using System;
using System.Collections.Generic;
using Gallium;
using Zio;

namespace Nitride.IO.Paths
{
    /// <summary>
    /// Changes the extension of the paths given.
    /// </summary>
    [WithProperties]
    public partial class ChangePathExtension : INitrideOperation
    {
        public ChangePathExtension()
        {
        }

        public ChangePathExtension(string extension)
        {
            this.Extension = extension;
        }

        /// <summary>
        /// Gets or sets the prefix for the path operations.
        /// </summary>
        public string? Extension { get; set; }

        public IEnumerable<Entity> Run(IEnumerable<Entity> input)
        {
            if (this.Extension == null)
            {
                throw new InvalidOperationException(
                    nameof(AddPathPrefix)
                    + ".Extension was not set "
                    + "(via constructor, property, or SetExtension) before "
                    + "Run() was called.");
            }

            ReplacePaths replacePaths = new ReplacePaths()
                .WithReplacement(this.RunReplacement);

            return replacePaths.Run(input);
        }

        private UPath RunReplacement(Entity _, UPath path)
        {
            return path.ChangeExtension(this.Extension!);
        }
    }
}