using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;
using System.Windows.Media.Animation;

/// <summary>
/// Contains a collection of <see cref="DependencyObject"/> extension methods.
/// </summary>
public static class DependencyObjectExtensions
{
    /// <summary>
    /// Invokes the current dependency object dispatcher.
    /// </summary>
    /// <param name="dependencyObject">The dependency object.</param>
    /// <param name="action">The action.</param>
    public static void BeginInvoke(this DependencyObject dependencyObject, Action action)
    {
        dependencyObject.Dispatcher.BeginInvoke(action);
    }

    /// <summary>
    /// Invokes the specified action.
    /// </summary>
    /// <param name="dependencyObject">The dependency object.</param>
    /// <param name="action">The action.</param>
    public static void Invoke(this DependencyObject dependencyObject, Action action)
    {
        dependencyObject.Dispatcher.Invoke(action);
    }

    /// <summary>
    /// Determines whether this object is currently in design time mode.
    /// </summary>
    /// <param name="obj">The object.</param>
    /// <returns></returns>
    public static bool IsInDesignMode(this DependencyObject obj)
    {
        return (DesignerProperties.GetIsInDesignMode(obj));
    }

    /// <summary>
    /// Binds the specified dependency property to a another object property.
    /// </summary>
    /// <param name="target">The target dependency object.</param>
    /// <param name="targetDP">The target dependency property.</param>
    /// <param name="source">The source object.</param>
    /// <param name="sourceDP">The source dependency property.</param>
    /// <param name="mode">Binding mode.</param>
    /// <param name="converter">Binding converter.</param>
    /// <returns></returns>
    public static Binding Bind(this DependencyObject target, DependencyProperty targetDP, DependencyObject source, DependencyProperty sourceDP, BindingMode mode, IValueConverter converter)
    {
        Binding binding = new Binding();
        binding.Mode = mode;
        binding.Source = source;
        binding.Path = new PropertyPath(sourceDP);
        binding.Converter = converter;
        BindingOperations.SetBinding(target, targetDP, binding);
        return binding;
    }

    /// <summary>
    /// Binds the specified dependency property to a another object property.
    /// </summary>
    /// <param name="target">The target dependency object.</param>
    /// <param name="targetDP">The target dependency property.</param>
    /// <param name="source">The source object.</param>
    /// <param name="sourceDP">The source dependency property.</param>
    /// <param name="mode">Binding mode.</param>
    /// <returns></returns>
    public static Binding Bind(this DependencyObject target, DependencyProperty targetDP, DependencyObject source, DependencyProperty sourceDP, BindingMode mode = BindingMode.Default)
    {
        Binding binding = new Binding();
        binding.Mode = mode;
        binding.Source = source;
        binding.Path = new PropertyPath(sourceDP);
        BindingOperations.SetBinding(target, targetDP, binding);
        return binding;
    }

    /// <summary>
    /// Create asynchronous binding between target and source.
    /// </summary>
    /// <param name="target">The target dependency object.</param>
    /// <param name="targetDP">The target dependency property.</param>
    /// <param name="source">The source object.</param>
    /// <param name="sourceDP">The source dependency property.</param>
    /// <param name="mode">Binding mode.</param>
    /// <returns></returns>
    public static Binding BindAsync(this DependencyObject target, DependencyProperty targetDP, DependencyObject source, DependencyProperty sourceDP, BindingMode mode = BindingMode.Default)
    {
        Binding binding = new Binding();
        binding.Mode = mode;
        binding.Source = source;
        binding.Path = new PropertyPath(sourceDP);
        binding.IsAsync = true;
        binding.BindsDirectlyToSource = true;
        BindingOperations.SetBinding(target, targetDP, binding);
        return binding;
    }

    /// <summary>
    /// Binds the specified dependency property to a another object property.
    /// </summary>
    /// <param name="target">The target dependency object.</param>
    /// <param name="targetDP">The target dependency property.</param>
    /// <param name="source">The source object.</param>
    /// <param name="sourceDP">The source dependency property name.</param>
    /// <param name="mode">Binding mode.</param>
    /// <returns></returns>
    public static Binding Bind(this DependencyObject target, DependencyProperty targetDP, DependencyObject source, String sourceDP, BindingMode mode = BindingMode.Default)
    {
        Binding binding = new Binding();
        binding.Mode = mode;
        binding.Source = source;
        binding.Path = new PropertyPath(sourceDP);
        BindingOperations.SetBinding(target, targetDP, binding);
        return binding;
    }

