//   SparkleShare, an instant update workflow to Git.
//   Copyright (C) 2010  Hylke Bons <hylkebons@gmail.com>
//
//   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 3 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.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Xml;

using Mono.Unix;
using SparkleLib;

namespace SparkleShare {

    public abstract class SparkleController {

        public List <SparkleRepoBase> Repositories;
        public string FolderSize;
        public bool FirstRun;
        public readonly string SparklePath;

        public event OnQuitWhileSyncingEventHandler OnQuitWhileSyncing;
        public delegate void OnQuitWhileSyncingEventHandler ();

        public event FolderFetchedEventHandler FolderFetched;
        public delegate void FolderFetchedEventHandler ();
        
        public event FolderFetchErrorEventHandler FolderFetchError;
        public delegate void FolderFetchErrorEventHandler ();
        
        public event FolderListChangedEventHandler FolderListChanged;
        public delegate void FolderListChangedEventHandler ();

        public event FolderSizeChangedEventHandler FolderSizeChanged;
        public delegate void FolderSizeChangedEventHandler (string folder_size);
        
        public event AvatarFetchedEventHandler AvatarFetched;
        public delegate void AvatarFetchedEventHandler ();

        public event OnIdleEventHandler OnIdle;
        public delegate void OnIdleEventHandler ();

        public event OnSyncingEventHandler OnSyncing;
        public delegate void OnSyncingEventHandler ();

        public event OnErrorEventHandler OnError;
        public delegate void OnErrorEventHandler ();

        public event OnInvitationEventHandler OnInvitation;
        public delegate void OnInvitationEventHandler (string server, string folder, string token);

        public event ConflictNotificationRaisedEventHandler ConflictNotificationRaised;
        public delegate void ConflictNotificationRaisedEventHandler ();

        public event NotificationRaisedEventHandler NotificationRaised;
        public delegate void NotificationRaisedEventHandler (string user_name, string user_email,
                                                             string message, string repository_path);

        public event NewVersionAvailableEventHandler NewVersionAvailable;
        public delegate void NewVersionAvailableEventHandler (string new_version);

        public event VersionUpToDateEventHandler VersionUpToDate;
        public delegate void VersionUpToDateEventHandler ();

        
        // Short alias for the translations
        public static string _ (string s)
        {
            return Catalog.GetString (s);
        }


        public SparkleController ()
        {
            SparklePath = SparklePaths.SparklePath;

            // Remove temporary file
            if (Directory.Exists (SparklePaths.SparkleTmpPath))
                Directory.Delete (SparklePaths.SparkleTmpPath, true);

            InstallLauncher ();
            EnableSystemAutostart ();

            // Create the SparkleShare folder and add it to the bookmarks
            if (CreateSparkleShareFolder ())
                AddToBookmarks ();

            FolderSize = GetFolderSize ();

            string global_config_file_path     = Path.Combine (SparklePaths.SparkleConfigPath, "config.xml");
            string old_global_config_file_path = Path.Combine (SparklePaths.SparkleConfigPath, "config");

            // Show the introduction screen if SparkleShare isn't configured
            if (!File.Exists (global_config_file_path)) {
                if (File.Exists (old_global_config_file_path)) {
                    MigrateConfig ();
                    FirstRun = false;

                } else {
                    FirstRun = true;
                }

            } else {
                FirstRun = false;
                AddKey ();
            }

            // Watch the SparkleShare folder
            FileSystemWatcher watcher = new FileSystemWatcher (SparklePaths.SparklePath) {
                IncludeSubdirectories = false,
                EnableRaisingEvents   = true,
                Filter                = "*"
            };

            // Remove the repository when a delete event occurs
            watcher.Deleted += delegate (object o, FileSystemEventArgs args) {
                RemoveRepository (args.FullPath);

                if (FolderListChanged != null)
                    FolderListChanged ();

                FolderSize = GetFolderSize ();

                if (FolderSizeChanged != null)
                    FolderSizeChanged (FolderSize);
            };


            watcher.Created += delegate (object o, FileSystemEventArgs args) {

                // Handle invitations when the user saves an
                // invitation into the SparkleShare folder
                if (args.Name.EndsWith (".sparkle") && !FirstRun) {
                    XmlDocument xml_doc = new XmlDocument (); 
                    xml_doc.Load (args.Name);

                    string server = xml_doc.GetElementsByTagName ("server") [0].InnerText;
                    string folder = xml_doc.GetElementsByTagName ("folder") [0].InnerText;
                    string token  = xml_doc.GetElementsByTagName ("token") [0].InnerText;
            
