using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace GraphingCalculator
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        #region Constructor
        public MainWindow()
        {
            InitializeComponent();
            
            // Update textboxes
            graphingCanvas.CanvasBounds.BoundsChanged += new EventHandler(CanvasBounds_BoundsChanged);
            graphingCanvas.CanvasBounds.Right = graphingCanvas.CanvasBounds.Right;
        }
        #endregion

        #region Function list
        private void updateList()
        {
            listExpressions.Items.Clear();

            foreach (var i in graphingCanvas.Expressions)
            {
                CheckBox chk = new CheckBox();
                chk.Content = i.ExpressionString;
                chk.IsChecked = i.IsVisible;
                chk.Foreground = new SolidColorBrush(i.Color);
                chk.FontWeight = FontWeights.Bold;
                chk.Click += new RoutedEventHandler(Visibility_Checked);

                listExpressions.Items.Add(chk);
            }
        }

        void Visibility_Checked(object sender, RoutedEventArgs e)
        {
            int index = listExpressions.Items.IndexOf(sender);
            CheckBox c = sender as CheckBox;
            if (index < 0 || c == null || !c.IsChecked.HasValue) return;

            graphingCanvas.SetExpressionVisibility(index, c.IsChecked.Value);
        }

        private void buttonDelete_Click(object sender, RoutedEventArgs e)
        {
            int index = listExpressions.SelectedIndex;
            if (index == -1) return;

            listExpressions.Items.RemoveAt(index);
            graphingCanvas.Expressions.RemoveAt(index);

            graphingCanvas.EvaluateExpressions();
            graphingCanvas.Redraw();
        }

        private void buttonClear_Click(object sender, RoutedEventArgs e)
        {
            listExpressions.Items.Clear();
            graphingCanvas.Expressions.Clear();
            graphingCanvas.EvaluateExpressions();
            graphingCanvas.Redraw();
        }

        private void buttonHideAll_Click(object sender, RoutedEventArgs e)
        {
            for (int i = 0; i < listExpressions.Items.Count; i++)
            {
                CheckBox c = listExpressions.Items[i] as CheckBox;

                if (c != null) c.IsChecked = false;
                graphingCanvas.SetExpressionVisibility(i, false);
            }
        }

        #endregion

        #region Keyboard/mouse input
        private void Window_MouseWheel(object sender, MouseWheelEventArgs e)
        {
            graphingCanvas.PeformMouseWheelChange(e);
        }

        private bool EditingTextbox()
        {
            TextBox box = Keyboard.FocusedElement as TextBox;
            return (box != null); 
        }

        private void Window_KeyDown(object sender, KeyEventArgs e)
        {
            e.Handled = true;

            if (e.KeyboardDevice.Modifiers == ModifierKeys.None)
            {
                switch (e.Key)
                {
                    case Key.F1: menuHelp_Click(this, new RoutedEventArgs()); break;

                    case Key.NumPad8:
                    case Key.Up:
                        if (!EditingTextbox()) graphingCanvas.PerformMoveUp();
                        else e.Handled = false;
                        break;

                    case Key.NumPad4:
                    case Key.Left: 
                        if (!EditingTextbox()) graphingCanvas.PerformMoveLeft();
                        else e.Handled = false;
                        break;

                    case Key.NumPad6:
                    case Key.Right:
                        if (!EditingTextbox()) graphingCanvas.PerformMoveRight();
                        else e.Handled = false;
                        break;

                    case Key.NumPad2:
                    case Key.Down: 
                        if (!EditingTextbox()) graphingCanvas.PerformMoveDown();
                        else e.Handled = false;
                        break;

                    case Key.NumPad5:
                        if (!EditingTextbox()) graphingCanvas.PerformReset();
                        else e.Handled = false;
                        break;

                    case Key.Add: 
                        if (!EditingTextbox()) graphingCanvas.PerformZoomIn();
                        else e.Handled = false;
                        break;

                    case Key.Subtract: 
                        if (!EditingTextbox()) graphingCanvas.PerformZoomOut();
                        else e.Handled = false;
                        break;

