using System.Globalization;
using Avalonia.Data.Converters;

namespace GUI.Converters;

public class DurationFormatConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is not double duration) return "--:--";
        TimeSpan ts = TimeSpan.FromSeconds(duration);
        if (ts.TotalHours >= 1)
            return ts.ToString(@"h\:mm\:ss\.ff");
        return ts.ToString(@"m\:ss\.ff");
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class SampleRateFormatConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is not double rate) return "--";
        return $"{rate / 1000.0:F1}k";
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class ChannelsFormatConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        return value switch
        {
            int ch when ch == 1 => "Mono",
            int ch when ch == 2 => "Stereo",
            null => "--",
            int ch => $"{ch}ch",
            _ => "--",
        };
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class RatingStarsConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is not uint rating || rating == 0) return "☆☆☆☆☆";
        return new string('★', (int)rating) + new string('☆', 5 - (int)rating);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class DurationToSliderMaxConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is not double duration) return 1.0;
        return Math.Ceiling(duration);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class PositionFormatConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is not double pos) return "0:00";
        TimeSpan ts = TimeSpan.FromSeconds(pos);
        return ts.ToString(@"m\:ss");
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class InverseBoolConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is bool b) return !b;
        return true;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is bool b) return !b;
        return true;
    }
}

public class HalfDoubleConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is double d && !double.IsNaN(d) && !double.IsInfinity(d))
            return d / 2.0;
        return 400.0;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public class MiddleTruncateConverter : IValueConverter
{
    private const int KeepTail = 10;

    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is not string text || string.IsNullOrEmpty(text)) return value;

        int maxLength = 60;
        if (parameter != null && int.TryParse(parameter.ToString(), NumberStyles.Integer, CultureInfo.InvariantCulture, out int parsed))
            maxLength = parsed;

        if (text.Length <= maxLength) return text;

        int head = maxLength - KeepTail - 3;
        if (head <= 0) return text[..maxLength];

        return string.Concat(text.AsSpan(0, head), "...", text.AsSpan(text.Length - KeepTail, KeepTail));
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        => throw new NotSupportedException();
}

public static class ValueConverters
{
    public static readonly IValueConverter DurationFormat = new DurationFormatConverter();
    public static readonly IValueConverter SampleRateFormat = new SampleRateFormatConverter();
    public static readonly IValueConverter ChannelsFormat = new ChannelsFormatConverter();
    public static readonly IValueConverter RatingStars = new RatingStarsConverter();
    public static readonly IValueConverter DurationToSliderMax = new DurationToSliderMaxConverter();
    public static readonly IValueConverter PositionFormat = new PositionFormatConverter();
    public static readonly IValueConverter InverseBool = new InverseBoolConverter();
    public static readonly IValueConverter HalfDouble = new HalfDoubleConverter();
    public static readonly IValueConverter MiddleTruncate = new MiddleTruncateConverter();
}