AIModel.cs

using MaIN.Domain.Configuration;
using MaIN.Domain.Exceptions.Models.LocalModels;

namespace MaIN.Domain.Models.Abstract;

public abstract record AIModel(
    string Id,
    BackendType Backend,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null)
{
    /// <summary> Internal Id. For cloud models it is the cloud Id. </summary>
    public string Id { get; } = Id;

    /// <summary> Name displayed to users. </summary>
    public string Name { get; } = Name ?? Id;

    /// <summary> Gets the type of backend used by the model eg OpenAI or Self (Local). </summary>
    public BackendType Backend { get; } = Backend;

    /// <summary> System Message added before first prompt. </summary>
    public string? SystemMessage { get; } = SystemMessage;

    /// <summary> Model description eg. capabilities or purpose. </summary>
    public string? Description { get; } = Description;

    /// <summary> Max context window size supported by the model. </summary>
    public uint MaxContextWindowSize { get; } = MaxContextWindowSize;

    /// <summary> Checks if model supports reasoning/thinking mode. </summary>
    public bool HasReasoning => this is IReasoningModel;
    
    /// <summary> Checks if model supports vision/image input. </summary>
    public bool HasVision => this is IVisionModel;

    /// <summary> Checks if model generates images from text prompts. </summary>
    public bool HasImageGeneration => this is IImageGenerationModel;
}

/// <summary> Base class for local models. </summary>
public abstract record LocalModel(
    string Id,
    string FileName,
    Uri? DownloadUrl = null,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null,
        string? CustomPath = null) : AIModel(Id, BackendType.Self, Name, MaxContextWindowSize, Description, SystemMessage)
{
    /// <summary> Name of the model file on the hard drive eg. Gemma2-2b.gguf </summary>
    public string FileName { get; } = FileName;

    /// <summary> Uri to download model eg. https://huggingface.co/Inza124/gemma2_2b/resolve/main/gemma2-2b-maIN.gguf?download=true </summary>
    public Uri? DownloadUrl { get; } = DownloadUrl;

    /// <summary> Gets or sets the custom file system path (excluding file name eg. your\path\). If not null will be prioritized over the default base path. </summary>
    public string? CustomPath { get; } = CustomPath;

    public bool IsDownloaded(string? basePath)
    {
        try
        {
            return File.Exists(GetFullPath(basePath));
        }
        catch (ModelPathNullOrEmptyException)
        {
            return false;
        }
    }
        
    /// <summary>
    /// Combines the specified base path with the file name to generate a full file path.
    /// </summary>
    /// <remarks>This method ensures that a valid path is generated by requiring at least one of the
    /// CustomPath or basePath to be provided.</remarks>
    /// <param name="basePath">The base path to combine with the file name. If null or empty, the method uses the custom path.</param>
    /// <returns>A string representing the full file path formed by combining the base path and the file name.</returns>
    /// <exception cref="ModelPathNullOrEmptyException">Thrown if both CustomPath and basePath are null or empty.</exception>
    public string GetFullPath(string? basePath = null)
    {
        if (string.IsNullOrEmpty(CustomPath) && string.IsNullOrEmpty(basePath))
        {
            throw new ModelPathNullOrEmptyException();
        }

        return Path.Combine((CustomPath ?? basePath)!, FileName);
    }
}

/// <summary> Base class for cloud models. </summary>
public abstract record CloudModel(
    string Id,
    BackendType Backend,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null) : AIModel(Id, Backend, Name, MaxContextWindowSize, Description, SystemMessage);

/// <summary> Generic class for runtime defined cloud models. </summary>
public record GenericCloudModel(
    string Id,
    BackendType Backend,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null
) : CloudModel(Id, Backend, Name, MaxContextWindowSize, Description, SystemMessage);

/// <summary> Generic class for runtime defined cloud models with reasoning capability. </summary>
public record GenericCloudReasoningModel(
    string Id,
    BackendType Backend,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null,
    string? AdditionalPrompt = null
) : CloudModel(Id, Backend, Name, MaxContextWindowSize, Description, SystemMessage), IReasoningModel
{   
    // IReasoningModel - null for cloud (handled by provider API)
    public Func<string, ThinkingState, LLMTokenValue>? ReasonFunction => null;
    public string? AdditionalPrompt { get; } = AdditionalPrompt;
}

