// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : 04.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes SCSI MODE PAGE 04h: Rigid disk drive geometry page.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     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, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2018 Natalia Portillo
// ****************************************************************************/

using System.Text;

namespace DiscImageChef.Decoders.SCSI
{
    public static partial class Modes
    {
        #region Mode Page 0x04: Rigid disk drive geometry page
        /// <summary>
        /// Disconnect-reconnect page
        /// Page code 0x04
        /// 24 bytes in SCSI-2, SBC-1
        /// </summary>
        public struct ModePage_04
        {
            /// <summary>
            /// Parameters can be saved
            /// </summary>
            public bool PS;
            /// <summary>
            /// Cylinders used for data storage
            /// </summary>
            public uint Cylinders;
            /// <summary>
            /// Heads for reading and/or writing
            /// </summary>
            public byte Heads;
            /// <summary>
            /// Cylinder where write precompensation starts
            /// </summary>
            public uint WritePrecompCylinder;
            /// <summary>
            /// Cylinder where write current reduction starts
            /// </summary>
            public uint WriteReduceCylinder;
            /// <summary>
            /// Step rate in 100 ns units
            /// </summary>
            public ushort DriveStepRate;
            /// <summary>
            /// Cylinder where the heads park
            /// </summary>
            public int LandingCylinder;
            /// <summary>
            /// Rotational position locking
            /// </summary>
            public byte RPL;
            /// <summary>
            /// Rotational skew to apply when synchronized
            /// </summary>
            public byte RotationalOffset;
            /// <summary>
            /// Medium speed in rpm
            /// </summary>
            public ushort MediumRotationRate;
        }

        public static ModePage_04? DecodeModePage_04(byte[] pageResponse)
        {
            if((pageResponse?[0] & 0x40) == 0x40) return null;

            if((pageResponse?[0] & 0x3F) != 0x04) return null;

            if(pageResponse[1] + 2 != pageResponse.Length) return null;

            if(pageResponse.Length < 20) return null;

            ModePage_04 decoded = new ModePage_04();

            decoded.PS |= (pageResponse[0] & 0x80) == 0x80;
            decoded.Cylinders = (uint)((pageResponse[2] << 16) + (pageResponse[3] << 8) + pageResponse[4]);
            decoded.Heads = pageResponse[5];
            decoded.WritePrecompCylinder = (uint)((pageResponse[6] << 16) + (pageResponse[7] << 8) + pageResponse[8]);
            decoded.WriteReduceCylinder = (uint)((pageResponse[9] << 16) + (pageResponse[10] << 8) + pageResponse[11]);
            decoded.DriveStepRate = (ushort)((pageResponse[12] << 8) + pageResponse[13]);
            decoded.LandingCylinder = (pageResponse[14] << 16) + (pageResponse[15] << 8) + pageResponse[16];
            decoded.RPL = (byte)(pageResponse[17] & 0x03);
            decoded.RotationalOffset = pageResponse[18];

            if(pageResponse.Length >= 22)
                decoded.MediumRotationRate = (ushort)((pageResponse[20] << 8) + pageResponse[21]);

            return decoded;
        }

        public static string PrettifyModePage_04(byte[] pageResponse)
        {
            return PrettifyModePage_04(DecodeModePage_04(pageResponse));
        }

        public static string PrettifyModePage_04(ModePage_04? modePage)
        {
            if(!modePage.HasValue) return null;

            ModePage_04 page = modePage.Value;
            StringBuilder sb = new StringBuilder();

            sb.AppendLine("SCSI Rigid disk drive geometry page:");

            if(page.PS) sb.AppendLine("\tParameters can be saved");

            sb.AppendFormat("\t{0} heads", page.Heads).AppendLine();
            sb.AppendFormat("\t{0} cylinders", page.Cylinders).AppendLine();
            if(page.WritePrecompCylinder < page.Cylinders)
                sb.AppendFormat("\tWrite pre-compensation starts at cylinder {0}", page.WritePrecompCylinder)
                  .AppendLine();
            if(page.WriteReduceCylinder < page.Cylinders)
                sb.AppendFormat("\tWrite current reduction starts at cylinder {0}", page.WriteReduceCylinder)
                  .AppendLine();
            if(page.DriveStepRate > 0)
                sb.AppendFormat("\tDrive steps in {0} ns", (uint)page.DriveStepRate * 100).AppendLine();

            sb.AppendFormat("\tHeads park in cylinder {0}", page.LandingCylinder).AppendLine();

            if(page.MediumRotationRate > 0)
                sb.AppendFormat("\tMedium rotates at {0} rpm", page.MediumRotationRate).AppendLine();

            switch(page.RPL)
            {
                case 0:
                    sb.AppendLine("\tSpindle synchronization is disable or unsupported");
                    break;
                case 1:
                    sb.AppendLine("\tTarget operates as a synchronized-spindle slave");
                    break;
                case 2:
                    sb.AppendLine("\tTarget operates as a synchronized-spindle master");
                    break;
                case 3:
                    sb.AppendLine("\tTarget operates as a synchronized-spindle master control");
                    break;
            }

            return sb.ToString();
        }
        #endregion Mode Page 0x04: Rigid disk drive geometry page
    }
}