// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
/***************************************************************************\
*
*  Class for converting a given value (for Setter/Trigger/Condition) to and from a string
*
\***************************************************************************/
using System.ComponentModel;        // for TypeConverter
using System.Globalization;               // for CultureInfo
using System.Xaml;
using System.IO;
 
namespace System.Windows.Markup
{
    /// <summary>
    ///     Class for converting a given DependencyProperty to and from a string
    /// </summary>
    public sealed class SetterTriggerConditionValueConverter : TypeConverter
    {
        #region Public Methods
 
        /// <summary>
        ///     CanConvertFrom()
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="sourceType">type to convert from</param>
        /// <returns>true if the given type can be converted, false otherwise</returns>
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            // We can only convert from a string and that too only if we have all the contextual information
            // Note: Sometimes even the serializer calls CanConvertFrom in order 
            // to determine if it is a valid converter to use for serialization.
            if (sourceType == typeof(string) || sourceType == typeof(byte[]))
            {
                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)
        {
            return false;
        }
 
        /// <summary>
        ///     ConvertFrom() -TypeConverter method override. using the givein name to return DependencyProperty
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="culture">CultureInfo</param>
        /// <param name="source">Object to convert from</param>
        /// <returns>instance of Command</returns>
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object source)
        {
            return SetterTriggerConditionValueConverter.ResolveValue(context, null, culture, source);
        }
        //    
 
        /// <summary>
        ///     ConvertTo() - Serialization purposes, returns the string from Command.Name by adding ownerType.FullName
        /// </summary>
        /// <param name="context">ITypeDescriptorContext</param>
        /// <param name="culture">CultureInfo</param>
        /// <param name="value">the	object to convert from</param>
        /// <param name="destinationType">the type to convert to</param>
        /// <returns>string object, if the destination type is string</returns>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            throw GetConvertToException(value, destinationType);
        }
 
        #endregion Public Methods
 
        internal static object ResolveValue(ITypeDescriptorContext serviceProvider,
            DependencyProperty property, CultureInfo culture, object source)
        {
            ArgumentNullException.ThrowIfNull(serviceProvider);
            ArgumentNullException.ThrowIfNull(source);
 
            // Only need to type convert strings and byte[]
            if (!(source is byte[] || source is String || source is Stream))
            {
                return source;
            }
 
            IXamlSchemaContextProvider ixsc = (serviceProvider.GetService(typeof(IXamlSchemaContextProvider))
                as IXamlSchemaContextProvider);
            if (ixsc == null)
            {
                throw new NotSupportedException(SR.Format(SR.ParserCannotConvertPropertyValue, "Value", typeof(Object).FullName));
            }
            XamlSchemaContext schemaContext = ixsc.SchemaContext;
 
            if (property != null)
            {
                //Get XamlMember from dp
                System.Xaml.XamlMember xamlProperty = 
                    schemaContext.GetXamlType(property.OwnerType).GetMember(property.Name);
                if (xamlProperty == null)
                    xamlProperty = 
                        schemaContext.GetXamlType(property.OwnerType).GetAttachableMember(property.Name);
 
                System.Xaml.Schema.XamlValueConverter<TypeConverter> typeConverter = null;
                
                if (xamlProperty != null)
                { 
                    // If we have a Baml2006SchemaContext and the property is of type Enum, we already know that the 
                    // type converter must be the EnumConverter.
                    if (xamlProperty.Type.UnderlyingType.IsEnum && schemaContext is Baml2006.Baml2006SchemaContext)
                    {
                        typeConverter = XamlReader.BamlSharedSchemaContext.GetTypeConverter(xamlProperty.Type.UnderlyingType);
                    }
                    else
                    {
                        typeConverter = xamlProperty.TypeConverter;
 
                        if (typeConverter == null)
                        {
                            typeConverter = xamlProperty.Type.TypeConverter;
                        }
                    }
                }
                else
                {
                    typeConverter = schemaContext.GetXamlType(property.PropertyType).TypeConverter;
                }
 
 
                // No Type converter case...
                if (typeConverter.ConverterType == null)
                {
                    return source;
                }
 
                TypeConverter converter = null;
 
                if (xamlProperty != null && xamlProperty.Type.UnderlyingType == typeof(Boolean))
                {
                    if (source is String)
                    {
                        converter = new BooleanConverter();
                    }
                    else if (source is byte[])
                    {
                        byte[] bytes = source as byte[];
                        if (bytes != null && bytes.Length == 1)
                        {
                            return (bytes[0] != 0);
                        }
                        else
                        {
                            throw new NotSupportedException(SR.Format(SR.ParserCannotConvertPropertyValue, "Value", typeof(Object).FullName));
                        }
                    }
                    else
                    {
                        throw new NotSupportedException(SR.Format(SR.ParserCannotConvertPropertyValue, "Value", typeof(Object).FullName));
                    }
                }
                else
                {
                    converter = (TypeConverter)typeConverter.ConverterInstance;
                }
 
                return converter.ConvertFrom(serviceProvider, culture, source);
            }
            else
            {
                return source;
            }
        }
    }
}