//
// C++ Implementation: gptpart
//
// Description: Class to implement a SINGLE GPT partition
//
//
// Author: Rod Smith <rodsmith@rodsbooks.com>, (C) 2009-2018
//
// Copyright: See COPYING file that comes with this distribution
//
//
// This program is copyright (c) 2009 by Roderick W. Smith. It is distributed
// under the terms of the GNU GPL version 2, as detailed in the COPYING file.

#define __STDC_LIMIT_MACROS
#define __STDC_CONSTANT_MACROS

#include <string.h>
#include <stdio.h>
#include <iostream>
#include "gptpart.h"
#include "attributes.h"
#ifdef USE_UTF16
#include <unicode/ustdio.h>
#else
#define UnicodeString std::string
#endif

using namespace std;

GPTPart::GPTPart(void) {
   partitionType.Zero();
   uniqueGUID.Zero();
   firstLBA = 0;
   lastLBA = 0;
   attributes = 0;
   memset(name, 0, NAME_SIZE * sizeof(name[0]) );
} // Default constructor

GPTPart::GPTPart(const GPTPart & orig) {
   partitionType = orig.partitionType;
   uniqueGUID = orig.uniqueGUID;
   firstLBA = orig.firstLBA;
   lastLBA = orig.lastLBA;
   attributes = orig.attributes;
   memcpy(name, orig.name, NAME_SIZE * sizeof( name[ 0 ] ) );
} // Copy constructor

GPTPart::~GPTPart(void) {
} // destructor

// Return the gdisk-specific two-byte hex code for the partition
uint16_t GPTPart::GetHexType(void) const {
   return partitionType.GetHexType();
} // GPTPart::GetHexType()

// Return a plain-text description of the partition type (e.g., "Linux/Windows
// data" or "Linux swap").
string GPTPart::GetTypeName(void) {
   return partitionType.TypeName();
} // GPTPart::GetNameType()

#ifdef USE_UTF16
// Return a Unicode description of the partition type (e.g., "Linux/Windows
// data" or "Linux swap").
UnicodeString GPTPart::GetUTypeName(void) {
   return partitionType.UTypeName();
} // GPTPart::GetNameType()
#endif

// Compute and return the partition's length (or 0 if the end is incorrectly
// set before the beginning).
uint64_t GPTPart::GetLengthLBA(void) const {
   uint64_t length = 0;

   if (firstLBA <= lastLBA)
      length = lastLBA - firstLBA + UINT64_C(1);
   return length;
} // GPTPart::GetLengthLBA()

#ifdef USE_UTF16
// Return partition's name field, converted to a Unicode string
UnicodeString GPTPart::GetDescription(void) {
   return (UChar*) name;
} // GPTPart::GetDescription()
#else
// Return partition's name field, converted to a C++ UTF-8 string
string GPTPart::GetDescription(void) {
   // convert name to utf32 then to utf8
   string utf8 ;
   size_t pos = 0 ;
   while ( ( pos < NAME_SIZE ) && ( name[ pos ] != 0 ) ) {
      uint16_t cp = name[ pos ++ ] ;
      // first to utf32
      uint32_t uni ;
      if ( cp < 0xd800 || cp > 0xdfff ) {
         uni = cp ;
      } // if
      else if ( cp < 0xdc00 ) {
         // lead surrogate
         uni = ( (uint32_t)( cp & 0x3ff ) ) << 10 ;
         if ( pos >= NAME_SIZE ) {
            // missing trail surrogate, name[] is invalid
            break ;
         } // if
         cp = name[ pos ++ ] ;
         if ( cp < 0xdc00 || cp > 0xdfff ) {
            // invalid trail surrogate, name[] is invalid
            break ;
         } // if
         // trail surrogate
         uni |= cp & 0x3ff ;
         uni += 0x10000 ;
      } // if
      else {
         // unexpected trail surrogate, name[] is invalid
         break ;
      } // if
      // then to utf8
      if ( uni < 0x80 ) {
         utf8 += (char) uni ;
      } // if
      else if ( uni < 0x800 ) {
         utf8 += (char) ( 0xc0 | ( uni >> 6 ) ) ;
         utf8 += (char) ( 0x80 | ( uni & 0x3f ) ) ;
      } // if
      else if ( uni < 0x10000 ) {
         utf8 += (char) ( 0xe0 | ( uni >> 12 ) ) ;
         utf8 += (char) ( 0x80 | ( ( uni >> 6 ) & 0x3f ) ) ;
         utf8 += (char) ( 0x80 | ( uni & 0x3f ) ) ;
      } // if
      else {
         utf8 += (char) ( 0xf0 | ( uni >> 18 ) ) ;
         utf8 += (char) ( 0xe0 | ( ( uni >> 12 ) & 0x3f ) ) ;
         utf8 += (char) ( 0x80 | ( ( uni >> 6 ) & 0x3f ) ) ;
         utf8 += (char) ( 0x80 | ( uni & 0x3f ) ) ;
      } // if
   }
   return utf8 ;
} // GPTPart::GetDescription(), UTF-8 version
#endif

