using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.IO.Compression;
using System.Security.Cryptography;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
using Microsoft.WindowsAPICodePack.Dialogs;
using System.Text.RegularExpressions;

namespace AM2R_ModPacker
{
    public partial class ModPacker : Form
    {
        private static readonly string ORIGINAL_MD5 = "f2b84fe5ba64cb64e284be1066ca08ee";
        private bool isOriginalLoaded, isModLoaded, isApkLoaded, isLinuxLoaded;
        private string localPath, originalPath, modPath, apkPath, linuxPath;
        private static readonly string[] DATAFILES_BLACKLIST = { "data.win", "AM2R.exe", "D3DX9_43.dll", "game.unx" };
        private static string saveFilePath = null;
        private ModProfileXML profile;
        public ModPacker()
        {
            InitializeComponent();
            profile = new ModProfileXML("", 1, "", "", "", false, "", false, false, ""); // (1, "", "", false, "default", false, false);
            isOriginalLoaded = false;
            isModLoaded = false;
            isApkLoaded = false;
            isLinuxLoaded = false;

            localPath = Directory.GetCurrentDirectory();
            originalPath = "";
            modPath = "";
            linuxPath = "";
            apkPath = "";

        }

        #region WinForms events

        private void OriginalButton_Click(object sender, EventArgs e)
        {
            // Open window to select AM2R 1.1
            (isOriginalLoaded, originalPath) = SelectFile("Please select AM2R_11.zip", "zip", "zip files (*.zip)|*.zip");

            OriginalLabel.Visible = isOriginalLoaded; 

            UpdateCreateButton();
        }

        private void ModButton_Click(object sender, EventArgs e)
        {
            // Open window to select modded AM2R
            (isModLoaded, modPath) = SelectFile("Please select your custom AM2R .zip", "zip", "zip files (*.zip)|*.zip");

            ModLabel.Visible = isModLoaded;

            UpdateCreateButton();
        }

        private void CreateButton_Click(object sender, EventArgs e)
        {
            if (NameTextBox.Text == "" || AuthorTextBox.Text == "" || versionTextBox.Text == "")
            {
                MessageBox.Show("Text field missing! Mod packaging aborted.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            CreateLabel.Visible = true;
            CreateLabel.Text = "Packaging mod(s)... This could take a while!";

            string output;

            using (SaveFileDialog saveFile = new SaveFileDialog { InitialDirectory = localPath, Title = "Save Windows mod profile", Filter = "zip files (*.zip)|*.zip", AddExtension = true })
            {
                if (saveFile.ShowDialog() == DialogResult.OK)
                {
                    output = saveFile.FileName;
                }
                else
                {
                    CreateLabel.Text = "Mod packaging aborted!";
                    return;
                }
            }

            CreateModPack("Windows", modPath, output);

            if (linuxCheckBox.Checked)
            {
                using (SaveFileDialog saveFile = new SaveFileDialog { InitialDirectory = localPath, Title = "Save Linux mod profile", Filter = "zip files (*.zip)|*.zip", AddExtension = true })
                {
                    if (saveFile.ShowDialog() == DialogResult.OK)
                    {
                        output = saveFile.FileName;
                    }
                    else
                    {
                        CreateLabel.Text = "Mod packaging aborted!";
                        return;
                    }
                }

                CreateModPack("Linux", linuxPath, output);
            }

            CreateLabel.Text = "Mod package(s) created!";
        }

        private void CreateModPack(string operatingSystem, string input, string output)
        {
            LoadProfileParameters(operatingSystem);

            // Cleanup in case of previous errors
            if (Directory.Exists(Path.GetTempPath() + "\\AM2RModPacker"))
            {
                Directory.Delete(Path.GetTempPath() + "\\AM2RModPacker", true);
            }

            // Create temp work folders
            string tempPath = "",
                   tempOriginalPath = "",
                   tempModPath = "",
                   tempProfilePath = "";

            // We might not have permission to access to the temp directory, so we need to catch the exception.
            try
            {
                tempPath = Directory.CreateDirectory(Path.GetTempPath() + "\\AM2RModPacker").FullName;
                tempOriginalPath = Directory.CreateDirectory(tempPath + "\\original").FullName;
                tempModPath = Directory.CreateDirectory(tempPath + "\\mod").FullName;
                tempProfilePath = Directory.CreateDirectory(tempPath + "\\profile").FullName;
            }
            catch (System.Security.SecurityException)
            {
                MessageBox.Show("Could not create temp directory! Please run the application with administrator rights.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                AbortPatch();

                return;
            }

            // Extract 1.1 and modded AM2R to their own directories in temp work
            ZipFile.ExtractToDirectory(originalPath, tempOriginalPath);
            ZipFile.ExtractToDirectory(input, tempModPath);

