feat: add Google Vertex AI connector implementation

infra/main.bicep

@@ -19,6 +19,9 @@ param githubModelsModel string = ''
 @secure()
 param githubModelsToken string = ''
 // Google Vertex AI
+param googleVertexAIModel string = ''
+@secure()
+param googleVertexAIApiKey string = ''
 // Docker Model Runner
 // Foundry Local
 // Hugging Face
@@ -68,6 +71,8 @@ module resources 'resources.bicep' = {
     connectorType: connectorType
     githubModelsModel: githubModelsModel
     githubModelsToken: githubModelsToken
+    googleVertexAIModel: googleVertexAIModel
+    googleVertexAIApiKey: googleVertexAIApiKey
     huggingFaceModel: huggingFaceModel
     openAIModel: openAIModel
     openAIApiKey: openAIApiKey

infra/main.parameters.json

@@ -17,6 +17,12 @@
     "githubModelsToken": {
       "value": "${GH_MODELS_TOKEN}"
     },
+    "googleVertexAIModel": {
+      "value": "${GOOGLE_VERTEX_AI_MODEL}"
+    },
+    "googleVertexAIApiKey": {
+      "value": "${GOOGLE_VERTEX_AI_API_KEY}"
+    },
     "huggingFaceModel": {
       "value": "${HUGGING_FACE_MODEL}"
     },

infra/resources.bicep

@@ -13,6 +13,9 @@ param githubModelsModel string = ''
 @secure()
 param githubModelsToken string = ''
 // Google Vertex AI
+param googleVertexAIModel string = ''
+@secure()
+param googleVertexAIApiKey string = ''
 // Docker Model Runner
 // Foundry Local
 // Hugging Face
@@ -120,6 +123,17 @@ var envGitHubModels = (connectorType == '' || connectorType == 'GitHubModels') ?
   }
 ] : []) : []
 // Google Vertex AI
+var envGoogleVertexAI = (connectorType == '' || connectorType == 'GoogleVertexAI') ? concat(googleVertexAIModel != '' ? [
+  {
+    name: 'GoogleVertexAI__Model'
+    value: googleVertexAIModel
+  }
+] : [], googleVertexAIApiKey != '' ? [
+  {
+    name: 'GoogleVertexAI__ApiKey'
+    secretRef: 'google-vertex-ai-api-key'
+  }
+] : []) : []
 // Docker Model Runner
 // Foundry Local
 // Hugging Face

src/OpenChat.PlaygroundApp/Abstractions/LanguageModelConnector.cs

@@ -37,6 +37,7 @@ public static async Task<IChatClient> CreateChatClientAsync(AppSettings settings
         LanguageModelConnector connector = settings.ConnectorType switch
         {
             ConnectorType.GitHubModels => new GitHubModelsConnector(settings),
+            ConnectorType.GoogleVertexAI => new GoogleVertexAIConnector(settings),
             ConnectorType.HuggingFace => new HuggingFaceConnector(settings),
             ConnectorType.OpenAI => new OpenAIConnector(settings),
             _ => throw new NotSupportedException($"Connector type '{settings.ConnectorType}' is not supported.")

