DeutschLernen/GermanApp/Infrastructure/Configuration/CoquiConfig.cs

namespace GermanApp.Infrastructure.Configuration;

/// <summary>
/// Configuration settings for Coqui TTS service.
/// This is part of the Infrastructure layer.
/// 
/// Setup Instructions:
/// 1. Install Python 3.8+: https://www.python.org/downloads/
/// 2. Install Coqui TTS: pip install TTS
/// 3. Coqui will automatically download the model on first use based on ModelName
/// 4. Recommended German model: tts_models/de/deu/fairseq/vits
/// 5. Set AudioStoragePath to a directory with write permissions
/// 
/// Note: Models require ~1.5GB disk space. First run will download the model automatically.
/// Alternative: Pre-download with: python -m TTS.server --model_name tts_models/de/deu/fairseq/vits
/// </summary>
public class CoquiConfig
{
    /// <summary>
    /// Path to the Python executable.
    /// Default: python3
    /// </summary>
    public string PythonPath { get; set; } = "python3";

    /// <summary>
    /// Name of the Coqui TTS model to use.
    /// Example: tts_models/de/deu/fairseq/vits
    /// </summary>
    public string ModelName { get; set; } = "tts_models/de/deu/fairseq/vits";

    /// <summary>
    /// Path to the TTS Python package/module.
    /// Default: TTS
    /// </summary>
    public string ModulePath { get; set; } = "TTS";

    /// <summary>
    /// Output audio format.
    /// Supported: wav, mp3, ogg, flac
    /// Default: wav
    /// </summary>
    public string OutputFormat { get; set; } = "wav";

    /// <summary>
    /// Output audio sample rate in Hz.
    /// Default: 22050
    /// </summary>
    public int SampleRate { get; set; } = 22050;

    /// <summary>
    /// Voice speaker ID for the model.
    /// Default: (empty - uses model default)
    /// </summary>
    public string Speaker { get; set; } = string.Empty;

    /// <summary>
    /// Language code for TTS.
    /// Default: de
    /// </summary>
    public string Language { get; set; } = "de";

    /// <summary>
    /// Maximum text length in characters for a single TTS request.
    /// Longer texts will be split.
    /// Default: 500 characters
    /// </summary>
    public int MaxTextLength { get; set; } = 500;

    /// <summary>
    /// Timeout in seconds for TTS processing.
    /// Default: 60 seconds
    /// </summary>
    public int TimeoutSeconds { get; set; } = 60;

    /// <summary>
    /// Path to store generated audio files.
    /// Default: /var/audio/tts
    /// </summary>
    public string AudioStoragePath { get; set; } = "/var/audio/tts";

    /// <summary>
    /// Whether to use GPU acceleration if available.
    /// Default: false
    /// </summary>
    public bool UseGPU { get; set; } = false;

    /// <summary>
    /// Validates the configuration.
    /// </summary>
    /// <exception cref="ArgumentException">Thrown when configuration is invalid</exception>
    public void Validate()
    {
        if (string.IsNullOrWhiteSpace(PythonPath))
        {
            throw new ArgumentException("Coqui PythonPath is required");
        }

        if (string.IsNullOrWhiteSpace(ModelName))
        {
            throw new ArgumentException("Coqui ModelName is required");
        }

        if (string.IsNullOrWhiteSpace(ModulePath))
        {
            throw new ArgumentException("Coqui ModulePath is required");
        }

        if (string.IsNullOrWhiteSpace(OutputFormat))
        {
            throw new ArgumentException("Coqui OutputFormat is required");
        }

        var validFormats = new[] { "wav", "mp3", "ogg", "flac" };
        if (!validFormats.Contains(OutputFormat.ToLower()))
        {
            throw new ArgumentException(
                $"Invalid OutputFormat '{OutputFormat}'. Valid formats: {string.Join(", ", validFormats)}");
        }

        if (SampleRate <= 0)
        {
            throw new ArgumentException("SampleRate must be greater than 0");
        }

        if (MaxTextLength <= 0)
        {
            throw new ArgumentException("MaxTextLength must be greater than 0");
        }

        if (TimeoutSeconds <= 0)
        {
            throw new ArgumentException("TimeoutSeconds must be greater than 0");
        }

        if (string.IsNullOrWhiteSpace(AudioStoragePath))
        {
            throw new ArgumentException("AudioStoragePath is required");
        }
    }
}