#include "stdstuff.h"
#include "CustomerDB.h"

// four methods included to help you out (as they are quite similar to 
// the other methods that involve going through the database)

// returns the lowest customer ID of all customers 
// (returns -1 if there are no customers in the database)
int CustomerDB::getLowestID() const {
   CNode *lowestIDptr;
   
   if(numCusts==0) return -1; // return -1 if database empty
   
   // assume first customer has the lowest id and check the rest
   lowestIDptr = head;
   
   for(CNode *c=head->next; c!=NULL; c=c->next) { 
      if(c->ci<lowestIDptr->ci)
         lowestIDptr = c;
   }
   
   return (lowestIDptr->ci).getID(); // return the lowest ID
}

// returns the highest total of all customers 
// (returns -1 if there are no customers in the database)
double CustomerDB::getBestTotal() const {
   double maxtotal;
       
   if(numCusts==0) return -1; // return -1 if database empty
   
   // assume first total is largest and then check the rest
   maxtotal = (head->ci).getTotal();  // **must** use getTotal
   
   for(CNode *c=head->next; c!=NULL; c=c->next) { 
      if((c->ci).getTotal()>maxtotal) // use getTotal
         maxtotal=(c->ci).getTotal(); // **must** use getTotal
   }
   
   return maxtotal;
}

// prints (to cout) the earliest purchase date of all customers 
// (prints 31 12 2099 if there are no customers in the database)
void CustomerDB::outputFirstDate() const {
   Date max(31,12,2099); 
   
   cout << "The first purchase date is: ";
   
   for(CNode *c=head->next; c!=NULL; c=c->next) { 
      if((c->ci).getDate().compareTo(max)<0) // **must** use getDate
         max = (c->ci).getDate(); // **must** use getDate
   }
   max.write(cout);
   cout << endl;
}

// returns the customer name that's first in case insensitive alphabetical order 
// (returns "" if there are no customers in the database)
String2002 CustomerDB::getFirstName() const {
   String2002 lowerFirstName, firstName, lowerName, name;
   
   if (numCusts==0) return ""; // return empty string if no customers
   
   // start with index 0 as the first name (convert to lower case)
   name = (head->ci).getName(); // **must** use getName
   lowerFirstName = name;
   firstName = name;
   for(int i=0;i<(int)lowerFirstName.length();i++)
      lowerFirstName[i] = tolower(lowerFirstName[i]);
   
   // go through the rest, checking to see if each (converted to lower
   // case) is the first one so far
   for(CNode *c=head->next; c!=NULL; c=c->next) { 
      name = (c->ci).getName(); // **must** use getName
      lowerName = name;
      for(int j=0;j<(int)lowerName.length();j++)
         lowerName[j] = tolower(lowerName[j]);
      if(lowerName<lowerFirstName) {
         lowerFirstName=lowerName; // case insensitive lowest (in all lower case)
         firstName=name; // original name that is first so far
      }
   }
   
   return firstName; // returns the first name
}