Function calling

ChatGPT.sln

@@ -56,6 +56,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ChatGPT.UI.Game", "samples\
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "samples", "samples", "{5EDF3913-3E89-44F6-A11F-52DA003AD315}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ChatGPT.CLI.FunctionCalling", "samples\ChatGPT.CLI.FunctionCalling\ChatGPT.CLI.FunctionCalling.csproj", "{0590592D-CDF7-4705-9F34-D8E779B66644}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -122,6 +124,10 @@ Global
 		{B0A8A296-575A-443A-BD55-12713EAFE506}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B0A8A296-575A-443A-BD55-12713EAFE506}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B0A8A296-575A-443A-BD55-12713EAFE506}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0590592D-CDF7-4705-9F34-D8E779B66644}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0590592D-CDF7-4705-9F34-D8E779B66644}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0590592D-CDF7-4705-9F34-D8E779B66644}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0590592D-CDF7-4705-9F34-D8E779B66644}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -142,5 +148,6 @@ Global
 		{A9793A98-235E-4877-A3FC-C7C3DB4852FA} = {62EB4E5F-59EB-4D59-83A0-2A8B5B2397ED}
 		{F9D8D17B-228B-4D5E-8126-39E8F41B87A2} = {D3B27217-AB31-4AB0-8FF9-C7528DA03FDE}
 		{B0A8A296-575A-443A-BD55-12713EAFE506} = {5EDF3913-3E89-44F6-A11F-52DA003AD315}
+		{0590592D-CDF7-4705-9F34-D8E779B66644} = {5EDF3913-3E89-44F6-A11F-52DA003AD315}
 	EndGlobalSection
 EndGlobal

samples/ChatGPT.CLI.FunctionCalling/ChatGPT.CLI.FunctionCalling.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <RuntimeIdentifiers>win-x64;linux-x64;linux-arm64;osx-x64;osx-arm64</RuntimeIdentifiers>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <TrimMode>full</TrimMode>
+    <IsPackable>False</IsPackable>
+    <RootNamespace>ChatGPT.CLI</RootNamespace>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'">
+    <PublishAot>True</PublishAot>
+    <TrimmerSingleWarn>false</TrimmerSingleWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\ChatGPT.Core\ChatGPT.Core.csproj" />
+  </ItemGroup>
+</Project>

samples/ChatGPT.CLI.FunctionCalling/Program.cs

@@ -0,0 +1,113 @@
+using ChatGPT;
+using ChatGPT.ViewModels.Chat;
+
+Defaults.ConfigureDefaultServices();
+
+var directions = 
+"""
+You are a helpful assistant.
+Write answers in plain text.
+Do not use markdown.
+Only use the functions you have been provided with.
+""";
+
+if (args.Length == 1)
+{
+    directions = args[0];
+}
+
+using var cts = new CancellationTokenSource();
+
+var functions = GetFunctions();
+
+var chat = new ChatViewModel(new ChatSettingsViewModel
+{
+    MaxTokens = 2000,
+    Model = "gpt-3.5-turbo-0613",
+    Functions = functions,
+    FunctionCall = "auto"
+    // Force function call by setting FunctionCall property.
+    // FunctionCall = new { name = "GetCurrentWeather" }
+});
+
+// Enable to debug json requests and responses.
+// chat.Debug = true;
+
+chat.AddSystemMessage(directions);
+
+while (true)
+{
+    Console.Write("> ");
+
+    var input = Console.ReadLine();
+    if (string.IsNullOrWhiteSpace(input) || input == Environment.NewLine)
+    {
+        continue;
+    }
+
+    try
+    {
+        chat.AddUserMessage(input);
+        var result = await chat.SendAsync(chat.CreateChatMessages(), cts.Token);
+
+        chat.AddAssistantMessage(result?.Message);
+
+        if (result?.Message is { })
+        {
+            Console.WriteLine(result.Message);
+        }
+
+        if (result?.FunctionCall is { } functionCall)
+        {
+            if (functionCall.Name == "GetCurrentWeather" && functionCall.Arguments is { })
+            {
+                functionCall.Arguments.TryGetValue("location", out var location);
+                functionCall.Arguments.TryGetValue("unit", out var unit);
+                var functionCallResult = GetCurrentWeather(location, unit ?? "celsius");
+                chat.AddFunctionMessage(functionCallResult, functionCall.Name);
+
+                Console.WriteLine(functionCallResult);
+            }
+        }
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine("Error: " + ex.Message);
+    }
+}
+
+string GetCurrentWeather(string? location, string? unit)
+{
+    Console.WriteLine($"Weather for {location} [{unit}].");
+    return "Cloudy.";
+}
+
+object GetFunctions()
+{
+    return new[]
+    {
+        new
+        {
+            name = "GetCurrentWeather",
+            description = "Get the current weather in a given location",
+            parameters = new
+            {
+                type = "object",
+                properties = new
+                {
+                    location = new
+                    {
+                        type = "string",
+                        description = "The city and state, e.g. San Francisco, CA"
+                    },
+                    unit = new
+                    {
+                        type = "string",
+                        @enum = new[] {"celsius", "fahrenheit"}
+                    },
+                },
+                required = new[] {"location"}
+            },
+        }
+    };
+}

src/ChatGPT.Core/ViewModels/Chat/ChatFunctionCallViewModel.cs

@@ -0,0 +1,35 @@
+using System.Text.Json.Serialization;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace ChatGPT.ViewModels.Chat;
+
+public class ChatFunctionCallViewModel : ObservableObject
+{
+    private string? _name;
+
+    [JsonConstructor]
+    public ChatFunctionCallViewModel()
+    {
+    }
+
+    public ChatFunctionCallViewModel(string name) 
+        : this()
+    {
+        _name = name;
+    }
+
+    [JsonPropertyName("name")]
+    public string? Name
+    {
+        get => _name;
+        set => SetProperty(ref _name, value);
+    }
+
+    public ChatFunctionCallViewModel Copy()
+    {
+        return new ChatFunctionCallViewModel
+        {
+            Name = _name,
+        };
+    }
+}