                    // FIXME: this is broken :\
                    if (OnInvitation != null)
                        OnInvitation (server, folder, token);
                }
            };

            CreateConfigurationFolders ();
            new Thread (new ThreadStart (PopulateRepositories)).Start ();
        }


        // TODO: remove this later
        private void MigrateConfig () {
            string old_global_config_file_path = Path.Combine (SparklePaths.SparkleConfigPath, "config");

            StreamReader reader = new StreamReader (old_global_config_file_path);
            string global_config_file = reader.ReadToEnd ();
            reader.Close ();

            Regex regex = new Regex (@"name.+= (.+)");
            Match match = regex.Match (global_config_file);

            string user_name = match.Groups [1].Value;

            regex = new Regex (@"email.+= (.+)");
            match = regex.Match (global_config_file);

            string user_email = match.Groups [1].Value;

            UserName  = user_name;
            UserEmail = UserEmail;
            File.Delete (old_global_config_file_path);
        }


        // Uploads the user's public key to the server
        public bool AcceptInvitation (string server, string folder, string token)
        {
            // The location of the user's public key for SparkleShare
            string public_key_file_path = SparkleHelpers.CombineMore (SparklePaths.HomePath, ".ssh",
                "sparkleshare." + UserEmail + ".key.pub");

            if (!File.Exists (public_key_file_path))
                return false;

            StreamReader reader = new StreamReader (public_key_file_path);
            string public_key = reader.ReadToEnd ();
            reader.Close ();

            string url = "https://" + server + "/?folder=" + folder +
                         "&token=" + token + "&pubkey=" + public_key;

            SparkleHelpers.DebugInfo ("WebRequest", url);

            HttpWebRequest request   = (HttpWebRequest) WebRequest.Create (url);
            HttpWebResponse response = (HttpWebResponse) request.GetResponse();

            if (response.StatusCode == HttpStatusCode.OK) {
                response.Close ();
                return true;

            } else {
                response.Close ();
                return false;
            }
        }


        public List<string> Folders {
            get {
                List<string> folders = new List <string> ();
                
                foreach (SparkleRepoBase repo in Repositories)
                    folders.Add (repo.LocalPath);

                return folders;
            }
        }
        
        
        public List <SparkleChangeSet> GetLog (string name)
        {
            string path = Path.Combine (SparklePaths.SparklePath, name);
            int log_size = 30;
            
            foreach (SparkleRepoBase repo in Repositories) {
                if (repo.LocalPath.Equals (path))            
                    return repo.GetChangeSets (log_size);
            }

            return null;
        }
        
        
        public abstract string EventLogHTML { get; }
        public abstract string DayEntryHTML { get; }
        public abstract string EventEntryHTML { get; }
        
        
        public string GetHTMLLog (string name)
        {
            List <SparkleChangeSet> change_sets = GetLog (name);
            List <ActivityDay> activity_days    = new List <ActivityDay> ();
            
            if (change_sets.Count == 0)
                return null;

            foreach (SparkleChangeSet change_set in change_sets) {
                GetAvatar (change_set.UserEmail, 36);

                bool change_set_inserted = false;
                foreach (ActivityDay stored_activity_day in activity_days) {
                    if (stored_activity_day.DateTime.Year  == change_set.Timestamp.Year &&
                        stored_activity_day.DateTime.Month == change_set.Timestamp.Month &&
                        stored_activity_day.DateTime.Day   == change_set.Timestamp.Day) {

                        stored_activity_day.Add (change_set);
                        change_set_inserted = true;
                        break;
                    }
                }
                
                if (!change_set_inserted) {
                    ActivityDay activity_day = new ActivityDay (change_set.Timestamp);
                    activity_day.Add (change_set);
                    activity_days.Add (activity_day);
                }
            }

            string event_log_html   = EventLogHTML;
            string day_entry_html   = DayEntryHTML;
            string event_entry_html = EventEntryHTML;
            string event_log        = "";

            foreach (ActivityDay activity_day in activity_days) {
                string event_entries = "";

                foreach (SparkleChangeSet change_set in activity_day) {
                    string event_entry = "<dl>";
                    
                    if (change_set.IsMerge) {
                        event_entry += "<dt>Merged a branch</dt>";

                    } else {
                        if (change_set.Edited.Count > 0) {
                            event_entry += "<dt>Edited</dt>";
    
                            foreach (string file_path in change_set.Edited) {
                                string absolute_file_path = SparkleHelpers.CombineMore (SparklePaths.SparklePath,
                                    name, file_path);
                                