                    case Key.Enter: buttonPlot_Click(this, new RoutedEventArgs()); break;

                    default: e.Handled = false; break;
                }
            }

            else if (Keyboard.Modifiers == ModifierKeys.Control)
            {
                if (e.Key == Key.F1) menuAbout_Click(this, new RoutedEventArgs());
                else if (e.Key == Key.S) menuFileSave_Click(this, new RoutedEventArgs());
                else if (e.Key == Key.O) menuFileImport_Click(this, new RoutedEventArgs());
                else if (e.Key == Key.Q) menuFileExit_Click(this, new RoutedEventArgs());
                else e.Handled = false;
            }

            else e.Handled = false;
        }
        #endregion

        #region Buttons
        private void buttonPlot_Click(object sender, RoutedEventArgs e)
        {
            if (inputExpression.Text == "") return;

            VisualExpression expr = new VisualExpression();

            try
            {
                expr.ExpressionString = inputExpression.Text;
                expr.Process();
                expr.Variables["x"] = expr.Variables["X"] = 0;
                expr.Evaluate();
            }

            catch (Exception ex)
            {
                MessageBox.Show("Error: " + ex.Message, "Error!");

                #region Log
                Log.LogEvent("Failed to plot expression '{0}'. Message: {1}", expr.ExpressionString, ex.Message);
                Log.LogEvent("> Stack trace: {0}", ex.StackTrace);
                #endregion
                return;
            }

            graphingCanvas.AddExpression(expr);
            updateList();
        }

        private void buttonEvaluate_Click(object sender, RoutedEventArgs e)
        {
            EvaluateWindow window = new EvaluateWindow(inputExpression.Text);
            window.Show();
        }

        private void buttonIntegrate_Click(object sender, RoutedEventArgs e)
        {
            Controls.IntegralWindow window = new Controls.IntegralWindow(inputExpression.Text);
            window.Show();
        }

        private bool IsNanInf (params double[] items)
        {
            bool result = false;

            foreach (var i in items)
                result = result || double.IsNaN(i) || double.IsInfinity(i);

            return result;
        }

        private void buttonChangeBounds_Click(object sender, RoutedEventArgs e)
        {
            Expression el, er, et, eb;
            double l, r, t, b;
            bool ok = true;

            // Initialize stuff
            el = new Expression(inputBoundsLeft.Text);
            er = new Expression(inputBoundsRight.Text);
            et = new Expression(inputBoundsTop.Text);
            eb = new Expression(inputBoundsBottom.Text);
            l = r = t = b = 0;

            // Initialize visuals
            inputBoundsLeft.Background = SystemColors.WindowBrush;
            inputBoundsTop.Background = SystemColors.WindowBrush;
            inputBoundsRight.Background = SystemColors.WindowBrush;
            inputBoundsBottom.Background = SystemColors.WindowBrush;

            // Evaluate left
            try { l = el.Evaluate();  }
            catch { 
                if (!double.TryParse(el.ExpressionString, out l)) {
                    inputBoundsLeft.Background = Brushes.Pink; ok = false;
                }
            }

            // Evaluate top
            try { t = et.Evaluate();  }
            catch {
                if (!double.TryParse(et.ExpressionString, out t)) {
                    inputBoundsTop.Background = Brushes.Pink; ok = false;
                }
            }

            // Evaluate right
            try { r = er.Evaluate();  }
            catch {
                if (!double.TryParse(er.ExpressionString, out r)) {
                    inputBoundsRight.Background = Brushes.Pink; ok = false;
                }
            }

            // Evaluate bottom
            try { b = eb.Evaluate();  }
            catch {
                if (!double.TryParse(eb.ExpressionString, out b)) {
                    inputBoundsBottom.Background = Brushes.Pink; ok = false;
                }
            }

            // Preview results
            inputBoundsTop.Text = Math.Round(t, 15).ToString();
            inputBoundsLeft.Text = Math.Round(l, 15).ToString();
            inputBoundsRight.Text = Math.Round(r, 15).ToString();
            inputBoundsBottom.Text = Math.Round(b, 15).ToString();

