// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : 11.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes SCSI MODE PAGE 11h: Medium partition page (1).
//
// --[ 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;
using System.Text;

namespace DiscImageChef.Decoders.SCSI
{
    public static partial class Modes
    {
        #region Mode Page 0x11: Medium partition page (1)
        public enum PartitionSizeUnitOfMeasures : byte
        {
            /// <summary>
            /// Partition size is measures in bytes
            /// </summary>
            Bytes = 0,
            /// <summary>
            /// Partition size is measures in Kilobytes
            /// </summary>
            Kilobytes = 1,
            /// <summary>
            /// Partition size is measures in Megabytes
            /// </summary>
            Megabytes = 2,
            /// <summary>
            /// Partition size is 10eUNITS bytes
            /// </summary>
            Exponential = 3
        }

        public enum MediumFormatRecognitionValues : byte
        {
            /// <summary>
            /// Logical unit is incapable of format or partition recognition
            /// </summary>
            Incapable = 0,
            /// <summary>
            /// Logical unit is capable of format recognition only
            /// </summary>
            FormatCapable = 1,
            /// <summary>
            /// Logical unit is capable of partition recognition only
            /// </summary>
            PartitionCapable = 2,
            /// <summary>
            /// Logical unit is capable of both format and partition recognition
            /// </summary>
            Capable = 3
        }

        /// <summary>
        /// Medium partition page(1)
        /// Page code 0x11
        /// </summary>
        public struct ModePage_11
        {
            /// <summary>
            /// Parameters can be saved
            /// </summary>
            public bool PS;
            /// <summary>
            /// Maximum number of additional partitions supported
            /// </summary>
            public byte MaxAdditionalPartitions;
            /// <summary>
            /// Number of additional partitions to be defined for a volume
            /// </summary>
            public byte AdditionalPartitionsDefined;
            /// <summary>
            /// Device defines partitions based on its fixed definition
            /// </summary>
            public bool FDP;
            /// <summary>
            /// Device should divide medium according to the additional partitions defined field using sizes defined by device
            /// </summary>
            public bool SDP;
            /// <summary>
            /// Initiator defines number and size of partitions
            /// </summary>
            public bool IDP;
            /// <summary>
            /// Defines the unit on which the partition sizes are defined
            /// </summary>
            public PartitionSizeUnitOfMeasures PSUM;
            public bool POFM;
            public bool CLEAR;
            public bool ADDP;
            /// <summary>
            /// Defines the capabilities for the unit to recognize media partitions and format
            /// </summary>
            public MediumFormatRecognitionValues MediumFormatRecognition;
            public byte PartitionUnits;
            /// <summary>
            /// Array of partition sizes in units defined above
            /// </summary>
            public ushort[] PartitionSizes;
        }

        public static ModePage_11? DecodeModePage_11(byte[] pageResponse)
        {
            if((pageResponse?[0] & 0x40) == 0x40) return null;

            if((pageResponse?[0] & 0x3F) != 0x11) return null;

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

            if(pageResponse.Length < 8) return null;

            ModePage_11 decoded = new ModePage_11();

            decoded.PS |= (pageResponse[0] & 0x80) == 0x80;

            decoded.MaxAdditionalPartitions = pageResponse[2];
            decoded.AdditionalPartitionsDefined = pageResponse[3];
            decoded.FDP |= (pageResponse[4] & 0x80) == 0x80;
            decoded.SDP |= (pageResponse[4] & 0x40) == 0x40;
            decoded.IDP |= (pageResponse[4] & 0x20) == 0x20;
            decoded.PSUM = (PartitionSizeUnitOfMeasures)((pageResponse[4] & 0x18) >> 3);
            decoded.POFM |= (pageResponse[4] & 0x04) == 0x04;
            decoded.CLEAR |= (pageResponse[4] & 0x02) == 0x02;
            decoded.ADDP |= (pageResponse[4] & 0x01) == 0x01;
            decoded.PartitionUnits = (byte)(pageResponse[6] & 0x0F);
            decoded.MediumFormatRecognition = (MediumFormatRecognitionValues)pageResponse[5];
            decoded.PartitionSizes = new ushort[(pageResponse.Length - 8) / 2];

            for(int i = 8; i < pageResponse.Length; i += 2)
            {
                decoded.PartitionSizes[(i - 8) / 2] = (ushort)(pageResponse[i] << 8);
                decoded.PartitionSizes[(i - 8) / 2] += pageResponse[i + 1];
            }

            return decoded;
        }

        public static string PrettifyModePage_11(byte[] pageResponse)
        {
            return PrettifyModePage_11(DecodeModePage_11(pageResponse));
        }

        public static string PrettifyModePage_11(ModePage_11? modePage)
        {
            if(!modePage.HasValue) return null;

