using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Security.Policy;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using DamienG.Security.Cryptography;

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

        private void button1_Click(object sender, EventArgs e)
        {
            string[] files = { "eqgame.exe", "eqgraphicsdx9.dll", "eqmain.dll", "eqgfx_dx8.dll", "mss32.dll" };

            logEntry("\r\nBeginning Process...");
            if (!File.Exists("eqgame.exe"))
            {
                logEntry("Could not find a complete EverQuest installation in the current directory.");
                logEntry("Please move EQVerCheck.exe to your EverQuest folder and re-run.");
                return;
            }
            if (File.Exists("eqgraphicsdx9.dll"))
                logEntry("EQGraphicsDX9.dll and eqgame.exe FOUND.");
            else
            {
                if (File.Exists("eqgfx_dx7.dll"))
                {
                    logEntry("eqgfx_dx7.dll and eqgame.exe FOUND.");
                    files = new string[] { "eqgame.exe", "eqgfx_dx7.dll", "eqmain.dll", "eqgfx_dx8.dll", "mss32.dll" };
                }
            }
            logEntry("Assuming EQ Installation is complete.");
            string sVersionCode = "SHORT VERSION: SEQ";
            string lVersionCode = "LONG VERSION: EQ";

            logEntry("Generating Version Strings...");
            foreach (var file in files)
            {
                string checksum = GetChecksum(file);
                lVersionCode += checksum;
                sVersionCode += checksum[checksum.Length - 1];
            }
            logEntry(sVersionCode);
            logEntry(lVersionCode);
        }

        static string GetChecksum(string fileName)
        {
            if (!File.Exists(fileName))
                return "00000000";

            var crc32 = new Crc32();
            var hash = String.Empty;

            using (var fs = File.OpenRead(fileName))
            {
                foreach (byte b in crc32.ComputeHash(fs))
                    hash += b.ToString("x2").ToLower();
            }

            return hash;
        }

        private void logEntry(string entry)
        {
            textBox1.Text += entry + Environment.NewLine;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}