//
// System.Security.Policy.FileCodeGroup
//
// Author(s):
//   Nick Drochak (ndrochak@gol.com)
//
// (C) 2001 Nick Drochak, All rights reserved.
// Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System.Collections;
using System.Runtime.InteropServices;
using System.Security.Permissions;

namespace System.Security.Policy {

	[Serializable]
	[ComVisible (true)]
	public sealed class FileCodeGroup : CodeGroup {

		private FileIOPermissionAccess m_access;

		public FileCodeGroup (IMembershipCondition membershipCondition, FileIOPermissionAccess access) 
			: base (membershipCondition, null)
		{
			// note: FileIOPermissionAccess is a [Flag]
			m_access = access;
		}

		// for PolicyLevel (to avoid validation duplication)
		internal FileCodeGroup (SecurityElement e, PolicyLevel level)
			: base (e, level)
		{
		}

		public override CodeGroup Copy ()
		{
			FileCodeGroup copy = new FileCodeGroup (MembershipCondition, m_access);
			copy.Name = this.Name;
			copy.Description = this.Description;
			foreach (CodeGroup child in Children) {
				copy.AddChild (child.Copy ());	// deep copy
			}
			return copy;
		}
		
		public override string MergeLogic {
			get { return "Union";}
		}

		public override PolicyStatement Resolve (Evidence evidence)
		{
			if (null == evidence)
				throw new ArgumentNullException("evidence");

			if (!MembershipCondition.Check (evidence))
				return null;

			PermissionSet ps = null;
			if (this.PolicyStatement == null)
				ps = new PermissionSet (PermissionState.None);
			else
				ps = this.PolicyStatement.PermissionSet.Copy ();

			if (this.Children.Count > 0) {
				foreach (CodeGroup child_cg in this.Children) {
					PolicyStatement child_pst = child_cg.Resolve (evidence);
					if (child_pst != null) {
						ps = ps.Union (child_pst.PermissionSet);
					}
				}
			}

			PolicyStatement pst = null;
			if (this.PolicyStatement != null)
				pst = this.PolicyStatement.Copy ();
			else
				pst = PolicyStatement.Empty ();
			pst.PermissionSet = ps;
			return pst;
		}

		public override CodeGroup ResolveMatchingCodeGroups(Evidence evidence)
		{
			if (null == evidence)
				throw new ArgumentNullException("evidence");

			if (!MembershipCondition.Check (evidence))
				return null;

			FileCodeGroup matchRoot = new FileCodeGroup (MembershipCondition, m_access);

			foreach (CodeGroup child in Children) {
				CodeGroup childMatchingCodeGroup = child.ResolveMatchingCodeGroups (evidence);
				if (childMatchingCodeGroup != null)
					matchRoot.AddChild (childMatchingCodeGroup);
			}

			return matchRoot;
		}

		public override string AttributeString {
			get { return null; }
		}

		public override string PermissionSetName {
			get { return "Same directory FileIO - " + m_access.ToString (); }
		}

		public override bool Equals (object o)
		{
			if (!(o is FileCodeGroup))
				return false;

			if (this.m_access != ((FileCodeGroup)o).m_access)
				return false;

			return Equals((CodeGroup)o, false);
		}

		public override int GetHashCode ()
		{
			return m_access.GetHashCode ();
		}

		protected override void ParseXml (SecurityElement e, PolicyLevel level)
		{
			string a = e.Attribute ("Access");
			if (a != null)
				m_access = (FileIOPermissionAccess) Enum.Parse (typeof (FileIOPermissionAccess), a, true);
			else
				m_access = FileIOPermissionAccess.NoAccess;
		}
		
		protected override void CreateXml (SecurityElement element, PolicyLevel level)
		{
			element.AddAttribute ("Access", m_access.ToString ());
		}
	}
}