// Return 1 if the partition is in use
int GPTPart::IsUsed(void) {
   return (partitionType != GUIDData("0x00"));
} // GPTPart::IsUsed()

// Returns MBR_SIZED_GOOD, MBR_SIZED_IFFY, or MBR_SIZED_BAD; see comments
// in header file for details.
int GPTPart::IsSizedForMBR(void) {
   int retval = MBR_SIZED_GOOD;

   if ((firstLBA > UINT32_MAX) || ((lastLBA - firstLBA) > UINT32_MAX) || (firstLBA > lastLBA))
      retval = MBR_SIZED_BAD;
   else if (lastLBA > UINT32_MAX)
      retval = MBR_SIZED_IFFY;

   return (retval);
} // GPTPart::IsSizedForMBR()

// Set the type code to the specified one. Also changes the partition
// name *IF* the current name is the generic one for the current partition
// type.
void GPTPart::SetType(PartType t) {
#ifdef USE_UTF16
   if (GetDescription() == partitionType.UTypeName()) {
#else
   if (GetDescription() == partitionType.TypeName()) {
#endif
      SetName(t.TypeName());
   } // if
   partitionType = t;
} // GPTPart::SetType()

#ifdef USE_UTF16
// Set the name for a partition to theName, using a C++-style string as
// input.
void GPTPart::SetName(const string & theName) {
   SetName((UnicodeString) theName.c_str());
} // GPTPart::SetName()

// Set the name for a partition to theName, using a Unicode string as
// input.
void GPTPart::SetName(const UnicodeString & theName) {
   if (theName.isBogus()) {
      cerr << "Bogus UTF-16 name found in GPTPart::SetName()! Name not changed!\n";
   } else {
      memset(name, 0, NAME_SIZE * sizeof(name[0]) );
      theName.extractBetween(0, NAME_SIZE, (UChar*) name);
   } // if/else
} // GPTPart::SetName()

