#ifndef TUT_RESTARTABLE_H_GUARD
#define TUT_RESTARTABLE_H_GUARD

#include <wibble/tests/tut.h>
#include <fstream>
#include <iostream>

/**
 * Template Unit Tests Framework for C++.
 * http://tut.dozen.ru
 *
 * Optional restartable wrapper for test_runner.
 * Allows to restart test runs finished due to
 * abnormal test application termination (such as
 * segmentation fault or math error).
 *
 * @author dozen, tut@dozen.ru
 */
namespace tut
{
  namespace util
  {
    /**
     * Escapes non-alphabetical characters in string.
     */
    std::string escape(const std::string& orig)
    {
      std::string rc;
      std::string::const_iterator i,e;
      i = orig.begin();
      e = orig.end();

      while( i != e )
      {
        if( (*i >= 'a' && *i <= 'z') ||
            (*i >= 'A' && *i <= 'Z') ||
            (*i >= '0' && *i <= '9') )
        {
          rc += *i;
        }
        else
        {
          rc += '\\';
          rc += ('a'+(((unsigned int)*i)>>4));
          rc += ('a'+(((unsigned int)*i)&0xF));
        }

        ++i;         
      }
      return rc;
    }

    /**
     * Un-escapes string.
     */
    std::string unescape(const std::string& orig)
    {
      std::string rc;
      std::string::const_iterator i,e;
      i = orig.begin();
      e = orig.end();

      while( i != e )
      {
        if( *i != '\\' )
        {
          rc += *i;
        }
        else
        {
          ++i; if( i == e ) throw std::invalid_argument("unexpected end of string");
          unsigned int c1 = *i;
          ++i; if( i == e ) throw std::invalid_argument("unexpected end of string");
          unsigned int c2 = *i;
          rc += (((c1-'a')<<4) + (c2-'a'));
        }
 
        ++i;
      }
      return rc;         
    }

    /**
     * Serialize test_result avoiding interfering with operator <<.
     */
    void serialize(std::ostream& os,const tut::test_result& tr)
    {
      os << escape(tr.group) << std::endl;
      os << tr.test << ' ';
      switch(tr.result)
      {
        case test_result::ok: os << 0; break;
        case test_result::fail: os << 1; break;
        case test_result::ex: os << 2; break;
        case test_result::warn: os << 3; break;
        case test_result::term: os << 4; break;
        default: throw std::logic_error("operator << : bad result_type");
      }  
      os << ' ' << escape(tr.message) << std::endl;
    }

    /**
     * deserialization for test_result
     */
    void deserialize(std::istream& is,tut::test_result& tr)
    {
      std::getline(is,tr.group);
      if( is.eof() ) throw tut::no_more_tests();
      tr.group = unescape(tr.group);

      tr.test = -1;
      is >> tr.test;
      if( tr.test < 0 ) throw std::logic_error("operator >> : bad test number");

      int n = -1; is >> n;
      switch(n)
      {
        case 0: tr.result = test_result::ok; break;
        case 1: tr.result = test_result::fail; break;
        case 2: tr.result = test_result::ex; break;
        case 3: tr.result = test_result::warn; break;
        case 4: tr.result = test_result::term; break;
        default: throw std::logic_error("operator >> : bad result_type");
      }  
 
      is.ignore(1); // space
      std::getline(is,tr.message);
      tr.message = unescape(tr.message);
      if( !is.good() ) throw std::logic_error("malformed test result");
    }
  };

  /**
   * Restartable test runner wrapper.
   */
  class restartable_wrapper
  {
    test_runner& runner_;
    callback* callback_;

    std::string dir_;
    std::string log_; // log file: last test being executed
    std::string jrn_; // journal file: results of all executed tests

    public:
    /**
     * Default constructor.
     * @param dir Directory where to search/put log and journal files
     */
    restartable_wrapper(const std::string& dir = ".") 
      : runner_(runner.get()), callback_(0), dir_(dir)
    {
      // dozen: it works, but it would be better to use system path separator
      jrn_ = dir_+'/'+"journal.tut";
      log_ = dir_+'/'+"log.tut";
    }

