using UnityEditor;
using UnityEngine;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using Perforce.P4;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Xml.Linq;
using SyntaxTree.VisualStudio.Unity.Bridge;

namespace P4Connect
{
    // Hook into Unitys Project File Generation.
    [InitializeOnLoad]
    public class VSTUFileHook
    {
        // necessary for XLinq to sae the xml project file in utf8
        class Utf8StringWriter : StringWriter
        {
            public override Encoding Encoding
            {
                get { return Encoding.UTF8; }
            }
        }

        static void ProjectFileHook()
        {
            ProjectFilesGenerator.ProjectFileGeneration += (string name, string content) =>
            {
                var document = XDocument.Parse(content);
                document.Root.Add(new XComment("PRJ FIX ME"));

                var str = new Utf8StringWriter();
                document.Save(str);
                return str.ToString();
            };
        }

        static void SolutionFileHook()
        {
            ProjectFilesGenerator.SolutionFileGeneration += (string name, string content) =>
            {
                var document = XDocument.Parse(content);
                document.Root.Add(new XComment("SLN FIX ME"));

                var str = new Utf8StringWriter();
                document.Save(str);
                return str.ToString();
            };
        }
    }


	/// <summary>
	/// This class hooks up to and handles UnityVS modifying the project files
	/// VSTU has changed a lot, this stuff may be useless by now....
	/// </summary>
	public class UnityVSBridge
	{
		// A bunch of strings used to find the project file generation event through reflection
		public const string UnityVSAssemblyName = "SyntaxTree.VisualStudio.Unity.Bridge";
		public const string UnityVSProjectFileGeneratorTypename = "SyntaxTree.VisualStudio.Unity.Bridge.ProjectFilesGenerator";
		public const string UnityVSProjectFileGenerationEventName = "ProjectFileGeneration";
		public const string UnityVSProjectFileGenerationEventHandlerType = "SyntaxTree.VisualStudio.Unity.Bridge.FileGenerationHandler";

		/// <summary>
		/// Static constructor 
		/// </summary>
		public static void Initialize()
		{
			// And hook us up to UnityVS
			if (Config.UnityVsSupport)
				SetupUnityVSHook();

			// Hook the connection settings event
			Config.PrefsChanged += OnConnectionSettingsChanged;

			// Register for project changes
			EditorApplication.projectWindowChanged += OnProjectWindowChanged;
		}

		/// <summary>
		/// Event handler called when the connection settings change
		/// </summary>
		static void OnConnectionSettingsChanged()
		{
			// Setup the root directories based on the updated path
			if (Config.UnityVsSupport)
				SetupUnityVSHook();
		}

		/// <summary>
		/// Hook up to UnityVS ProjectFile event through reflection
		/// </summary>
		static void SetupUnityVSHook()
		{
			// First, find the UnityVS assembly
			Assembly unityVSAssembly = null;
			Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
			for (int i = 0; unityVSAssembly == null && i < assemblies.Length; ++i)
			{
				if (assemblies[i].FullName.Contains(UnityVSAssemblyName))
					unityVSAssembly = assemblies[i];
			}

			if (unityVSAssembly != null)
			{
				// Now that we have the assembly, find the project file generator class
				Type projectFileGeneratorType = unityVSAssembly.GetType(UnityVSProjectFileGeneratorTypename);
				if (projectFileGeneratorType != null)
				{
					// Then the project file generation event itself
					FieldInfo projectGeneration = projectFileGeneratorType.GetField(UnityVSProjectFileGenerationEventName);
					if (projectGeneration != null)
					{
						// Make a bridge delegate to our function
						Func<string, string, string> currentDelegate = OnUnityVSProjectFilesChange;
						Type handlerType = unityVSAssembly.GetType(UnityVSProjectFileGenerationEventHandlerType);
						Delegate unityVSBridgeDelegate = Delegate.CreateDelegate(handlerType, currentDelegate.Target, currentDelegate.Method);
						if (unityVSBridgeDelegate != null)
						{
							// Register with the event handler
							projectGeneration.SetValue(null, unityVSBridgeDelegate);
						}
						else
						{
							Debug.LogError("P4Connect - Could not create conversion delegate to UnityVS ProjectFileGenerator");
						}
					}
					else
					{
						Debug.LogError("P4Connect - Could not find ProjectFileGeneration.ProjectFileGeneration() in UnityVS namespace");
					}
				}
				else
				{
					Debug.LogError("P4Connect - Could not find ProjectFileGeneration class in UnityVS namespace");
				}
			}
			else
			{
				Debug.LogError("P4Connect - UnityVS Assembly doesn't appear to be loaded");
			}
		}

		/// <summary>
		/// Called when unityVS re-creates project files
		/// </summary>
		/// <param name="name">The project being modified</param>
		/// <param name="content">The content of the project file</param>
		/// <returns>modified content if desired, we don't, we just use this method as an event</returns>
		static string OnUnityVSProjectFilesChange(string name, string content)
		{
			if (Config.UnityVsSupport)
			{
				string[] files = new string[2];

				// First file is the solution file, which we derive from the project name
				files[0] = "UnityVS." + Main.ProjectName + ".sln";

				// Second file is the project file itself
				files[1] = name;

				Engine.CheckoutAssets(files);
			}

			// We don't touch the content
			return content;
		}

		// Called whenever the project files change
		public static void OnProjectWindowChanged()
		{
			// The following files don't exist unless you have UnityVS
			if (Config.UnityVsSupport)
			{
				// Build a list of project and solution files we may want to check out
				List<string> filesToTryAndCheckOut = new List<string>(10);

				filesToTryAndCheckOut.Add(System.IO.Path.Combine(Main.RootPath, "UnityVS." + Main.ProjectName + ".CSharp.csproj"));
				filesToTryAndCheckOut.Add(System.IO.Path.Combine(Main.RootPath, "UnityVS." + Main.ProjectName + ".CSharp.Editor.csproj"));
				filesToTryAndCheckOut.Add(System.IO.Path.Combine(Main.RootPath, "UnityVS." + Main.ProjectName + ".CSharp.Plugins.csproj"));
				filesToTryAndCheckOut.Add(System.IO.Path.Combine(Main.RootPath, "UnityVS." + Main.ProjectName + ".sln"));
				filesToTryAndCheckOut.Add(System.IO.Path.Combine(Main.RootPath, "UnityVS." + Main.ProjectName + ".sln.DotSettings"));
				filesToTryAndCheckOut.Add(System.IO.Path.Combine(Main.RootPath, "UnityVS." + Main.ProjectName + ".UnityScript.Plugins.unityproj"));

				// These files may not exist (the -vs ones only exist if you have Visual Studio set up)
				// so don't try to add them and get an error if they don't exist
				List<string> filesToCheckOut = new List<string>(filesToTryAndCheckOut.Where(file => System.IO.File.Exists(file)));

				// Now pass those off to the Add method
				// The using statement will make sure the connection is Disposed (i.e. closed)
				Engine.CheckoutAssets(filesToCheckOut.ToArray());
			}
		}

       

	}
}