            // Verify 1.1 with an MD5. If it does not match, exit cleanly and provide a warning window.
            try
            {
                string newMD5 = CalculateMD5(tempOriginalPath + "\\data.win");

                if (newMD5 != ORIGINAL_MD5)
                {
                    // Show error box
                    MessageBox.Show("1.1 data.win does not meet MD5 checksum! Mod packaging aborted.\n1.1 MD5: " + ORIGINAL_MD5 + "\nYour MD5: " + newMD5, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                    AbortPatch();

                    return;
                }
            }
            catch (FileNotFoundException)
            {
                // Show error message
                MessageBox.Show("data.win not found! Are you sure you selected AM2R 1.1? Mod packaging aborted.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                AbortPatch();

                return;
            }

            // Create AM2R.exe and data.win patches
            if (profile.OperatingSystem == "Windows")
            {
                if (profile.UsesYYC)
                {
                    CreatePatch(tempOriginalPath + "\\data.win", tempModPath + "\\AM2R.exe", tempProfilePath + "\\AM2R.xdelta");
                }
                else
                {
                    CreatePatch(tempOriginalPath + "\\data.win", tempModPath + "\\data.win", tempProfilePath + "\\data.xdelta");

                    CreatePatch(tempOriginalPath + "\\AM2R.exe", tempModPath + "\\AM2R.exe", tempProfilePath + "\\AM2R.xdelta");
                }
            }
            else if (profile.OperatingSystem == "Linux")
            {
                CreatePatch(tempOriginalPath + "\\data.win", tempModPath + "\\assets\\game.unx", tempProfilePath + "\\game.xdelta");
                CreatePatch(tempOriginalPath + "\\AM2R.exe", tempModPath + "\\AM2R", tempProfilePath + "\\AM2R.xdelta");
            }

            // Create game.droid patch and wrapper if Android is supported
            if (profile.Android)
            {
                string tempAndroid = Directory.CreateDirectory(tempPath + "\\android").FullName;

                // Extract APK 
                // - java -jar apktool.jar d "%~dp0AM2RWrapper_old.apk"

                // Process startInfo
                ProcessStartInfo procStartInfo = new ProcessStartInfo
                {
                    FileName = "cmd.exe",
                    WorkingDirectory = tempAndroid,
                    Arguments = "/C java -jar \"" + localPath + "\\utilities\\android\\apktool.jar\" d -f -o \"" + tempAndroid + "\" \"" + apkPath + "\"",
                    UseShellExecute = false,
                    CreateNoWindow = true
                };

                // Run process
                using (Process proc = new Process { StartInfo = procStartInfo })
                {
                    proc.Start();

                    proc.WaitForExit();
                }

                // Create game.droid patch
                CreatePatch(tempOriginalPath + "\\data.win", tempAndroid + "\\assets\\game.droid", tempProfilePath + "\\droid.xdelta");

                // Delete excess files in APK

                // Create whitelist
                string[] whitelist = { "splash.png", "portrait_splash.png" };

                // Get directory
                DirectoryInfo androidAssets = new DirectoryInfo(tempAndroid + "\\assets");

                


                // Delete files
                foreach (FileInfo file in androidAssets.GetFiles())
                {
                    if (file.Name.EndsWith(".ini") && file.Name != "modifiers.ini")
                    {
                        if (File.Exists(tempProfilePath + "\\AM2R.ini"))
                        {
                            // This shouldn't be a problem... normally...
                            File.Delete(tempProfilePath + "\\AM2R.ini");
                        }
                        File.Copy(file.FullName, tempProfilePath + "\\AM2R.ini");
                    }

                    if (!whitelist.Contains(file.Name))
                    {
                        File.Delete(file.FullName);
                    }
                }

                foreach (DirectoryInfo dir in androidAssets.GetDirectories())
                {
                    Directory.Delete(dir.FullName, true);
                }

                // Create wrapper

                // Process startInfo
                // - java -jar apktool.jar b "%~dp0AM2RWrapper_old" -o "%~dp0AM2RWrapper.apk"
                ProcessStartInfo procStartInfo2 = new ProcessStartInfo
                {
                    FileName = "cmd.exe",
                    WorkingDirectory = tempAndroid,
                    Arguments = "/C java -jar \"" + localPath + "\\utilities\\android\\apktool.jar\" b -f \"" + tempAndroid + "\" -o \"" + tempProfilePath + "\\AM2RWrapper.apk\"",
                    UseShellExecute = false,
                    CreateNoWindow = true
                };

