feat(GoogleGemini): added api usage with costs

src/Directory.Packages.props

@@ -19,7 +19,7 @@
     <PackageVersion Include="DotNet.ReproducibleBuilds" Version="1.1.1" />
     <PackageVersion Include="FluentAssertions" Version="6.12.0" />
     <PackageVersion Include="GitHubActionsTestLogger" Version="2.3.3" />
-    <PackageVersion Include="Google_GenerativeAI" Version="0.1.20" />
+    <PackageVersion Include="Google_GenerativeAI" Version="1.0.0" />
     <PackageVersion Include="GroqSharp" Version="1.1.2" />
     <PackageVersion Include="H.Generators.Extensions" Version="1.22.0" />
     <PackageVersion Include="H.NSwag.Generator" Version="14.0.7.76">

src/Providers/Google/src/Extensions/GoogleGeminiExtensions.cs

@@ -27,7 +27,7 @@ public static string GetString(this IDictionary<string, object>? arguments)
         if (arguments == null)
             return string.Empty;
 
-        return JsonSerializer.Serialize(arguments, SourceGenerationContext.Default.DictionaryStringObject);
+        return JsonSerializer.Serialize(arguments);
     }
 }
 

src/Providers/Google/src/GoogleChatModel.cs

@@ -9,13 +9,19 @@ namespace LangChain.Providers.Google;
 /// </summary>
 public partial class GoogleChatModel(
     GoogleProvider provider,
-    string id)
+    string id,
+    int contextLength = 0,
+    double inputTokenPriceUsd = 0,
+    double outputTokenPriceUsd = 0,
+    double secondaryInputTokenPrice = 0,
+    double secondaryOutputTokenPrice = 0)
     : ChatModel(id)
 {
     #region Properties
 
     /// <inheritdoc />
-    public override int ContextLength => 0;
+    public override int ContextLength => contextLength;
+
 
     private GenerativeModel Api { get; } = new(
         provider.ApiKey,
@@ -138,11 +144,13 @@ public override async Task<ChatResponse> GenerateAsync(
             OnPartialResponseGenerated(Environment.NewLine);
             OnCompletedResponseGenerated(response.Text() ?? string.Empty);
 
-            // Unsupported
-            var usage2 = Usage.Empty with
+
+            var usage2 = GetUsage(response) with
             {
                 Time = watch.Elapsed
             };
+
+            //Add Usage
             AddUsage(usage2);
             provider.AddUsage(usage2);
 
@@ -176,7 +184,8 @@ public override async Task<ChatResponse> GenerateAsync(
 
                     messages.Add(message);
 
-                    usage2 = Usage.Empty with
+                    //Add Usage
+                    usage2 = GetUsage(response) with
                     {
                         Time = watch.Elapsed
                     };
@@ -185,12 +194,8 @@ public override async Task<ChatResponse> GenerateAsync(
                 }
             }
         }
-
-
-        //Function Call
-
-
-        // Unsupported
+
+        //Add Usage
         var usage = Usage.Empty with
         {
             Time = watch.Elapsed
@@ -201,11 +206,42 @@ public override async Task<ChatResponse> GenerateAsync(
         return new ChatResponse
         {
             Messages = messages,
-            Usage = usage,
+            Usage = Usage,
             UsedSettings = ChatSettings.Default
         };
     }
+    private Usage GetUsage(EnhancedGenerateContentResponse response)
+    {
+        var outputTokens = response.UsageMetadata?.CandidatesTokenCount ?? 0;
+        var inputTokens = response.UsageMetadata?.PromptTokenCount ?? 0;
+        var priceInUsd = CalculatePriceInUsd(
+            outputTokens: outputTokens,
+            inputTokens: inputTokens);
 
+        return Usage.Empty with
+        {
+            InputTokens = inputTokens,
+            OutputTokens = outputTokens,
+            Messages = 1,
+            PriceInUsd = priceInUsd,
+        };
+    }
+    /// <inheritdoc/>
+    public double CalculatePriceInUsd(int inputTokens, int outputTokens)
+    {
+        if (inputTokens < 128 * 1024)
+        {
+            var inputCost = inputTokenPriceUsd * inputTokens;
+            var outputCost = outputTokenPriceUsd * outputTokens;
+            return inputCost + outputCost;
+        }
+        else
+        {
+            var inputCost = secondaryInputTokenPrice * inputTokens;
+            var outputCost = secondaryOutputTokenPrice * outputTokens;
+            return inputCost + outputCost;
+        }
+    }
     private static Message ToFunctionCallMessage(string jsonResult, string functionName)
     {
         //var result = JsonSerializer.Deserialize<JsonNode>(jsonResult, SerializerOptions);

src/Providers/Google/src/Predefined/GeminiModels.cs

@@ -6,10 +6,22 @@ namespace LangChain.Providers.Google.Predefined;
 public class GeminiProModel(GoogleProvider provider)
     : GoogleChatModel(
         provider,
-        GoogleAIModels.GeminiPro);
+        GoogleAIModels.GeminiPro, 32 * 1024, 0.5 * 0.000001, 1.5 * 0.000001);
 
 /// <inheritdoc cref="GoogleAIModels.GeminiProVision" />
 public class GeminiProVisionModel(GoogleProvider provider)
     : GoogleChatModel(
         provider,
-        GoogleAIModels.GeminiProVision);
+        GoogleAIModels.GeminiProVision, 32 * 1024, 0.5 * 0.000001, 1.5 * 0.000001);
+
+/// <inheritdoc cref="GoogleAIModels.GeminiProVision" />
+public class Gemini15FlashModel(GoogleProvider provider)
+    : GoogleChatModel(
+        provider,
+        GoogleAIModels.Gemini15Flash, 1024 * 1024, 0.35 * 0.000001, 1.05 * 0.000001, 0.70 * 0.000001, 2.1 * 0.000001);
+
+/// <inheritdoc cref="GoogleAIModels.GeminiProVision" />
+public class Gemini15ProModel(GoogleProvider provider)
+    : GoogleChatModel(
+        provider,
+        GoogleAIModels.Gemini15Flash, 2 * 1024 * 1024, 3.5 * 0.000001, 10.50 * 0.000001, 7.0 * 0.000001, 21.00 * 0.000001);

src/Providers/Google/test/Tests.cs

@@ -1,4 +1,5 @@
 using GenerativeAI.Models;
+using GeminiProModel = LangChain.Providers.Google.Predefined.GeminiProModel;
 
 namespace LangChain.Providers.Google.Tests;
 
@@ -13,7 +14,7 @@ public async Task GetWeather()
             throw new InvalidOperationException("Gemini_API_Key is not set");
 
 
-        var model = new GoogleChatModel(apiKey, GoogleAIModels.GeminiPro);
+        var model = new GeminiProModel(apiKey);//, GoogleAIModels.GeminiPro);
 
         var service = new WeatherService();
         model.AddGlobalTools(service.AsGoogleFunctions(), service.AsGoogleCalls());
@@ -25,6 +26,9 @@ public async Task GetWeather()
                  "Sure! Could you please provide me with your location?".AsAiMessage(),
                  "Dubai, UAE".AsHumanMessage(),
             });
+        response.Usage.InputTokens.Should().BeGreaterThan(0);
+        response.Usage.OutputTokens.Should().BeGreaterThan(0);
+        response.Usage.PriceInUsd.Should().BeGreaterThan(0);
 
         Console.WriteLine(response.Messages.AsHistory());
     }