#nullable enable

using System.Collections.Generic;
using System.Linq;

namespace BizHawk.Client.Common
{
	public sealed class FilesystemFilter
	{
		public readonly string Description;

		public readonly IReadOnlyCollection<string> Extensions;

		public FilesystemFilter(string description, IReadOnlyCollection<string> extensions, bool addArchiveExts = false)
		{
			Description = description;
			Extensions = addArchiveExts ? extensions.Concat(ArchiveExtensions).ToList() : extensions;
		}

		/// <remarks>When <see cref="VersionInfo.DeveloperBuild"/> is set to <see langword="false"/> for release, this behaves identically to <see cref="FilesystemFilter(string,IReadOnlyCollection{string},bool)">the other ctor</see>.
		/// On dev builds, <paramref name="devBuildExtraExts"/> are appended to <paramref name="extensions"/>.
		/// </remarks>
		public FilesystemFilter(
			string description,
			IReadOnlyCollection<string> extensions,
			IReadOnlyCollection<string> devBuildExtraExts,
			bool addArchiveExts = false,
			bool devBuildAddArchiveExts = false)
		{
			Description = description;
			if (!VersionInfo.DeveloperBuild)
			{
				// same as other ctor
				Extensions = addArchiveExts ? extensions.Concat(ArchiveExtensions).ToList() : extensions;
			}
			else
			{
				Extensions = addArchiveExts || devBuildAddArchiveExts
					? extensions.Concat(devBuildExtraExts).Concat(ArchiveExtensions).ToList()
					: extensions.Concat(devBuildExtraExts).ToList();
			}
		}

		/// <summary>delegated to <see cref="SerializeEntry"/></summary>
		/// <remarks>return value is a valid <c>Filter</c> for <c>Save-</c>/<c>OpenFileDialog</c></remarks>
		public override string ToString() => SerializeEntry(Description, Extensions);

		public const string AllFilesEntry = "All Files|*";

		public static readonly IReadOnlyCollection<string> ArchiveExtensions = new[] { "zip", "rar", "7z", "gz" };

		public static readonly FilesystemFilter Archives = new FilesystemFilter("Archives", ArchiveExtensions);

		public static readonly FilesystemFilter BizHawkMovies = new FilesystemFilter("Movie Files", new[] { MovieService.DefaultExtension });

		public static readonly FilesystemFilter EmuHawkSaveStates = new FilesystemFilter("Save States", new[] { "State" });

		public static readonly FilesystemFilter LuaScripts = new FilesystemFilter("Lua Scripts", new[] { "lua" });

		public static readonly FilesystemFilter Palettes = new FilesystemFilter("Palette Files", new[] { "pal" });

		public static readonly FilesystemFilter PNGs = new FilesystemFilter("PNG Files", new[] { "png" });

		public static readonly FilesystemFilter TAStudioProjects = new FilesystemFilter("TAS Project Files", new[] { TasMovie.Extension });

		public static readonly FilesystemFilter TextFiles = new FilesystemFilter("Text Files", new[] { "txt" });

		/// <remarks>return value is a valid <c>Filter</c> for <c>Save-</c>/<c>OpenFileDialog</c></remarks>
		public static string SerializeEntry(string desc, IEnumerable<string> exts)
			=> string.Format("{0} ({1})|{1}", desc, string.Join(";", exts.Select(ext => $"*.{ext}")));
	}
}