// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.ComponentModel;
using System.Globalization;
using System.Reflection;
using System.Windows.Media; // TypeConverterHelper, UriHolder
using MS.Internal.PresentationCore;
using MS.Internal; // BindUriHelper
 
namespace System.Windows.Input
{
    /// <summary>
    /// TypeConverter to convert CursorType to/from other types.
    /// Currently To/From string is only supported.
    /// </summary>
    public class CursorConverter : TypeConverter
    {
        /// <summary>
        /// TypeConverter method override.
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="sourceType">Type to convert from</param>
        /// <returns>true if conversion is possible</returns>
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            if(sourceType == typeof(string))
            {
                return true;
            }
            return false;
        }
    
        /// <summary>
        /// TypeConverter method override.
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="destinationType">Type to convert to</param>
        /// <returns>true if conversion is possible</returns>
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) 
        {
            if (destinationType == typeof(string)) 
            {
                return true;
            }
 
            return false;
        }
 
        /// <summary>
        ///     StandardValuesCollection method override
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <returns>TypeConverter.StandardValuesCollection</returns>
        public override TypeConverter.StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
        {
            if(_standardValues is null)
            {
                PropertyInfo[] properties = typeof(Cursors).GetProperties(BindingFlags.Public | BindingFlags.Static);
                object[] values = new object[properties.Length]; //Could use Cursor but its wrapped in ICollection anyways
 
                for (int i = 0; i < properties.Length; i++)
                {
                    PropertyInfo info = properties[i];
 
                    values[i] = info.GetValue(null, null);
                }
 
                _standardValues = new TypeConverter.StandardValuesCollection(values);
            }
 
            return _standardValues;
        }
 
        /// <summary>
        ///     Returns whether this object supports a standard set of values that can be
        ///     picked from a list, using the specified context.
        /// </summary>
        /// <param name="context">An ITypeDescriptorContext that provides a format context.</param>
        /// <returns>
        ///     true if GetStandardValues should be called to find a common set
        ///     of values the object supports; otherwise, false.
        /// </returns>
        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
        {
            return true;
        }
 
        /// <summary>
        /// TypeConverter method implementation.
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="culture">current culture (see CLR specs)</param>
        /// <param name="value">value to convert from</param>
        /// <returns>value that is result of conversion</returns>
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            if (value is string)
            {                
                string text = ((string)value).Trim();
 
                if (text != String.Empty)
                {
                    if (text.LastIndexOf('.') == -1)
                    {
                        CursorType ct = Enum.Parse<CursorType>(text);
 
                        switch (ct)
                        {
                            case CursorType.Arrow:
                                return Cursors.Arrow;
                            case CursorType.AppStarting:
                                return Cursors.AppStarting;
                            case CursorType.Cross:
                                return Cursors.Cross;
                            case CursorType.Help:
                                return Cursors.Help;
                            case CursorType.IBeam:
                                return Cursors.IBeam;
                            case CursorType.SizeAll:
                                return Cursors.SizeAll;
                            case CursorType.SizeNESW:
                                return Cursors.SizeNESW;
                            case CursorType.SizeNS:
                                return Cursors.SizeNS;
                            case CursorType.SizeNWSE:
                                return Cursors.SizeNWSE;
                            case CursorType.SizeWE:
                                return Cursors.SizeWE;
                            case CursorType.UpArrow:
                                return Cursors.UpArrow;
                            case CursorType.Wait:
                                return Cursors.Wait;
                            case CursorType.Hand:
                                return Cursors.Hand;
                            case CursorType.No:
                                return Cursors.No;
                            case CursorType.None:
                                return Cursors.None;
                            case CursorType.Pen:
                                return Cursors.Pen;
                            case CursorType.ScrollNS:
                                return Cursors.ScrollNS;
                            case CursorType.ScrollWE:
                                return Cursors.ScrollWE;
                            case CursorType.ScrollAll:
                                return Cursors.ScrollAll;
                            case CursorType.ScrollN:
                                return Cursors.ScrollN;
                            case CursorType.ScrollS:
                                return Cursors.ScrollS;
                            case CursorType.ScrollW:
                                return Cursors.ScrollW;
                            case CursorType.ScrollE:
                                return Cursors.ScrollE;
                            case CursorType.ScrollNW:
                                return Cursors.ScrollNW;
                            case CursorType.ScrollNE:
                                return Cursors.ScrollNE;
                            case CursorType.ScrollSW:
                                return Cursors.ScrollSW;
                            case CursorType.ScrollSE:
                                return Cursors.ScrollSE;
                            case CursorType.ArrowCD:
                                return Cursors.ArrowCD;
                        }
                    }
                    else 
                    {
                        if (text.EndsWith(".cur", StringComparison.OrdinalIgnoreCase) || text.EndsWith(".ani", StringComparison.OrdinalIgnoreCase))
                        {
                            UriHolder uriHolder = TypeConverterHelper.GetUriFromUriContext(context, text);
                            Uri finalUri = BindUriHelper.GetResolvedUri(uriHolder.BaseUri, uriHolder.OriginalUri);
 
                            if (finalUri.IsAbsoluteUri && finalUri.IsFile)
                            {
                                return new Cursor(finalUri.LocalPath);
                            }
                            else
                            {
                                System.Net.WebRequest request = WpfWebRequestHelper.CreateRequest(finalUri);
                                WpfWebRequestHelper.ConfigCachePolicy(request, false);
                                return new Cursor(WpfWebRequestHelper.GetResponseStream(request));
                            }
                        }
                    }
                }
                else
                {
                    // An empty string means no cursor.
                    return null;
                }
            }
 
            throw GetConvertFromException(value);
        }
 
        /// <summary>
        /// TypeConverter method implementation.
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="culture">current culture (see CLR specs)</param>
        /// <param name="value">value to convert from</param>
        /// <param name="destinationType">Type to convert to</param>
        /// <returns>converted value</returns>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            ArgumentNullException.ThrowIfNull(destinationType);
 
            // If value is not a Cursor or null, it will throw GetConvertToException.
            if (destinationType == typeof(string))
            {
                Cursor cursor = value as Cursor;
                if (cursor != null)
                {
                    return cursor.ToString();
                }
                else
                {
                    return String.Empty;
                }
            }
            throw GetConvertToException(value, destinationType);
        }
        
        /// <summary>
        /// Cached value for GetStandardValues
        /// </summary>
        private TypeConverter.StandardValuesCollection _standardValues;
}
}