using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Text.RegularExpressions;
using System.Globalization;

namespace ReScene
{
    public class SfvEntry
    {
        public string FileName { get; set; }
        public uint Crc32 { get; set; }
    }

    /// <summary>
    /// Implements a simple Reader class that reads through SFV files one line (entry) at a time.
    /// </summary>
    public class SfvReader : IDisposable
    {
        protected StreamReader reader;

        public SfvReader(string sfvPath)
        {
            reader = new StreamReader(sfvPath, Encoding.ASCII);
        }

        public SfvReader(Stream sfvStream)
        {
            reader = new StreamReader(sfvStream, Encoding.ASCII);
        }

        public SfvEntry Read()
        {
            // comment lines in sfv start with ';', so skip those.  also skip any lines that are too short to have both a file name and CRC
            string line;
            do
                line = reader.ReadLine();
            while (line != null && (line.Trim().Length < 10 || line.StartsWith(";")));

            if (line == null)
                return null;

            uint i;
            if (uint.TryParse(line.Substring(line.Length - 8), NumberStyles.HexNumber, null, out i))
                return new SfvEntry()
                {
                    FileName = line.Substring(0, line.Length - 9).Trim(),
                    Crc32 = i
                };
            else
                return null;
        }

        public void Dispose()
        {
            reader.Close();
        }
    }
}