using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace JeffWilcox.Controls
{
    // Based upon Headered Content Control as it often comes up in these templates.

    public class WindowBase : HeaderedContentControl
    {
        private PhoneApplicationPage _page;

        private bool _transitionedIn;

        private Panel _templateRoot;

        public event EventHandler PressedBack;

        private Grid _overlay;

        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();

            _templateRoot = MoreVisualTreeExtensions.FindFirstChildOfType<Panel>(this);
            if (_templateRoot == null)
            {
                throw new InvalidOperationException("Must include a Panel in the root of the template.");
            }

            if (!_transitionedIn)
            {
                var @in = GetTransitionIn();
                if (@in != null)
                {
                    var transition = @in.GetTransition(_templateRoot);
                    transition.Completed += (x, xe) => transition.Stop();
                    transition.Begin();
                }
                _transitionedIn = true;
            }
        }

        private void BuildOverlay()
        {
            var bg = (Color)Resources["PhoneBackgroundColor"];
            _overlay = new Grid();
            _overlay.IsHitTestVisible = true;
            _overlay.Background = new SolidColorBrush(Color.FromArgb(0xa0, bg.R, bg.G, bg.B));
        }

        protected void InsertIntoVisualTree(Panel parentPanel)
        {
            BuildOverlay();
            parentPanel.Children.Add(_overlay);
            parentPanel.Children.Add(this);

            // WARNING: This version will not attach to page back button
            // key presses and could fail ingestion.
        }

        protected void InsertIntoFrame()
        {
            IExposeRootFrame ie = Application.Current as IExposeRootFrame;
            if (ie != null)
            {
                WilcoxTransitionFrame wtf = ie.RootFrame;
                InsertIntoVisualTree(wtf.OverlayGrid);

                _page = wtf.Content as PhoneApplicationPage;
                if (_page != null)
                {
                    _page.BackKeyPress += OnBackKeyPress;
                }
            }
            else throw new InvalidOperationException("Root must be of WilcoxTransitionFrame type.");
        }

        private void OnBackKeyPress(object sender, System.ComponentModel.CancelEventArgs e)
        {
            e.Cancel = true;

            var handler = PressedBack;
            if (handler != null)
            {
                handler(this, EventArgs.Empty);
            }

            CloseWindow();
        }

        protected void CloseWindow()
        {
            // Remove from the parent visual tree.
            var me = this;

            if (_page != null)
            {
                _page.BackKeyPress -= OnBackKeyPress;
                _page = null;
            }

            Action removeVisualFromParent = () =>
                {
                    Dispatcher.BeginInvoke(() =>
                    {
                        Panel p = me.Parent as Panel;
                        if (p != null)
                        {
                            p.Children.Remove(me);
                        }
                    });
                };
            Action removeOverlay = () =>
                {
                    Grid overlay = _overlay;
                    _overlay = null;
                    if (overlay != null)
                    {
                        Panel p = overlay.Parent as Panel;
                        if (p != null)
                        {
                            p.Children.Remove(overlay);
                        }
                    }
                };
            Action removeVisuals = () =>
                {
                    removeOverlay();
                    removeVisualFromParent();
                };

            // Animate.
            var @out = GetTransitionOut();
            if (@out != null)
            {
                var transition = @out.GetTransition(_templateRoot);
                transition.Completed += (x, xe) =>
                    {
                        me.Opacity = 0;

                        transition.Stop();

                        removeVisuals();
                    };
                transition.Begin();
            }
            else
            {
                removeVisuals();
            }
        }

        protected virtual TransitionElement GetTransitionIn()
        {
            return new SwivelTransition
            {
                Mode = SwivelTransitionMode.BackwardIn,
            };
        }

        protected virtual TransitionElement GetTransitionOut()
        {
            return new SwivelTransition
            {
                Mode = SwivelTransitionMode.BackwardOut,
            };
        }
    }
}