                                if (File.Exists (absolute_file_path))
                                    event_entry += "<dd><a href='" + absolute_file_path + "'>" + file_path + "</a></dd>";
                                else
                                    event_entry += "<dd>" + file_path + "</dd>";
                            }
                        }
    
                        if (change_set.Added.Count > 0) {
                            event_entry += "<dt>Added</dt>";
    
                            foreach (string file_path in change_set.Added) {
                                string absolute_file_path = SparkleHelpers.CombineMore (SparklePaths.SparklePath,
                                    name, file_path);
                                
                                if (File.Exists (absolute_file_path))
                                    event_entry += "<dd><a href='" + absolute_file_path + "'>" + file_path + "</a></dd>";
                                else
                                    event_entry += "<dd>" + file_path + "</dd>";
                            }
                        }
    
                        if (change_set.Deleted.Count > 0) {
                            event_entry += "<dt>Deleted</dt>";
    
                            foreach (string file_path in change_set.Deleted) {
                                string absolute_file_path = SparkleHelpers.CombineMore (SparklePaths.SparklePath,
                                    name, file_path);
                                
                                if (File.Exists (absolute_file_path))
                                    event_entry += "<dd><a href='" + absolute_file_path + "'>" + file_path + "</a></dd>";
                                else
                                    event_entry += "<dd>" + file_path + "</dd>";
                            }
                        }

                        if (change_set.MovedFrom.Count > 0) {
                            event_entry += "<dt>Moved</dt>";

                            int i = 0;
                            foreach (string file_path in change_set.MovedFrom) {
                                string to_file_path = change_set.MovedTo [i];
                                string absolute_file_path = SparkleHelpers.CombineMore (SparklePaths.SparklePath,
                                    name, file_path);
                                string absolute_to_file_path = SparkleHelpers.CombineMore (SparklePaths.SparklePath,
                                    name, to_file_path);

                                if (File.Exists (absolute_file_path))
                                    event_entry += "<dd><a href='" + absolute_file_path + "'>" + file_path + "</a><br/>" +
                                                   "<span class='moved-arrow'>&rarr;</span> ";
                                else
                                    event_entry += "<dd>" + file_path + "<br/>" +
                                                   "<span class='moved-arrow'>&rarr;</span> ";

                                if (File.Exists (absolute_to_file_path))
                                    event_entry += "<a href='" + absolute_to_file_path + "'>" + to_file_path + "</a></dd>";
                                else
                                    event_entry += to_file_path + "</dd>";

                                i++;
                            }
                        }
                    }
                        
                    event_entry   += "</dl>";
                    event_entries += event_entry_html.Replace ("<!-- $event-entry-content -->", event_entry)
                        .Replace ("<!-- $event-user-name -->", change_set.UserName)
                        .Replace ("<!-- $event-avatar-url -->", "file://" + GetAvatar (change_set.UserEmail, 36) )
                        .Replace ("<!-- $event-time -->", change_set.Timestamp.ToString ("H:mm"));
                }

                string day_entry   = "";
                DateTime today     = DateTime.Now;
                DateTime yesterday = DateTime.Now.AddDays (-1);

                if (today.Day   == activity_day.DateTime.Day &&
                    today.Month == activity_day.DateTime.Month && 
                    today.Year  == activity_day.DateTime.Year) {

                    day_entry = day_entry_html.Replace ("<!-- $day-entry-header -->", "<b>Today</b>");

                } else if (yesterday.Day   == activity_day.DateTime.Day &&
                           yesterday.Month == activity_day.DateTime.Month &&
                           yesterday.Year  == activity_day.DateTime.Year) {

                    day_entry = day_entry_html.Replace ("<!-- $day-entry-header -->", "<b>Yesterday</b>");

                } else {
                    if (activity_day.DateTime.Year != DateTime.Now.Year) {
                        // TRANSLATORS: This is the date in the event logs
                        day_entry = day_entry_html.Replace ("<!-- $day-entry-header -->",
                            "<b>" + activity_day.DateTime.ToString (_("ddd MMM d, yyyy")) + "</b>");

                    } else {
                        // TRANSLATORS: This is the date in the event logs, without the year
                        day_entry = day_entry_html.Replace ("<!-- $day-entry-header -->",
                            "<b>" + activity_day.DateTime.ToString (_("ddd MMM d")) + "</b>");
                    }
                }

                event_log += day_entry.Replace ("<!-- $day-entry-content -->", event_entries);
            }

            string html = event_log_html.Replace ("<!-- $event-log-content -->", event_log);
            return html;
        }
        
