// Include Files							/*{{{*/
#include <config.h>

#include <apt-pkg/algorithms.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/edsp.h>
#include <apt-pkg/error.h>
#include <apt-pkg/progress.h>
#include <apt-pkg/upgrade.h>
#include <apt-pkg/depcache.h>
#include <apt-pkg/pkgcache.h>
#include <apt-pkg/cacheiterators.h>

#include <string>

#include <apti18n.h>
									/*}}}*/

// DistUpgrade - Distribution upgrade					/*{{{*/
// ---------------------------------------------------------------------
/* This autoinstalls every package and then force installs every 
   pre-existing package. This creates the initial set of conditions which 
   most likely contain problems because too many things were installed.
   
   The problem resolver is used to resolve the problems.
 */
bool pkgDistUpgrade(pkgDepCache &Cache)
{
   std::string const solver = _config->Find("APT::Solver", "internal");
   if (solver != "internal") {
      OpTextProgress Prog(*_config);
      return EDSP::ResolveExternal(solver.c_str(), Cache, false, true, false, &Prog);
   }

   pkgDepCache::ActionGroup group(Cache);

   /* Upgrade all installed packages first without autoinst to help the resolver
      in versioned or-groups to upgrade the old solver instead of installing
      a new one (if the old solver is not the first one [anymore]) */
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      if (I->CurrentVer != 0)
	 Cache.MarkInstall(I, false, 0, false);

   /* Auto upgrade all installed packages, this provides the basis 
      for the installation */
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      if (I->CurrentVer != 0)
	 Cache.MarkInstall(I, true, 0, false);

   /* Now, install each essential package which is not installed
      (and not provided by another package in the same name group) */
   std::string essential = _config->Find("pkgCacheGen::Essential", "all");
   if (essential == "all")
   {
      for (pkgCache::GrpIterator G = Cache.GrpBegin(); G.end() == false; ++G)
      {
	 bool isEssential = false;
	 bool instEssential = false;
	 for (pkgCache::PkgIterator P = G.PackageList(); P.end() == false; P = G.NextPkg(P))
	 {
	    if ((P->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential)
	       continue;
	    isEssential = true;
	    if (Cache[P].Install() == true)
	    {
	       instEssential = true;
	       break;
	    }
	 }
	 if (isEssential == false || instEssential == true)
	    continue;
	 pkgCache::PkgIterator P = G.FindPreferredPkg();
	 Cache.MarkInstall(P, true, 0, false);
      }
   }
   else if (essential != "none")
      for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
	 if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
	    Cache.MarkInstall(I, true, 0, false);
   
   /* We do it again over all previously installed packages to force 
      conflict resolution on them all. */
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      if (I->CurrentVer != 0)
	 Cache.MarkInstall(I, false, 0, false);

   pkgProblemResolver Fix(&Cache);

   // Hold back held packages.
   if (_config->FindB("APT::Ignore-Hold",false) == false)
   {
      for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      {
	 if (I->SelectedState == pkgCache::State::Hold)
	 {
	    Fix.Protect(I);
	    Cache.MarkKeep(I, false, false);
	 }
      }
   }
   
   return Fix.Resolve();
}
									/*}}}*/
// AllUpgradeNoNewPackages - Upgrade but no removals or new pkgs        /*{{{*/
static bool pkgAllUpgradeNoNewPackages(pkgDepCache &Cache)
{
   std::string const solver = _config->Find("APT::Solver", "internal");
   if (solver != "internal") {
      OpTextProgress Prog(*_config);
      return EDSP::ResolveExternal(solver.c_str(), Cache, true, false, false, &Prog);
   }

   pkgDepCache::ActionGroup group(Cache);

   pkgProblemResolver Fix(&Cache);

   if (Cache.BrokenCount() != 0)
      return false;
   
