using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;

namespace blp_res_checker
{
    internal class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                Console.WriteLine("Please drag and drop the folder onto the exe file.");
                Console.ReadLine();
                return;
            }

            var directory = args[0];
            var files = Directory.GetFiles(directory, "*.blp", SearchOption.AllDirectories);

            List<string> validFiles = new List<string>();
            List<string> invalidFiles = new List<string>();

            foreach (var file in files)
            {
                using (var stream = File.OpenRead(file))
                {
                    var buffer = new byte[4];
                    stream.Read(buffer, 0, buffer.Length);
                    var magic = System.Text.Encoding.Default.GetString(buffer);
                    if (magic != "BLP1")
                    {
                        continue;
                    }

                    stream.Seek(8, SeekOrigin.Current);
                    buffer = new byte[8];
                    stream.Read(buffer, 0, buffer.Length);

                    var val1 = BitConverter.ToUInt32(buffer.Take(4).ToArray(), 0);
                    var val2 = BitConverter.ToUInt32(buffer.Skip(4).Take(4).ToArray(), 0);

                    if (!IsPowerOfTwo(val1) || !IsPowerOfTwo(val2))
                    {
                        invalidFiles.Add($"{file} is a broken file. Resolution: {val1} x {val2}");
                    }
                    else
                    {
                        validFiles.Add($"{file} is a valid file. Resolution: {val1} x {val2}");
                    }
                }
            }

            string outputFilePath = Path.Combine(directory, "output.txt");
            using (StreamWriter sw = new StreamWriter(outputFilePath))
            {
                WriteOutput(sw, $"Total BLP files checked: {files.Length}");
                WriteOutput(sw, $"Valid BLP files: {validFiles.Count}");
                WriteOutput(sw, $"Invalid BLP files: {invalidFiles.Count}");

                WriteOutput(sw, "\nInvalid Files:");
                foreach (var file in invalidFiles)
                {
                    WriteOutput(sw, file);
                }

                WriteOutput(sw, "\nValid Files:");
                foreach (var file in validFiles)
                {
                    WriteOutput(sw, file);
                }
            }

            Console.WriteLine($"\nThe results have been written to {outputFilePath}");
            Console.ReadLine();
        }

        static bool IsPowerOfTwo(uint x)
        {
            return (x != 0) && ((x & (x - 1)) == 0);
        }

        static void WriteOutput(StreamWriter sw, string output)
        {
            sw.WriteLine(output);
            Console.WriteLine(output);
        }
    }
}