using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Windows.Forms;
using Dalamud.DiscordBot;
using Dalamud.Game.Chat;
using EasyHook;
using Newtonsoft.Json;

namespace Dalamud.Injector {
    internal static class Program {
        static private Process process = null;

        private static void Main(string[] args) {

            AppDomain.CurrentDomain.UnhandledException += delegate(object sender, UnhandledExceptionEventArgs eventArgs)
            {
                File.WriteAllText("InjectorException.txt", eventArgs.ExceptionObject.ToString());
#if !DEBUG
                MessageBox.Show("Failed to inject the XIVLauncher in-game addon.\nPlease try restarting your game and your PC.\nIf this keeps happening, please report this error.", "XIVLauncher Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
#else
                MessageBox.Show("Couldn't inject.\nMake sure that Dalamud was not injected into your target process as a release build before and that the target process can be accessed with VM_WRITE permissions.\n\n" + eventArgs.ExceptionObject, "Debug Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
#endif
                Environment.Exit(0);
            };


            var pid = -1;
            if (args.Length == 1) {
                pid = int.Parse(args[0]);
            }

            switch (pid) {
                case -1:
                    process = Process.GetProcessesByName("ffxiv_dx11")[0];
                    break;
                case -2:
                    process = Process.Start(
                        "C:\\Program Files (x86)\\SquareEnix\\FINAL FANTASY XIV - A Realm Reborn\\game\\ffxiv_dx11.exe",
                        "DEV.TestSID=0 DEV.UseSqPack=1 DEV.DataPathType=1 DEV.LobbyHost01=127.0.0.1 DEV.LobbyPort01=54994 DEV.LobbyHost02=127.0.0.1 DEV.LobbyPort02=54994 DEV.LobbyHost03=127.0.0.1 DEV.LobbyPort03=54994 DEV.LobbyHost04=127.0.0.1 DEV.LobbyPort04=54994 DEV.LobbyHost05=127.0.0.1 DEV.LobbyPort05=54994 DEV.LobbyHost06=127.0.0.1 DEV.LobbyPort06=54994 DEV.LobbyHost07=127.0.0.1 DEV.LobbyPort07=54994 DEV.LobbyHost08=127.0.0.1 DEV.LobbyPort08=54994 SYS.Region=0 language=1 version=1.0.0.0 DEV.MaxEntitledExpansionID=2 DEV.GMServerHost=127.0.0.1 DEV.GameQuitMessageBox=0");
                    Thread.Sleep(1000);
                    break;
                default:
                    process = Process.GetProcessById(pid);
                    break;
            }

            DalamudStartInfo startInfo;
            if (args.Length <= 1) {
                startInfo = GetDefaultStartInfo();
                Console.WriteLine("\nA Dalamud start info was not found in the program arguments. One has been generated for you.");
                Console.WriteLine("\nCopy the following contents into the program arguments:");
                Console.WriteLine();
                Console.WriteLine(Convert.ToBase64String(Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(startInfo))));
            } else {
                startInfo = JsonConvert.DeserializeObject<DalamudStartInfo>(Encoding.UTF8.GetString(Convert.FromBase64String(args[1])));
            }

            startInfo.WorkingDirectory = Directory.GetCurrentDirectory();

            // Seems to help with the STATUS_INTERNAL_ERROR condition
            Thread.Sleep(1000);

            //Thread.Sleep(10000);

            // Inject to process
            Inject(process, startInfo);

            // Inject exception handler
            NativeInject(process);
        }

        private static void Inject(Process process, DalamudStartInfo info) {
            Console.WriteLine($"Injecting to {process.Id}");

            // File check
            var libPath = Path.GetFullPath("Dalamud.dll");
            if (!File.Exists(libPath)) {
                Console.WriteLine($"Can't find a dll on {libPath}");
                return;
            }

            RemoteHooking.Inject(process.Id, InjectionOptions.DoNotRequireStrongName, libPath, libPath, info);

            Console.WriteLine("Injected");
        }

        private static void NativeInject(Process process) {
            var libPath = Path.GetFullPath("DalamudDebugStub.dll");

            var handle = NativeFunctions.OpenProcess(
                NativeFunctions.ProcessAccessFlags.All,
                false,
                process.Id);

            if (handle == IntPtr.Zero)
                throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not OpenProcess");

            var dllMem = NativeFunctions.VirtualAllocEx(
                handle,
                IntPtr.Zero,
                libPath.Length,
                NativeFunctions.AllocationType.Reserve | NativeFunctions.AllocationType.Commit,
                NativeFunctions.MemoryProtection.ExecuteReadWrite);

            if (dllMem == IntPtr.Zero)
                throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not alloc memory");

            var pathBytes = Encoding.ASCII.GetBytes(libPath);
            if (!NativeFunctions.WriteProcessMemory(
                    handle,
                    dllMem,
                    pathBytes,
                    pathBytes.Length,
                    out var bytesread
                ))
                throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not write DLL");

            var kernel32 = NativeFunctions.GetModuleHandle("Kernel32.dll");
            var loadLibA = NativeFunctions.GetProcAddress(kernel32, "LoadLibraryA");

            var remoteThread = NativeFunctions.CreateRemoteThread(
                handle,
                IntPtr.Zero,
                0,
                loadLibA,
                dllMem,
                0,
                IntPtr.Zero
            );

            if (remoteThread == IntPtr.Zero)
                throw new Win32Exception(Marshal.GetLastWin32Error(), "Could not alloc memory");

            NativeFunctions.VirtualFreeEx(
                handle,
                dllMem,
                0,
                NativeFunctions.AllocationType.Release);

            NativeFunctions.CloseHandle(remoteThread);
            NativeFunctions.CloseHandle(handle);
        }

        private static DalamudStartInfo GetDefaultStartInfo() {
            var ffxivDir = Path.GetDirectoryName(process.MainModule.FileName);
            var startInfo = new DalamudStartInfo {
                WorkingDirectory = null,
                ConfigurationPath = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) +
                                    @"\XIVLauncher\dalamudConfig.json",
                PluginDirectory = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) +
                                  @"\XIVLauncher\installedPlugins",
                DefaultPluginDirectory = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) +
                                         @"\XIVLauncher\devPlugins",

                GameVersion = File.ReadAllText(Path.Combine(ffxivDir, "ffxivgame.ver")),
                Language = ClientLanguage.English
            };

            Console.WriteLine("Creating a StartInfo with:\n" +
                              $"ConfigurationPath: {startInfo.ConfigurationPath}\n" +
                              $"PluginDirectory: {startInfo.PluginDirectory}\n" +
                              $"DefaultPluginDirectory: {startInfo.DefaultPluginDirectory}\n" +
                              $"Language: {startInfo.Language}\n" +
                              $"GameVersion: {startInfo.GameVersion}");

            return startInfo;
        }
    }
}