#include<iostream>
#include<fstream>
#include<string>
#include<cstdlib>
using namespace std;

int DatesFromString(string, int &, int &, int&);
int DayOfYear(int, int, int);
int DaysInMonth(int, int);
int DaysBetweenDates(string, string);
float InterpolateWeight(int, char);
string PupWeightStatus(string, string, int, char);

////////////////////////////////
// global constants for things that won't change 
// like puppy average weights.
int male_week_4 = 2000;
int male_week_5 = 2750;
int male_week_6 = 3750;
int male_week_7 = 5100;
int male_week_8 = 6500;
int male_week_9 = 7700;
int female_week_4 = 1800;
int female_week_5 = 2500;
int female_week_6 = 3450;
int female_week_7 = 4550;
int female_week_8 = 5750;
int female_week_9 = 7200;

int main(){
  
  // Variables for the input and output files
  ifstream inputfile;
  ofstream outputfile;
  string inputfile_name, outputfile_name;


  // Variables for holding data read from files
  string puppy_name, puppy_bday, puppy_sex, puppy_color,
    puppy_dad, puppy_mom, date1, date2, date3, date4;
  int weight1, weight2, weight3, weight4;
  char pup_sex;

  // Tell what the program does
  cout << "This program parses puppy data files and labels the" << endl
       << "puppies' weight as underweight, average, or overweight" << endl
       << endl;

  // Open the files and make sure they worked ok
  cout << "Please enter the input file name: ";
  getline (cin, inputfile_name);
  inputfile.open(inputfile_name.c_str());
  if (!inputfile){
    cerr << "Could not open " << inputfile_name << endl;
    exit (1);
  }
    
  cout << "Please enter the output file name: ";
  getline (cin, outputfile_name);
  outputfile.open(outputfile_name.c_str());
  if (!outputfile){
    cerr << "Could not open " << outputfile_name << endl;
    exit (1);
  }
  

  // Since the files are short, and a fixed format, 
  // just read the input file all at once
  getline (inputfile, puppy_name);
  getline (inputfile, puppy_bday);
  getline (inputfile, puppy_sex);
  getline (inputfile, puppy_color);
  getline (inputfile, puppy_dad);
  getline (inputfile, puppy_mom);
  inputfile >> date1 >> weight1;
  inputfile >> date2 >> weight2;
  inputfile >> date3 >> weight3;
  inputfile >> date4 >> weight4;

  // Mark the sex of the pup by grabbing the first letter of the sex
  // from the string
  pup_sex = puppy_sex.at(0);

  // now output what we can right off,
  // which is everything, since fuctions are so nice!
  outputfile << puppy_name << endl;
  outputfile << puppy_bday << endl;
  outputfile << puppy_sex << endl;
  outputfile << puppy_color << endl;
  outputfile << puppy_dad << endl;
  outputfile << puppy_mom << endl;
  outputfile << date1 << " " << weight1 << " " 
	     << PupWeightStatus(puppy_bday,date1, weight1, pup_sex) << endl;
  outputfile << date2 << " " << weight2 << " " 
	     << PupWeightStatus(puppy_bday,date2, weight2, pup_sex) << endl;
  outputfile << date3 << " " << weight3 << " " 
	     << PupWeightStatus(puppy_bday,date3, weight3, pup_sex) << endl;
  outputfile << date4 << " " << weight4 << " " 
	     << PupWeightStatus(puppy_bday,date4, weight4, pup_sex) << endl;

  return 0;
}


///// DatesFromString(string date_string, int & day, int & month, int & year)
// This function takes a string in the format: mm/dd/yyyy and extracts the
// month, day, and year as integers. These are set in the reference parameters.
// returns 0 if it thinks it worked OK, or -1 otherwise.

int DatesFromString(string date_string, int & day, int & month, int & year){
  
  int first_slash = 0, second_slash = 0;
  string day_string, month_string, year_string;

