// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
//
//
// Description: class for input scope type-converter
//
// Please refer to the design specfication http://avalon/Cicero/Specifications/Stylable%20InputScope.mht
// 
//
 
using System.ComponentModel;
using System.Globalization;
 
 
namespace System.Windows.Input
{
    ///<summary>
    /// type-converter which performs type conversions for inputscope
    ///</summary>
    /// <speclink>http://avalon/Cicero/Specifications/Stylable%20InputScope.mht</speclink>
    public class InputScopeNameConverter : TypeConverter
    {
        ///<summary>
        /// Returns whether this converter can convert an object of one type to InputScope type
        /// InputScopeConverter only supports string type to convert from
        ///</summary>
        ///<param name="context">
        /// The conversion context.
        ///</param>
        ///<param name="sourceType">
        /// The type to convert from.
        ///</param>
        ///<returns>
        /// True if conversion is possible, false otherwise.
        ///</returns>
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            // We can only handle string.
            if (sourceType == typeof(string))
            {
                return true;
            }
            return false;
        }
 
        ///<summary>
        /// Returns whether this converter can convert the object to the specified type. 
        /// InputScopeConverter only supports string type to convert to
        ///</summary>
        ///<param name="context">
        /// The conversion context.
        ///</param>
        ///<param name="destinationType">
        /// The type to convert to.
        ///</param>
        ///<returns>
        /// True if conversion is possible, false otherwise.
        ///</returns>
 
         public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        {
            if (typeof (string) == destinationType && null != context && null != context.Instance && context.Instance is InputScopeName)
            {
                return true;
            }
            return false;
        }
 
        ///<summary>
        /// Converts the given value to InputScope type
        ///</summary>
        /// <param name="context">
        /// The conversion context.
        /// </param>
        /// <param name="culture">
        /// The current culture that applies to the conversion.
        /// </param>
        /// <param name="source">
        /// The source object to convert from.
        /// </param>
        /// <returns>
        /// InputScope object with a specified scope name, otherwise InputScope with Default scope.
        /// </returns>
 
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object source)
        {
            string stringSource = source as string;
            InputScopeNameValue nameValue = InputScopeNameValue.Default;
            InputScopeName inputScopeName;
 
            if (null != stringSource)
            {
                stringSource = stringSource.Trim();
 
                if (-1 != stringSource.LastIndexOf('.'))
                    stringSource = stringSource.Substring(stringSource.LastIndexOf('.')+1);
                    
                if (!stringSource.Equals(String.Empty))
                {
                    nameValue = Enum.Parse<InputScopeNameValue>(stringSource);
                }
            }
 
            inputScopeName = new InputScopeName
            {
                NameValue = nameValue
            };
            return inputScopeName;    
        }
 
        ///<summary>
        /// Converts the given value as InputScope object to the specified type. 
        /// This converter only supports string type as a type to convert to.
        ///</summary>
        /// <param name="context">
        /// The conversion context.
        /// </param>
        /// <param name="culture">
        /// The current culture that applies to the conversion.
        /// </param>
        /// <param name="value">
        /// The value to convert.
        /// </param>
        /// <param name="destinationType">
        /// The type to convert to.
        /// </param>
        /// <returns>
        /// A new object of the specified type (string) converted from the given InputScope object.
        /// </returns>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            InputScopeName inputScopeName = value as InputScopeName;
            if (null != destinationType && null != inputScopeName)
            {
                if (destinationType == typeof(string))
                {
                    return Enum.GetName(inputScopeName.NameValue);
                }
            }
            return base.ConvertTo(context, culture, value, destinationType);
        }
    }
}