);
+      return this with { Providers = [.. updatedProviders, newProvider] };
+    }
+
+    return this with { Providers = [.. updatedProviders] };
+  }
+}
+
+record ProviderSettings(string Provider, string Key, bool Default);
+
+class ConfigException(string message) : Exception(message)
+{
+}

src/AltGen.Console/Program.cs

@@ -1,16 +1,4 @@
-// TODO: Need to implement config
-// command. This should allow
-// the user to set default values
-// for provider keys and a default
-// provider.
-//
-// For example setting a providers key
-// i.e. altgen config gemini mykey
-//
-// Or setting provider as default
-// i.e. altgen config gemini mykey --default
-
-await Host.CreateDefaultBuilder(args)
+await Host.CreateDefaultBuilder(args)
   .ConfigureLogging(static l => l.ClearProviders())
   .ConfigureServices(static (_, services) =>
   {

src/AltGen.Console/Usings.cs

@@ -4,8 +4,9 @@ global using System.Net.Http.Headers;
 global using System.Text.Json;
 
 global using AltGen.Console.Common;
-global using AltGen.Console.Generated;
+global using AltGen.Console.Config;
 global using AltGen.Console.Generate;
+global using AltGen.Console.Generated;
 
 global using Microsoft.Extensions.DependencyInjection;
 global using Microsoft.Extensions.Hosting;