﻿//  Copyright 2016 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

using NtApiDotNet;
using System.Management.Automation;

namespace NtObjectManager.Cmdlets.Object
{
    /// <summary>
    /// <para type="synopsis">Get the target path for an existing NT symbolic link object.</para>
    /// <para type="description">This cmdlet opens a existing NT symbolic link object and queries its target path. That can be done using Get-NtSymbolicLink and the Query method but
    /// this simplifies the operation so that the object handle doesn't have to be closed.</para>
    /// </summary>
    /// <example>
    ///   <code>Get-NtSymbolicLinkTarget \DosDevices\ABC</code>
    ///   <para>Gets the symbolic link object target with an absolute path.</para>
    /// </example>
    /// <example>
    ///   <code>$root = Get-NtDirectory \DosDevices&#x0A;Get-NtSymbolicLinkTarget ABC -Root $root</code>
    ///   <para>Gets the symbolic link object target with a relative path.</para>
    /// </example>
    /// <para type="link">about_ManagingNtObjectLifetime</para>
    [Cmdlet(VerbsCommon.Get, "NtSymbolicLinkTarget")]
    public class GetNtSymbolicLinkTargetCmdlet : NtObjectBaseCmdlet
    {
        /// <summary>
        /// Determine if the cmdlet can create objects.
        /// </summary>
        /// <returns>True if objects can be created.</returns>
        protected override bool CanCreateDirectories()
        {
            return false;
        }

        /// <summary>
        /// <para type="description">The NT object manager path to the object to use.</para>
        /// </summary>
        [Parameter(Position = 0, Mandatory = true)]
        public override string Path { get; set; }

        /// <summary>
        /// <para type="description">Resolve the final target. This will follow the target if it's still a symbolic link.</para>
        /// </summary>
        [Parameter]
        public SwitchParameter Resolve { get; set; }

        /// <summary>
        /// Method to create an object from a set of object attributes.
        /// </summary>
        /// <param name="obj_attributes">The object attributes to create/open from.</param>
        /// <returns>The newly created object.</returns>
        protected override object CreateObject(ObjectAttributes obj_attributes)
        {
            using (NtSymbolicLink link = NtSymbolicLink.Open(obj_attributes, SymbolicLinkAccessRights.Query))
            {
                if (Resolve)
                    return NtSymbolicLink.ResolveTarget(link.Target);
                return link.Target;
            }
        }
    }
    
}
