// Simple performance test program.
// Objectives: To see if gcc 3.4.1 makes iostreams significantly faster than
// gcc 3.3, and to compare it to "raw c".
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <stdexcept>
#include <sstream>

/**
 * Convert a string to an arbitrary type.
 * \param C the type to convert to.
 * \param value the value to convert.
 */
template <class C>
C to(const std::string &value) {
  std::istringstream s(value);
  C c;
  if(s >> c) {
    if(!s.eof() && s.peek() != EOF)
      throw std::runtime_error("Trailing junk in \"" + value + '"');
    return c;
  } else
    throw std::runtime_error("Bad value: \"" + value + '"');
}

/**
 * Test reading integers.
 */
unsigned long long sumints(std::istream& in) {
  unsigned long long sum = 0;
  int i;
  while(in >> i)
    sum += i;
  
  return sum;
}

/**
 * Test reading integers (or something else), and growing and sorting a
 * vector.
 */
template<class Num>
Num median(std::istream& in) {
  std::vector<Num> nums;
  
  Num num;
  while(in >> num) nums.push_back(num);

  sort(nums.begin(), nums.end());
  
  if(/* odd */ nums.size() % 2)
    return nums[nums.size()/2];
  else
    return ((nums[nums.size()/2] + nums[nums.size()/2-1]) / 2);
}

/**
 * Test reading raw characters.  Result should be similar to wc.
 */
class WordCount {
public:
  WordCount(std::istream& in)
    : chars_(0), words_(0), lines_(0)
  {
    char ch;
    bool inword = false;
    while(in.get(ch)) {
      if(!(ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r')) {
	inword = true;
      } else {
	if(inword) {
	  ++words_;
	  inword = false;
	}
      }
      
      if(ch == '\n') ++lines_;
      
      ++chars_;
    }
  }

  int chars() const { return chars_; }
  int words() const { return words_; }
  int lines() const { return lines_; }

private:
  int chars_, words_, lines_;
};


/**
 * Main programs, run a specified number of iterations of a specified
 * selection of tests.
 */
int main(int argc, char* argv[]) {
  try {
    int iterations = 1;
    bool do_median = false, do_sum = false, do_wc = false;
    
    for(int i = 1; i < argc; ++i) {
      if(argv[i][0] == '-') switch(argv[i][1]) {
      case 'i':  iterations = to<int>(argv[++i]);
	break;
	
      case 'm':  do_median = true;
	break;
	
      case 's':  do_sum = true;
	break;
	
      case 'w':  do_wc = true;
	break;
	
      default:
	std::cerr << "Unknown flag: " << argv[i] << std::endl;
	exit(1);
      }
      else {
	std::cerr << "Unknown argument: " << argv[i] << std::endl;
	exit(1);
      }
    }
    
    for(int i = 0; i < iterations; ++i) {
      if(do_median) {
	std::ifstream data("numbers.txt");
	if(!data) {
	  std::cerr << "No data." << std::endl;
	  exit(1);
	}
	std::cout << "Median: " << median<int>(data) << std::endl;
      }
      if(do_sum) {
	std::ifstream data("numbers.txt");
	if(!data) {
	  std::cerr << "No data." << std::endl;
	  exit(1);
	}
	std::cout << "Sum: " << sumints(data) << std::endl;
      }
      if(do_wc) {
	std::ifstream data("numbers.txt");
	if(!data) {
	  std::cerr << "No data." << std::endl;
	  exit(1);
	}
	WordCount wc(data);
	std::cout << ' ' << wc.lines() << ' ' << wc.words()
		  << ' ' << wc.chars() << " numbers.txt" << std::endl;
      }
    }
  }
  catch(const std::exception& err) {
    std::cerr << "Error: " << err.what() << std::endl;
    exit(1);
  }
}