FeatureSet.cs

namespace NanoXLSX.Internal
{
    internal sealed class FeatureSet
    {
        private enum FeatureSetType
        {
            Aggregate,
            Formula,
            DefinedName
        }
 
        private FeatureSetType type;
        private FeatureSet parent;

        internal int FormulaCount { get; private set; }

        internal int DefinedNameCount { get; private set; }

        internal int DefinedNameFormulaCount { get; private set; }

        internal int DefinedNameReferenceFormulaCount { get; private set; }

        internal int WorksheetFormulaCount
        {
            get
            {
                return FormulaCount - DefinedNameFormulaCount;
            }
        }

        internal int ExternalLinkCount { get; private set; }

        internal bool ContainsFormulas => FormulaCount > 0;
        internal bool ContainsDefinedNames => DefinedNameCount > 0;
        internal bool ContainsDefinedNameFormulas => DefinedNameFormulaCount > 0;
        internal bool ContainsDefinedNameReferences => DefinedNameReferenceFormulaCount > 0;
        internal bool ContainsWorksheetFormulas => WorksheetFormulaCount > 0;
        internal bool ContainsExternalLinks => ExternalLinkCount > 0;
 

        internal static FeatureSet CreateFormula()
        {
            return new FeatureSet(FeatureSetType.Formula);
        }

        internal static FeatureSet CreateDefinedName()
        {
            return new FeatureSet(FeatureSetType.DefinedName);
        }
        internal FeatureSet()
        {
            type = FeatureSetType.Aggregate;
        }

        private FeatureSet(FeatureSetType type)
        {
            this.type = type;
            if (type == FeatureSetType.Formula)
            {
                FormulaCount = 1;
            }
            else if (type == FeatureSetType.DefinedName)
            {
                DefinedNameCount = 1;
            }
        }

        internal void Add(FeatureSet parent)
        {
            parent.ApplyDelta(
                FormulaCount,
                DefinedNameCount,
                DefinedNameFormulaCount,
                DefinedNameReferenceFormulaCount,
                ExternalLinkCount);
 
            this.parent = parent;
        }

        internal void Remove(FeatureSet parent)
        {
            parent.ApplyDelta(
                -FormulaCount,
                -DefinedNameCount,
                -DefinedNameFormulaCount,
                -DefinedNameReferenceFormulaCount,
                -ExternalLinkCount);
 
            this.parent = null;
        }

        internal void SetFormulaFeatures(bool containsDefinedName, bool containsExternalLink)
        {
            int newDefinedNameReferenceFormulaCount = containsDefinedName ? 1 : 0;
            int newExternalLinkCount = containsExternalLink ? 1 : 0;
 
            int definedNameReferenceFormulaDelta =
                newDefinedNameReferenceFormulaCount - DefinedNameReferenceFormulaCount;
 
            int externalLinkDelta =
                newExternalLinkCount - ExternalLinkCount;
 
            if (definedNameReferenceFormulaDelta == 0 && externalLinkDelta == 0)
            {
                return;
            }
 
            if (parent != null)
            {
                parent.ApplyDelta(
                    0,
                    0,
                    0,
                    definedNameReferenceFormulaDelta,
                    externalLinkDelta);
            }
 
            DefinedNameReferenceFormulaCount = newDefinedNameReferenceFormulaCount;
            ExternalLinkCount = newExternalLinkCount;
        }

        internal void SetDefinedNameFeatures(bool isFormula, bool containsExternalLink)
        {
            int newFormulaCount = isFormula ? 1 : 0;
            int formulaDelta = newFormulaCount - FormulaCount;
 
            int newDefinedNameFormulaCount = isFormula ? 1 : 0;
            int definedNameFormulaDelta = newDefinedNameFormulaCount - DefinedNameFormulaCount;
 
            int newExternalLinkCount = containsExternalLink ? 1 : 0;
            int externalLinkDelta = newExternalLinkCount - ExternalLinkCount;
 
            if (externalLinkDelta == 0 && formulaDelta == 0 && definedNameFormulaDelta == 0)
            {
                return;
            }
 
            if (parent != null)
            {
                parent.ApplyDelta(formulaDelta, 0, definedNameFormulaDelta, 0, externalLinkDelta);
            }
 
            FormulaCount = newFormulaCount;
            DefinedNameFormulaCount = newDefinedNameFormulaCount;
            ExternalLinkCount = newExternalLinkCount;
        }

        private void ApplyDelta(
            int formulaDelta,
            int definedNameDelta,
            int definedNameFormulaDelta,
            int definedNameReferenceFormulaDelta,
            int externalLinkDelta)
        {
            FormulaCount += formulaDelta;
            DefinedNameCount += definedNameDelta;
            DefinedNameFormulaCount += definedNameFormulaDelta;
            DefinedNameReferenceFormulaCount += definedNameReferenceFormulaDelta;
            ExternalLinkCount += externalLinkDelta;
 
            if (parent != null)
            {
                parent.ApplyDelta(
                    formulaDelta,
                    definedNameDelta,
                    definedNameFormulaDelta,
                    definedNameReferenceFormulaDelta,
                    externalLinkDelta);
            }
        }

        internal FeatureSet Copy()
        {
            FeatureSet copy = new FeatureSet(type)
            {
                FormulaCount = FormulaCount,
                DefinedNameCount = DefinedNameCount,
                DefinedNameFormulaCount = DefinedNameFormulaCount,
                DefinedNameReferenceFormulaCount = DefinedNameReferenceFormulaCount,
                ExternalLinkCount = ExternalLinkCount
            };
 
            return copy;
        }
    }
}