﻿// <copyright file="TextToFlowDocumentConverter.cs" company="APE Engineering GmbH">Copyright (c) APE Engineering GmbH. All rights reserved.</copyright>

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;

namespace APE.PostgreSQL.Teamwork.GUI.Markdown
{
    public class TextToFlowDocumentConverter : DependencyObject, IValueConverter
    {
        // Using a DependencyProperty as the backing store for Markdown.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty MarkdownProperty =
            DependencyProperty.Register("Markdown", typeof(Markdown), typeof(TextToFlowDocumentConverter), new PropertyMetadata(null));

        private Lazy<Markdown> markdown = new Lazy<Markdown>(() => new Markdown());

        public Markdown Markdown
        {
            get { return (Markdown)this.GetValue(MarkdownProperty); }
            set { this.SetValue(MarkdownProperty, value); }
        }

        /// <summary>
        /// Converts a value.
        /// </summary>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        /// <param name="value">The value produced by the binding source.</param>
        /// <param name="targetType">The type of the binding target property.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null)
            {
                return null;
            }

            var text = (string)value;

            var engine = this.Markdown ?? this.markdown.Value;

            return engine.Transform(text);
        }

        /// <summary>
        /// Converts a value.
        /// </summary>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        /// <param name="value">The value that is produced by the binding target.</param>
        /// <param name="targetType">The type to convert to.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}
