MiniHttpd: an HTTP web server library

using System;
using System.Runtime.Serialization;
using System.Collections;
using System.IO;

namespace MiniHttpd
{
	/// <summary>
	/// Represents a physical directory on disk.
	/// </summary>
	[Serializable]
	public class DriveDirectory : IDirectory, IPhysicalResource
	{

		/// <summary>
		/// Creates a <see cref="DriveDirectory"/> with the specified alias, path and parent.
		/// </summary>
		/// <param name="alias">The name of the directory as it should be recognized in the parent directory.</param>
		/// <param name="path">The full path of the directory on disk.</param>
		/// <param name="parent">An <see cref="IDirectory"/> specifying the parent directory. This should be set to <c>null</c> to specify that this directory is root.</param>
		public DriveDirectory(string alias, string path, IDirectory parent) : this(alias, path, parent, true)
		{
		}

		private DriveDirectory(string alias, string path, IDirectory parent, bool checkPath)
		{
			if(checkPath)
			{
				path = System.IO.Path.GetFullPath(path);
				if(!Directory.Exists(path))
					throw new DirectoryNotFoundException("Directory " + path + " not found");
				if(path.IndexOfAny(System.IO.Path.InvalidPathChars) >= 0)
					throw new ArgumentException("Path cantains invalid characters.", "path");
			}
			this.alias = alias;
			this.path = path;
			this.parent = parent;
		}

		/// <summary>
		/// Creates a <see cref="DriveDirectory"/> with the specified path and parent. 
		/// </summary>
		/// <param name="path">The full path of the directory on disk.</param>
		/// <param name="parent">An <see cref="IDirectory"/> specifying the parent directory. This should be set to <c>null</c> to specify that this directory is root.</param>
		public DriveDirectory(string path, IDirectory parent) : this(path, parent, true)
		{
		}

		/// <summary>
		/// Creates a root <see cref="DriveDirectory"/> with the specified path.
		/// </summary>
		/// <param name="path">The full path of the directory on disk.</param>
		public DriveDirectory(string path) : this(path, null, true)
		{
		}

		private DriveDirectory(string path, IDirectory parent, bool checkValid)
		{
			if(checkValid)
			{
				path = System.IO.Path.GetFullPath(path);
				if(!Directory.Exists(path))
					throw new DirectoryNotFoundException("Directory " + path + " not found");
				if(path.IndexOfAny(System.IO.Path.InvalidPathChars) >= 0)
					throw new ArgumentException("Path cantains invalid characters.", "path");
			}
			this.path = path;
			this.parent = parent;
			this.alias = GetName(path);
		}

		static int rootPathLen = -1;

		string GetName(string path)
		{
			if(parent == null)
			{
				return null;
			}
			if(path.Length == 2 && path[1] == ':')
				path = path + '\\';
			if(rootPathLen == -1)
				rootPathLen = System.IO.Path.GetPathRoot(path).Length;

			if(path.Length == rootPathLen)
				return path;
            
			if(path[path.Length-1] == System.IO.Path.DirectorySeparatorChar || path[path.Length-1] == System.IO.Path.AltDirectorySeparatorChar)
				return System.IO.Path.GetFileName(path.Substring(0, path.Length-1));

			return System.IO.Path.GetFileName(path);
		}

		string alias;
		string path;
		IDirectory parent;

		/// <summary>
		/// Gets the full path of the directory on disk.
		/// </summary>
		public string Path
		{
			get
			{
				return path;
			}
		}

		#region IDirectory Members

		/// <summary>
		/// Returns the specified subdirectory.
		/// </summary>
		/// <param name="dir">The name of the subdirectory to retrieve.</param>
		/// <returns>An <see cref="IDirectory"/> representing the specified directory, or <c>null</c> if one doesn't exist.</returns>
		public IDirectory GetDirectory(string dir)
		{
			if(dir != null)
				if(dir.StartsWith("."))
					return null;
			string retDirPath = System.IO.Path.Combine(path, dir);
			if(!Directory.Exists(retDirPath))
				return null;
			return new DriveDirectory(retDirPath, this, false);
		}

		/// <summary>
		/// Returns the specified file.
		/// </summary>
		/// <param name="filename">The name of the file to retrieve.</param>
		/// <returns>An <see cref="IFile"/> representing the specified file, or <c>null</c> if one doesn't exist.</returns>
		public IFile GetFile(string filename)
		{
			if(filename != null)
				if(filename.StartsWith("."))
					return null;

			string ret = System.IO.Path.Combine(path, filename);
			if(File.Exists(ret))
				return new DriveFile(ret, this, false);
			else
				return null;
		}

		/// <summary>
		/// Returns a collection of subdirectories available in the directory.
		/// </summary>
		/// <returns>An <see cref="ICollection"/> containing <see cref="IDirectory"/> objects available in the directory.</returns>
		public ICollection GetDirectories()
		{
			string[] dirs = Directory.GetDirectories(path);

			ArrayList ret = new ArrayList();

			for(int i = 0; i < dirs.Length; i++)
				if(System.IO.Path.GetFileName(dirs[i])[0] != '.')
					ret.Add(new DriveDirectory(dirs[i], this, false));

			return ret;

		}

		/// <summary>
		/// Returns a collection of files available in the directory.
		/// </summary>
		/// <returns>An <see cref="ICollection"/> containing <see cref="IFile"/> objects available in the directory.</returns>
		public ICollection GetFiles()
		{
			string[] files = Directory.GetFiles(path);

			ArrayList ret = new ArrayList();

			for(int i = 0; i < files.Length; i++)
				if(System.IO.Path.GetFileName(files[i])[0] != '.')
					ret.Add(new DriveFile(System.IO.Path.Combine(this.Path, files[i]), this, false));

			return ret;
		}

		/// <summary>
		/// Gets the name of the directory.
		/// </summary>
		public string Name
		{
			get
			{
				return alias;
			}
		}

		/// <summary>
		/// Gets the parent directory of the directory.
		/// </summary>
		public IDirectory Parent
		{
			get
			{
				return parent;
			}
		}

		/// <summary>
		/// Returns the resource (file or directory) with the specified name.
		/// </summary>
		/// <param name="name">The name of the resource.</param>
		/// <returns>An IFile or IDirectory with the given name.</returns>
		public IResource GetResource(string name)
		{
			IFile file = GetFile(name);
			if(file != null)
				return file;

			return GetDirectory(name);
		}

		#endregion

		#region IDisposable Members

		/// <summary>
		/// DriveDirectory can only contain <see cref="DriveDirectory"/> and <see cref="DriveFile"/> objects, neither of which require disposal logic.
		/// </summary>
		public virtual void Dispose()
		{
		}

		#endregion

		/// <summary>
		/// Returns the name of the directory.
		/// </summary>
		/// <returns>The name of the directory.</returns>
		public override string ToString()
		{
			return alias;
		}
	}
}