using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using Microsoft.Win32;
using Shadowsocks.Controller;
using Shadowsocks.Model;
using Shadowsocks.Properties;

namespace Shadowsocks.View
{
    public partial class ConfigForm : Form
    {
        private ShadowsocksController controller;

        // this is a copy of configuration that we are working on
        private Configuration _modifiedConfiguration;
        private int _oldSelectedIndex = -1;

        private ContextMenuStrip ServersListBoxContextMenu = null;

        public ConfigForm(ShadowsocksController controller)
        {
            this.Font = System.Drawing.SystemFonts.MessageBoxFont;
            InitializeComponent();

            // a dirty hack
            this.ServersListBox.Dock = System.Windows.Forms.DockStyle.Fill;
            this.PerformLayout();

            UpdateTexts();
            this.Icon = Icon.FromHandle(Resources.ssw128.GetHicon());

            this.controller = controller;
            controller.ConfigChanged += controller_ConfigChanged;

            LoadCurrentConfiguration();
        }

        private void ServersListBoxContextMenu_Opening(object sender, CancelEventArgs e)
        {
            //clear the menu and add custom items
            string contextItemText = I18N.GetString("Select");

            ServersListBoxContextMenu.Items.Clear();
            ToolStripItem item = new ToolStripMenuItem();
            item.Name = string.Format("{0}", ServersListBox.SelectedIndex.ToString());
            item.Text = string.Format("{0} - {1}", contextItemText, ServersListBox.SelectedItem.ToString());
            ServersListBoxContextMenu.Items.Add(item);
            ServersListBoxContextMenu.ItemClicked += new ToolStripItemClickedEventHandler(ServersListBoxContextMenu_ItemClicked);
        }

        void ServersListBoxContextMenu_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {
            ToolStripItem item = e.ClickedItem;
            controller.SelectServerIndex(int.Parse(item.Name));
        }

        private void ServersListBox_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                //select the item under the mouse pointer
                ServersListBox.SelectedIndex = ServersListBox.IndexFromPoint(e.Location);
                if (ServersListBox.SelectedIndex != -1)
                {
                    ServersListBoxContextMenu.Show();
                }
            }
        }

        private void UpdateTexts()
        {
            AddButton.Text = I18N.GetString("&Add");
            DeleteButton.Text = I18N.GetString("&Delete");
            IPLabel.Text = I18N.GetString("Server IP");
            ServerPortLabel.Text = I18N.GetString("Server Port");
            PasswordLabel.Text = I18N.GetString("Password");
            EncryptionLabel.Text = I18N.GetString("Encryption");
            ProxyPortLabel.Text = I18N.GetString("Proxy Port");
            RemarksLabel.Text = I18N.GetString("Remarks");
            ServerGroupBox.Text = I18N.GetString("Server");
            OKButton.Text = I18N.GetString("OK");
            MyCancelButton.Text = I18N.GetString("Cancel");
            URIButton.Text = I18N.GetString("URI Parse");
            this.Text = I18N.GetString("Edit Servers");
        }

        private void controller_ConfigChanged(object sender, EventArgs e)
        {
            LoadCurrentConfiguration();
        }
        
        private void ShowWindow()
        {
            this.Opacity = 1;
            this.Show();
            IPTextBox.Focus();
        }

        private bool SaveOldSelectedServer()
        {
            try
            {
                if (_oldSelectedIndex == -1 || _oldSelectedIndex >= _modifiedConfiguration.configs.Count)
                {
                    return true;
                }
                Server server = new Server
                {
                    server = IPTextBox.Text,
                    server_port = int.Parse(ServerPortTextBox.Text),
                    password = PasswordTextBox.Text,
                    local_port = int.Parse(ProxyPortTextBox.Text),
                    method = EncryptionSelect.Text,
                    remarks = RemarksTextBox.Text
                };
                Configuration.CheckServer(server);
                _modifiedConfiguration.configs[_oldSelectedIndex] = server;
                
                return true;
            }
            catch (FormatException)
            {
                MessageBox.Show(I18N.GetString("Illegal port number format"));
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return false;
        }

        private void LoadSelectedServer()
        {
            if (ServersListBox.SelectedIndex >= 0 && ServersListBox.SelectedIndex < _modifiedConfiguration.configs.Count)
            {
                Server server = _modifiedConfiguration.configs[ServersListBox.SelectedIndex];