        
        // Creates a folder in the user's home folder to store configuration
        private void CreateConfigurationFolders ()
        {
            if (!Directory.Exists (SparklePaths.SparkleTmpPath))
                Directory.CreateDirectory (SparklePaths.SparkleTmpPath);

            string config_path     = SparklePaths.SparkleConfigPath;
            string local_icon_path = SparklePaths.SparkleLocalIconPath;

            if (!Directory.Exists (config_path)) {

                // Create a folder to store settings
                Directory.CreateDirectory (config_path);
                SparkleHelpers.DebugInfo ("Config", "Created '" + config_path + "'");

                // Create a folder to store the avatars
                Directory.CreateDirectory (local_icon_path);
                SparkleHelpers.DebugInfo ("Config", "Created '" + local_icon_path + "'");

                string notify_setting_file = SparkleHelpers.CombineMore (config_path, "sparkleshare.notify");

                // Enable notifications by default                
                if (!File.Exists (notify_setting_file))
                    File.Create (notify_setting_file);
            }
        }


        // Creates a .desktop entry in autostart folder to
        // start SparkleShare automatically at login
        public abstract void EnableSystemAutostart ();

        // Installs a launcher so the user can launch SparkleShare
        // from the Internet category if needed
        public abstract void InstallLauncher ();

        // Adds the SparkleShare folder to the user's
        // list of bookmarked places
        public abstract void AddToBookmarks ();

        // Creates the SparkleShare folder in the user's home folder
        public abstract bool CreateSparkleShareFolder ();

        // Opens the SparkleShare folder or an (optional) subfolder
        public abstract void OpenSparkleShareFolder (string subfolder);


        // Fires events for the current syncing state
        private void UpdateState ()
        {
            foreach (SparkleRepoBase repo in Repositories) {
                if (repo.Status == SyncStatus.SyncDown ||
                    repo.Status == SyncStatus.SyncUp   ||
                    repo.IsBuffering) {

                    if (OnSyncing != null)
                        OnSyncing ();

                    return;

                } else if (repo.HasUnsyncedChanges) {
                    if (OnError != null)
                        OnError ();

                    return;
                }
            }

            if (OnIdle != null)
                OnIdle ();

            FolderSize = GetFolderSize ();

            if (FolderSizeChanged != null)
                FolderSizeChanged (FolderSize);
        }


        // Adds a repository to the list of repositories
        private void AddRepository (string folder_path)
        {
            if (folder_path.Equals (SparklePaths.SparkleTmpPath))
                return;

            SparkleRepoBase repo = null;
            if (Directory.Exists (Path.Combine (folder_path, ".git"))) {
                repo = new SparkleRepoGit (folder_path, SparkleBackend.DefaultBackend);

            } else if (Directory.Exists (Path.Combine (folder_path, ".hg"))) {
                SparkleBackend hg_backend = new SparkleBackend ("Hg", new string [] {"/opt/local/bin/hg", "/usr/bin/hg"});
                repo = new SparkleRepoHg (folder_path, hg_backend);
            } else if (Directory.Exists (Path.Combine (folder_path, ".sparkleshare"))) {
                SparkleBackend scp_backend = new SparkleBackend ("Scp", new string [] {"/usr/bin/scp"});
                repo = new SparkleRepoScp (folder_path, scp_backend);
            }

            repo.NewChangeSet += delegate (SparkleChangeSet change_set, string repository_path) {
                string message = FormatMessage (change_set);

                if (NotificationRaised != null)
                    NotificationRaised (change_set.UserName, change_set.UserEmail, message, repository_path);
            };

            repo.ConflictResolved += delegate {
                if (ConflictNotificationRaised != null)
                    ConflictNotificationRaised ();
            };

            repo.SyncStatusChanged += delegate (SyncStatus status) {
                if (status == SyncStatus.Idle     ||
                    status == SyncStatus.SyncUp   ||
                    status == SyncStatus.SyncDown ||
                    status == SyncStatus.Error) {

                    UpdateState ();
                }
            };

            repo.ChangesDetected += delegate {
                UpdateState ();
            };

            Repositories.Add (repo);
        }


        // Removes a repository from the list of repositories and
        // updates the statusicon menu
        private void RemoveRepository (string folder_path)
        {
            string folder_name = Path.GetFileName (folder_path);

            for (int i = 0; i < Repositories.Count; i++) {
                SparkleRepoBase repo = Repositories [i];

                if (repo.Name.Equals (folder_name)) {
                    repo.Dispose ();
                    Repositories.Remove (repo);
                    repo = null;
                    break;
                }
            }
        }


