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

namespace Sandbox.Utils.Storage
{
    public class DBCFile<T> where T : new()
    {
        public SortedList<uint, T> Entries
        {
            get;
            private
            set;
        }

        public DBCFile()
        {
            Entries = new SortedList<uint, T>();
        }

        public bool InitFile(string fileName)
        {
            BinaryReader reader = null;
            try
            {
                reader = new BinaryReader(File.Open(fileName, FileMode.Open));
            }
            catch (Exception)
            {
                Console.WriteLine("File {0} could not be opened!", fileName);
                return false;
            }

            reader.BaseStream.Position = 4;
            uint numRecords = reader.ReadUInt32();
            uint numFields = reader.ReadUInt32();
            uint recordSize = reader.ReadUInt32();
            uint stringSize = reader.ReadUInt32();

            Type t = typeof(T);
            PropertyInfo[] infos = t.GetProperties();
            uint realNumFields = 0;
            foreach (PropertyInfo inf in infos)
            {
                if (inf.PropertyType.Equals(typeof(float)))
                    ++realNumFields;
                else if (inf.PropertyType.Equals(typeof(uint)))
                    ++realNumFields;
                else if (inf.PropertyType.Equals(typeof(int)))
                    ++realNumFields;
                else if (inf.PropertyType.Equals(typeof(string)))
                    realNumFields += 17;
                else if (inf.PropertyType.Equals(typeof(StringBuilder)))
                    ++realNumFields;
                else if (inf.PropertyType.Equals(typeof(bool)))
                    ++realNumFields;
            }

            if (realNumFields != numFields)
            {
                Console.WriteLine("{0} {1}", realNumFields, numFields);
                Console.WriteLine("Incorrect format in dbc '" + fileName + "'!");
                return false;
            }

            byte[] data = reader.ReadBytes((int)numRecords * (int)recordSize);
            byte[] strings = reader.ReadBytes((int)stringSize);

            reader.Close();

            int blockPtr = 0;

            for (uint i = 0; i < numRecords; ++i)
            {
                T record = new T();

                foreach (PropertyInfo inf in infos)
                {
                    if (inf.PropertyType.Equals(typeof(float)))
                    {
                        inf.SetValue((object)record, (object)BitConverter.ToSingle(data, blockPtr), null);
                        blockPtr += 4;
                    }
                    if (inf.PropertyType.Equals(typeof(uint)))
                    {
                        inf.SetValue((object)record, (object)BitConverter.ToUInt32(data, blockPtr), null);
                        blockPtr += 4;
                    }
                    if (inf.PropertyType.Equals(typeof(int)))
                    {
                        inf.SetValue((object)record, (object)BitConverter.ToInt32(data, blockPtr), null);
                        blockPtr += 4;
                    }
                    if (inf.PropertyType.Equals(typeof(bool)))
                    {
                        uint val = BitConverter.ToUInt32(data, blockPtr);
                        blockPtr += 4;
                        inf.SetValue((object)record, (object)(val > 0 ? true : false), null);
                    }
                    if (inf.PropertyType.Equals(typeof(string)))
                    {
                        uint strOfs = 0xFFFFFFFF;
                        for (int j = 0; j < 16; ++j)
                        {
                            uint ofs = BitConverter.ToUInt32(data, blockPtr);
                            blockPtr += 4;
                            if (ofs != 0 && ofs < strings.Length)
                                strOfs = ofs;
                        }
                        blockPtr += 4;
                        if (strOfs != 0xFFFFFFFF)
                        {
                            string txt = Encoding.ASCII.GetString(strings, (int)strOfs, strings.Length - (int)strOfs);
                            if (txt.IndexOf('\0') != -1)
                                txt = txt.Substring(0, txt.IndexOf('\0'));

                            inf.SetValue((object)record, (object)txt, null);
                        }
                        else
                            inf.SetValue((object)record, (object)"", null);
                    }
                    if (inf.PropertyType.Equals(typeof(StringBuilder)))
                    {
                        uint ofs = BitConverter.ToUInt32(data, blockPtr);
                        blockPtr += 4;
                        if (ofs < strings.Length)
                        {
                            string txt = Encoding.ASCII.GetString(strings, (int)ofs, strings.Length - (int)ofs);
                            if (txt.IndexOf('\0') != -1)
                                txt = txt.Substring(0, txt.IndexOf('\0'));
                            StringBuilder bldr = new StringBuilder(txt);
                            inf.SetValue((object)record, (object)bldr, null);
                        }
                        else
                        {
                            StringBuilder bldr = new StringBuilder("");
                            inf.SetValue((object)record, (object)bldr, null);
                        }
                    }

                }

                Entries.Add((uint)infos[0].GetValue((object)record, null), record);
            }

            Console.WriteLine("Loaded {0} records from file '{1}'!", Entries.Values.Count, fileName);
            return true;
        }
    }
}