  //traverse the string to find the slashes
  for (int i =0; i < date_string.length(); i++){    
    // is this a slash?
    if (date_string.at(i) == '/'){
      // is it the first?
      if (first_slash == 0) {
        first_slash = i;
      }
      else 
        // is it the second slash?
        if (second_slash == 0) {
	  second_slash = i;
	}
    }
  } // end for loop

  //////////////
  // check to make sure we found two slashes
  // if we didn't, then return an error code

  if ( ! (first_slash && second_slash && (first_slash != second_slash))){
    // one or both of the slashes was in the same spot, or they were equal
    return (-1);
  }
  
  ///////////////////////////////////////////
  // Now we should know where the slashes are.
  // We can cut the string into three substrings, 
  // each with a piece of the date in it.
  
  month_string = date_string.substr(0, first_slash);
  day_string = date_string.substr(first_slash + 1, second_slash - first_slash - 1);
  year_string = date_string.substr(second_slash + 1, date_string.length() - second_slash);

  day = atoi(day_string.c_str());
  month = atoi(month_string.c_str());
  year = atoi(year_string.c_str());
  
  return 0;

}
////  End DatesFromString

///// DayOfYear(int day, int month, int year)
// This function finds the ordinal day of the year, from 1 to 366. 
// 
int DayOfYear(int day, int month, int year){
  
  int total_days = 0;

  // add up all the days from the months before the one entered
  for (int i = 1; i < month; i++){
    total_days += DaysInMonth(i,year);
  }

  // Now add the days in this month
  total_days += day;

  return total_days;
}
//// End DayOfYear


///// int DaysInMonth(int month, int year)
// This function returns the number of days in a particular month
//
int DaysInMonth(int month, int year){

  switch (month){
  case 1: //January
    return 31;
  case 2: // February
    if (year % 4 == 0)
      return 29;
    else
      return 28;
  case 3: // March
    return 31;
  case 4: // April
    return 30;
  case 5: // May
    return 31;
  case 6: // June
    return 30;
  case 7: // July
    return 31;
  case 8: // August
    return 31;
  case 9: // September
    return 30; 
  case 10: // October 
    return 31;
  case 11: // November 
    return 30;
  case 12: // December
    return 31;
  }
} //// end DaysInMonth


// int DaysBetweenDates (string first, string second)
// This function computes the number of days between two dates, given
// dates of the format MM/DD/YYYY.
// Assumes that the first date is lower than the second date
int DaysBetweenDates (string first, string second){

  int first_month, first_day, first_year, 
    second_month, second_day, second_year,
    first_ordinal_day, second_ordinal_day, days_to_end;
  

  // convert the strings to numerical dates
  DatesFromString(first, first_day, first_month, first_year);
  DatesFromString(second, second_day, second_month, second_year);
  
  // find the ordinal day for each date
  first_ordinal_day = DayOfYear(first_day, first_month, first_year);
  second_ordinal_day = DayOfYear(second_day, second_month, second_year);

  // Now compute the days between
  // If the year is the same, just subtract the ordinal days
  
  if (first_year == second_year)
    return (second_ordinal_day - first_ordinal_day);
  else {
    // Different years, so things get a little more complicated
    // We know that they will always be adjacent years,
    // so just find out how long to the end of year1 and add that to
    // the days of year 2.
    if (first_year % 4 == 0){ // leap year
      days_to_end = 366 - first_ordinal_day;
      return (days_to_end + second_ordinal_day);
    }
    else {
      days_to_end = 365 - first_ordinal_day;
      return (days_to_end + second_ordinal_day);
    }
  }
    
} /// end days between dates
 
float InterpolateWeight(int AgeInDays, char Sex){

  int AgeInWeeks, extra_days;
  float weight_per_day;

  // Figure out which week the puppy is in
  // Notice this is int division, so it rounds down, so we always
  // get the bottom of the range
  AgeInWeeks = AgeInDays/7;
  cerr << "Pup is: " << AgeInWeeks << " weeks and ";

  // For each case:
  // Figure out how many days older than the earlier week the puppy is
  // Estimate how much weight the puppy shoud gain each day
  // Compute how much the puppy should weigh by adding
  // (gain/day * days) to the base weight for the week.