    /**
     * Stores another group for getting by name.
     */
    void register_group(const std::string& name,group_base* gr)
    {
      runner_.register_group(name,gr);
    }

    /**
     * Stores callback object.
     */
    void set_callback(callback* cb)
    {
      callback_ = cb;
    }

    /**
     * Returns callback object.
     */
    callback& get_callback() const
    {
      return runner_.get_callback();
    }

    /**
     * Returns list of known test groups.
     */
    groupnames list_groups() const
    {
      return runner_.list_groups();
    }

    /**
     * Runs all tests in all groups.
     */
    void run_tests() const
    {
      // where last run was failed
      std::string fail_group;
      int fail_test;
      read_log_(fail_group,fail_test);
      bool fail_group_reached = (fail_group == "");

      // iterate over groups
      tut::groupnames gn = list_groups();
      tut::groupnames::const_iterator gni,gne;
      gni = gn.begin();
      gne = gn.end();
      while( gni != gne )
      {
        // skip all groups before one that failed
        if( !fail_group_reached )
        {
          if( *gni != fail_group )
          {
            ++gni;
            continue;
          }
          fail_group_reached = true;
        }

        // first or restarted run
        int test = (*gni == fail_group && fail_test>=0)? fail_test+1:1;
        while(true)
        {
          // last executed test pos
          register_execution_(*gni,test);

          try
          {
            tut::test_result tr = runner_.run_test(*gni,test);
            register_test_(tr);
          }
          catch( const tut::beyond_last_test& ex )
          {
            break;
          }
          catch( const tut::no_such_test& ex )
          {
            // it's ok
          }

          ++test;
        }

        ++gni;      
      }

      // show final results to user
      invoke_callback_();

      // truncate files as mark of successful finish
      truncate_();
    }

  private:
    /**
     * Shows results from journal file.
     */
    void invoke_callback_() const
    {
      runner_.set_callback(callback_);
      runner_.get_callback().run_started();

      std::string current_group;
      std::ifstream ijournal(jrn_.c_str());
      while( ijournal.good() )
      {
        // read next test result
        try
        {
          tut::test_result tr;
          util::deserialize(ijournal,tr);
          runner_.get_callback().test_completed(tr);
        }
        catch( const no_more_tests& )
        {
          break;
        }
      }

      runner_.get_callback().run_completed();
    }

    /**
     * Register test into journal.
     */
    void register_test_(const test_result& tr) const
    {
      std::ofstream ojournal(jrn_.c_str(),std::ios::app);
      util::serialize(ojournal,tr);
      ojournal << std::flush;
      if( !ojournal.good() ) throw std::runtime_error("unable to register test result in file "+jrn_);
    }

    /**
     * Mark the fact test going to be executed
     */
    void register_execution_(const std::string& grp,int test) const
    {
      // last executed test pos
      std::ofstream olog(log_.c_str());
      olog << util::escape(grp) << std::endl << test << std::endl << std::flush;
      if( !olog.good() ) throw std::runtime_error("unable to register execution in file "+log_);
    }

    /**
     * Truncate tests.
     */
    void truncate_() const
    {
      std::ofstream olog(log_.c_str());
      std::ofstream ojournal(jrn_.c_str());
    }

    /**
     * Read log file
     */
    void read_log_(std::string& fail_group,int& fail_test) const
    {
      // read failure point, if any
      std::ifstream ilog(log_.c_str());
      std::getline(ilog,fail_group);
      fail_group = util::unescape(fail_group);
      ilog >> fail_test;
      if( !ilog.good() )
      { 
        fail_group = ""; fail_test = -1; 
        truncate_();
      }
      else
      {
        // test was terminated...
        tut::test_result tr(fail_group,fail_test,tut::test_result::term);
        register_test_(tr);
      }
    }
  };
}

#endif