using System.Text.Json;

namespace VoiceCat.App.Models;

/// <summary>
/// User's send-side voice input preferences — transmission mode, VAD sensitivity, mic input
/// gain, and the push-to-talk key. Persisted to %AppData%\VoiceCat\voice.json, same pattern as
/// <see cref="ServerListStore"/> and FeedbackSettings: a missing or corrupt file yields defaults
/// rather than throwing. Slider-position values are stored as-is so MainForm can restore the
/// TrackBars directly.
/// </summary>
public sealed class VoiceSettings
{
    /// <summary>Transmission mode: 0 = voice activation, 1 = push-to-talk, 2 = always on
    /// (matches Interop's VcInputMode).</summary>
    public int InputMode { get; set; } = 0;

    /// <summary>VAD sensitivity slider position, 1–100 (default mirrors the designer's 76).</summary>
    public int VadThresholdSlider { get; set; } = 76;

    /// <summary>Microphone input gain slider position, 0–300 percent (100 = unity).</summary>
    public int MicGain { get; set; } = 100;

    /// <summary>Push-to-talk key, stored as the integer value of System.Windows.Forms.Keys.</summary>
    public int PttKey { get; set; } = (int)Keys.F8;

    /// <summary>Saved device ID from the last session; null means use the system default.</summary>
    public string? InputDeviceId { get; set; } = null;

    private static readonly JsonSerializerOptions JsonOptions = new() { WriteIndented = true };

    private static string AppDataDir => Path.Combine(
        Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "VoiceCat");

    private static string FilePath => Path.Combine(AppDataDir, "voice.json");

    public static VoiceSettings Load()
    {
        try
        {
            if (!File.Exists(FilePath)) return new VoiceSettings();
            string json = File.ReadAllText(FilePath);
            return JsonSerializer.Deserialize<VoiceSettings>(json) ?? new VoiceSettings();
        }
        catch
        {
            return new VoiceSettings();
        }
    }

    public void Save()
    {
        Directory.CreateDirectory(AppDataDir);
        File.WriteAllText(FilePath, JsonSerializer.Serialize(this, JsonOptions));
    }
}