src/ChatGPT.Core/ViewModels/Chat/ChatFunctionViewModel.cs

@@ -0,0 +1,63 @@
+using System.Text.Json.Serialization;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace ChatGPT.ViewModels.Chat;
+
+public class ChatFunctionViewModel : ObservableObject
+{
+    private string? _name;
+    private string? _description;
+    private object? _parameters;
+
+    [JsonConstructor]
+    public ChatFunctionViewModel()
+    {
+    }
+
+    public ChatFunctionViewModel(string name, string description) 
+        : this()
+    {
+        _name = name;
+        _description = description;
+    }
+
+    public ChatFunctionViewModel(string name, string description, object parameters) 
+        : this()
+    {
+        _name = name;
+        _description = description;
+        _parameters = parameters;
+    }
+
+    [JsonPropertyName("name")]
+    public string? Name
+    {
+        get => _name;
+        set => SetProperty(ref _name, value);
+    }
+
+    [JsonPropertyName("description")]
+    public string? Description
+    {
+        get => _description;
+        set => SetProperty(ref _description, value);
+    }
+
+    [JsonPropertyName("parameters")]
+    public object? Parameters
+    {
+        get => _parameters;
+        set => SetProperty(ref _parameters, value);
+    }
+
+    public ChatFunctionViewModel Copy()
+    {
+        return new ChatFunctionViewModel
+        {
+            Name = _name,
+            Description = _description,
+            // TODO: Copy Parameters if type is reference.
+            Parameters = _parameters
+        };
+    }
+}

src/ChatGPT.Core/ViewModels/Chat/ChatMessageFunctionCallViewModel.cs

@@ -0,0 +1,52 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json.Serialization;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace ChatGPT.ViewModels.Chat;
+
+public class ChatMessageFunctionCallViewModel : ObservableObject
+{
+    private string? _name;
+    private Dictionary<string, string>? _arguments;
+
+    [JsonConstructor]
+    public ChatMessageFunctionCallViewModel()
+    {
+    }
+
+    public ChatMessageFunctionCallViewModel(string role, Dictionary<string, string> arguments) 
+        : this()
+    {
+        _name = role;
+        _arguments = arguments;
+    }
+
+    [JsonPropertyName("name")]
+    public string? Name
+    {
+        get => _name;
+        set => SetProperty(ref _name, value);
+    }
+
+    [JsonPropertyName("arguments")]
+    public Dictionary<string, string>? Arguments
+    {
+        get => _arguments;
+        set => SetProperty(ref _arguments, value);
+    }
+
+    public ChatMessageFunctionCallViewModel Copy()
+    {
+        var functionCall = new ChatMessageFunctionCallViewModel
+        {
+            Name = _name,
+            // TODO: Copy entry Value if it's reference value.
+            Arguments = _arguments?.ToDictionary(
+                e => e.Key, 
+                e => e.Value)
+        };
+
+        return functionCall;
+    }
+}

src/ChatGPT.Core/ViewModels/Chat/ChatMessageViewModel.cs

@@ -13,6 +13,8 @@ public class ChatMessageViewModel : ObservableObject
 {
     private string? _role;
     private string? _message;
+    private string? _name;
+    private ChatMessageFunctionCallViewModel? _functionCall;
     private string? _format;
     private bool _isSent;
     private bool _isAwaiting;
@@ -52,20 +54,63 @@ public ChatMessageViewModel(string role, string message)
         _message = message;
     }
 
+    public ChatMessageViewModel(string role, string message, string name) 
+        : this()
+    {
+        _role = role;
+        _message = message;
+        _name = name;
+    }
+
+    public ChatMessageViewModel(string role, string? message, string name, ChatMessageFunctionCallViewModel functionCall) 
+        : this()
+    {
+        _role = role;
+        _message = message;
+        _name = name;
+        _functionCall = functionCall;
+    }
+
+    /// <summary>
+    /// The role of the messages author. One of system, user, assistant, or function.
+    /// </summary>
     [JsonPropertyName("role")]
     public string? Role
     {
         get => _role;
         set => SetProperty(ref _role, value);
     }
 
+    /// <summary>
+    /// The contents of the message. content is required for all messages, and may be null for assistant messages with function calls.
+    /// </summary>
     [JsonPropertyName("message")]
     public string? Message
     {
         get => _message;
         set => SetProperty(ref _message, value);
     }
 
+    /// <summary>
+    /// The name of the author of this message. name is required if role is function, and it should be the name of the function whose response is in the content. May contain a-z, A-Z, 0-9, and underscores, with a maximum length of 64 characters.
+    /// </summary>
+    [JsonPropertyName("name")]
+    public string? Name
+    {
+        get => _name;
+        set => SetProperty(ref _name, value);
+    }
+
+    /// <summary>
+    /// The name and arguments of a function that should be called, as generated by the model.
+    /// </summary>
+    [JsonPropertyName("function_call")]
+    public ChatMessageFunctionCallViewModel? FunctionCall
+    {
+        get => _functionCall;
+        set => SetProperty(ref _functionCall, value);
+    }
+
     [JsonPropertyName("format")]
     public string? Format
     {
@@ -299,6 +344,8 @@ public ChatMessageViewModel Copy()
         {
             Role = _role,
             Message = _message,
+            Name = _name,
+            FunctionCall = _functionCall?.Copy(),
             Format = _format,
             IsSent = _isSent,
             IsAwaiting = _isAwaiting,