bfr/BFR/Operations/Add.cs

using System.Collections.Generic;
using System.Xml.Serialization;
using System.Linq;

using Avalonia;

using BFR.DataModels;

namespace BFR.Operations
{
    public class Add : Operation
    {
        public override string Name => nameof(Add);
        public override string Description => "Adds the specified text to the file name.";

        [XmlIgnore]
        public static readonly AvaloniaProperty<AddMode> ModeProperty =
            AvaloniaProperty.Register<MainWindow, AddMode>(nameof(Mode), AddMode.Prepend);
        public AddMode Mode { get => GetValue(ModeProperty); set => SetValue(ModeProperty, value); }

        public AddOperationMode[] Modes => AddOperationMode.Modes;

        public int InsertPosition { get; set; } = 0;
        public string Text { get; set; } = "";
        public bool FullName { get; set; } = false;

        protected override void ApplyToInternal(IList<FileModel> files)
        {
            // Fail conditions: Out of bounds insert
            var shortestLength = files.Min(x => FullName ? x.FullName.Length : x.Name.Length);
            if (Mode == AddMode.Insert && InsertPosition > shortestLength) throw new OperationException($"Index can't be greater than the shortest file name length ({shortestLength}).");

            // Apply operation
            foreach (var file in files)
            {
                var newName = FullName ? file.FullName : file.Name;

                newName = Mode switch
                {
                    AddMode.Prepend => $"{Text}{newName}",
                    AddMode.Append => $"{newName}{Text}",
                    AddMode.Insert => newName.Insert(InsertPosition, Text),
                    _ => newName
                };

                if (FullName) file.FullName = newName;
                else file.Name = newName;
            }
        }
    }
}