        // Updates the list of repositories with all the
        // folders in the SparkleShare folder
        private void PopulateRepositories ()
        {
            Repositories = new List<SparkleRepoBase> ();

            foreach (string folder_path in Directory.GetDirectories (SparklePaths.SparklePath))
                AddRepository (folder_path);

            if (FolderListChanged != null)
                FolderListChanged ();
            
            FolderSize = GetFolderSize ();

            if (FolderSizeChanged != null)
                FolderSizeChanged (FolderSize);
        }


        public bool NotificationsEnabled {
            get {
                string notify_setting_file_path = Path.Combine (SparklePaths.SparkleConfigPath,
                    "sparkleshare.notify");

                return File.Exists (notify_setting_file_path);
            }
        } 


        public void ToggleNotifications () {
            string notify_setting_file_path = Path.Combine (SparklePaths.SparkleConfigPath,
                "sparkleshare.notify");
                                                     
            if (File.Exists (notify_setting_file_path))
                File.Delete (notify_setting_file_path);
            else
                File.Create (notify_setting_file_path);
        }


        private string GetFolderSize ()
        {
            double folder_size = CalculateFolderSize (new DirectoryInfo (SparklePaths.SparklePath));
            return FormatFolderSize (folder_size);
        }


        private string FormatMessage (SparkleChangeSet change_set)
        {
            string file_name = "";
            string message   = "";

            if (change_set.Added.Count > 0) {
                file_name = change_set.Added [0];
                message = String.Format (_("added ‘{0}’"), file_name);
            }

            if (change_set.MovedFrom.Count > 0) {
                file_name = change_set.MovedFrom [0];
                message = String.Format (_("moved ‘{0}’"), file_name);
            }

            if (change_set.Edited.Count > 0) {
                file_name = change_set.Edited [0];
                message = String.Format (_("edited ‘{0}’"), file_name);
            }

            if (change_set.Deleted.Count > 0) {
                file_name = change_set.Deleted [0];
                message = String.Format (_("deleted ‘{0}’"), file_name);
            }

            int changes_count = (change_set.Added.Count +
                                 change_set.Edited.Count +
                                 change_set.Deleted.Count +
                                 change_set.MovedFrom.Count) - 1;

            if (changes_count > 0) {
                string msg = Catalog.GetPluralString ("and {0} more", "and {0} more", changes_count);
                message += " " + String.Format (msg, changes_count);
            } else if (changes_count < 0) {
                message += _("did something magical");
            }

            return message;
        }


        // Recursively gets a folder's size in bytes
        private double CalculateFolderSize (DirectoryInfo parent)
        {
            if (!Directory.Exists (parent.ToString ()))
                return 0;

            double size = 0;

            // Ignore the temporary 'rebase-apply' and '.tmp' directories. This prevents potential
            // crashes when files are being queried whilst the files have already been deleted.
            if (parent.Name.Equals ("rebase-apply") ||
                parent.Name.Equals (".tmp"))
                return 0;

            try {
                foreach (FileInfo file in parent.GetFiles()) {
                    if (!file.Exists)
                        return 0;

                    size += file.Length;
                }

                foreach (DirectoryInfo directory in parent.GetDirectories())
                    size += CalculateFolderSize (directory);

            } catch (DirectoryNotFoundException) {
                return 0;
            }

            return size;
        }


        // Format a file size nicely with small caps.
        // Example: 1048576 becomes "1 ᴍʙ"
        private string FormatFolderSize (double byte_count)
        {
            if (byte_count >= 1099511627776)
                return String.Format ("{0:##.##}  ᴛʙ", Math.Round (byte_count / 1099511627776, 1));
            else if (byte_count >= 1073741824)
                return String.Format ("{0:##.##} ɢʙ", Math.Round (byte_count / 1073741824, 1));
            else if (byte_count >= 1048576)
                return String.Format ("{0:##.##} ᴍʙ", Math.Round (byte_count / 1048576, 1));
            else if (byte_count >= 1024)
                return String.Format ("{0:##.##} ᴋʙ", Math.Round (byte_count / 1024, 1));
            else
                return byte_count.ToString () + " bytes";
        }


        public void OpenSparkleShareFolder ()
        {
            OpenSparkleShareFolder ("");
        }

        
        // Adds the user's SparkleShare key to the ssh-agent,
        // so all activity is done with this key
        public void AddKey ()
        {
            string keys_path = SparklePaths.SparkleKeysPath;
            string key_file_name = "sparkleshare." + UserEmail + ".key";