                // Run process
                using (Process proc = new Process { StartInfo = procStartInfo2 })
                {
                    proc.Start();

                    proc.WaitForExit();
                }

                string tempAndroidProfilePath = tempProfilePath + "\\android";
                Directory.CreateDirectory(tempAndroidProfilePath);

                File.Move(tempProfilePath + "\\AM2RWrapper.apk", tempAndroidProfilePath + "\\AM2RWrapper.apk");
                if (File.Exists(tempProfilePath + "\\AM2R.ini"))
                    File.Move(tempProfilePath + "\\AM2R.ini", tempAndroidProfilePath + "\\AM2R.ini");
            }

            // Copy datafiles (exclude .ogg if custom music is not selected)

            DirectoryInfo dinfo = new DirectoryInfo(tempModPath);
            if (profile.OperatingSystem == "Linux")
                dinfo = new DirectoryInfo(tempModPath + "\\assets");

            Directory.CreateDirectory(tempProfilePath + "\\files_to_copy");

            if (profile.UsesCustomMusic)
            {
                // Copy files, excluding the blacklist
                CopyFilesRecursive(dinfo, DATAFILES_BLACKLIST, tempProfilePath + "\\files_to_copy");
            }
            else
            {
                // Get list of 1.1's music files
                string[] musFiles = Directory.GetFiles(tempOriginalPath, "*.ogg").Select(file => Path.GetFileName(file)).ToArray();

                if (profile.OperatingSystem == "Linux")
                    musFiles = Directory.GetFiles(tempOriginalPath, "*.ogg").Select(file => Path.GetFileName(file).ToLower()).ToArray();


                // Combine musFiles with the known datafiles for a blacklist
                string[] blacklist = musFiles.Concat(DATAFILES_BLACKLIST).ToArray();

                // Copy files, excluding the blacklist
                CopyFilesRecursive(dinfo, blacklist, tempProfilePath + "\\files_to_copy");
            }

            // Export profile as XML
            string xmlOutput = Serializer.Serialize<ModProfileXML>(profile);
            File.WriteAllText(tempProfilePath + "\\profile.xml", xmlOutput);

            // Compress temp folder to .zip
            if (File.Exists(output))
            {
                File.Delete(output);
            }

            ZipFile.CreateFromDirectory(tempProfilePath, output);

            // Delete temp folder
            Directory.Delete(tempPath, true);
        }

        private void ApkButton_Click(object sender, EventArgs e)
        {
            // Open window to select modded AM2R APK
            (isApkLoaded, apkPath) = SelectFile("Please select your custom AM2R .apk", "apk", "android application packages (*.apk)|*.apk");

            ApkLabel.Visible = isApkLoaded;

            UpdateCreateButton();
        }

        private void AndroidCheckBox_CheckedChanged(object sender, EventArgs e)
        {
            ApkButton.Enabled = AndroidCheckBox.Checked;
            UpdateCreateButton();
        }

        private void SaveCheckBox_CheckedChanged(object sender, EventArgs e)
        {
            winSaveButton.Enabled = SaveCheckBox.Checked;
            saveTextBox.Enabled = SaveCheckBox.Checked;
            UpdateCreateButton();
        }

        #endregion

        private void LoadProfileParameters(string operatingSystem)
        {
            profile.Name = NameTextBox.Text;
            profile.Author = AuthorTextBox.Text;
            profile.Version = versionTextBox.Text;
            profile.UsesCustomMusic = MusicCheckBox.Checked;            
            profile.UsesYYC = YYCCheckBox.Checked;
            profile.Android = AndroidCheckBox.Checked;
            profile.ProfileNotes = modNotesTextBox.Text;
            profile.OperatingSystem = operatingSystem;
            if (SaveCheckBox.Checked && saveTextBox.Text != "")
            {
                profile.SaveLocation = saveTextBox.Text;
            }
            else
            {
                profile.SaveLocation = "%localappdata%/AM2R";
            }
            if (operatingSystem == "Linux")
            {
                profile.SaveLocation = profile.SaveLocation.Replace("%localappdata%", "~/.config");
            }
        }

        private void AbortPatch()
        {
            // Unload files
            isOriginalLoaded = false;
            isModLoaded = false;
            isApkLoaded = false;
            isLinuxLoaded = false;
            originalPath = "";
            modPath = "";
            apkPath = "";
            linuxPath = "";
            saveFilePath = null;

            // Set labels
            CreateLabel.Text = "Mod packaging aborted!";
            OriginalLabel.Visible = false;
            ModLabel.Visible = false;
            ApkLabel.Visible = false;
            linuxLabel.Visible = false;

