replicate.maui/Replicate.Maui/ReplicateTransformerFactory.cs

using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace MarketAlly.Replicate.Maui
{
    /// <summary>
    /// Factory for creating IReplicateTransformer instances with custom API tokens.
    /// Useful for BYOK (Bring Your Own Key) scenarios.
    /// </summary>
    public interface IReplicateTransformerFactory
    {
        /// <summary>
        /// Creates a transformer using the default configured settings.
        /// </summary>
        IReplicateTransformer Create();

        /// <summary>
        /// Creates a transformer with a custom API token, using default settings for everything else.
        /// </summary>
        /// <param name="apiToken">The Replicate API token to use.</param>
        IReplicateTransformer CreateWithToken(string apiToken);

        /// <summary>
        /// Creates a transformer with fully custom settings.
        /// </summary>
        /// <param name="configure">Action to configure the settings.</param>
        IReplicateTransformer CreateWithSettings(Action<ReplicateSettings> configure);
    }

    public class ReplicateTransformerFactory : IReplicateTransformerFactory
    {
        private readonly IHttpClientFactory _httpClientFactory;
        private readonly ReplicateSettings _defaultSettings;
        private readonly ILoggerFactory? _loggerFactory;

        public ReplicateTransformerFactory(
            IHttpClientFactory httpClientFactory,
            IOptions<ReplicateSettings> defaultSettings,
            ILoggerFactory? loggerFactory = null)
        {
            _httpClientFactory = httpClientFactory;
            _defaultSettings = defaultSettings.Value;
            _loggerFactory = loggerFactory;
        }

        public IReplicateTransformer Create()
        {
            var httpClient = _httpClientFactory.CreateClient();
            var logger = _loggerFactory?.CreateLogger<ReplicateTransformer>();
            return new ReplicateTransformer(httpClient, Options.Create(_defaultSettings), logger);
        }

        public IReplicateTransformer CreateWithToken(string apiToken)
        {
            var settings = CloneSettings(_defaultSettings);
            settings.ApiToken = apiToken;

            var httpClient = _httpClientFactory.CreateClient();
            var logger = _loggerFactory?.CreateLogger<ReplicateTransformer>();
            return new ReplicateTransformer(httpClient, Options.Create(settings), logger);
        }

        public IReplicateTransformer CreateWithSettings(Action<ReplicateSettings> configure)
        {
            var settings = CloneSettings(_defaultSettings);
            configure(settings);

            var httpClient = _httpClientFactory.CreateClient();
            var logger = _loggerFactory?.CreateLogger<ReplicateTransformer>();
            return new ReplicateTransformer(httpClient, Options.Create(settings), logger);
        }

        private static ReplicateSettings CloneSettings(ReplicateSettings source)
        {
            return new ReplicateSettings
            {
                ApiToken = source.ApiToken,
                ApiUrl = source.ApiUrl,
                AuthScheme = source.AuthScheme,
                ModelVersion = source.ModelVersion,
                ModelName = source.ModelName,
                TimeoutSeconds = source.TimeoutSeconds,
                PollingDelayMs = source.PollingDelayMs,
                ImagePrompt = source.ImagePrompt,
                VideoModelName = source.VideoModelName,
                VideoModelVersion = source.VideoModelVersion,
                VideoPrompt = source.VideoPrompt,
                VideoTimeoutSeconds = source.VideoTimeoutSeconds,
                VideoPollingDelayMs = source.VideoPollingDelayMs,
                DefaultSettings = new ImageTransformSettings
                {
                    Seed = source.DefaultSettings.Seed,
                    GuidanceScale = source.DefaultSettings.GuidanceScale,
                    Strength = source.DefaultSettings.Strength,
                    NumInferenceSteps = source.DefaultSettings.NumInferenceSteps
                },
                VideoSettings = new VideoTransformSettings
                {
                    Seed = source.VideoSettings.Seed,
                    Duration = source.VideoSettings.Duration,
                    Size = source.VideoSettings.Size,
                    AudioUrl = source.VideoSettings.AudioUrl,
                    NegativePrompt = source.VideoSettings.NegativePrompt,
                    EnablePromptExpansion = source.VideoSettings.EnablePromptExpansion
                }
            };
        }
    }
}