//
// Block.cs: Represents a Flac metadata block.
//
// Author:
//   Brian Nickel (brian.nickel@gmail.com)
//
// Copyright (C) 2007 Brian Nickel
// 
// This library is free software; you can redistribute it and/or modify
// it  under the terms of the GNU Lesser General Public License version
// 2.1 as published by the Free Software Foundation.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
// USA
//

using System;

namespace TagLib.Flac {
	/// <summary>
	///    This class represents a Flac metadata block.
	/// </summary>
	public class Block
	{
		#region Private Fields
		
		/// <summary>
		///    Contains the block header.
		/// </summary>
		private BlockHeader header;
		
		/// <summary>
		///    Contains the block data.
		/// </summary>
		private ByteVector data;
		
		#endregion
		
		
		
		#region Constructors
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="Block" /> with a specified header and internal
		///    data.
		/// </summary>
		/// <param name="header">
		///    A <see cref="BlockHeader" /> object containing the
		///    header to use for the new instance.
		/// </param>
		/// <param name="data">
		///    A <see cref="ByteVector" /> object containing the data
		///    to be contained in the new instance.
		/// </param>
		/// <exception cref="ArgumentNullException">
		///    <paramref name="data" /> is <see langword="null" />.
		/// </exception>
		/// <exception cref="CorruptFileException">
		///    The size of <paramref name="data" /> does not match the
		///    size specified in <paramref name="header" />.
		/// </exception>
		public Block (BlockHeader header, ByteVector data)
		{
			if (data == null)
				throw new ArgumentNullException (nameof(data));
			
			if (header.BlockSize != data.Count)
				throw new CorruptFileException (
					"Data count not equal to block size.");
			
			this.header = header;
			this.data = data;
		}
		
		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="Block" /> with of a specified type and internal
		///    data.
		/// </summary>
		/// <param name="type">
		///    A <see cref="BlockType" /> value indicating the type of
		///    data stored in <paramref name="data" />.
		/// </param>
		/// <param name="data">
		///    A <see cref="ByteVector" /> object containing the data
		///    to be contained in the new instance.
		/// </param>
		/// <exception cref="ArgumentNullException">
		///    <paramref name="data" /> is <see langword="null" />.
		/// </exception>
		public Block (BlockType type, ByteVector data)
		{
			if (data == null)
				throw new ArgumentNullException (nameof(data));
			
			header = new BlockHeader (type, (uint) data.Count);
			
			this.data = data;
		}
		
		#endregion
		
		
		
		#region Public Properties
		
		/// <summary>
		///    Gets the type of data contained in the current instance.
		/// </summary>
		/// <value>
		///    A <see cref="BlockType" /> value indicating the type of
		///    data contained in <see cref="Data" />.
		/// </value>
		public BlockType Type {
			get {return header.BlockType;}
		}
		
		/// <summary>
		///    Gets whether or not the block represented by the current
		///    instance is the last metadata block in the Flac stream.
		/// </summary>
		/// <value>
		///    <see langword="true" /> if the block represented by the
		///    current instance was the last one to appear in the file
		///    and is followed immediately by the audio data, or <see
		///    langword="false" /> if another block appears after the
		///    current one or the block was not read from disk.
		/// </value>
		public bool IsLastBlock {
			get {return header.IsLastBlock;}
		}
		
		/// <summary>
		///    Gets the size of the data contained in the current
		///    instance.
		/// </summary>
		public uint DataSize {
			get {return header.BlockSize;}
		}
		
		/// <summary>
		///    Gets the total size of the block represented by the
		///    current instance as it appears on disk.
		/// </summary>
		public uint TotalSize {
			get {return DataSize + BlockHeader.Size;}
		}
		
		/// <summary>
		///    Gets the data contained in the current instance.
		/// </summary>
		/// <value>
		///    A <see cref="ByteVector" /> object containing the data
		///    stored in the current instance.
		/// </value>
		public ByteVector Data {
			get {return data;}
		}
		
		#endregion
		
		
		
		#region Public Methods
		
		/// <summary>
		///    Renders the current instance as a raw Flac metadata
		///    block.
		/// </summary>
		/// <param name="isLastBlock">
		///    A <see cref="bool" /> value indicating whether or not the
		///    block is to be marked as the last metadata block.
		/// </param>
		/// <returns>
		///    A <see cref="ByteVector" /> object containing the
		///    rendered version of the current instance.
		/// </returns>
		public ByteVector Render (bool isLastBlock)
		{
			if (this.data == null)
				throw new InvalidOperationException (
					"Cannot render empty blocks.");
			
			ByteVector data = header.Render (isLastBlock);
			data.Add (this.data);
			return data;
		}
		
		#endregion
	}
}