using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace _3DS_Rom_Decryptor_Key_Generator
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        string FileLocation;
        string aesString;
        string ctrString;
        byte[] aes = new byte[16];
        byte[] titleID = new byte[8];
        private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "3DS Rom File (*.3ds)|*.3ds|Gateway 3DS 3DZ Rom File (*.3dz)|*.3dz";
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                FileLocation = ofd.FileName;
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (comboBox1.SelectedIndex != -1)
            {
                GetKey();
            }
            else
            {
                MessageBox.Show("Please select an archive type.");
            }
        }

        private void GetKey()
        {
            aesString = "";
            ctrString = "";
            FileStream fs = new FileStream(FileLocation, FileMode.Open);
            fs.Seek(0x4000, SeekOrigin.Begin);
            fs.Read(aes, 0, 16);
            fs.Seek(0x4108, SeekOrigin.Begin);
            fs.Read(titleID, 0, 8);
            aesString = aes[3].ToString("X2") + aes[2].ToString("X2") + aes[1].ToString("X2") + aes[0].ToString("X2")
                + " " + aes[7].ToString("X2") + aes[6].ToString("X2") + aes[5].ToString("X2") + aes[4].ToString("X2")
                + " " + aes[11].ToString("X2") + aes[10].ToString("X2") + aes[9].ToString("X2") + aes[8].ToString("X2")
                + " " + aes[15].ToString("X2") + aes[14].ToString("X2") + aes[13].ToString("X2") + aes[12].ToString("X2");
            ctrString = titleID[4].ToString("X2") + titleID[5].ToString("X2") + titleID[6].ToString("X2") + titleID[7].ToString("X2")
                + " " + titleID[0].ToString("X2") + titleID[1].ToString("X2") + titleID[2].ToString("X2") + titleID[3].ToString("X2");
            switch (comboBox1.SelectedIndex)
            {
                case 0:
                    ctrString += " 00000001 00000000";
                    break;
                case 1:
                    ctrString += " 00000002 00000000";
                    break;
                case 2:
                    ctrString += " 00000003 00000000";
                    break;
            }
            textBox1.Text = "AES Key: " + aesString + Environment.NewLine + "CTR Key: " + ctrString;
            button3.Enabled = true;
            fs.Close();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd = new SaveFileDialog();
            sfd.Filter = "Text file (*.txt)|*.txt";
            if (sfd.ShowDialog() == DialogResult.OK)
            {
                StreamWriter sw = new StreamWriter(sfd.FileName);
                sw.Write(textBox1.Text);
                sw.Close();
            }
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (comboBox1.SelectedIndex != -1)
            {
                button2.Enabled = true;
            }
        }
    }
}