using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace System.Fire.Container {

    public partial class ContainerList {

        
        public byte[] ReadBytes(int FileIndex) {
            return ReadBytes(this._files[FileIndex]);
        }

        public byte[] ReadBytes(ContainerFile File) {
            return ReadBytes(File, 0, File.Size);
        }
        // ---
        public byte[] ReadBytes(int FileIndex, long StartPos) {
            return ReadBytes(this._files[FileIndex], StartPos);
        }

        public byte[] ReadBytes(ContainerFile File, long StartPos) {
            return ReadBytes(File, StartPos, File.Size - StartPos);
        }
        // ---
        public byte[] ReadBytes(int FileIndex, long StartPos, long Length) {
            return this.ReadBytes(this._files[FileIndex], StartPos, Length);
        }

        public byte[] ReadBytes(ContainerFile File, long StartPos, long Length) {
            long len = Length;
            if (len > File.Size - StartPos)
                len = File.Size - StartPos;
            byte[] res = new byte[0];

            System.Diagnostics.Debug.WriteLine("ReadBytes 1: " + StartPos + " | " + Length + " | " + len);

            for (int i = 0, c = File.NumChunks; i < c; i++) {
                int containerSize = this.GetContainerLenFromChunk(File.ChunkPos, i);
                long xStart = Math.Max(0, StartPos);
                System.Diagnostics.Debug.WriteLine("ReadBytes 2: " + i + " | " + xStart + " | " + containerSize);
                if(StartPos <= containerSize) {
                    int bytesToReadFromContainer = (int)Math.Min(len, containerSize - StartPos);
                    byte[] b = this.ReadChunk(File.ChunkPos, i).Skip((int)xStart).Take(bytesToReadFromContainer).ToArray();
                    System.Diagnostics.Debug.WriteLine("ReadBytes X: " + xStart + " | " + bytesToReadFromContainer + " | " + b.Length);
                    res.Concat(b);
                    StartPos -= bytesToReadFromContainer;
                    len -= b.Length;
                } else {
                    StartPos -= containerSize;
                }
                if (len <= 0)
                    break;
            }
            return res;
        }

    }


}