            // Remove temp directory
            if (Directory.Exists(Path.GetTempPath() + "\\AM2RModPacker"))
            {
                Directory.Delete(Path.GetTempPath() + "\\AM2RModPacker", true);
            }
        }

        private void linuxCheckBox_CheckedChanged(object sender, EventArgs e)
        {
            linuxButton.Enabled = linuxCheckBox.Checked;
            UpdateCreateButton();
        }

        private void linuxButton_Click(object sender, EventArgs e)
        {
            // Open window to select modded Linux .zip
            (isLinuxLoaded, linuxPath) = SelectFile("Please select your custom Linux AM2R .zip", "zip", "zip archives (*.zip)|*.zip");

            linuxLabel.Visible = isLinuxLoaded;

            UpdateCreateButton();
        }

        private void CustomSaveDataButton_Click(object sender, EventArgs e)
        {
            bool wasSuccessfull = false;
            Regex saveRegex = new Regex(@"C:\\Users\\.*\\AppData\\Local\\");     //this is to ensure, that the save directory is valid. so far, this is only important for windows

            // we either use this nuget package. Or we choose a very bad native solution. Went for nuget instead.
            CommonOpenFileDialog dialog = new CommonOpenFileDialog();
            dialog.InitialDirectory = Environment.GetEnvironmentVariable("LocalAppData");
            dialog.IsFolderPicker = true;
            while (!wasSuccessfull)
            {
                if (dialog.ShowDialog() == CommonFileDialogResult.Ok)
                {
                    Match match = saveRegex.Match(dialog.FileName);
                    if (match.Success == false)
                        MessageBox.Show("Invalid Save Directory! Please choose one in %LocalAppData%");
                    else
                    {
                        wasSuccessfull = true;
                        saveFilePath = dialog.FileName.Replace(match.Value, "%LOCALAPPDATA%");
                    }
                }
                else
                {
                    wasSuccessfull = true;
                    saveFilePath = null;
                }
            }
            saveTextBox.Text = saveFilePath;
        }

        private void CopyFilesRecursive(DirectoryInfo source, string[] blacklist, string destination)
        {
            foreach (FileInfo file in source.GetFiles())
            {
                if (!blacklist.Contains(file.Name))
                {
                    file.CopyTo(destination + "\\" + file.Name);
                }
            }

            foreach (DirectoryInfo dir in source.GetDirectories())
            {
                string newDir = Directory.CreateDirectory(destination + "\\" + dir.Name).FullName;
                CopyFilesRecursive(dir, blacklist, newDir);
            }
        }

        private void UpdateCreateButton()
        {
            if (isOriginalLoaded && 
                isModLoaded && 
                (!AndroidCheckBox.Checked || isApkLoaded) && 
                (!linuxCheckBox.Checked || isLinuxLoaded) && 
                (!SaveCheckBox.Checked || saveTextBox.Text != ""))
            {
                CreateButton.Enabled = true;
            }
            else
            {
                CreateButton.Enabled = false;
            }
        }

        // Thanks, stackoverflow: https://stackoverflow.com/questions/10520048/calculate-md5-checksum-for-a-file
        private string CalculateMD5(string filename)
        {
            using (var stream = File.OpenRead(filename))
            {
                using (var md5 = MD5.Create())
                {
                    var hash = md5.ComputeHash(stream);
                    return BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
                }
            }
        }

        private void CreatePatch(string original, string modified, string output)
        {
            // Specify process start info
            ProcessStartInfo parameters = new ProcessStartInfo
            {
                FileName = localPath + "\\utilities\\xdelta\\xdelta3.exe",
                WorkingDirectory = localPath,
                UseShellExecute = false,
                CreateNoWindow = true,
                Arguments = "-f -e -s \"" + original + "\" \"" + modified + "\" \"" + output + "\""
            };

            // Launch process and wait for exit. using statement automatically disposes the object for us!
            using (Process proc = new Process { StartInfo = parameters })
            {
                proc.Start();

                proc.WaitForExit();
            }
        }

        private (bool, string) SelectFile(string title, string extension, string filter)
        {
            using (OpenFileDialog fileFinder = new OpenFileDialog())
            {
                fileFinder.InitialDirectory = localPath;
                fileFinder.Title = title;
                fileFinder.DefaultExt = extension;
                fileFinder.Filter = filter;
                fileFinder.CheckFileExists = true;
                fileFinder.CheckPathExists = true;
                fileFinder.Multiselect = false;

                if (fileFinder.ShowDialog() == DialogResult.OK)
                {
                    string location = fileFinder.FileName;
                    return (true, location);

                }
                else return (false, "");
            }
        }
    }
}