#region Disclaimer / License

// Copyright (C) 2012, Jackie Ng
// http://trac.osgeo.org/mapguide/wiki/maestro, jumpinjackie@gmail.com
//
// Original code from SharpDevelop 3.2.1 licensed under the same terms (LGPL 2.1)
// Copyright 2002-2010 by
//
//  AlphaSierraPapa, Christoph Wille
//  Vordernberger Strasse 27/8
//  A-8700 Leoben
//  Austria
//
//  email: office@alphasierrapapa.com
//  court of jurisdiction: Landesgericht Leoben
//
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//

#endregion Disclaimer / License

using ICSharpCode.Core;
using IronPython.Hosting;
using IronPython.Runtime;
using Maestro.Editors.Common;
using Microsoft.Scripting.Hosting;
using Microsoft.Scripting.Hosting.Providers;
using Microsoft.Scripting.Hosting.Shell;
using System;
using System.Text;
using System.Threading;

namespace Maestro.AddIn.Scripting.Lang.Python
{
    internal interface IConsoleLineHook
    {
        void OnBeginWaitForNextLine();
    }

    /// <summary>
    /// Hosts the python console.
    /// </summary>
    internal class PythonConsoleHost : ConsoleHost, IDisposable, IConsoleLineHook
    {
        private Thread thread;
        private ITextEditor textEditor;
        private PythonConsole pythonConsole;

        public PythonConsole Console => pythonConsole;

        public PythonConsoleHost(ITextEditor textEditor)
        {
            this.textEditor = textEditor;
        }

        protected override Type Provider => typeof(PythonContext);

        /// <summary>
        /// Runs the console host in its own thread.
        /// </summary>
        public void Run()
        {
            thread = new Thread(RunConsole);
            thread.Start();
        }

        public void Dispose()
        {
            if (pythonConsole != null)
            {
                pythonConsole.Dispose();
            }

            if (thread != null)
            {
                thread.Join();
            }
        }

        protected override CommandLine CreateCommandLine() => new PythonCommandLine();

        protected override OptionsParser CreateOptionsParser() => new PythonOptionsParser();

        protected override ScriptRuntimeSetup CreateRuntimeSetup()
        {
            ScriptRuntimeSetup srs = ScriptRuntimeSetup.ReadConfiguration();
            var paths = PropertyService.Get(ScriptingConfigProperties.IronPythonModulePath, ScriptingConfigProperties.DefaultIronPythonModulePath).Split(';');
            if (srs.LanguageSetups.Count > 0)
            {
                foreach (var langSetup in srs.LanguageSetups)
                {
                    if (langSetup.FileExtensions.Contains(".py")) //NOXLATE
                    {
                        langSetup.Options["SearchPaths"] = paths; //NOXLATE
                    }
                }
            }
            else
            {
                srs.Options["SearchPaths"] = paths; //NOXLATE
            }
            return srs;
        }

        protected override void ExecuteInternal()
        {
            var pc = HostingHelpers.GetLanguageContext(Engine) as PythonContext;
            pc.SetModuleState(typeof(ScriptEngine), Engine);
            base.ExecuteInternal();
        }

        /// <remarks>
        /// After the engine is created the standard output is replaced with our custom Stream class so we
        /// can redirect the stdout to the text editor window.
        /// This can be done in this method since the Runtime object will have been created before this method
        /// is called.
        /// </remarks>
        protected override IConsole CreateConsole(ScriptEngine engine, CommandLine commandLine, ConsoleOptions options)
        {
            pythonConsole = new PythonConsole(textEditor, commandLine, this);
            SetScriptStream(new PythonOutputStream(pythonConsole, textEditor));
            return pythonConsole;
        }

        private PythonOutputStream _pyStream;

        void IConsoleLineHook.OnBeginWaitForNextLine()
        {
            if (_pyStream != null)
                _pyStream.DoneReadingForNow = false;
        }

        protected virtual void SetScriptStream(PythonOutputStream stream)
        {
            _pyStream = stream;
            Runtime.IO.SetInput(_pyStream, Encoding.UTF8);
            Runtime.IO.SetOutput(_pyStream, Encoding.UTF8);
        }

        /// <summary>
        /// Runs the console.
        /// </summary>
        private void RunConsole() => Run(new string[0]);
    }
}