            Process process = new Process ();
            process.StartInfo.RedirectStandardOutput = true;
            process.StartInfo.UseShellExecute        = false;
            process.StartInfo.FileName               = "ssh-add";
            process.StartInfo.Arguments              = Path.Combine (keys_path, key_file_name);
            process.Start ();
            process.WaitForExit ();
        }


        public bool BackendIsPresent {
            get {
                return SparkleBackend.DefaultBackend.IsPresent;
            }
        }


        // Looks up the user's name from the global configuration
        public string UserName
        {
            get {
                return SparkleConfig.DefaultConfig.UserName;
            }

            set {
                SparkleConfig.DefaultConfig.UserName = value;
            }
        }


        // Looks up the user's email from the global configuration
        public string UserEmail
        {
            get {
                string global_config_file_path = Path.Combine (SparklePaths.SparkleConfigPath, "config.xml");

                if (File.Exists (global_config_file_path)) {
                    XmlDocument xml = new XmlDocument();
                    xml.Load (global_config_file_path);

                    XmlNode node = xml.SelectSingleNode("//user/email/text()");
                    return node.Value;

                } else {
                    string keys_path = SparklePaths.SparkleKeysPath;

                    if (!Directory.Exists (keys_path))
                        return "";

                    foreach (string file_path in Directory.GetFiles (keys_path)) {
                        Regex regex = new Regex (@"sparkleshare\.(.+)\.key");
                        Match match = regex.Match (Path.GetFileName (file_path));

                        if (match.Success)
                            return match.Groups [1].Value;
                    }

                    return "";
                }
            }
                    
            set {
                SparkleConfig.DefaultConfig.UserEmail = value;
            }
        }
        
        
        private void WriteDefaultConfig (string user_name, string user_email)
        {
            string global_config_file_path = Path.Combine (SparklePaths.SparkleConfigPath, "config.xml");

            // Write the user's information to a text file
            TextWriter writer = new StreamWriter (global_config_file_path);
            string n          = Environment.NewLine;
            writer.WriteLine ("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>" + n +
                              "<sparkleshare>" + n +
                              "  <user>" + n +
                              "    <name>" + user_name + "</name>" + n +
                              "    <email>" + user_email + "</email>" + n +
                              "  </user>" + n +
                              "</sparkleshare>" + n);
            writer.Close ();

            SparkleHelpers.DebugInfo ("Config", "Updated '" + global_config_file_path + "'");
        }


        // Generates and installs an RSA keypair to identify this system
        public void GenerateKeyPair ()
        {
            string keys_path     = SparklePaths.SparkleKeysPath;
            string key_file_name = "sparkleshare." + UserEmail + ".key";
            string key_file_path = Path.Combine (keys_path, key_file_name);

            if (File.Exists (key_file_path)) {
                SparkleHelpers.DebugInfo ("Config", "Key already exists ('" + key_file_name + "'), " +
                                          "leaving it untouched");
                return;
            }

            if (!Directory.Exists (keys_path))
                Directory.CreateDirectory (keys_path);

            if (!File.Exists (key_file_name)) {
                Process process = new Process () {
                    EnableRaisingEvents = true
                };
                
                process.StartInfo.WorkingDirectory = keys_path;
                process.StartInfo.UseShellExecute = false;
                process.StartInfo.RedirectStandardOutput = true;
                process.StartInfo.FileName = "ssh-keygen";

                // -t is the crypto type
                // -P is the password (none)
                // -f is the file name to store the private key in
                process.StartInfo.Arguments = "-t rsa -P \"\" -f " + key_file_name;

                process.Exited += delegate {
                    SparkleHelpers.DebugInfo ("Config", "Created private key '" + key_file_name + "'");
                    SparkleHelpers.DebugInfo ("Config", "Created public key  '" + key_file_name + ".pub'");

                    // Create an easily accessible copy of the public
                    // key in the user's SparkleShare folder
                    File.Copy (key_file_path + ".pub",
                        Path.Combine (SparklePath, UserName + "'s key.txt"));
                };
                
                process.Start ();
                process.WaitForExit ();
            }
        }

        
        private void DisableHostKeyCheckingForHost (string host)
        {
            string ssh_config_file_path = SparkleHelpers.CombineMore (
                SparklePaths.HomePath, ".ssh", "config");
            
            string ssh_config = Environment.NewLine + "Host " + host + 
                                Environment.NewLine + "\tStrictHostKeyChecking no";

            if (File.Exists (ssh_config_file_path)) {
                TextWriter writer = File.AppendText (ssh_config_file_path);
                writer.WriteLine (ssh_config);
                writer.Close ();