  switch(Sex){ 
  case 'M':    // Male puppies
  case 'm':    
    switch (AgeInWeeks){
    case 4:
      extra_days = (AgeInDays - (4*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (male_week_5 - male_week_4)/7;
      return (male_week_4 + (extra_days * weight_per_day));
    break;
    case 5:
      extra_days = (AgeInDays - (5*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (male_week_6 - male_week_5)/7;
      return (male_week_5 + (extra_days * weight_per_day));
    break;
    case 6:
      extra_days = (AgeInDays - (6*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (male_week_7 - male_week_6)/7;
      return (male_week_6 + (extra_days * weight_per_day));
    break;
    case 7:
      extra_days = (AgeInDays - (7*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (male_week_8 - male_week_7)/7;
      return (male_week_7 + (extra_days * weight_per_day));
    break;
    case 8:
      extra_days = (AgeInDays - (8*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (male_week_9 - male_week_8)/7;
      return (male_week_8 + (extra_days * weight_per_day));
    break;
    default:
      cerr << "Age out of range: " << AgeInDays << " days" <<endl;
      exit(1);
    }// end switch on male age in weeks
  case 'F':
  case 'f':
    switch (AgeInWeeks){
    case 4:
      extra_days = (AgeInDays - (4*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (female_week_5 - female_week_4)/7;
      return (female_week_4 + (extra_days * weight_per_day));
    break;
    case 5:
      extra_days = (AgeInDays - (5*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (female_week_6 - female_week_5)/7;
      return (female_week_5 + (extra_days * weight_per_day));
    break;
    case 6:
      extra_days = (AgeInDays - (6*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (female_week_7 - female_week_6)/7;
      return (female_week_6 + (extra_days * weight_per_day));
    break;
    case 7:
      extra_days = (AgeInDays - (7*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (female_week_8 - female_week_7)/7;
      return (female_week_7 + (extra_days * weight_per_day));
    break;
    case 8:
      extra_days = (AgeInDays - (8*7));
      cerr << extra_days << " days old" << endl;
      weight_per_day = (female_week_9 - female_week_8)/7;
      return (female_week_8 + (extra_days * weight_per_day));
    break;
    default:
      cerr << "Age out of range: " << AgeInDays << " days" <<endl;
      exit(1);
    }// end switch on female age in weeks
    break;
  default:
    cerr << "Error in switch on sex: " << Sex << endl;
    exit (1);
  }
} /// end Interpolate Weight


/////////
/// int PupWeightStatus(string birthday, string weigh_date, 
//                      int weight, char sex)
// This function returns a string with the pup's status
string PupWeightStatus(string birthday, string weigh_date, 
		       int weight, char sex){

  int age_in_days;
  float interpolated_weight;

  age_in_days = DaysBetweenDates(birthday,weigh_date);

  interpolated_weight = InterpolateWeight(age_in_days,sex);
  cerr << "Interpolated weight was: " << interpolated_weight << endl;
  if (weight > (1.2 * interpolated_weight))
    return "Overweight";
  else
    if (weight < (.8 * interpolated_weight))
      return "Underweight";
    else
      return "Average";
}// end PupWeightStatus





/*
This is the main I used for testing. It isn't neat, but you can get an
idea of what I did.
int main(){

  int day,month,year;
  string input1, input2;


    cin >> input1 >> input2;
    DatesFromString(input1,day,month,year);
    cerr << "Day: " << DayOfYear(day,month,year) << endl;
    DatesFromString(input2,day,month,year);
    cerr << "Day: " << DayOfYear(day,month,year) << endl;
    cerr << DaysBetweenDates(input1,input2) << endl;

    
    for (int i = 29; i < 63; i++){
    cerr << i << " day male weight: " << InterpolateWeight(i,'M') << endl;
    }
    
    for (int i = 29; i < 63; i++){
    cerr << i << " day female weight: " << InterpolateWeight(i,'F') << endl;
    }

  return 0;
}

*/