using UnityEditor;
using UnityEngine;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Reflection;
using Perforce.P4;

namespace P4Connect
{
	[InitializeOnLoad]
	public class Main
	{
		// Path to the Asset folder
		public static string DataPath { get; private set; }

		// Path the project folder
		public static string RootPath { get; private set; }

		// The name of the current project
		public static string ProjectName { get; private set; }

		// Import this method to override the DLLImport search directory, so that P4API.NET can load P4Bridge
		[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
		static extern bool SetDllDirectory(string lpPathName);

        // Import this method to retrieve the DLLImport search directory
        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        static extern int GetDllDirectory(int nBufferLength, StringBuilder lpPathName);

        // Import this method to retrieve the DLLImport search directory
        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        static extern IntPtr LoadLibrary(string lpModuleName);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        static extern bool FreeLibrary(IntPtr href);

		/// <summary>
		/// Static constructor
		/// </summary>
		static Main()
		{
			//Initialized = false;
			Initialize();
			//Initialized = true;
		}

		/// <summary>
		/// Initialize the different parts of P4Connect
		/// </summary>
		static public void Initialize()
		{
            Debug.Log("P4Connect Initialize");
            DateTime startTimestamp = DateTime.Now;
            SetupRootDirectory();
            SetDLLDirectory();
			Config.Initialize();
            Logger.Initialize();
			Engine.Initialize();
			AssetBridge.Initialize();
			UnityVSBridge.Initialize();
			AssetStatusCache.Initialize();
			Icons.Initialize();

			// First time - always check out sln files
			if (Config.IncludeSolutionFiles)
			{
				AssetBridge.CheckoutProjectFiles(false, true);
			}

			PendingChanges.UpdateDisplay();
            if (Config.DisplayP4Timings)
            {
                double deltaTime = (DateTime.Now - startTimestamp).TotalMilliseconds;
                StringBuilder builder = new StringBuilder();
                UnityEngine.Debug.Log("P4Connect - Initialization Time: " + deltaTime + " ms");
            }
        }

		/// <summary>
		/// Initializes the root directory, asset directory and project name
		/// </summary>
		static void SetupRootDirectory()
		{
			// Grab all the directories and project names from the asset folder
			DataPath = Application.dataPath;
			string[] path = DataPath.Split(System.IO.Path.DirectorySeparatorChar, System.IO.Path.AltDirectorySeparatorChar);
			RootPath = "";
			for (int i = 0; i < path.Length - 1; ++i)
				RootPath += path[i] + System.IO.Path.DirectorySeparatorChar;
			ProjectName = path[path.Length - 2];
		}

        // Return the currently stored DLL Directory
        public static string GetDLLDirectory()
        {
            StringBuilder tmp = new StringBuilder(10240);
            if (GetDllDirectory(10240, tmp) == 0)
            {
                int err = Marshal.GetLastWin32Error();
                UnityEngine.Debug.Log("GetDllDirectory returned error:" + err.ToString());
                return null;
            }
            
            return tmp.ToString();
        }

        public static IntPtr href = IntPtr.Zero;

		/// <summary>
		/// Allow users to override the dll search directory
		/// </summary>
		public static void SetDLLDirectory()
		{
			if (Application.platform == RuntimePlatform.WindowsEditor)
			{
                if (Utils.IsRunningUnity5())  // Unity 5.X on Windows
                {
                    // Do nothing.  Unity5 will mess up any SetDLLDirectory we try to do.
                }
                else  // Unity 4.X on Windows
                {
				// Force the DLL search directory as soon as possible
                string path = Utils.GetBridgeDirectory();
                    // Debug.Log("SetDLLDirectory to " + path);
				SetDllDirectory(path);

                    href = LoadLibrary("p4bridge");    // This global handle is never freed
                if (href == IntPtr.Zero)
                {
                    int err = Marshal.GetLastWin32Error();
                        UnityEngine.Debug.Log("p4bridge LoadLibrary Error: " + err.ToString());
                }
                else
                {
                        UnityEngine.Debug.Log("LoadLibrary Success!");
                    }
                }
			}
			else if (Application.platform == RuntimePlatform.OSXEditor)
			{
                bool copyit = false;

				string dylibSourcePath = System.IO.Path.Combine(Utils.GetBridgeDirectory(), Config.P4BridgeDYLIBName);
				string dylibDestPath = System.IO.Path.Combine(RootPath, Config.P4BridgeDYLIBName);
                Debug.Log("src: " + dylibSourcePath);
                Debug.Log("dst: " + dylibDestPath);

                if (System.IO.File.Exists(dylibDestPath))  // Compare the filesizes if both files exist.
                {
                    System.IO.FileInfo fisrc = new System.IO.FileInfo(dylibSourcePath);
                    System.IO.FileInfo fidst = new System.IO.FileInfo(dylibDestPath);
                    if (fisrc.Length != fidst.Length)
                    {
                        copyit = true;
                    }
                }
                else 
				{
                    copyit = true;  
                }
                
                if (copyit)
				{
                    System.IO.File.Copy(dylibSourcePath, dylibDestPath, true);
					EditorUtility.DisplayDialog("Restart Unity?",
						"In order for P4Connect to function on OSX, P4Connect\n" +
						"had to copy libP4Bridge.dylib to the root folder of your project\n" +
						"You now have to restart Unity for it to properly load the dylib.", "Ok");
				}
			}
		}

	}
}