            } else {
                TextWriter writer = new StreamWriter (ssh_config_file_path);
                writer.WriteLine (ssh_config);
                writer.Close ();
            }
            
            UnixFileSystemInfo file_info = new UnixFileInfo (ssh_config_file_path);
            file_info.FileAccessPermissions = (FileAccessPermissions.UserRead |
                                               FileAccessPermissions.UserWrite);
        }
        

        private void EnableHostKeyCheckingForHost (string host)
        {
            string ssh_config_file_path = SparkleHelpers.CombineMore (
                SparklePaths.HomePath, ".ssh", "config");

            string ssh_config = Environment.NewLine + "Host " + host + 
                                Environment.NewLine + "\tStrictHostKeyChecking no";

            if (File.Exists (ssh_config_file_path)) {
                StreamReader reader = new StreamReader (ssh_config_file_path);
                string current_ssh_config = reader.ReadToEnd ();
                reader.Close ();

                current_ssh_config = current_ssh_config.Remove (
                    current_ssh_config.IndexOf (ssh_config), ssh_config.Length);

                bool has_some_ssh_config = new Regex (@"[a-z]").IsMatch (current_ssh_config);
                if (!has_some_ssh_config) {
                    File.Delete (ssh_config_file_path);

                } else {
                    TextWriter writer = new StreamWriter (ssh_config_file_path);
                    writer.WriteLine (current_ssh_config);
                    writer.Close ();
                    
                    UnixFileSystemInfo file_info = new UnixFileInfo (ssh_config_file_path);
                    file_info.FileAccessPermissions = (FileAccessPermissions.UserRead |
                                                       FileAccessPermissions.UserWrite);
                }
            }
        }            

        
        // Gets the avatar for a specific email address and size
        public string GetAvatar (string email, int size)
        {
            string avatar_path = SparkleHelpers.CombineMore (SparklePaths.SparkleLocalIconPath,
                size + "x" + size, "status");

            if (!Directory.Exists (avatar_path)) {
                Directory.CreateDirectory (avatar_path);
                SparkleHelpers.DebugInfo ("Config", "Created '" + avatar_path + "'");
            }

            string avatar_file_path = SparkleHelpers.CombineMore (avatar_path, "avatar-" + email);

            if (File.Exists (avatar_file_path)) {
                return avatar_file_path;

            } else {
                // Let's try to get the person's gravatar for next time
                WebClient web_client = new WebClient ();
                Uri uri = new Uri ("http://www.gravatar.com/avatar/" + GetMD5 (email) +
                    ".jpg?s=" + size + "&d=404");

                string tmp_file_path = SparkleHelpers.CombineMore (SparklePaths.SparkleTmpPath, email + size);

                if (!File.Exists (tmp_file_path)) {
                    web_client.DownloadFileAsync (uri, tmp_file_path);

                    web_client.DownloadFileCompleted += delegate {
                        if (File.Exists (avatar_file_path))
                            File.Delete (avatar_file_path);

                        FileInfo tmp_file_info = new FileInfo (tmp_file_path);

                        if (tmp_file_info.Length > 255)
                            File.Move (tmp_file_path, avatar_file_path);
                        
                        if (AvatarFetched != null)
                            AvatarFetched ();
                    };
                }

                // Fall back to a generic icon if there is no gravatar
                if (File.Exists (avatar_file_path))
                    return avatar_file_path;
                else
                    return null;
            }
        }


        public void FetchFolder (string url, string name)
        {
            SparkleHelpers.DebugInfo ("Controller", "Formed URL: " + url);

            string host = GetHost (url);

            if (String.IsNullOrEmpty (host)) {
                if (FolderFetchError != null)
                    FolderFetchError ();

                return;
            }

            DisableHostKeyCheckingForHost (host);

            // Strip the '.git' from the name
            string canonical_name = Path.GetFileNameWithoutExtension (name);
            string tmp_folder     = Path.Combine (SparklePaths.SparkleTmpPath, canonical_name);

            SparkleFetcherBase fetcher;
            if (url.EndsWith (".hg")) {
                url = url.Substring (0, (url.Length - 3));
                fetcher = new SparkleFetcherHg (url, tmp_folder);
            } else if (url.EndsWith (".scp")) {
                url = url.Substring (0, (url.Length - 4));
                fetcher = new SparkleFetcherScp (url, tmp_folder);
            } else {
                fetcher = new SparkleFetcherGit (url, tmp_folder);
            }

            bool target_folder_exists = Directory.Exists (Path.Combine (SparklePaths.SparklePath, canonical_name));

