// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Text.Json.Serialization;
using Microsoft.Shared.Diagnostics;
 
namespace Microsoft.Extensions.AI;
 
/// <summary>Represents the options for an embedding generation request.</summary>
public class EmbeddingGenerationOptions
{
    private int? _dimensions;
 
    /// <summary>Gets or sets the number of dimensions requested in the embedding.</summary>
    public int? Dimensions
    {
        get => _dimensions;
        set
        {
            if (value is not null)
            {
                _ = Throw.IfLessThan(value.Value, 1, nameof(value));
            }
 
            _dimensions = value;
        }
    }
 
    /// <summary>Gets or sets the model ID for the embedding generation request.</summary>
    public string? ModelId { get; set; }
 
    /// <summary>Gets or sets additional properties for the embedding generation request.</summary>
    public AdditionalPropertiesDictionary? AdditionalProperties { get; set; }
 
    /// <summary>
    /// Gets or sets a callback responsible for creating the raw representation of the embedding generation options from an underlying implementation.
    /// </summary>
    /// <remarks>
    /// The underlying <see cref="IEmbeddingGenerator" /> implementation may have its own representation of options.
    /// When <see cref="IEmbeddingGenerator{TInput, TEmbedding}.GenerateAsync" /> 
    /// is invoked with an <see cref="EmbeddingGenerationOptions" />, that implementation may convert the provided options into
    /// its own representation in order to use it while performing the operation. For situations where a consumer knows
    /// which concrete <see cref="IEmbeddingGenerator" /> is being used and how it represents options, a new instance of that
    /// implementation-specific options type may be returned by this callback, for the <see cref="IEmbeddingGenerator" />
    /// implementation to use instead of creating a new instance. Such implementations may mutate the supplied options
    /// instance further based on other settings supplied on this <see cref="EmbeddingGenerationOptions" /> instance or from other inputs,
    /// therefore, it is <b>strongly recommended</b> to not return shared instances and instead make the callback return a new instance on each call.
    /// This is typically used to set an implementation-specific setting that isn't otherwise exposed from the strongly-typed
    /// properties on <see cref="EmbeddingGenerationOptions" />.
    /// </remarks>
    [JsonIgnore]
    public Func<IEmbeddingGenerator, object?>? RawRepresentationFactory { get; set; }
 
    /// <summary>Produces a clone of the current <see cref="EmbeddingGenerationOptions"/> instance.</summary>
    /// <returns>A clone of the current <see cref="EmbeddingGenerationOptions"/> instance.</returns>
    /// <remarks>
    /// The clone will have the same values for all properties as the original instance. Any collections, like <see cref="AdditionalProperties"/>
    /// are shallow-cloned, meaning a new collection instance is created, but any references contained by the collections are shared with the original.
    /// </remarks>
    public virtual EmbeddingGenerationOptions Clone() =>
        new()
        {
            ModelId = ModelId,
            Dimensions = Dimensions,
            AdditionalProperties = AdditionalProperties?.Clone(),
        };
}