using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using JD.Collections.Extensions;
using JD.Kernel.StaticHelpers;

namespace JD.MessageService
{
    /// <summary>
    /// This form represents a custom message box, with a variable number
    /// of buttons and a information box. Do not use this class directly. Instead, use
    /// the <see cref="MessageService"/>.
    /// </summary>
    internal partial class CustomDialog : Form
    {
        private const int Spacing = 10;
        private const int SpacingBetweenButton = 4;
        private const int ButtonLocationY = 8;
        private const int SpacingBetweenInformationBoxAndPanel = 6;
        private const int ScreenSpacing = 50;
        
        private readonly MessageDialog m_dialog;
        private MessageDialog.Button m_result;
        
        public CustomDialog(MessageDialog dialog)
        {
            Throw.IfNull(dialog, "dialog");

            m_dialog = dialog;

            InitializeComponent();
            Tag = "RemoveLock";
            SuspendLayout();

            Icon = null;

            Text = m_dialog.Caption;
            m_informationBox.Text = m_dialog.MainMessage + Environment.NewLine + Environment.NewLine + m_dialog.Content;
            m_informationBox.Icon = GetSystemIconType(m_dialog.MainIcon);

            using (Graphics g = CreateGraphics())
            {
                var buttons = CreateButtons(g);

                // start the client size to the minimum size of the information box
                int[] positions = new int[buttons.Count];
                int pos = Spacing;
                for (int i = 0; i < buttons.Count; i++)
                {
                    positions[i] = pos;
                    pos += buttons[i].Width + SpacingBetweenButton;
                }

                pos = pos - SpacingBetweenButton + Spacing; // remove space after last button + add spacing

                Size clientSize = GetClientSize(g, pos);

                ClientSize = clientSize;
                m_buttonPanel.Width = clientSize.Width;
                int start = (m_buttonPanel.Width - pos + Spacing) / 2;
                for (int i = 0; i < buttons.Count; i++)
                {
                    buttons[i].Location = new Point(start + positions[i], ButtonLocationY);
                }
                m_buttonPanel.Controls.AddRange(buttons.ToArray());

                SetupCheckbox();
            }

            ResumeLayout(false);
        }

        private Size GetClientSize(Graphics g, int pos)
        {
            Size clientSize = m_informationBox.GetMiniumSize(g);
            if (pos > clientSize.Width)
            {
                clientSize.Width = pos;
            }

            clientSize.Width += m_informationBox.Location.X * 2;
            clientSize.Height += m_informationBox.Location.Y + SpacingBetweenInformationBoxAndPanel + m_buttonPanel.Height;

            // Check that the message box will be smaller than the primary screen
            Rectangle screen = Screen.PrimaryScreen.WorkingArea;

            clientSize.Width = clientSize.Width > screen.Width ? screen.Width : clientSize.Width;
            clientSize.Height = clientSize.Height > screen.Height ? screen.Height - ScreenSpacing : clientSize.Height;
            return clientSize;
        }

        private void SetupCheckbox()
        {
            if (!string.IsNullOrEmpty(m_dialog.CheckBoxText))
            {
                CheckBox checkbox = new CheckBox
                {
                    AutoSize = true,
                    Text = m_dialog.CheckBoxText,
                    Checked = m_dialog.IsChecked
                };
                checkbox.CheckedChanged += checkbox_CheckedChanged;

                m_checkBoxPanel.Height = checkbox.Height;
                Height += m_checkBoxPanel.Height;
                m_checkBoxPanel.Controls.Add(checkbox);
                checkbox.BringToFront();

                checkbox.Location = new Point(SpacingBetweenInformationBoxAndPanel, SpacingBetweenInformationBoxAndPanel);
            }
        }

        private IList<MessageDialog.Button> SortButtons()
        {
            return m_dialog.Buttons.AsSortedStable((a, b) => GetWeight(a).CompareTo(GetWeight(b)));
        }

        private static int GetWeight(MessageDialog.Button button)
        {
            // Cancel is always last
            if (button.Id == (int)MessageDialogCommonButton.Cancel)
            {
                return 10;
            }

            // Common buttons are always last
            if (button.IsCommonButton)
            {
                return 5;
            }

            return 0;
        }

        private List<Button> CreateButtons(Graphics g)
        {
            List<Button> buttons = new List<Button>();

            foreach (var dialogButton in SortButtons())
            {
                var button = CreateButton(g, dialogButton);
                buttons.Add(button);

                if (dialogButton.IsDefault)
                {
                    AcceptButton = button;
                }

                if (dialogButton.Id == (int)MessageDialogCommonButton.Cancel)
                {
                    m_result = dialogButton;
                    CancelButton = button;
                }
            }

            if (AcceptButton == null)
            {
                AcceptButton = buttons.First();
            }

            return buttons;
        }

        private Button CreateButton(Graphics g, MessageDialog.Button dialogButton)
        {
            Button newButton = new Button
            {
                Anchor = AnchorStyles.Right,
                Enabled = dialogButton.Enabled,
                FlatStyle = FlatStyle.System,
                Tag = dialogButton,
                Text = dialogButton.Text
            };
            newButton.Click += ButtonClick;

            SizeF buttonSize = g.MeasureString(dialogButton.Text, newButton.Font);
            newButton.Width = Math.Max(newButton.Width, ((int)Math.Ceiling(buttonSize.Width / 8.0) + 1) * 8);
            return newButton;
        }
        
        #region Properties

        public MessageDialog.Button Result
        {
            get
            {
                return m_result;
            }
        }

        #endregion

        #region Methods

        private static SystemIconType GetSystemIconType(MessageDialogIcon icon)
        {
            switch (icon)
            {
                case MessageDialogIcon.Error:
                    return SystemIconType.Error;

                case MessageDialogIcon.Information:
                    return SystemIconType.Information;

                case MessageDialogIcon.Warning:
                    return SystemIconType.Warning;
            }

            return SystemIconType.Information;
        }

        #endregion

        #region Event Handlers

        private void ButtonClick(object sender, EventArgs e)
        {
            m_result = (MessageDialog.Button)((Control)sender).Tag;
            Close();
        }

        void checkbox_CheckedChanged(object sender, EventArgs e)
        {
            CheckBox checkBox = (CheckBox)sender;
            m_dialog.IsChecked = checkBox.Checked;
        }

        #endregion
    }
}