/*
 * File Association Class Created By Farbod D
 */
using System;
using Microsoft.Win32;
using System.Windows.Forms;

namespace SHNDecrypt
{
    class FileAssociation
    {
        private static void AssociationInformation(String Ext, String ProgID, String ContentType, String Description)
        {
            Registry.ClassesRoot.CreateSubKey(Ext, RegistryKeyPermissionCheck.ReadWriteSubTree).SetValue("", ProgID);
            Registry.ClassesRoot.CreateSubKey(Ext, RegistryKeyPermissionCheck.ReadWriteSubTree).SetValue("Content Type", ContentType);
            Registry.ClassesRoot.CreateSubKey(ProgID + "\\shell\\open\\command").SetValue("", Application.ExecutablePath + " \"%1\"", RegistryValueKind.String);
            Registry.ClassesRoot.CreateSubKey(ProgID, RegistryKeyPermissionCheck.ReadWriteSubTree).SetValue("", Description, RegistryValueKind.String);
            Registry.ClassesRoot.CreateSubKey(ProgID + "\\DefaultIcon").SetValue("", Application.ExecutablePath, RegistryValueKind.String);
        }

        public static String AssociationCreation(String Ext, String ProgID, String ContentType, String[] OpenWithList = null, Boolean DeleteOldCreateNew = true, String Description = "No descrption")
        {
            String creationString = "null";

            try
            {
                Registry.ClassesRoot.OpenSubKey(Ext);
                if (DeleteOldCreateNew == true)
                {
                    try { Registry.ClassesRoot.DeleteSubKeyTree(Ext, false); }
                    catch (Exception) { }

                    if (Ext == null || ProgID == null || ContentType == null)
                    {
                        if (Ext == null) { return creationString = "Please check extension."; }
                        else if (ProgID == null) { return creationString = "Please check program ID."; }
                        else if (ContentType == null) { return creationString = "Please check content type."; }
                        else { return creationString = "An unknown error occured."; }
                    }
                    else
                    {
                        if (OpenWithList == null)
                        {
                            AssociationInformation(Ext, ProgID, ContentType, Description);
                            return creationString = "Association with " + Ext + " files have been created successfully without an open list.";
                        }
                        else
                        {
                            foreach (string Prog in OpenWithList)
                            {
                                Registry.ClassesRoot.CreateSubKey(Ext + "\\OpenWithList\\" + Prog, RegistryKeyPermissionCheck.ReadWriteSubTree);
                            }
                            AssociationInformation(Ext, ProgID, ContentType, Description);
                            return creationString = "Association with " + Ext + " files have been created successfully with the appropriate open list.";
                        }
                    }
                }
                return creationString = "A sub key already exsists for this file extension.";
            }
            catch (NullReferenceException)
            {
                if (Ext == null || ProgID == null || ContentType == null)
                {
                    if (Ext == null) { return creationString = "Please check extension."; }
                    else if (ProgID == null) { return creationString = "Please check program ID."; }
                    else if (ContentType == null) { return creationString = "Please check content type."; }
                    else { return creationString = "An unknown error occured."; }
                }
                else
                {
                    if (OpenWithList == null)
                    {
                        AssociationInformation(Ext, ProgID, ContentType, Description);
                        return creationString = "Association with " + Ext + " files have been created successfully without an open list.";
                    }
                    else
                    {
                        foreach (string Prog in OpenWithList)
                        {
                            Registry.ClassesRoot.CreateSubKey(Ext + "\\OpenWithList\\" + Prog, RegistryKeyPermissionCheck.ReadWriteSubTree);
                        }
                        AssociationInformation(Ext, ProgID, ContentType, Description);
                        return creationString = "Association with " + Ext + " files have been created successfully with the appropriate open list.";
                    }
                }
            }
            catch (Exception ex)
            {
                return creationString = "An unknown error occured: " + ex.Message;
            }
        }

        public static void AssociationDeletion(String Ext, String ProgID)
        {
            try
            {
                Registry.ClassesRoot.DeleteSubKeyTree(Ext, false);
                Registry.ClassesRoot.DeleteSubKeyTree(ProgID, false);
                Registry.CurrentUser.DeleteSubKeyTree("Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\FileExts\\" + Ext, false);
            }
            catch (Exception) { }
        }

        public static Boolean AssociationCheck(String Ext, String ProgID)
        {
            try
            {
                Registry.ClassesRoot.OpenSubKey(Ext);
                if (Registry.ClassesRoot.OpenSubKey(Ext).GetValue("").ToString() != ProgID) return false;
                return true;
            }
            catch (NullReferenceException)
            {
                return false;
            }
        }
    }
}