#else

// Set the name for a partition to theName. Note that theName is a
// standard C++-style ASCII string, although the GUID partition definition
// requires a UTF-16LE string. This function creates a simple-minded copy
// for this.
void GPTPart::SetName(const string & theName) {
   // convert utf8 to utf32 then to utf16le
   size_t len = theName.length() ;
   size_t pos = 0 ;
   for ( size_t i = 0 ; pos < NAME_SIZE && i < len ; ) {
      uint32_t uni ;
      uint8_t cp = theName[ i ++ ] ;
      int todo ;
      if ( cp < 0x80 ) {
         uni = cp ;
         todo = 0 ;
      } // if
      else if ( cp < 0xc0 || cp > 0xf7 ) {
         // invalid byte, theName is broken
         break ;
      } // if
      else if ( cp < 0xe0 ) {
         uni = cp & 0x1f ;
         todo = 1 ;
      } // if
      else if ( cp < 0xf0 ) {
         uni = cp & 0x0f ;
         todo = 2 ;
      } // if
      else {
         uni = cp & 0x7 ;
         todo = 3 ;
      } // if
      while ( todo > 0 ) {
         if ( i >= len ) {
            // missing continuation byte, theName is broken
            goto break_converter ;
         } // if
         cp = theName[ i ++ ] ;
         if ( cp > 0xbf || cp < 0x80 ) {
            // invalid continuation byte, theName is broken
            goto break_converter ;
         } // if
         uni <<= 6 ;
         uni |= cp & 0x3f ;
         todo -- ;
      } // while
      // then to utf16le
      if ( uni < 0x10000 ) {
         name[ pos ] = (uint16_t) uni ;
         pos ++ ;
      } // if
      else {
         if ( pos > NAME_SIZE - 2 ) {
             // not enough room for two surrogates, truncate
             break ;
         } // if
         uni -= 0x10000 ;
         name[ pos ] = (uint16_t)( uni >> 10 ) | 0xd800 ;
         pos ++ ;
         name[ pos ] = (uint16_t)( uni & 0x3ff ) | 0xdc00 ;
         pos ++ ;
      }
   } // for
   break_converter : ;
   // finally fill with zeroes
   while ( pos < NAME_SIZE ) {
      name[ pos ++ ] = 0 ;
   } // while
} // GPTPart::SetName(), UTF-8 version
#endif

// Set the name for the partition based on the current GUID partition type
// code's associated name
void GPTPart::SetDefaultDescription(void) {
   SetName(partitionType.TypeName());
} // GPTPart::SetDefaultDescription()

GPTPart & GPTPart::operator=(const GPTPart & orig) {
   partitionType = orig.partitionType;
   uniqueGUID = orig.uniqueGUID;
   firstLBA = orig.firstLBA;
   lastLBA = orig.lastLBA;
   attributes = orig.attributes;
   memcpy(name, orig.name, NAME_SIZE * sizeof( name[ 0 ] ) );
   return *this;
} // assignment operator

// Compare the values, and return a bool result.
// Because this is intended for sorting and a firstLBA value of 0 denotes
// a partition that's not in use and so that should be sorted upwards,
// we return the opposite of the usual arithmetic result when either
// firstLBA value is 0.
bool GPTPart::operator<(const GPTPart &other) const {
   if (firstLBA && other.firstLBA)
      return (firstLBA < other.firstLBA);
   else
      return (other.firstLBA < firstLBA);
} // GPTPart::operator<()

// Display summary information; does nothing if the partition is empty.
void GPTPart::ShowSummary(int partNum, uint32_t blockSize) {
   string sizeInIeee;
   UnicodeString description;
   size_t i;

   if (firstLBA != 0) {
      sizeInIeee = BytesToIeee(lastLBA - firstLBA + 1, blockSize);
      cout.fill(' ');
      cout.width(4);
      cout << partNum + 1 << "  ";
      cout.width(14);
      cout << firstLBA << "  ";
      cout.width(14);
      cout << lastLBA  << "   ";
      cout << sizeInIeee << "  ";
      if (sizeInIeee.length() < 10)
         for (i = 0; i < 10 - sizeInIeee.length(); i++)
            cout << " ";
      cout.fill('0');
      cout.width(4);
      cout.setf(ios::uppercase);
      cout << hex << partitionType.GetHexType() << "  " << dec;
      cout.fill(' ');
#ifdef USE_UTF16
      GetDescription().extractBetween(0, 23, description);
      cout << description << "\n";
#else
      string desc = GetDescription() ;
      size_t n = 0 ;
      size_t i = 0 ;
      size_t len = desc.length() ;
      while ( n < 22 && i < len ) {
         i ++ ;
         if ( i >= len ) {
            // short description
            break ;
         } // if
         // skip continuation bytes
         while ( i < len && ( ( desc[ i ] & 0xC0 ) == 0x80 ) ) {
             // utf8 continuation byte
             i ++ ;
         } // while
         n ++ ;
      } // while
      if ( i < len ) {
         n = 0 ;
         i = 0 ;
         // description is long we will truncate it
         while ( n < 19 && i < len ) {
            i ++ ;
            if ( i >= len ) {
               // should not happen
               break ;
            } // if
            // skip continuation bytes
            while ( i < len && ( ( desc[ i ] & 0xC0 ) == 0x80 ) ) {
                // utf8 continuation byte
                i ++ ;
            } // while
            n ++ ;
         } // while
      } // for
      cout << GetDescription().substr( 0 , i ) ;
      if ( i < len ) cout << "..." ;
      cout << "\n";
#endif
      cout.fill(' ');
   } // if
} // GPTPart::ShowSummary()

