using Microsoft.AspNet.Identity;
using System;
using System.CodeDom.Compiler;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;
using System.Windows.Forms;

namespace MiscToolSet
{
    public partial class MainForm : Form
    {
        private readonly RandomNumberGenerator _rng = RandomNumberGenerator.Create();
        private readonly PasswordHasher _passwordHasher = new PasswordHasher();
        private readonly MD5 _md5 = new MD5Cng();
        private readonly Encoding _asciiEncoding = Encoding.ASCII;

        [STAThread]
        private static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new MainForm());
        }

        public MainForm()
        {
            InitializeComponent();
        }

        private void Md5HasherUpperCaseCheckBox_CheckedChanged(object sender, EventArgs e)
        {
            MD5HasherInputTextBox_TextChanged(null, null);
        }

        private void MD5HasherInputTextBox_TextChanged(object sender, EventArgs e)
        {
            var fmt = Md5HasherUpperCaseCheckBox.Checked ? "X2" : "x2";
            Md5HasherOutputTextBox.Text = string.Join("", _md5.ComputeHash(Encoding.UTF8.GetBytes(MD5HasherInputTextBox.Text)).Select(p => p.ToString(fmt)));
        }

        private void txtToPasswordHash_TextChanged(object sender, System.EventArgs e)
        {
            PasswordHasherOutputTextBox.Text = _passwordHasher.HashPassword(PasswordHasherInputTextBox.Text);
        }

        private void txtResultOfPasswordHash_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            PasswordHasherOutputTextBox.SelectAll();
        }

        private void btnNewGuid_Click(object sender, EventArgs e)
        {
            var g = Guid.NewGuid();
            GuidGeneratorResultDTextBox.Text = g.ToString("D").ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper());
            GuidGeneratorResultNTextBox.Text = g.ToString("N").ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper());
            GuidGeneratorResultAttributeTextBox.Text = $"[Guid(\"{g.ToString("D").ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper()) }\")]";
            GuidGeneratorResultNewTextBox.Text = $"new Guid(\"{g.ToString("D").ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper())}\")";
        }

        private void btnCpN_Click(object sender, EventArgs e) => Clipboard.SetText(GuidGeneratorResultNTextBox.Text);

        private void btnCpD_Click(object sender, EventArgs e) => Clipboard.SetText(GuidGeneratorResultDTextBox.Text);

        private void btnCpA_Click(object sender, EventArgs e) => Clipboard.SetText(GuidGeneratorResultAttributeTextBox.Text);

        private void GuidGeneratorCopyNewButton_Click(object sender, EventArgs e) => Clipboard.SetText(GuidGeneratorResultNewTextBox.Text);

        private void NewMachineKeyButton_Click(object sender, EventArgs e)
        {
            var rng = new RNGCryptoServiceProvider();
            string CreateKey(int numBytes)
            {
                var buff = new byte[numBytes];
                rng.GetBytes(buff);
                return string.Join("", buff.Select(p => $"{p:X2}"));
            }

            MachineKeyResult.Text =
                $"<machineKey" +
                $" validationKey=\"{CreateKey(64)}\"" +
                $" decryptionKey=\"{CreateKey(24)}\"" +
                $" decryption=\"3DES\"" +
                $" validation=\"3DES\" />";
        }

        private void CopyMachineKeyButton_Click(object sender, EventArgs e)
        {
            Clipboard.SetText(MachineKeyResult.Text);
        }

        private void PasswordGenerateButton_Click(object sender, EventArgs e)
        {
            int GetIntRandomly()
            {
                var buf = new byte[4];
                _rng.GetBytes(buf);
                return BitConverter.ToInt32(buf, 0);
            }

            var stringBuilder = new StringBuilder();
            if (PasswordGenerateIncludeUpperCaseCheckBox.Checked) stringBuilder.Append(Enumerable.Range('A', 'Z' - 'A' + 1).Select(p => (char)p).ToArray());
            if (PasswordGenerateIncludeLowerCaseCheckBox.Checked) stringBuilder.Append(Enumerable.Range('a', 'z' - 'a' + 1).Select(p => (char)p).ToArray());
            if (PasswordGenerateIncludeNumberCheckBox.Checked) stringBuilder.Append(Enumerable.Range('0', '9' - '0' + 1).Select(p => (char)p).ToArray());
            if (PasswordGenerateIncludeSymbolCheckBox.Checked) stringBuilder.Append("!@#$%&*");

            var charPool = stringBuilder.ToString();
            string GetRandomString()
            {
                return new string(
                    Enumerable.Range(0, (int)PasswordGenerateLengthUpDownBox.Value)
                        .Select(p => charPool[Math.Abs(GetIntRandomly() % charPool.Length)])
                        .ToArray()
                );
            }

            string HashString(string str)
            {
                if (PasswordGenerateUseMd5RadioButton.Checked)
                {
                    var fmt = PasswordGeneratorHashUseUpperCaseCheckBox.Checked ? "X2" : "x2";
                    return string.Join("", _md5.ComputeHash(_asciiEncoding.GetBytes(str)).Select(p => p.ToString(fmt)));
                }

                if (PasswordGenerateUsePasswordHasherRadioButton.Checked)
                {
                    return _passwordHasher.HashPassword(str);
                }

                throw new NotImplementedException();
            }

            PasswordGenerateResultRichTextBox.Clear();
            for (var i = 0; i < PasswordGenerateNumberUpDownBox.Value; i++)
            {
                var str = GetRandomString();

