//-----------------------------------------------------------------------
// <copyright file="MultiFrameData.cs" company="bedug.com">
//     Copyright © 2012 Nils Hammar. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------
/*
 * Software to access vehicle information via the OBD-II connector.
 * 
 * Copyright © 2012 Nils Hammar
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * This program 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 General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Alternative licensing is possible, see the licensing document.
 * 
 * The above text may not be removed or modified.
 */

namespace SimProtocol
{
    /// <summary>
    /// Container for multi-framed data.
    /// </summary>
    public class MultiFrameData
    {
        /// <summary>
        /// Gets a value indicating whether an error was detected. (Unexpected data segment number).
        /// </summary>
        public bool error { get; private set; }

        /// <summary>
        /// Gets a value indicating whether complete data has been received.
        /// </summary>
        public bool complete { get; private set; }

        /// <summary>
        /// Gets total length of expected data.
        /// </summary>
        public uint length { get; private set; }

        /// <summary>
        /// Gets data array.
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1819:PropertiesShouldNotReturnArrays", Justification = "Reviewed, intentional")]
        public byte[] data { get; private set; }

        /// <summary>
        /// Pointer to current byte in data array.
        /// </summary>
        private int n = 0;

        /// <summary>
        /// Number of next expected segment.
        /// </summary>
        private int nextSegment = 0;

        /// <summary>
        /// Initializes a new instance of the <see cref="MultiFrameData" /> class.
        /// </summary>
        /// <param name="zLen">Msb 4 bits.</param>
        /// <param name="data0">Data packet.</param>
        /// <param name="p0">Pointer to first data.</param>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1062:Validate arguments of public methods", MessageId = "1", Justification = "Reviewed, intentional")]
        public MultiFrameData(uint zLen, byte[] data0, uint p0)
        {
            this.error = true;
            this.complete = false;
            this.length = (zLen & 0x0f) << 8 | data0[p0++];
            this.data = new byte[this.length];

            this.addData(0, data0, p0);
        }

        /// <summary>
        /// Add a new data segment.
        /// <para>
        /// Checks if correct segment is received and sets 'error' to 'true' if not.
        /// </para>
        /// <para>
        /// If complete data is received 'complete' is set to 'true'.
        /// </para>
        /// </summary>
        /// <param name="segment">Segment number.</param>
        /// <param name="data0">Data to add.</param>
        /// <param name="p0">Pointer to first data.</param>
        public void addData(uint segment, byte[] data0, uint p0)
        {
            if (data0 != null)
            {
                if ((this.nextSegment & 0x0f) == (segment & 0x0f))
                {
                    this.error = false;
                    this.nextSegment++;
                    while (p0 < data0.Length && this.n < this.data.Length)
                    {
                        this.data[this.n++] = data0[p0++];
                    }

                    this.complete = this.n >= this.data.Length;
                }
                else
                {
                    this.error = true;
                }
            }
            else
            {
                this.error = true;
            }
        }
    }
}