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

namespace Sarand.Net.Standard.Base.Data
{
	//=======================================================================
	public class SacsData
	{
		//-------------------------------------------------------------------
		// Data members.

		//-------------------------------------------------------------------
		// Construction.
		/// <summary>Construction - Empty data.</summary>
		public SacsData () { }
		/// <summary>Construction - Data from byte array.</summary>
		public SacsData (byte[] data)
		{
			DataBuffer = new byte[data?.Length ?? 0];
			DataLength = data?.Length ?? 0;
			if (DataLength > 0)
				Array.Copy(data, 0, DataBuffer, 0, DataLength);
			CheckForNull();
		}
		/// <summary>
		/// Construction - Data from string.
		/// <para>Encoding: ASCII</para>
		/// </summary>
		public SacsData (string data) :
			this(data, Encoding.ASCII)
		{ }
		/// <summary>Construction - Data from string with specific encoding.</summary>
		public SacsData (string data, Encoding encoding) :
			this(encoding.GetBytes(data))
		{
			StringEncoding = encoding;
		}
		/// <summary>Copy construction.</summary>
		public SacsData (SacsData data) :
			this(data.DataBuffer)
		{
			StringEncoding = data.StringEncoding;
		}

		//-------------------------------------------------------------------
		// Properties.
		/// <summary>Data buffer - cannot be replaced but individual entries can be amended.</summary>
		public byte[] DataBuffer { get; protected set; } = new byte[0];
		/// <summary>Length of data may be less than the buffer length.</summary>
		public int DataLength { get; protected set; }
		/// <summary>Encoding used to convert data to String.</summary>
		public Encoding StringEncoding { get; set; } = Encoding.ASCII;
		/// <summary>Does the data contain null (0x00) values?<para>In which case conversion to String will be invalid.</para></summary>
		public bool ContainsNull { get; protected set; }

		//-------------------------------------------------------------------
		// Utilities.
		private void CheckForNull()
		{
			ContainsNull = Array.Exists(DataBuffer, item => item == 0);
		}

		//-------------------------------------------------------------------
		// Conversion to String.
		public override String ToString ()
		{
			return String.Format(GetType().Name + " [Length: {0}]", DataLength);
		}
		public static implicit operator String (SacsData data)
		{
			return data.StringEncoding.GetString(data.DataBuffer);
		}
		public String NullTerminatedString
		{
			get
			{
				int nullIdx = Array.IndexOf(DataBuffer,(byte)0);
				if (nullIdx >= 0)
					return StringEncoding.GetString(DataBuffer.Take(nullIdx).ToArray());
				return StringEncoding.GetString(DataBuffer);
			}
		}

		//-------------------------------------------------------------------
		// Append data.

		//-------------------------------------------------------------------
	}
	//=======================================================================
}