src/OpenChat.PlaygroundApp/Connectors/GoogleVertexAIConnector.cs

@@ -0,0 +1,51 @@
+using System.ClientModel;
+
+using Microsoft.Extensions.AI;
+
+using Mscc.GenerativeAI.Microsoft;
+
+using OpenChat.PlaygroundApp.Abstractions;
+using OpenChat.PlaygroundApp.Configurations;
+
+namespace OpenChat.PlaygroundApp.Connectors;
+
+/// <summary>
+/// This represents the connector entity for Google Vertex AI.
+/// </summary>
+public class GoogleVertexAIConnector(AppSettings settings) : LanguageModelConnector(settings.GoogleVertexAI)
+{
+    /// <inheritdoc/>
+    public override bool EnsureLanguageModelSettingsValid()
+    {
+        var settings = this.Settings as GoogleVertexAISettings;
+        if (settings is null)
+        {
+            throw new InvalidOperationException("Missing configuration: GoogleVertexAI.");
+        }
+
+        if (string.IsNullOrWhiteSpace(settings.ApiKey?.Trim()) == true)
+        {
+            throw new InvalidOperationException("Missing configuration: GoogleVertexAI:ApiKey.");
+        }
+
+        if (string.IsNullOrWhiteSpace(settings.Model?.Trim()) == true)
+        {
+            throw new InvalidOperationException("Missing configuration: GoogleVertexAI:Model.");
+        }
+
+        return true;
+    }
+
+    /// <inheritdoc/>
+    public override async Task<IChatClient> GetChatClientAsync()
+    {
+        var settings = this.Settings as GoogleVertexAISettings;
+
+        var apiKey = settings?.ApiKey ?? throw new InvalidOperationException("Missing configuration: GoogleVertexAI:ApiKey.");
+        var model = settings?.Model ?? throw new InvalidOperationException("Missing configuration: GoogleVertexAI:Model.");
+
+        var chatClient = new GeminiChatClient(apiKey, model);
+
+        return await Task.FromResult(chatClient).ConfigureAwait(false);
+    }
+}