/// <summary> Generic class for runtime defined cloud models with vision capability. </summary>
public record GenericCloudVisionModel(
    string Id,
    BackendType Backend,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null
) : CloudModel(Id, Backend, Name, MaxContextWindowSize, Description, SystemMessage), IVisionModel
{   
    // IVisionModel - cloud models don't need MMProjectPath
    public string? MMProjectName => null;
}

/// <summary> Generic class for runtime defined cloud models with both vision and reasoning capabilities. </summary>
public record GenericCloudVisionReasoningModel(
    string Id,
    BackendType Backend,
    string? Name = null,
    uint MaxContextWindowSize = ModelDefaults.DefaultMaxContextWindow,
    string? Description = null,
    string? SystemMessage = null,
    string? AdditionalPrompt = null
) : CloudModel(Id, Backend, Name, MaxContextWindowSize, Description, SystemMessage), IVisionModel, IReasoningModel
{   
    // IVisionModel - null for cloud (handled by provider API)
    public string? MMProjectName => null;
    
    // IReasoningModel - null for cloud (handled by provider API)
    public Func<string, ThinkingState, LLMTokenValue>? ReasonFunction => null;
    public string? AdditionalPrompt { get; } = AdditionalPrompt;
}

/// <summary> Generic class for runtime defined local models. </summary>
public record GenericLocalModel(
    string FileName,
    string? Name = null,
    string? Id = null,
    Uri? DownloadUrl = null,
    uint MaxContextWindowSize = 4096,
    string? CustomPath = null,
    string? Description = null,
    string? SystemMessage = null
) : LocalModel(Id ?? FileName, FileName, DownloadUrl, Name ?? FileName, MaxContextWindowSize, Description, SystemMessage, CustomPath);

/// <summary> Generic class for runtime defined local models with reasoning capability. </summary>
public record GenericLocalReasoningModel(
    string FileName,
    Func<string, ThinkingState, LLMTokenValue> ReasonFunction,
    string? Name = null,
    string? Id = null,
    Uri? DownloadUrl = null,
    uint MaxContextWindowSize = 4096,
    string? CustomPath = null,
    string? AdditionalPrompt = null,
    string? Description = null,
    string? SystemMessage = null
) : LocalModel(Id ?? FileName, FileName, DownloadUrl, Name ?? FileName, MaxContextWindowSize, Description, SystemMessage, CustomPath), IReasoningModel
{    
    // IReasoningModel implementation
    public Func<string, ThinkingState, LLMTokenValue> ReasonFunction { get; } = ReasonFunction;
    public string? AdditionalPrompt { get; } = AdditionalPrompt;
}

/// <summary> Generic class for runtime defined local models with vision capability. </summary>
public record GenericLocalVisionModel(
    string FileName,
    string MMProjectPath,
    string? Name = null,
    string? Id = null,
    Uri? DownloadUrl = null,
    uint MaxContextWindowSize = 4096,
    string? CustomPath = null,
    string? Description = null,
    string? SystemMessage = null
) : LocalModel(Id ?? FileName, FileName, DownloadUrl, Name ?? FileName, MaxContextWindowSize, Description, SystemMessage, CustomPath), IVisionModel
{    
    // IVisionModel implementation
    public string MMProjectName { get; } = MMProjectPath;
}

/// <summary> Generic class for runtime defined local models with both vision and reasoning capabilities. </summary>
public record GenericLocalVisionReasoningModel(
    string FileName,
    string MMProjectPath,
    Func<string, ThinkingState, LLMTokenValue> ReasonFunction,
    string? Name = null,
    string? Id = null,
    Uri? DownloadUrl = null,
    uint MaxContextWindowSize = 4096,
    string? CustomPath = null,
    string? AdditionalPrompt = null,
    string? Description = null,
    string? SystemMessage = null
) : LocalModel(Id ?? FileName, FileName, DownloadUrl, Name ?? FileName, MaxContextWindowSize, Description, SystemMessage, CustomPath), IVisionModel, IReasoningModel
{
    // IVisionModel implementation
    public string MMProjectName { get; } = MMProjectPath;
    
    // IReasoningModel implementation
    public Func<string, ThinkingState, LLMTokenValue> ReasonFunction { get; } = ReasonFunction;
    public string? AdditionalPrompt { get; } = AdditionalPrompt;
}

public static class ModelDefaults
{
    public const uint DefaultMaxContextWindow = 128000;
}