            ModePage_11 page = modePage.Value;
            StringBuilder sb = new StringBuilder();

            sb.AppendLine("SCSI medium partition page:");

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

            sb.AppendFormat("\t{0} maximum additional partitions", page.MaxAdditionalPartitions).AppendLine();
            sb.AppendFormat("\t{0} additional partitions defined", page.AdditionalPartitionsDefined).AppendLine();

            if(page.FDP) sb.AppendLine("\tPartitions are fixed under device definitions");
            if(page.SDP) sb.AppendLine("\tNumber of partitions can be defined but their size is defined by the device");
            if(page.IDP) sb.AppendLine("\tNumber and size of partitions can be manually defined");
            if(page.POFM)
                sb.AppendLine("\tPartition parameters will not be applied until a FORMAT MEDIUM command is received");
            if(!page.CLEAR && !page.ADDP)
                sb.AppendLine("\tDevice may erase any or all partitions on MODE SELECT for partitioning");
            else if(page.CLEAR && !page.ADDP)
                sb.AppendLine("\tDevice shall erase all partitions on MODE SELECT for partitioning");
            else if(!page.CLEAR)
                sb.AppendLine("\tDevice shall not erase any partition on MODE SELECT for partitioning");
            else
                sb.AppendLine("\tDevice shall erase all partitions differing on size on MODE SELECT for partitioning");

            string measure;

            switch(page.PSUM)
            {
                case PartitionSizeUnitOfMeasures.Bytes:
                    sb.AppendLine("\tPartitions are defined in bytes");
                    measure = "bytes";
                    break;
                case PartitionSizeUnitOfMeasures.Kilobytes:
                    sb.AppendLine("\tPartitions are defined in kilobytes");
                    measure = "kilobytes";
                    break;
                case PartitionSizeUnitOfMeasures.Megabytes:
                    sb.AppendLine("\tPartitions are defined in megabytes");
                    measure = "megabytes";
                    break;
                case PartitionSizeUnitOfMeasures.Exponential:
                    sb.AppendFormat("\tPartitions are defined in units of {0} bytes", Math.Pow(10, page.PartitionUnits))
                      .AppendLine();
                    measure = $"units of {Math.Pow(10, page.PartitionUnits)} bytes";
                    break;
                default:
                    sb.AppendFormat("\tUnknown partition size unit code {0}", (byte)page.PSUM).AppendLine();
                    measure = "units";
                    break;
            }

            switch(page.MediumFormatRecognition)
            {
                case MediumFormatRecognitionValues.Capable:
                    sb.AppendLine("\tDevice is capable of recognizing both medium partitions and format");
                    break;
                case MediumFormatRecognitionValues.FormatCapable:
                    sb.AppendLine("\tDevice is capable of recognizing medium format");
                    break;
                case MediumFormatRecognitionValues.PartitionCapable:
                    sb.AppendLine("\tDevice is capable of recognizing medium partitions");
                    break;
                case MediumFormatRecognitionValues.Incapable:
                    sb.AppendLine("\tDevice is not capable of recognizing neither medium partitions nor format");
                    break;
                default:
                    sb.AppendFormat("\tUnknown medium recognition code {0}", (byte)page.MediumFormatRecognition)
                      .AppendLine();
                    break;
            }

            sb.AppendFormat("\tMedium has defined {0} partitions", page.PartitionSizes.Length).AppendLine();

            for(int i = 0; i < page.PartitionSizes.Length; i++)
                if(page.PartitionSizes[i] == 0)
                    if(page.PartitionSizes.Length == 1)
                        sb.AppendLine("\tDevice recognizes one single partition spanning whole medium");
                    else sb.AppendFormat("\tPartition {0} runs for rest of medium", i).AppendLine();
                else
                    sb.AppendFormat("\tPartition {0} is {1} {2} long", i, page.PartitionSizes[i], measure).AppendLine();

            return sb.ToString();
        }
        #endregion Mode Page 0x11: Medium partition page (1)
    }
}