#include "IdManager.h"

#include <sstream>


bool IdManager::add(const std::string &id) {
  if(!valid(id)) return false;
  
  return usedIds.insert(id).second;
}

bool IdManager::remove(const std::string &id) {
  return (usedIds.erase(id) > 0);
}

bool IdManager::valid(const std::string &id) const {
  if(id.empty()) return false;
  if(id[0] >= '0' && id[0] <= '9') return false;
  
  for(std::string::const_iterator c = id.begin(); c != id.end(); c++) {
    if(!(*c >= '0' && *c <= '9') && !(*c >= 'A' && *c <= 'Z') && !(*c >= 'a' && *c <= 'z')
        && *c != '_' && *c != '-' && *c != '.')
      return false;
  }
  
  return true;
}

bool IdManager::unique(const std::string &id) const {
  if(!valid(id)) return false;
  
  return (usedIds.find(id) == usedIds.end());
}

std::string IdManager::generate(const std::string &prefix) {
  if(!valid(prefix)) return std::string();
  
  unsigned long n = 0;
  
  std::map<std::string, unsigned long>::iterator it = prefixMap.find(prefix);
  if(it != prefixMap.end()) {
    n = it->second + 1;
    prefixMap.erase(it);
  }
  
  std::ostringstream id;
  
  do {
    id.str(std::string());
    id << prefix << n++;
  } while(!unique(id.str()));
  
  prefixMap.insert(std::make_pair<std::string, unsigned long>(prefix, n-1));
  usedIds.insert(id.str());
  
  return id.str();
}