            // Verify
            if (ok)
            {
                if (l >= r || b >= t || IsNanInf(l, r, b, t)) MessageBox.Show("Invalid interval! Make sure left is smaller than right, bottom is smaller than top, and the intervals are finite.", "Error");
                else graphingCanvas.SetCanvasBounds(new Bounds(l, t, r, b));
            }
        }
        #endregion

        #region Menu items
        private void menuFileSave_Click(object sender, RoutedEventArgs e)
        {
            Microsoft.Win32.SaveFileDialog save = new Microsoft.Win32.SaveFileDialog();
            save.Filter = "XML Expression list|*.xml|All files|*.*";
            save.Title = "Save expression list...";
            bool? result = save.ShowDialog();
            if (!result.HasValue || !result.Value) return;

            IO.ExpressionFile file = new IO.ExpressionFile();
            file.Expressions.AddRange(graphingCanvas.Expressions);

            try { file.SaveToFile(save.FileName); }
            catch (Exception ex)
            {
                MessageBox.Show("Error: " + ex.Message, "Error!");

                Log.LogEvent("Failed to save to file '{0}': {1}", save.FileName, ex.Message);
                Log.LogEvent("> Stack trace: {0}", ex.StackTrace);
            }
        }

        private void menuFileImport_Click(object sender, RoutedEventArgs e)
        {
            IO.ExpressionFile file = new IO.ExpressionFile();
            Microsoft.Win32.OpenFileDialog open = new Microsoft.Win32.OpenFileDialog();
            bool? res;

            // Show dialog
            open.Filter = "XML Expression list|*.xml|All files|*.*";
            open.Title = "Import expression list";
            res = open.ShowDialog();

            if (!res.HasValue || !res.Value) return;

            // Try to load data
            try {
                file.LoadFromFile(open.FileName);
            }
            catch (Exception ex) {
                MessageBox.Show("Error: " + ex.Message, "Error!");

                Log.LogEvent("Failed to import from file '{0}': {1}", open.FileName, ex.Message);
                Log.LogEvent("> Stack trace: {0}", ex.StackTrace);
            }

            // Add expressions to our list
            foreach (var i in file.Expressions)
                this.graphingCanvas.AddExpression(i);

            updateList();
        }

        private void menuFileExit_Click(object sender, RoutedEventArgs e)
        {
            this.Close();
        }

        private void menuAppLog_Click(object sender, RoutedEventArgs e)
        {
            new LogWindow().Show();
        }

        private void menuAppPref_Click(object sender, RoutedEventArgs e)
        {
            new SettingsWindow().ShowDialog();
            graphingCanvas.SetCanvasBounds(graphingCanvas.CanvasBounds);
        }

        private void menuHelp_Click(object sender, RoutedEventArgs e)
        {
            DynamicLink.Launcher.StartModule("Help", "graphingcalc");
        }

        private void menuAbout_Click(object sender, RoutedEventArgs e)
        {
            DynamicLink.Launcher.About();
        }

        #endregion

        #region Misc
        void CanvasBounds_BoundsChanged(object sender, EventArgs e)
        {
            int p = GraphingCalculator.Properties.Settings.Default.RoundDoublesGraph;

            this.inputBoundsBottom.Text = Math.Round(graphingCanvas.CanvasBounds.Bottom, p).ToString();
            this.inputBoundsLeft.Text = Math.Round(graphingCanvas.CanvasBounds.Left, p).ToString();
            this.inputBoundsTop.Text = Math.Round(graphingCanvas.CanvasBounds.Top, p).ToString();
            this.inputBoundsRight.Text = Math.Round(graphingCanvas.CanvasBounds.Right, p).ToString();

            #region Log
            Log.LogEvent("Canvas bounds changed: left={0}; top={1}; right={2}; bottom={3}", this.inputBoundsLeft.Text,
                this.inputBoundsTop.Text, this.inputBoundsRight.Text, this.inputBoundsBottom.Text);
            #endregion
        }
        #endregion
    }
}