// Show detailed partition information. Does nothing if the partition is
// empty (as determined by firstLBA being 0).
void GPTPart::ShowDetails(uint32_t blockSize) {
   uint64_t size;

   if (firstLBA != 0) {
      cout << "Partition GUID code: " << partitionType;
      cout << " (" << partitionType.TypeName() << ")\n";
      cout << "Partition unique GUID: " << uniqueGUID << "\n";

      cout << "First sector: " << firstLBA << " (at "
           << BytesToIeee(firstLBA, blockSize) << ")\n";
      cout << "Last sector: " << lastLBA << " (at "
           << BytesToIeee(lastLBA, blockSize) << ")\n";
      size = (lastLBA - firstLBA + 1);
      cout << "Partition size: " << size << " sectors ("
           << BytesToIeee(size, blockSize) << ")\n";
      cout << "Attribute flags: ";
      cout.fill('0');
      cout.width(16);
      cout << hex;
      cout << attributes << "\n";
      cout << dec;
      cout << "Partition name: '" << GetDescription() << "'\n";
      cout.fill(' ');
   }  // if
} // GPTPart::ShowDetails()

// Blank (delete) a single partition
void GPTPart::BlankPartition(void) {
   uniqueGUID.Zero();
   partitionType.Zero();
   firstLBA = 0;
   lastLBA = 0;
   attributes = 0;
   memset(name, 0, NAME_SIZE * sizeof( name[0]) );
} // GPTPart::BlankPartition

// Returns 1 if the two partitions overlap, 0 if they don't
int GPTPart::DoTheyOverlap(const GPTPart & other) {
   // Don't bother checking unless these are defined (both start and end points
   // are 0 for undefined partitions, so just check the start points)
   return firstLBA && other.firstLBA &&
          (firstLBA <= other.lastLBA) != (lastLBA < other.firstLBA);
} // GPTPart::DoTheyOverlap()

// Reverse the bytes of integral data types and of the UTF-16LE name;
// used on big-endian systems.
void GPTPart::ReversePartBytes(void) {
   ReverseBytes(&firstLBA, 8);
   ReverseBytes(&lastLBA, 8);
   ReverseBytes(&attributes, 8);
   ReverseNameBytes();
} // GPTPart::ReversePartBytes()

void GPTPart::ReverseNameBytes(void) {
   int i;

   for (i = 0; i < NAME_SIZE; i ++ )
      ReverseBytes(name + i, 2);
} // GPTPart::ReverseNameBytes()

/****************************************
 * Functions requiring user interaction *
 ****************************************/

// Change the type code on the partition. Also changes the name if the original
// name is the generic one for the partition type.
void GPTPart::ChangeType(void) {
   string line;
   int changeName;
   PartType tempType = PartType::unusedPartType;

#ifdef USE_UTF16
   changeName = (GetDescription() == GetUTypeName());
#else
   changeName = (GetDescription() == GetTypeName());
#endif

   cout << "Current type is " << hex << GetHexType() << dec << " (" << GetTypeName() << ")\n";
   do {
      cout << "Hex code or GUID (L to show codes, Enter = " << hex << GetHexType() << dec << "): ";
      line = ReadString();
      if ((line[0] == 'L') || (line[0] == 'l')) {
         partitionType.ShowAllTypes();
      } else {
         if (line.length() == 0)
            tempType = GetHexType();
         else
            tempType = line;
      } // if/else
   } while (tempType == PartType::unusedPartType);
   partitionType = tempType;
   cout << "Changed type of partition to '" << partitionType.TypeName() << "'\n";
   if (changeName) {
      SetDefaultDescription();
   } // if
} // GPTPart::ChangeType()