                IPTextBox.Text = server.server;
                ServerPortTextBox.Text = server.server_port.ToString();
                PasswordTextBox.Text = server.password;
                ProxyPortTextBox.Text = server.local_port.ToString();
                EncryptionSelect.Text = server.method ?? "aes-256-cfb";
                RemarksTextBox.Text = server.remarks;
                ServerGroupBox.Visible = true;
                //IPTextBox.Focus();
            }
            else
            {
                ServerGroupBox.Visible = false;
            }
        }

        private void LoadConfiguration(Configuration configuration)
        {
            ServersListBox.Items.Clear();
            foreach (Server server in _modifiedConfiguration.configs)
            {
                ServersListBox.Items.Add(server.FriendlyName());
            }
        }

        private void LoadCurrentConfiguration()
        {
            _modifiedConfiguration = controller.GetConfiguration();
            LoadConfiguration(_modifiedConfiguration);
            _oldSelectedIndex = _modifiedConfiguration.index;
            ServersListBox.SelectedIndex = _modifiedConfiguration.index;
            LoadSelectedServer();
        }

        private void ConfigForm_Load(object sender, EventArgs e)
        {
            ServersListBoxContextMenu = new ContextMenuStrip();
            ServersListBoxContextMenu.Opening += new CancelEventHandler(ServersListBoxContextMenu_Opening);
            ServersListBox.ContextMenuStrip = ServersListBoxContextMenu;
        }

        private void ServersListBox_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (_oldSelectedIndex == ServersListBox.SelectedIndex)
            {
                // we are moving back to oldSelectedIndex or doing a force move
                return;
            }
            if (!SaveOldSelectedServer())
            {
                // why this won't cause stack overflow?
                ServersListBox.SelectedIndex = _oldSelectedIndex;
                return;
            }
            LoadSelectedServer();
            _oldSelectedIndex = ServersListBox.SelectedIndex;
        }

        private void AddButton_Click(object sender, EventArgs e)
        {
            if (!SaveOldSelectedServer())
            {
                return;
            }
            Server server = Configuration.GetDefaultServer();
            _modifiedConfiguration.configs.Add(server);
            LoadConfiguration(_modifiedConfiguration);
            ServersListBox.SelectedIndex = _modifiedConfiguration.configs.Count - 1;
            _oldSelectedIndex = ServersListBox.SelectedIndex;
        }

        private void DeleteButton_Click(object sender, EventArgs e)
        {
            _oldSelectedIndex = ServersListBox.SelectedIndex;
            if (_oldSelectedIndex >= 0 && _oldSelectedIndex < _modifiedConfiguration.configs.Count)
            {
                _modifiedConfiguration.configs.RemoveAt(_oldSelectedIndex);
            }
            if (_oldSelectedIndex >= _modifiedConfiguration.configs.Count)
            {
                // can be -1
                _oldSelectedIndex = _modifiedConfiguration.configs.Count - 1;
            }
            ServersListBox.SelectedIndex = _oldSelectedIndex;
            LoadConfiguration(_modifiedConfiguration);
            ServersListBox.SelectedIndex = _oldSelectedIndex;
            LoadSelectedServer();
        }

        private void OKButton_Click(object sender, EventArgs e)
        {
            if (!SaveOldSelectedServer())
            {
                return;
            }
            if (_modifiedConfiguration.configs.Count == 0)
            {
                MessageBox.Show(I18N.GetString("Please add at least one server"));
                return;
            }
            controller.SaveServers(_modifiedConfiguration.configs);
            //this.Close();
        }

        private void CancelButton_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void ConfigForm_Shown(object sender, EventArgs e)
        {
            IPTextBox.Focus();
        }

        private void ConfigForm_FormClosed(object sender, FormClosedEventArgs e)
        {
            controller.ConfigChanged -= controller_ConfigChanged;
        }

        private void URIButton_Click(object sender, EventArgs e)
        {
            URIParseForm uriParseForm = new URIParseForm();
            uriParseForm.ShowDialog(this);
            if(uriParseForm.Parsed)
            {
                if (!SaveOldSelectedServer())
                {
                    return;
                }

                _modifiedConfiguration.configs.Add(uriParseForm.server);
                LoadConfiguration(_modifiedConfiguration);
                ServersListBox.SelectedIndex = _modifiedConfiguration.configs.Count - 1;
                _oldSelectedIndex = ServersListBox.SelectedIndex;
            }

        }

    }
}