test/OpenChat.PlaygroundApp.Tests/Connectors/GoogleVertexAIConnectorTests.cs

@@ -0,0 +1,193 @@
+using Microsoft.Extensions.AI;
+
+using OpenChat.PlaygroundApp.Abstractions;
+using OpenChat.PlaygroundApp.Configurations;
+using OpenChat.PlaygroundApp.Connectors;
+
+namespace OpenChat.PlaygroundApp.Tests.Connectors;
+
+public class GoogleVertexAIConnectorTests
+{
+    private const string ApiKey = "AIzaSyA1234567890abcdefgHIJKLMNOpqrstuv";
+    private const string Model = "test-model";
+    private static AppSettings BuildAppSettings(string? apiKey = ApiKey, string? model = Model)
+    {
+        return new AppSettings
+        {
+            ConnectorType = ConnectorType.GoogleVertexAI,
+            GoogleVertexAI = new GoogleVertexAISettings
+            {
+                ApiKey = apiKey,
+                Model = model
+            }
+        };
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Fact]
+    public void Given_Settings_Is_Null_When_EnsureLanguageModelSettingsValid_Invoked_Then_It_Should_Throw()
+    {
+        // Arrange
+        var appSettings = new AppSettings { ConnectorType = ConnectorType.GoogleVertexAI, GoogleVertexAI = null };
+        var connector = new GoogleVertexAIConnector(appSettings);
+
+        // Act
+        Action action = () => connector.EnsureLanguageModelSettingsValid();
+
+        // Assert
+        action.ShouldThrow<InvalidOperationException>()
+              .Message.ShouldContain("GoogleVertexAI");
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Theory]
+    [InlineData(null, typeof(InvalidOperationException), "GoogleVertexAI:ApiKey")]
+    [InlineData("", typeof(InvalidOperationException), "GoogleVertexAI:ApiKey")]
+    [InlineData("   ", typeof(InvalidOperationException), "GoogleVertexAI:ApiKey")]
+    public void Given_Invalid_ApiKey_When_EnsureLanguageModelSettingsValid_Invoked_Then_It_Should_Throw(string? apiKey, Type expectedType, string expectedMessage)
+    {
+        // Arrange
+        var appSettings = BuildAppSettings(apiKey: apiKey);
+        var connector = new GoogleVertexAIConnector(appSettings);
+
+        // Act
+        Action action = () => connector.EnsureLanguageModelSettingsValid();
+
+        // Assert
+        action.ShouldThrow<InvalidOperationException>()
+              .Message.ShouldContain(expectedMessage);
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Theory]
+    [InlineData(null, typeof(InvalidOperationException), "GoogleVertexAI:Model")]
+    [InlineData("", typeof(InvalidOperationException), "GoogleVertexAI:Model")]
+    [InlineData("   ", typeof(InvalidOperationException), "GoogleVertexAI:Model")]
+    public void Given_Invalid_Model_When_EnsureLanguageModelSettingsValid_Invoked_Then_It_Should_Throw(string? model, Type expectedType, string expectedMessage)
+    {
+        // Arrange
+        var appSettings = BuildAppSettings(apiKey: "valid-key", model: model);
+        var connector = new GoogleVertexAIConnector(appSettings);
+
+        // Act
+        Action action = () => connector.EnsureLanguageModelSettingsValid();
+
+        // Assert
+        action.ShouldThrow<InvalidOperationException>()
+              .Message.ShouldContain(expectedMessage);
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Fact]
+    public void Given_Valid_Settings_When_EnsureLanguageModelSettingsValid_Invoked_Then_It_Should_Return_True()
+    {
+        // Arrange
+        var appSettings = BuildAppSettings();
+        var connector = new GoogleVertexAIConnector(appSettings);
+
+        // Act
+        var result = connector.EnsureLanguageModelSettingsValid();
+
+        // Assert
+        result.ShouldBeTrue();
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Fact]
+    public async Task Given_Valid_Settings_When_GetChatClient_Invoked_Then_It_Should_Return_ChatClient()
+    {
+        var settings = BuildAppSettings();
+        var connector = new GoogleVertexAIConnector(settings);
+
+        var client = await connector.GetChatClientAsync();
+
+        client.ShouldNotBeNull();
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Fact]
+    public void Given_Settings_Is_Null_When_GetChatClientAsync_Invoked_Then_It_Should_Throw()
+    {
+        // Arrange
+        var appSettings = new AppSettings { ConnectorType = ConnectorType.GoogleVertexAI, GoogleVertexAI = null };
+        var connector = new GoogleVertexAIConnector(appSettings);
+
+        // Act
+        Func<Task> func = async () => await connector.GetChatClientAsync();
+
+        // Assert
+        func.ShouldThrow<InvalidOperationException>();
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Theory]
+    [InlineData(null, typeof(InvalidOperationException), "GoogleVertexAI:ApiKey")]
+    [InlineData("", typeof(ArgumentException), "key")]
+    public async Task Given_Missing_ApiKey_When_GetChatClient_Invoked_Then_It_Should_Throw(string? apiKey, Type expected, string message)
+    {
+        // Arrange
+        var settings = BuildAppSettings(apiKey: apiKey);
+        var connector = new GoogleVertexAIConnector(settings);
+
+        // Act
+        Func<Task> func = async () => await connector.GetChatClientAsync();
+
+        // Assert
+        func.ShouldThrow(expected)
+            .Message.ShouldContain(message);
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Theory]
+    [InlineData(null, typeof(InvalidOperationException), "model")]
+    public async Task Given_Missing_Model_When_GetChatClient_Invoked_Then_It_Should_Throw(string? model, Type expected, string message)
+    {
+        // Arrange
+        var settings = BuildAppSettings(model: model);
+        var connector = new GoogleVertexAIConnector(settings);
+
+        // Act
+        Func<Task> func = async () => await connector.GetChatClientAsync();
+
+        // Assert
+        func.ShouldThrow(expected)
+            .Message.ShouldContain(message);
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Fact]
+    public async Task Given_Valid_Settings_When_CreateChatClientAsync_Invoked_Then_It_Should_Return_ChatClient()
+    {
+        // Arrange
+        var settings = BuildAppSettings();
+
+        // Act
+        var result = await LanguageModelConnector.CreateChatClientAsync(settings);
+
+        // Assert
+        result.ShouldNotBeNull();
+        result.ShouldBeAssignableTo<IChatClient>();
+    }
+
+    [Trait("Category", "UnitTest")]
+    [Fact]
+    public void Given_Invalid_Settings_When_CreateChatClientAsync_Invoked_Then_It_Should_Throw()
+    {
+        // Arrange
+        var settings = new AppSettings
+        {
+            ConnectorType = ConnectorType.GoogleVertexAI,
+            GoogleVertexAI = new GoogleVertexAISettings
+            {
+                ApiKey = null,
+                Model = "test-model"
+            }
+        };
+
+        // Act
+        Func<Task> func = async () => await LanguageModelConnector.CreateChatClientAsync(settings);
+
+        // Assert
+        func.ShouldThrow<InvalidOperationException>();
+    }
+}