// @(#)root/reflex:$Id$
// Author: Pere Mato 2006

// Copyright CERN, CH-1211 Geneva 23, 2004-2006, All rights reserved.
//
// Permission to use, copy, modify, and distribute this software for any
// purpose is hereby granted without fee, provided that this copyright and
// permissions notice appear in all copies and derivatives.
//
// This software is provided "as is" without express or implied warranty.

#ifndef REFLEX_BUILD
# define REFLEX_BUILD
#endif

#include "PluginFactoryMap.h"

#include <cstring>
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <vector>
#include <map>
#include <set>

using namespace std;

#include "dir_manip.h"

#if defined(_WIN32)      /* Windows  */
# define PATHENV "PATH"
# define PATHSEP ";"
#elif defined(__APPLE__) /* MacOS */
# define PATHENV "DYLD_LIBRARY_PATH"
# define PATHSEP ":"
#else                    /* Linux */
# define PATHENV "LD_LIBRARY_PATH"
# define PATHSEP ":"
#endif

typedef std::list<std::string> Directive_t;
typedef std::map<std::string, Directive_t> Map_t;

//-------------------------------------------------------------------------------
static Map_t&
sMap() {
//-------------------------------------------------------------------------------
// Static wrapper for the map.
   static Map_t* s_map = 0;

   if (!s_map) {
      s_map = new Map_t;
   }
   return *s_map;
}


//-------------------------------------------------------------------------------
static void
DumpFactoryDirective(std::ostream& out,
                     const Directive_t& directive) {
//-------------------------------------------------------------------------------
// Dump a directive to out.
   bool first = true;

   for (Directive_t::const_iterator iLib = directive.begin();
        iLib != directive.end(); ++iLib) {
      if (!first) {
         out << ", ";
      } else { first = false; }
      out << *iLib;
   }
}


//-------------------------------------------------------------------------------
bool
ConflictingDirective(const Directive_t& lhs,
                     const Directive_t& rhs) {
//-------------------------------------------------------------------------------
// Check for inequality of directives, disregarding order of all but first.
   if (*lhs.begin() != *rhs.begin()) {
      return true;
   }

   if (lhs.size() < 2 || lhs.size() < 2) {
      return false;                                    // first entry equal, and it's all we have

   }
   set<string> setLHS, setRHS;

   // can't use insert(iter, iter) because of solaris :-/
   for (Directive_t::const_iterator iLHS = ++lhs.begin(); iLHS != lhs.end(); ++iLHS) {
      setLHS.insert(*iLHS);
   }

   for (Directive_t::const_iterator iRHS = ++rhs.begin(); iRHS != rhs.end(); ++iRHS) {
      setRHS.insert(*iRHS);
   }

   if (setLHS.size() != setRHS.size()) {
      return true;
   }

   for (set<string>::const_iterator iSetLHS = setLHS.begin();
        iSetLHS != setLHS.end(); ++iSetLHS) {
      if (setRHS.find(*iSetLHS) == setRHS.end()) {
         return true;
      }
   }
   return false;
} // ConflictingDirective


int Reflex::PluginFactoryMap::fgDebugLevel = 0;

//-------------------------------------------------------------------------------
Reflex::PluginFactoryMap::PluginFactoryMap(const std::string& pathenv) {
//-------------------------------------------------------------------------------
// Constructor.
   vector<char*> tokens;
   struct stat buf;
   dirent* e = 0;
   DIR* dir = 0;
   const char* envpath = ::getenv(pathenv.empty() ? PATHENV : pathenv.c_str());
   if (!envpath) return; // no path, no rootmap files.
   string path(envpath);

   for (char* t = strtok(const_cast<char*>(path.c_str()), PATHSEP); t; t = strtok(0, PATHSEP)) {
      if (0 == ::stat(t, &buf) && S_ISDIR(buf.st_mode)) {
         tokens.push_back(t);
      }
   }

   for (vector<char*>::iterator i = tokens.begin(); i != tokens.end(); ++i) {
      if (0 != (dir = ::opendir(*i))) {
         while (0 != (e = ::readdir(dir))) {
            if (strstr(::directoryname(e), "rootmap") != 0) {
               std::string fn = *i;
               fn += "/";
               fn += ::directoryname(e);
               FillMap(fn);
            }
         }
         ::closedir(dir);
      }
   }
}


//-------------------------------------------------------------------------------
Reflex::PluginFactoryMap::~PluginFactoryMap() {
//-------------------------------------------------------------------------------
// Destructor.
}


//-------------------------------------------------------------------------------
void
Reflex::PluginFactoryMap::FillMap(const std::string& filename) {
//-------------------------------------------------------------------------------
// Fill the map from the content of the map files.
   fstream file;
   string rawline;
   file.open(filename.c_str(), ios::in);

   if (Debug()) {
      cout << "FactoryMap: Processing file " << filename << endl;
   }

   while (!getline(file, rawline).eof() && file.good()) {
      string::size_type p1 = rawline.find_first_not_of(' ');
      string::size_type p2 = rawline.find_last_not_of(' ');
      string line = rawline.substr(p1 == string::npos ? 0 : p1,
                                   p2 == string::npos ? rawline.length() - 1 : p2 - p1 + 1);

      if (line.size() == 0 || line[0] == '#') {
         continue;
      }

      if (line.substr(0, 8) == "Library.") {
         string::size_type pc = line.find_first_of(':');
         string cname = line.substr(8, pc - 8);
         string::size_type pv = line.substr(pc + 1).find_first_not_of(' ');
         string vlibs = line.substr(pc + 1 + pv);
         Directive_t libs;

         for (char* t = strtok(const_cast<char*>(vlibs.c_str()), " "); t; t = strtok(0, " ")) {
            libs.push_back(t);
         }

         // Check whether cname already has a directive,
         // warn and ignore this one if it's conflicting
         Map_t::const_iterator iPreviousDirective = sMap().find(cname);

         if (iPreviousDirective != sMap().end()) {
            if (ConflictingDirective(libs, iPreviousDirective->second)) {
               if (Debug()) {
                  cerr << "Reflex::PluginFactoryMap::FillMap() - WARNING: "
                       << "conflicting directives for " << cname << endl
                       << "  Previous: \"";
                  DumpFactoryDirective(cerr, iPreviousDirective->second);
                  cerr << "\"" << endl
                       << "  Directive in " << filename << ": \"";
                  DumpFactoryDirective(cerr, libs);
                  cerr << "\"" << endl
                       << "  Previous takes precedence." << endl;
               }
            } else if (Debug() > 1) {
               cout << "FactoryMap: copy of directive detected for Name " << cname << ": ";
               DumpFactoryDirective(cout, libs);
               cout << endl;
            }
         } else {
            // Inserting name in map
            sMap()[cname] = libs;

            if (Debug() > 1) {
               cout << "FactoryMap:    Name " << cname << ": ";
               DumpFactoryDirective(cout, libs);
               cout << endl;
            }
         }
      }
   }
   file.close();
} // FillMap


//-------------------------------------------------------------------------------
std::list<std::string>
Reflex::PluginFactoryMap::GetLibraries(const std::string& name) const {
//-------------------------------------------------------------------------------
// Return all libs currently present.
   return sMap()[name];
}


//-------------------------------------------------------------------------------
void
Reflex::PluginFactoryMap::SetDebug(int l) {
//-------------------------------------------------------------------------------
// Set debug level.
   fgDebugLevel = l;
}


//-------------------------------------------------------------------------------
int
Reflex::PluginFactoryMap::Debug() {
//-------------------------------------------------------------------------------
// Get debug level.
   return fgDebugLevel;
}