            // Add a numbered suffix to the nameif a folder with the same name
            // already exists. Example: "Folder (2)"
            int i = 1;
            while (target_folder_exists) {
                i++;
                target_folder_exists = Directory.Exists (
                    Path.Combine (SparklePaths.SparklePath, canonical_name + " (" + i + ")"));
            }

            string target_folder_name = canonical_name;
            if (i > 1)
                target_folder_name += " (" + i + ")";

            fetcher.Finished += delegate {
                EnableHostKeyCheckingForHost (host);

                // Needed to do the moving
                SparkleHelpers.ClearAttributes (tmp_folder);
                string target_folder_path = Path.Combine (SparklePaths.SparklePath, target_folder_name);

                try {
                    Directory.Move (tmp_folder, target_folder_path);
                } catch (Exception e) {
                    SparkleHelpers.DebugInfo ("Controller", "Error moving folder: " + e.Message);
                }

                AddRepository (target_folder_path);

                if (FolderFetched != null)
                    FolderFetched ();

                FolderSize = GetFolderSize ();

                if (FolderSizeChanged != null)
                    FolderSizeChanged (FolderSize);

                if (FolderListChanged != null)
                    FolderListChanged ();

                fetcher.Dispose ();
            };


            fetcher.Failed += delegate {
                EnableHostKeyCheckingForHost (host);

                if (Directory.Exists (tmp_folder)) {
                    SparkleHelpers.ClearAttributes (tmp_folder);
                    Directory.Delete (tmp_folder, true);

                    SparkleHelpers.DebugInfo ("Config",
                        "Deleted temporary directory: " + tmp_folder);
                }

                if (FolderFetchError != null)
                    FolderFetchError ();

                fetcher.Dispose ();
            };


            fetcher.Start ();
        }


        // Creates an MD5 hash of input
        private string GetMD5 (string s)
        {
            MD5 md5 = new MD5CryptoServiceProvider ();
            Byte[] bytes = ASCIIEncoding.Default.GetBytes (s);
            Byte[] encoded_bytes = md5.ComputeHash (bytes);
            return BitConverter.ToString (encoded_bytes).ToLower ().Replace ("-", "");
        }


        private string GetHost (string url)
        {
            Regex regex = new Regex (@"(@|://)([a-z0-9\.]+)(/|:)");
            Match match = regex.Match (url);

            if (match.Success)
                return match.Groups [2].Value;
            else
                return null;
        }


        // Checks whether there are any folders syncing and
        // quits if safe
        public void TryQuit ()
        {
            foreach (SparkleRepoBase repo in Repositories) {
                if (repo.Status == SyncStatus.SyncUp   ||
                    repo.Status == SyncStatus.SyncDown ||
                    repo.IsBuffering) {

                    if (OnQuitWhileSyncing != null)
                        OnQuitWhileSyncing ();
                    
                    return;
                }
            }
            
            Quit ();
        }


        public void Quit ()
        {
            foreach (SparkleRepoBase repo in Repositories)
                repo.Dispose ();

            Environment.Exit (0);
        }


        // Checks to see if an email address is valid
        public bool IsValidEmail (string email)
        {
            Regex regex = new Regex (@"^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$", RegexOptions.IgnoreCase);
            return regex.IsMatch (email);
        }


        public void CheckForNewVersion ()
        {
            string new_version_file_path = System.IO.Path.Combine (SparklePaths.SparkleTmpPath,
                "version");

            if (File.Exists (new_version_file_path))
                File.Delete (new_version_file_path);

            WebClient web_client = new WebClient ();
            Uri uri = new Uri ("http://www.sparkleshare.org/version");

            web_client.DownloadFileCompleted += delegate {

                if (new FileInfo (new_version_file_path).Length > 0) {
                    StreamReader reader = new StreamReader (new_version_file_path);
                    string downloaded_version_number = reader.ReadToEnd ().Trim ();

                    if (Defines.VERSION.Equals (downloaded_version_number)) {
                        if (VersionUpToDate != null)
                            VersionUpToDate ();
                    } else {
                        if (NewVersionAvailable != null)
                            NewVersionAvailable (downloaded_version_number);
                    }
                }
            };

            web_client.DownloadFileAsync (uri, new_version_file_path);
        }
    }


    public class ChangeSet : SparkleChangeSet { }
    
    
    // All change sets that happened on a day
    public class ActivityDay : List <SparkleChangeSet>
    {
        public DateTime DateTime;

        public ActivityDay (DateTime date_time)
        {
            DateTime = date_time;
            DateTime = new DateTime (DateTime.Year, DateTime.Month, DateTime.Day);
        }
    }
}