    /// <summary>
    /// Binds the specified dependency property to a another object property.
    /// </summary>
    /// <param name="target">The target dependency object.</param>
    /// <param name="targetDP">The target dependency property.</param>
    /// <param name="source">The source object.</param>
    /// <param name="sourcePath">The source dependency property name.</param>
    /// <param name="mode">Binding mode.</param>
    /// <returns></returns>
    public static Binding Bind(this DependencyObject target, DependencyProperty targetDP, Object source, String sourcePath, BindingMode mode = BindingMode.Default)
    {
        Binding binding = new Binding();
        binding.Mode = mode;
        binding.Source = source;
        binding.Path = new PropertyPath(sourcePath);
        BindingOperations.SetBinding(target, targetDP, binding);
        return binding;
    }

    /// <summary>
    /// Clears bindings from the specified dependency property.
    /// </summary>
    /// <param name="target">The target dependency object.</param>
    /// <param name="dependencyProperty">The dependency property.</param>
    public static void Unbind(this DependencyObject target, DependencyProperty dependencyProperty)
    {
        BindingOperations.ClearBinding(target, dependencyProperty);
    }

    /// <summary>
    /// Finds the ancestor of type T.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="dependencyObject">The dependency object.</param>
    /// <returns></returns>
    public static T FindAncestor<T>(this DependencyObject dependencyObject) where T : class
    {
        var parent = VisualTreeHelper.GetParent(dependencyObject);

        if (parent == null) return null;

        var parentT = parent as T;
        return parentT ?? FindAncestor<T>(parent);
    }

    /// <summary>
    /// Finds an ancestor that matches the specified criteria.
    /// </summary>
    /// <param name="dependencyObject">The dependency object.</param>
    /// <param name="predicate">The predicate.</param>
    /// <returns></returns>
    public static DependencyObject FindAncestor(this DependencyObject dependencyObject, Predicate<DependencyObject> predicate)
    {
        var parent = VisualTreeHelper.GetParent(dependencyObject);

        if (parent == null) return null;

        if (predicate(parent))
        {
            return parent;
        }
        else
        {
            return FindAncestor(parent, predicate);
        }
    }

    /// <summary>
    /// Finds the child of type T.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="depObj">The dependency object.</param>
    /// <returns></returns>
    public static T FindChild<T>(this DependencyObject depObj) where T : DependencyObject
    {
        if (depObj == null) return null;

        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
        {
            var child = VisualTreeHelper.GetChild(depObj, i);

            var result = (child as T) ?? FindChild<T>(child);
            if (result != null) return result;
        }
        return null;
    }

    /// <summary>
    /// Finds a Child of a given item in the visual tree. 
    /// </summary>
    /// <param name="parent">A direct parent of the queried item.</param>
    /// <typeparam name="T">The type of the queried item.</typeparam>
    /// <param name="childName">x:Name or Name of child. </param>
    /// <returns>The first parent item that matches the submitted type parameter. 
    /// If not matching item can be found, 
    /// a null parent is being returned.</returns>
    public static T FindChild<T>(this DependencyObject parent, string childName)
           where T : DependencyObject
    {
        // Confirm parent and childName are valid. 
        if (parent == null) return null;

        T foundChild = null;

        int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
        for (int i = 0; i < childrenCount; i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);
            // If the child is not of the request child type child
            T childType = child as T;
            if (childType == null)
            {
                // recursively drill down the tree
                foundChild = FindChild<T>(child, childName);

                // If the child is found, break so we do not overwrite the found child. 
                if (foundChild != null) break;
            }
            else if (!string.IsNullOrEmpty(childName))
            {
                var frameworkElement = child as FrameworkElement;
                // If the child's name is set for search
                if (frameworkElement != null && frameworkElement.Name == childName)
                {
                    // if the child's name is of the request name
                    foundChild = (T)child;
                    break;
                }
            }
            else
            {
                // child element found.
                foundChild = (T)child;
                break;
            }
        }

        return foundChild;
    }

    /// <summary>
    /// Finds the visual children of type T.
    /// </summary>
    /// <typeparam name="T">type of visual</typeparam>
    /// <param name="depObj">The dependency object.</param>
    /// <returns></returns>
    public static IEnumerable<T> FindVisualChildren<T>(this DependencyObject depObj) where T : DependencyObject
    {
        if (depObj != null)
        {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
            {
                DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
                if (child != null && child is T)
                {
                    yield return (T)child;
                }

                foreach (T childOfChild in FindVisualChildren<T>(child))
                {
                    yield return childOfChild;
                }
            }
        }
    }
}