                PasswordGenerateResultRichTextBox.AppendText($"{str} {HashString(str)}{Environment.NewLine}");
            }
        }

        private void DropToBase64Label_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = e.Data.GetDataPresent(DataFormats.FileDrop)
                ? DragDropEffects.Copy
                : DragDropEffects.None;
        }

        private void DropToBase64Label_DragDrop(object sender, DragEventArgs e)
        {
            var files = (string[])e.Data.GetData(DataFormats.FileDrop);

            DropToBase64FileNameLabel.Text = Path.GetFileName(files[0]);

            var bytes = File.ReadAllBytes(files[0]);
            var base64String = Convert.ToBase64String(bytes, Base64FormattingOptions.None);
            DropToBase64TextBox.Text = DataUrlCheckBox.Checked
                ? $"data:{DataUrlMimeTypeTextBox.Text};base64,{base64String}"
                : base64String;
        }

        private void CopyBase64Button_Click(object sender, EventArgs e)
        {
            Clipboard.SetText(DropToBase64TextBox.Text);
        }

        private void BulkNewGuidButton_Click(object sender, EventArgs e)
        {
            var length = ((int)BulkNewGuidUpDown.Value);
            for (var i = 0; i < length; i++)
            {
                var guid = Guid.NewGuid();

                if (NormalBulkNewGuidRadioButton.Checked) BulkNewGuidTextBox.AppendText($"{guid:D}{Environment.NewLine}".ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper()));
                if (CtorBulkNewGuidRadioButton.Checked) BulkNewGuidTextBox.AppendText($"new Guid(\"{$"{guid:D}".ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper())}\");{Environment.NewLine}");
                if (AttrBulkNewGuidRadioButton.Checked) BulkNewGuidTextBox.AppendText($"[Guid(\"{$"{guid:D}".ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper())}\"]{Environment.NewLine}");
                if (NumberBulkNewGuidRadioButton.Checked) BulkNewGuidTextBox.AppendText($"{guid:N}{Environment.NewLine}".ProcessWhen(UpperCaseCheckBox.Checked, p => p.ToUpper()));
            }
        }

        private void MagicHuntingButton_Click(object sender, EventArgs e)
        {
            var magicPattern = new Regex(MagicPatternText.Text, RegexOptions.Compiled);

            var dicCollect = new System.Collections.Generic.Dictionary<string, string>();

            CodeConvertTextBox.Text = magicPattern.Replace(CodeInputTextBox.Text, match =>
            {
                var identity = match.Groups[1].Value;

                if (false == IdentifierChecker.Valid(identity)) return match.Value;
                if (false == dicCollect.ContainsKey(identity)) dicCollect[identity] = match.Result(CollectPatternTextBox.Text);

                return match.Result(ConvertPatternTextBox.Text);
            });

            CodeCollectTextBox.Text =
                "private static class Identities {"
                + Environment.NewLine + "// ReSharper disable InconsistentNaming" + Environment.NewLine;

            CodeCollectTextBox.Text += string.Join(Environment.NewLine, dicCollect.Values.OrderBy(p => p));

            CodeCollectTextBox.Text +=
                Environment.NewLine
                + "// ReSharper restore InconsistentNaming" + Environment.NewLine
                + "}";
        }

        private void RsaKeyGenerateButton_Click(object sender, EventArgs e)
        {
            // thanks to dotblogs.com.tw/supershowwei/2015/12/23/160510
            // docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.rsacryptoserviceprovider.keysize#remarks
            var rsa = new RSACryptoServiceProvider((int)RsaKeySizeUpDown.Value);
            RsaPrivateKeyTextBox.Text = rsa.ToXmlString(true);
            RsaPublicKeyTextBox.Text = rsa.ToXmlString(false);
        }

        private void ConvertCode_Click(object sender, EventArgs e)
        {
            //html encoding
            // <br /> append to end of line
            // spaces indent

            ConvertedCodeTextBox.Clear();

            var lines = InputCodeTextBox.Lines;
            for (var index = 0; index < lines.Length; index++)
            {
                var line = lines[index];
                var htmlEncode = HttpUtility.HtmlEncode(line);
                var spaces = line.TakeWhile(p => p == ' ').Count();
                ConvertedCodeTextBox.AppendText($"<span style=\"padding-left: {spaces / 2.0:00.0}em;\">{htmlEncode}</span>");
                if (index < lines.Length - 1)
                {
                    ConvertedCodeTextBox.AppendText($"<br />{Environment.NewLine}");
                }
            }
        }

        private void CopyButton_Click(object sender, EventArgs e)
        {
            Clipboard.SetText(ConvertedCodeTextBox.Text);
        }
    }

    internal static class CommonExtensionMetond
    {
        public static T ProcessWhen<T>(this T me, bool when, Func<T, T> process)
        {
            return when ? process(me) : me;
        }
    }

    internal static class IdentifierChecker
    {
        private static readonly CodeDomProvider Provider = CodeDomProvider.CreateProvider("C#");

        public static bool Valid(string word) => Provider.IsValidIdentifier(word);
    };
}