// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System;
#if NETFRAMEWORK
using System.Security;
#endif
using System.Xml;
using System.Xml.XPath;

namespace Microsoft.VisualStudio.TestPlatform.Utilities;

/// <summary>
/// Utilities class to read and operate on Xml content.
/// </summary>
internal class XmlUtilities
{
    /// <summary>
    /// Gets the Inner XML of the specified node.
    /// </summary>
    /// <param name="runSettingsNavigator"> The xml navigator. </param>
    /// <param name="nodeXPath"> The xPath of the node. </param>
    /// <returns></returns>
    internal static string? GetNodeXml(XPathNavigator runSettingsNavigator, string nodeXPath)
    {
        var node = runSettingsNavigator.SelectSingleNode(nodeXPath);
        return node?.InnerXml;
    }

    /// <summary>
    /// Validates if the Node value is correct according to the provided validator.
    /// </summary>
    /// <param name="xmlNodeValue"> The node value. </param>
    /// <param name="validator"> The validator. </param>
    /// <returns></returns>
    internal static bool IsValidNodeXmlValue(string xmlNodeValue, Func<string, bool> validator)
    {
        try
        {
            return validator.Invoke(xmlNodeValue);
        }
        catch (ArgumentException)
        {
            return false;
        }
    }

    /// <summary>
    /// If xml node exists with given path, its value is set to innerXml, otherwise a new node is created.
    /// </summary>
    /// <remarks> Ensure that the navigator is set to right parent.</remarks>
    internal static void AppendOrModifyChild(
        XmlDocument xmlDocument,
        string nodeXPath,
        string nodeName,
        string? innerXml)
    {
        var childNode = xmlDocument.SelectSingleNode(nodeXPath);

        // TODO: There isn't an equivalent API to SecurityElement.Escape in Core yet.
        // So trusting that the XML is always valid for now.
#if NETFRAMEWORK
        var secureInnerXml = SecurityElement.Escape(innerXml);
#else
        // fixing manually as we currently target to netcore 1.1 and we don't have default implementation for Escape functionality
        string secureInnerXml;
        if (innerXml.IsNullOrEmpty())
        {
            secureInnerXml = string.Empty;
        }
        else
        {
            secureInnerXml = innerXml.Replace("&", "&amp;").Replace("<", "&lt;").Replace(">", "&gt;").Replace("\"", "&quot;").Replace("'", "&apos;");
        }
#endif
        if (childNode == null)
        {
            var childElement = xmlDocument.CreateElement(nodeName);

            if (!innerXml.IsNullOrEmpty())
            {
                childElement.InnerXml = secureInnerXml;
            }

            var parentNode = xmlDocument.SelectSingleNode(nodeXPath.Substring(0, nodeXPath.LastIndexOf('/')));
            parentNode?.AppendChild(childElement);
        }
        else if (!innerXml.IsNullOrEmpty())
        {
            childNode.InnerXml = secureInnerXml;
        }
    }

    internal static void RemoveChildNode(XPathNavigator? parentNavigator, string nodeXPath, string childName)
    {
        if (parentNavigator?.SelectSingleNode(nodeXPath) is { })
        {
            parentNavigator.MoveToChild(childName, string.Empty);
            parentNavigator.DeleteSelf();
        }
    }
}