/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2016 Thomas Braun, Jens Klingen, Robin Krom
 * 
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
using System;
using System.Drawing;
using System.Windows.Forms;
using GreenshotPlugin.Core;
using GreenshotPlugin.Effects;

namespace Greenshot.Forms {
	/// <summary>
	/// A form to set the resize settings
	/// </summary>
	public partial class ResizeSettingsForm : BaseForm {
		private readonly ResizeEffect _effect;
		private readonly string _valuePercent;
		private double _newWidth, _newHeight;

		public ResizeSettingsForm(ResizeEffect effect) {
			_effect = effect;
			InitializeComponent();
			var valuePixel = Language.GetString("editor_resize_pixel");
			_valuePercent = Language.GetString("editor_resize_percent");
			combobox_width.Items.Add(valuePixel);
			combobox_width.Items.Add(_valuePercent);
			combobox_width.SelectedItem = valuePixel;
			combobox_height.Items.Add(valuePixel);
			combobox_height.Items.Add(_valuePercent);
			combobox_height.SelectedItem = valuePixel;
			
			textbox_width.Text = effect.Width.ToString();
			textbox_height.Text = effect.Height.ToString();
			_newWidth = effect.Width;
			_newHeight = effect.Height;
			combobox_width.SelectedIndexChanged += combobox_SelectedIndexChanged;
			combobox_height.SelectedIndexChanged += combobox_SelectedIndexChanged;

			checkbox_aspectratio.Checked = effect.MaintainAspectRatio;
		}

		private void buttonOK_Click(object sender, EventArgs e) {
			if (_newWidth != _effect.Width || _newHeight != _effect.Height) {
				_effect.Width = (int)_newWidth;
				_effect.Height = (int)_newHeight;
				_effect.MaintainAspectRatio = checkbox_aspectratio.Checked;
				DialogResult = DialogResult.OK;
			}
		}

		private static bool Validate(object sender) {
			TextBox textbox = sender as TextBox;
			if (textbox != null) {
				double numberEntered;
				if (!double.TryParse(textbox.Text, out numberEntered)) {
					textbox.BackColor = Color.Red;
					return false;
				}
				textbox.BackColor = Color.White;
			}
			return true;
		}

		private void DisplayWidth() {
			double displayValue;
			if (_valuePercent.Equals(combobox_width.SelectedItem)) {
				displayValue = _newWidth / _effect.Width * 100d;
			} else {
				displayValue = _newWidth;
			}
			textbox_width.Text = ((int)displayValue).ToString();
		}

		private void DisplayHeight() {
			double displayValue;
			if (_valuePercent.Equals(combobox_height.SelectedItem)) {
				displayValue = _newHeight / _effect.Height * 100d;
			} else {
				displayValue = _newHeight;
			}
			textbox_height.Text = ((int)displayValue).ToString();
		}

		private void textbox_KeyUp(object sender, KeyEventArgs e) {
			if (!Validate(sender)) {
				return;
			}
			TextBox textbox = sender as TextBox;
			if (string.IsNullOrEmpty(textbox?.Text)) {
				return;
			}
			bool isWidth = textbox == textbox_width;
			if (!checkbox_aspectratio.Checked) {
				if (isWidth) {
					_newWidth = double.Parse(textbox_width.Text);
				} else {
					_newHeight = double.Parse(textbox_height.Text);
				}
				return;
			}
			var isPercent = _valuePercent.Equals(isWidth ? combobox_width.SelectedItem : combobox_height.SelectedItem);
			double percent;
			if (isWidth) {
				if (isPercent) {
					percent = double.Parse(textbox_width.Text);
					_newWidth  = _effect.Width / 100d * percent;
				} else {
					_newWidth = double.Parse(textbox_width.Text);
					percent = double.Parse(textbox_width.Text) / _effect.Width * 100d;
				}
				if (checkbox_aspectratio.Checked) {
					_newHeight = _effect.Height / 100d * percent;
					DisplayHeight();
				}
			} else {
				if (isPercent) {
					percent = double.Parse(textbox_height.Text);
					_newHeight = _effect.Height / 100d * percent;
				} else {
					_newHeight = double.Parse(textbox_height.Text);
					percent = double.Parse(textbox_height.Text) / _effect.Height * 100d;
				}
				if (checkbox_aspectratio.Checked) {
					_newWidth = _effect.Width / 100d * percent;
					DisplayWidth();
				}
			}
		}

		private void textbox_Validating(object sender, System.ComponentModel.CancelEventArgs e) {
			Validate(sender);
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void combobox_SelectedIndexChanged(object sender, EventArgs e) {
			if (Validate(textbox_width)) {
				DisplayWidth();
			}
			if (Validate(textbox_height)) {
				DisplayHeight();
			}
		}
	}
}