using System;

using System.Collections.Generic;

using System.IO;

using System.Reflection;

using System.Text;

using System.Windows.Forms;

using IronPython.Hosting;

using IronPython.Runtime;

using IronPython.Runtime.Exceptions;

using Microsoft.Scripting;

using Microsoft.Scripting.Runtime;

using Microsoft.Scripting.Hosting;

using Plugins;

namespace EmbeddingPlugin

{

    internal class PythonStream: MemoryStream

    {

        TextBox _output;

        public PythonStream(TextBox textbox)

        {

            _output = textbox;

        }

        public override void Write(byte[] buffer, int offset, int count)

        {

            _output.AppendText(Encoding.UTF8.GetString(buffer, offset, count));

        }

    }

    internal class Engine

    {

        ScriptEngine _engine;

        ScriptRuntime _runtime;

        TextBox _box;

        public List<PluginBase> Plugins

        {

            get { return PluginStore.Plugins; }

        }

        public Engine(TextBox textbox)

        {

            _engine = Python.CreateEngine();

            _runtime = _engine.Runtime;

            _box = textbox;

            SetStreams();

            string rootDir = AddAssemblies();

            LoadPlugins(rootDir);

        }

        public void SetStreams()

        {

            PythonStream stream = new PythonStream(_box);

            _runtime.IO.SetOutput(stream, Encoding.UTF8);

            _runtime.IO.SetErrorOutput(stream, Encoding.UTF8);

        }

        public string AddAssemblies()

        {

            Assembly mainAssembly = Assembly.GetExecutingAssembly();

            string rootDir = Directory.GetParent(mainAssembly.Location).FullName;

            string pluginsPath = Path.Combine(rootDir, "Plugins.dll");

            Assembly pluginsAssembly = Assembly.LoadFile(pluginsPath);

            _runtime.LoadAssembly(mainAssembly);

            _runtime.LoadAssembly(pluginsAssembly);

            _runtime.LoadAssembly(typeof(String).Assembly);

            _runtime.LoadAssembly(typeof(Uri).Assembly);

            return rootDir;

        }

        public void LoadPlugins(string rootDir)

        {

            string pluginsDir = Path.Combine(rootDir, "plugins");

            foreach (string path in Directory.GetFiles(pluginsDir))

            {

                if (path.ToLower().EndsWith(".py"))

                {

                    CreatePlugin(path);

                }

            }

        }

        public void CreatePlugin(string path)

        {

            try

            {

                ScriptSource script = _engine.CreateScriptSourceFromFile(path);

                CompiledCode code = script.Compile();

                ScriptScope scope = _engine.CreateScope();

                script.Execute(scope);

            }

            catch (SyntaxErrorException e)

            {

                string msg = "Syntax error in \"{0}\"";

                ShowError(msg, Path.GetFileName(path), e);

            }

            catch (SystemExitException e)

            {

                string msg = "SystemExit in \"{0}\"";

                ShowError(msg, Path.GetFileName(path), e);

            }

            catch (Exception e)

            {

                string msg = "Error loading plugin \"{0}\"";

                ShowError(msg, Path.GetFileName(path), e);

            }

        }

        public void ShowError(string title, string name, Exception e)

        {

            string caption = String.Format(title, name);

            ExceptionOperations eo = _engine.GetService<ExceptionOperations>();

            string error = eo.FormatException(e);

            MessageBox.Show(error, caption, MessageBoxButtons.OK, MessageBoxIcon.Error);

        }

        public void ExecutePluginAtIndex(int index)

        {

            PluginBase plugin = Plugins[index];

            try

            {

                plugin.Execute(_box);

            }

            catch (Exception e)

            {

                string msg = "Error executing plugin \"{0}\"";

                ShowError(msg, plugin.Name, e);

            }

        }

    }

}