namespace QWERTYkez.ExcelProcessor;

/// <summary>
/// Определяет шрифтовое оформление всей ячейки: размер, семейство, цвет, начертание.
/// Все свойства опциональны.
/// </summary>
public readonly struct CellFont : IEquatable<CellFont>
{
    /// <summary>Размер шрифта в пунктах (например, 11).</summary>
    public double? FontSize { get; init; }

    /// <summary>Имя семейства шрифта (например, "Calibri", "Arial").</summary>
    public string? FontFamily { get; init; }

    /// <summary>Цвет текста.</summary>
    public System.Drawing.Color? FontColor { get; init; }

    /// <summary>Жирное начертание.</summary>
    public bool? IsBold { get; init; }

    /// <summary>Курсив.</summary>
    public bool? IsItalic { get; init; }

    /// <summary>Подчёркивание (одинарное).</summary>
    public bool? IsUnderline { get; init; }

    /// <summary>Зачёркивание.</summary>
    public bool? IsStrike { get; init; }


    internal bool TryMerge(CellFont other, out CellFont result)
    {
        if (other.FontSize == FontSize &&
            other.FontFamily == FontFamily &&
            other.FontColor == FontColor &&
            other.IsBold == IsBold &&
            other.IsItalic == IsItalic &&
            other.IsUnderline == IsUnderline &&
            other.IsStrike == IsStrike)
        {
            result = default;
            return false;
        }

        result = new CellFont
        {
            FontSize = other.FontSize ?? FontSize,
            FontFamily = other.FontFamily ?? FontFamily,
            FontColor = other.FontColor ?? FontColor,
            IsBold = other.IsBold ?? IsBold,
            IsItalic = other.IsItalic ?? IsItalic,
            IsUnderline = other.IsUnderline ?? IsUnderline,
            IsStrike = other.IsStrike ?? IsStrike
        };
        return true;
    }


    /// <summary>Создаёт элемент Font для Open XML.</summary>
    public Font? ToFont()
    {
        if (!FontSize.HasValue && FontFamily is null && FontColor is null &&
            !IsBold.HasValue && !IsItalic.HasValue && !IsUnderline.HasValue && !IsStrike.HasValue)
            return null;

        var font = new Font();
        if (FontSize.HasValue)
            font.FontSize = new FontSize { Val = FontSize.Value };
        if (FontFamily is not null)
            font.FontName = new FontName { Val = FontFamily };
        if (FontColor is { } c)
            font.Color = new Color { Rgb = $"{c.R:X2}{c.G:X2}{c.B:X2}" };
        if (IsBold == true) font.Bold = new Bold();
        if (IsItalic == true) font.Italic = new Italic();
        if (IsUnderline == true) font.Underline = new Underline();
        if (IsStrike == true) font.Strike = new Strike();
        return font;
    }

    /// <summary>Создаёт CellFont из элемента Font Open XML.</summary>
    public static CellFont FromFont(Font? font)
    {
        if (font == null)
            return default;

        var result = new CellFont
        {
            IsBold = font.Bold != null,
            IsItalic = font.Italic != null,
            IsUnderline = font.Underline != null,
            IsStrike = font.Strike != null
        };
        if (font.FontSize?.Val?.Value is { } size)
            result = result with { FontSize = size };
        if (font.FontName?.Val?.Value is { } name)
            result = result with { FontFamily = name };
        if (font.Color?.Rgb?.Value is { } rgb && rgb.Length >= 6)
        {
            var color = System.Drawing.Color.FromArgb(
                Convert.ToByte(rgb.Substring(0, 2), 16),
                Convert.ToByte(rgb.Substring(2, 2), 16),
                Convert.ToByte(rgb.Substring(4, 2), 16)
            );
            result = result with { FontColor = color };
        }
        return result;
    }

    public override bool Equals(object? obj) => obj is CellFont other && Equals(other);
    public bool Equals(CellFont other) => this == other;

    public static bool operator ==(CellFont left, CellFont right) =>
        left.FontSize == right.FontSize &&
        left.FontFamily == right.FontFamily &&
        Equals(left.FontColor, right.FontColor) &&
        left.IsBold == right.IsBold &&
        left.IsItalic == right.IsItalic &&
        left.IsUnderline == right.IsUnderline &&
        left.IsStrike == right.IsStrike;

    public static bool operator !=(CellFont left, CellFont right) => !(left == right);

    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 31 + (FontSize?.GetHashCode() ?? 0);
            hash = hash * 31 + (FontFamily?.GetHashCode() ?? 0);
            hash = hash * 31 + (FontColor?.GetHashCode() ?? 0);
            hash = hash * 31 + (IsBold?.GetHashCode() ?? 0);
            hash = hash * 31 + (IsItalic?.GetHashCode() ?? 0);
            hash = hash * 31 + (IsUnderline?.GetHashCode() ?? 0);
            hash = hash * 31 + (IsStrike?.GetHashCode() ?? 0);
            return hash;
        }
    }
}