   // Upgrade all installed packages
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
   {
      if (Cache[I].Install() == true)
	 Fix.Protect(I);
	  
      if (_config->FindB("APT::Ignore-Hold",false) == false)
	 if (I->SelectedState == pkgCache::State::Hold)
	    continue;
      
      if (I->CurrentVer != 0 && Cache[I].InstallVer != 0)
	 Cache.MarkInstall(I, false, 0, false);
   }
      
   return Fix.ResolveByKeep();
}
									/*}}}*/
// AllUpgradeWithNewInstalls - Upgrade + install new packages as needed /*{{{*/
// ---------------------------------------------------------------------
/* Right now the system must be consistent before this can be called.
 * Upgrade as much as possible without deleting anything (useful for
 * stable systems)
 */
static bool pkgAllUpgradeWithNewPackages(pkgDepCache &Cache)
{
   std::string const solver = _config->Find("APT::Solver", "internal");
   if (solver != "internal") {
      OpTextProgress Prog(*_config);
      return EDSP::ResolveExternal(solver.c_str(), Cache, true, false, false, &Prog);
   }

   pkgDepCache::ActionGroup group(Cache);

   pkgProblemResolver Fix(&Cache);

   if (Cache.BrokenCount() != 0)
      return false;

   // provide the initial set of stuff we want to upgrade by marking
   // all upgradable packages for upgrade
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
   {
      if (I->CurrentVer != 0 && Cache[I].InstallVer != 0)
      {
         if (_config->FindB("APT::Ignore-Hold",false) == false)
            if (I->SelectedState == pkgCache::State::Hold)
               continue;

	 Cache.MarkInstall(I, false, 0, false);
      }
   }

   // then let auto-install loose
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      if (Cache[I].Install())
	 Cache.MarkInstall(I, true, 0, false);

   // ... but it may remove stuff, we we need to clean up afterwards again
   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      if (Cache[I].Delete() == true)
	 Cache.MarkKeep(I, false, false);

   // resolve remaining issues via keep
   return Fix.ResolveByKeep();
}
									/*}}}*/
// AllUpgrade - Upgrade as many packages as possible			/*{{{*/
// ---------------------------------------------------------------------
/* Right now the system must be consistent before this can be called.
   It also will not change packages marked for install, it only tries
   to install packages not marked for install */
bool pkgAllUpgrade(pkgDepCache &Cache)
{
   return pkgAllUpgradeNoNewPackages(Cache);
}
									/*}}}*/
// MinimizeUpgrade - Minimizes the set of packages to be upgraded	/*{{{*/
// ---------------------------------------------------------------------
/* This simply goes over the entire set of packages and tries to keep 
   each package marked for upgrade. If a conflict is generated then 
   the package is restored. */
bool pkgMinimizeUpgrade(pkgDepCache &Cache)
{   
   pkgDepCache::ActionGroup group(Cache);

   if (Cache.BrokenCount() != 0)
      return false;
   
   // We loop for 10 tries to get the minimal set size.
   bool Change = false;
   unsigned int Count = 0;
   do
   {
      Change = false;
      for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
      {
	 // Not interesting
	 if (Cache[I].Upgrade() == false || Cache[I].NewInstall() == true)
	    continue;

	 // Keep it and see if that is OK
	 Cache.MarkKeep(I, false, false);
	 if (Cache.BrokenCount() != 0)
	    Cache.MarkInstall(I, false, 0, false);
	 else
	 {
	    // If keep didn't actually do anything then there was no change..
	    if (Cache[I].Upgrade() == false)
	       Change = true;
	 }	 
      }      
      ++Count;
   }
   while (Change == true && Count < 10);

   if (Cache.BrokenCount() != 0)
      return _error->Error("Internal Error in pkgMinimizeUpgrade");
   
   return true;
}
									/*}}}*/
// APT::Upgrade::Upgrade - Upgrade using a specific strategy     	/*{{{*/
bool APT::Upgrade::Upgrade(pkgDepCache &Cache, int mode)
{
   if (mode == 0) 
   {
      return pkgDistUpgrade(Cache);
   }
   else if ((mode & ~FORBID_REMOVE_PACKAGES) == 0)
   {
      return pkgAllUpgradeWithNewPackages(Cache);
   } 
   else if ((mode & ~(FORBID_REMOVE_PACKAGES|FORBID_INSTALL_NEW_PACKAGES)) == 0)
   {
      return pkgAllUpgradeNoNewPackages(Cache);
   }
   else
      _error->Error("pkgAllUpgrade called with unsupported mode %i", mode);

   return false;
}
									/*}}}*/