/*
** Copyright 2012 Kamil Rytarowski < kamil AT mageia DOT org >
**
** This Source Code Form is subject to the terms of the Mozilla Public
** License, v. 2.0. If a copy of the MPL was not distributed with this
** file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/

#include <chrono>
#include <cstdlib>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <locale>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <vector>

#include <boost/date_time/posix_time/posix_time.hpp>

#include "pugixml.hpp"

typedef std::tuple<unsigned long /* revision */,
		   std::string /* author */,
		   boost::posix_time::ptime /* date */> tuple;

int main(int argc, char **argv)
{
  /*
  ** Read text stream from stdin
  */

  std::cin >> std::noskipws; /* Don't skip whitespaces */

  /*
  ** Use iterators to slurp data from the standard input
  */

  std::istream_iterator<char> it(std::cin);
  std::istream_iterator<char> end;
  const std::string input(it, end);

  pugi::xml_document doc;
  pugi::xml_parse_result result = doc.load_buffer(input.c_str(), input.size());

#ifndef NDEBUG
  std::cerr << "Load result: " << result.description() << "\n";
#endif
  
  /*
  ** <?xml version="1.0" encoding="UTF-8"?>
  ** <log>
  ** <logentry
  **   revision="1234">
  ** <author>author</author>
  ** <date>2012-01-21T10:00:00.000000Z</date>
  ** </logentry>
  ** </log>
  */
  pugi::xml_node log = doc.child("log");

  std::vector<tuple> table;

  for (pugi::xml_node logentry: log.children())
    {
      unsigned long revision = std::stoul(logentry.attribute("revision").value());
      std::string author = logentry.child("author").text().get();

#ifndef NDEBUG
      std::cerr << revision << "\t" << author << "\t";
#endif

      std::string datetime = logentry.child("date").text().get();
      boost::posix_time::time_input_facet * facet =
	new boost::posix_time::time_input_facet("%Y-%m-%dT%H:%M:%sZ"); /* 'Z' stands for UTC */

      std::stringstream ss;
      ss.imbue(std::locale(std::locale(), facet));
      ss << datetime;
      boost::posix_time::ptime date;
      ss >> date;

#ifndef NDEBUG
      std::cerr << datetime << "\t" << date << "\n";
#endif

      table.push_back(std::make_tuple(revision, author, date));
    }

  /*
  ** Statistics:
  ** 
  **  1. Overall number of the commiters
  **  2. Number of commits per a commiter
  **  3. 
  */

  /*
  ** 1. Overall number of the commiters
  */

  unsigned int overall_commiters = 0;
  {
    std::set<std::string> tmp_set;
    overall_commiters =
      (unsigned int) count_if(table.begin(), table.end(), [&tmp_set](tuple & t)
			      {
				std::string author = std::get<1>(t);
			      
				if (tmp_set.empty())
				  {
				    tmp_set.insert(author);
				    return true;
				  }
				else
				  {
				    if (tmp_set.find(author) == tmp_set.end())
				      {
					tmp_set.insert(author);
					return true;
				      }
				    else
				      return false;
				  }  
			      }
			      );
  }

#ifndef NDEBUG
  std::cerr << "Overall commiters: " << overall_commiters << "\n";
#endif

  /*
  ** 2. Number of commits per a commiter
  */
  
  std::map<std::string, unsigned int> commits_per_a_commiter;
  {
    for(auto t : table)
      {
	std::string author = std::get<1>(t);
	if (commits_per_a_commiter.empty())
	  commits_per_a_commiter.insert(std::pair<std::string, unsigned int>(author, 1));
	else
	  {
	    auto a = commits_per_a_commiter.find(author);
	    if (a == commits_per_a_commiter.end())
	      commits_per_a_commiter.insert(std::pair<std::string, unsigned int>(author, 1));
	    else
	      commits_per_a_commiter.at(author) = (commits_per_a_commiter.at(author) + 1);
	  }
      }
  }

#ifndef NDEBUG
  std::cerr << "Commits per a commiter:\n";
  for(auto c : commits_per_a_commiter)
    {
      std::cerr << "\t" << (c.first) << "\t" << (c.second) << "\n";
    }
#endif

  return EXIT_SUCCESS;
}