//   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.IO;
using System.Diagnostics;
using System.Threading;

namespace SparkleLib {

    // Sets up a fetcher that can get remote folders
    public class SparkleFetcher {

        public delegate void StartedEventHandler (object o, SparkleEventArgs args);
        public delegate void FinishedEventHandler (object o, SparkleEventArgs args);
        public delegate void FailedEventHandler (object o, SparkleEventArgs args);

        public event StartedEventHandler Started;
        public event FinishedEventHandler Finished;
        public event FailedEventHandler Failed;

        private string target_folder;
        private string remote_url;
        private Thread thread;


        public SparkleFetcher (string remote_url, string target_folder)
        {
            this.target_folder = target_folder;
            this.remote_url    = remote_url;
        }


        // Clones the remote repository
        public void Start ()
        {
            SparkleHelpers.DebugInfo ("Fetcher", "[" + this.target_folder + "] Fetching folder...");

            if (Started != null)
                Started (this, new SparkleEventArgs ("Started"));

            if (Directory.Exists (this.target_folder))
                Directory.Delete (this.target_folder, true);

            this.thread = new Thread (new ThreadStart (delegate {
                if (Fetch ()) {
                    SparkleHelpers.DebugInfo ("Fetcher", "[" + this.target_folder + "] Fetching finished");

                    if (Finished != null)
                        Finished (this, new SparkleEventArgs ("Finished"));
                } else {
                    SparkleHelpers.DebugInfo ("Fetcher", "[" + this.target_folder + "] Fetching failed");

                    if (Failed != null)
                        Failed (this, new SparkleEventArgs ("Failed"));
                }
            }));

            this.thread.Start ();
        }


        public void Dispose ()
        {
            this.thread.Abort ();
            this.thread.Join ();
        }


        // TODO: abstract -> override
        public virtual bool Fetch ()
        {
            SparkleGit git = new SparkleGit (SparklePaths.SparkleTmpPath,
                "clone \"" + this.remote_url + "\" " + "\"" + this.target_folder + "\"");

            git.Start ();
            git.WaitForExit ();

            SparkleHelpers.DebugInfo ("Git", "Exit code " + git.ExitCode.ToString ());

            if (git.ExitCode != 0) {
                return false;
            } else {
                InstallConfiguration ();
                InstallExcludeRules ();
                return true;
            }
        }


        // Install the user's name and email and some config into
        // the newly cloned repository
        private void InstallConfiguration ()
        {
            string global_config_file_path = Path.Combine (SparklePaths.SparkleConfigPath, "config");

            if (File.Exists (global_config_file_path)) {
                StreamReader reader = new StreamReader (global_config_file_path);
                string user_info = reader.ReadToEnd ();
                reader.Close ();

                string repo_config_file_path = SparkleHelpers.CombineMore (this.target_folder, ".git", "config");
                string config = String.Join ("\n", File.ReadAllLines (repo_config_file_path));

                // Be case sensitive explicitly to work on Mac
                config = config.Replace ("ignorecase = true", "ignorecase = false");

                // Ignore permission changes
                config = config.Replace ("filemode = true", "filemode = false");

                // Add user info
                config += Environment.NewLine + user_info;

                TextWriter writer = new StreamWriter (repo_config_file_path);
                writer.WriteLine (config);
                writer.Close ();

                SparkleHelpers.DebugInfo ("Config", "Added configuration to '" + repo_config_file_path + "'");
            }
        }


        // Add a .gitignore file to the repo
        private void InstallExcludeRules ()
        {
            string exlude_rules_file_path = SparkleHelpers.CombineMore (
                this.target_folder, ".git", "info", "exclude");

            TextWriter writer = new StreamWriter (exlude_rules_file_path);

                // gedit and emacs
                writer.WriteLine ("*~");

                // vi(m)
                writer.WriteLine (".*.sw[a-z]");
                writer.WriteLine ("*.un~");
                writer.WriteLine ("*.swp");
                writer.WriteLine ("*.swo");
                
                // KDE
                writer.WriteLine (".directory");
    
                // Mac OSX
                writer.WriteLine (".DS_Store");
                writer.WriteLine ("Icon?");
                writer.WriteLine ("._*");
                writer.WriteLine (".Spotlight-V100");
                writer.WriteLine (".Trashes");

                // Mac OSX
                writer.WriteLine ("*(Autosaved).graffle");
            
                // Windows
                writer.WriteLine ("Thumbs.db");
                writer.WriteLine ("Desktop.ini");

                // CVS
                writer.WriteLine ("*/CVS/*");
                writer.WriteLine (".cvsignore");
                writer.WriteLine ("*/.cvsignore");
                
                // Subversion
                writer.WriteLine ("/.svn/*");
                writer.WriteLine ("*/.svn/*");

            writer.Close ();
        }
    }
}