using System;

namespace ICSharpCode.SharpZipLib.Zip.Compression.Streams
{
	// Token: 0x0200003E RID: 62
	public class StreamManipulator
	{
		// Token: 0x0600026E RID: 622 RVA: 0x0000CB18 File Offset: 0x0000BB18
		public int PeekBits(int bitCount)
		{
			if (this.bitsInBuffer_ < bitCount)
			{
				if (this.windowStart_ == this.windowEnd_)
				{
					return -1;
				}
				this.buffer_ |= (uint)((uint)((int)(this.window_[this.windowStart_++] & byte.MaxValue) | ((int)(this.window_[this.windowStart_++] & byte.MaxValue) << 8)) << this.bitsInBuffer_);
				this.bitsInBuffer_ += 16;
			}
			return (int)((ulong)this.buffer_ & (ulong)((long)((1 << bitCount) - 1)));
		}

		// Token: 0x0600026F RID: 623 RVA: 0x0000CBB5 File Offset: 0x0000BBB5
		public void DropBits(int bitCount)
		{
			this.buffer_ >>= bitCount;
			this.bitsInBuffer_ -= bitCount;
		}

		// Token: 0x06000270 RID: 624 RVA: 0x0000CBD8 File Offset: 0x0000BBD8
		public int GetBits(int bitCount)
		{
			int num = this.PeekBits(bitCount);
			if (num >= 0)
			{
				this.DropBits(bitCount);
			}
			return num;
		}

		// Token: 0x17000089 RID: 137
		// (get) Token: 0x06000271 RID: 625 RVA: 0x0000CBF9 File Offset: 0x0000BBF9
		public int AvailableBits
		{
			get
			{
				return this.bitsInBuffer_;
			}
		}

		// Token: 0x1700008A RID: 138
		// (get) Token: 0x06000272 RID: 626 RVA: 0x0000CC01 File Offset: 0x0000BC01
		public int AvailableBytes
		{
			get
			{
				return this.windowEnd_ - this.windowStart_ + (this.bitsInBuffer_ >> 3);
			}
		}

		// Token: 0x06000273 RID: 627 RVA: 0x0000CC19 File Offset: 0x0000BC19
		public void SkipToByteBoundary()
		{
			this.buffer_ >>= this.bitsInBuffer_ & 7;
			this.bitsInBuffer_ &= -8;
		}

		// Token: 0x1700008B RID: 139
		// (get) Token: 0x06000274 RID: 628 RVA: 0x0000CC42 File Offset: 0x0000BC42
		public bool IsNeedingInput
		{
			get
			{
				return this.windowStart_ == this.windowEnd_;
			}
		}

		// Token: 0x06000275 RID: 629 RVA: 0x0000CC54 File Offset: 0x0000BC54
		public int CopyBytes(byte[] output, int offset, int length)
		{
			if (length < 0)
			{
				throw new ArgumentOutOfRangeException("length");
			}
			if ((this.bitsInBuffer_ & 7) != 0)
			{
				throw new InvalidOperationException("Bit buffer is not byte aligned!");
			}
			int num = 0;
			while (this.bitsInBuffer_ > 0 && length > 0)
			{
				output[offset++] = (byte)this.buffer_;
				this.buffer_ >>= 8;
				this.bitsInBuffer_ -= 8;
				length--;
				num++;
			}
			if (length == 0)
			{
				return num;
			}
			int num2 = this.windowEnd_ - this.windowStart_;
			if (length > num2)
			{
				length = num2;
			}
			Array.Copy(this.window_, this.windowStart_, output, offset, length);
			this.windowStart_ += length;
			if (((this.windowStart_ - this.windowEnd_) & 1) != 0)
			{
				this.buffer_ = (uint)(this.window_[this.windowStart_++] & byte.MaxValue);
				this.bitsInBuffer_ = 8;
			}
			return num + length;
		}

		// Token: 0x06000276 RID: 630 RVA: 0x0000CD48 File Offset: 0x0000BD48
		public void Reset()
		{
			this.buffer_ = 0U;
			this.windowStart_ = (this.windowEnd_ = (this.bitsInBuffer_ = 0));
		}

		// Token: 0x06000277 RID: 631 RVA: 0x0000CD78 File Offset: 0x0000BD78
		public void SetInput(byte[] buffer, int offset, int count)
		{
			if (buffer == null)
			{
				throw new ArgumentNullException("buffer");
			}
			if (offset < 0)
			{
				throw new ArgumentOutOfRangeException("offset", "Cannot be negative");
			}
			if (count < 0)
			{
				throw new ArgumentOutOfRangeException("count", "Cannot be negative");
			}
			if (this.windowStart_ < this.windowEnd_)
			{
				throw new InvalidOperationException("Old input was not completely processed");
			}
			int num = offset + count;
			if (offset > num || num > buffer.Length)
			{
				throw new ArgumentOutOfRangeException("count");
			}
			if ((count & 1) != 0)
			{
				this.buffer_ |= (uint)((uint)(buffer[offset++] & byte.MaxValue) << this.bitsInBuffer_);
				this.bitsInBuffer_ += 8;
			}
			this.window_ = buffer;
			this.windowStart_ = offset;
			this.windowEnd_ = num;
		}

		// Token: 0x04000155 RID: 341
		private byte[] window_;

		// Token: 0x04000156 RID: 342
		private int windowStart_;

		// Token: 0x04000157 RID: 343
		private int windowEnd_;

		// Token: 0x04000158 RID: 344
		private uint buffer_;

		// Token: 0x04000159 RID: 345
		private int bitsInBuffer_;
	}
}