using System;
using System.ComponentModel;
using System.Drawing;
using System.IO;

namespace ShortcutKeyFinder
{
    /// <summary>Class to perform operations on shortcut (.lnk) files</summary>
    class Shortcut : INotifyPropertyChanged
    {
        private bool _hasDuplicateHotkey;
        private Hotkey _hotkey;
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>Name of the shortcut as displayed by Windows Explorer</summary>
        /// <remarks>Not necessarily the same as the shortcut's filename</remarks>
        public string Name { get; private set; }

        /// <summary>Full path of the shortcut file</summary>
        public string Path { get; private set; }

        /// <summary>Full path of the shortcut's parent directory</summary>
        public string Location
        {
            get { return System.IO.Path.GetDirectoryName(Path); }
        }

        /// <summary>Display name of the shortcut's parent directory</summary>
        /// <remarks>Gives the user a general idea of where the shortcut is located rather than the full path</remarks>
        public string DisplayLocation
        {
            get {
                return Location
                    .Replace(Environment.GetFolderPath(Environment.SpecialFolder.StartMenu), "Start Menu")
                    .Replace(Environment.GetFolderPath(Environment.SpecialFolder.CommonStartMenu), "Start Menu")
                    .Replace(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory), "Desktop")
                    .Replace(Environment.GetFolderPath(Environment.SpecialFolder.CommonDesktopDirectory), "Desktop");
            }

        }

        /// <summary>Hotkey associated with the shortcut</summary>
        public Hotkey Hotkey
        {
            get { return _hotkey; }
            set
            {
                if (value != _hotkey)
                {
                    _hotkey = value;
                    NotifyPropertyChanged("Hotkey");
                }
            }
        }

        /// <summary>Icon associated with the shortcut</summary>
        public Image Icon { get; private set; }

        /// <summary>Indicates whether this shortcut's hotkey is the same as that of another shortcut</summary>
        /// <remarks>Always false unless set to true by some other class</remarks>
        public bool HasDuplicateHotkey
        {
            get { return _hasDuplicateHotkey; }
            set
            {
                if (value != _hasDuplicateHotkey)
                {
                    _hasDuplicateHotkey = value;
                    NotifyPropertyChanged("HasDuplicateHotkey");
                }
            }
        }

        /// <summary>Indicates whether the user has permissions to modify the shortcut</summary>
        /// <remarks>Always false unless set to true by some other class</remarks>
        public bool ReadOnly { get; set; }

        /// <summary>Constructor</summary>
        /// <param name="path">Full path to a shortcut (.lnk) file</param>
        public Shortcut(string path)
        {
            Path = path;
            LoadShortcutInfo();
        }

        /// <summary>Implements the <see cref="INotifyPropertyChanged"/> interface</summary>
        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }

        /// <summary>Constructor</summary>
        private void LoadShortcutInfo()
        {
            ushort hotkey = Win32Helpers.GetShortcutHotkey(Path);
            if (hotkey != 0)
                Hotkey = new Hotkey(hotkey);
            FileInfo info = Win32Helpers.GetFileInfo(Path, true, true);
            if (info != null)
            {
                Name = info.DisplayName;
                Icon = info.Icon.ToBitmap();
            }
        }

        /// <summary>Shows the Windows Explorer properties window for the shortcut</summary>
        /// <param name="parentWindow">Optional handle to a parent window for use when displaying error messages</param>
        public void ShowExplorerPropertiesWindow(IntPtr parentWindow = default(IntPtr))
        {
            Win32Helpers.ShowFilePropertiesWindow(Path, parentWindow);
        }

        /// <summary>Writes the shortcut data to disk</summary>
        public void Save()
        {
            if (!Win32Helpers.SetShortcutHotkey(Path, Hotkey != null ? Hotkey.RawHotkey : (ushort)0))
                throw new UnauthorizedAccessException();
        }

        /// <summary>Determine whether two shortcuts are the same file</summary>
        public override bool Equals(object obj)
        {
            Shortcut shortcut = obj as Shortcut;
            return shortcut != null && shortcut.Path == Path;
        }

        public override int GetHashCode()
        {
            return Path.GetHashCode();
        }
    }
}