import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;

/* An instance of this class is for the purpose of processing, tabulating,
** and recording the votes in an election, and for updating a file that
** contains the (partial) results of that election.
** Author: R. McCloskey
*/

public class Election {

   // instance variable
   // -----------------

   // Each element of the candidates[] array stores a candidate's ID/name 
   // and vote count (in the form of an instance of the Candidate class,
   // which is a static inner class within this class).  The array
   // elements are maintained to be in descending order by vote count.
   private Candidate[] candidates; 


   // constructor
   // -----------

   /* The argument is assumed to be the name of a "candidates" file in 
   ** which is stored the partial results of an election.  The first 
   ** line of the file is assumed to contain an integer indicating the
   ** number of candidates on the ballot; each of the remaining lines
   ** contains the ID/name of a candidate, optionally followed by a colon
   ** and the number of votes already received by that candidate.
   */
   public Election(String fileName) throws FileNotFoundException {

      // Establish a Scanner object to read from the named file:
      //   << MISSING CODE >>

      // Read the # of candidates and then skip to the next line: 
      //   << MISSING CODE >>

      // Establish the candidates[] array to be of adequate size for holding
      // the Candidate objects representing the candidates competing in
      // this election:
      //   << MISSING CODE >>

      // Read the records describing the candidates and use them to populate
      // the candidates[] array.  Note that the constructor of the Candidate
      // class handles records of both allowed formats described above.
      //   << MISSING CODE >>
   }

   // observers
   // ---------

   /* Returns the number of votes that have been recorded for the candidate
   ** with the given name, or zero if there is no such candidate.
   */
   public int numVotesFor(String name) {
      return -1;    // STUB
   }

   /* Returns the rank of the candidate with the given name, which is
   ** one more than the number of candidates having higher vote counts.
   ** If there is no candidate of the given name, -1 is returned.
   */
   public int rankOf(String name) {
      return -2;   // STUB
   }


   // mutators
   // --------

   /* If a candidate with the given name exists, a vote for that candidate
   ** is recorded and true is returned.  Otherwise, no vote is recorded 
   ** and false is returned.
   */
   public boolean recordVoteFor(String name) {
      return false;      // STUB
   }

   /* Prints the current standings of the election; each line of output
   ** is of the form "<rank>. <name>:<vote_count>" showing the rank, name,
   ** and vote count of a candidate.  (E.g., "1. Lincoln:24567").  Ranks
   ** are numbered starting at 1. The candidates are listed in descending
   ** order of vote counts.
   */
   public void displayStandings() {
      System.out.println("Election Standings belong here!");  // STUB
   }

   /* Writes the current standings of the election to the file with
   ** the given name.
   */
   public void writeToFile(String fileName) throws FileNotFoundException {
      PrintWriter pw = new PrintWriter(new File(fileName)); 
      // On the first line of the file, write the # of candidates.
      pw.println(candidates.length);

      // On each subsequent line of the file, write the toString() 
      // image of a candidate.
      for (Candidate cand : candidates) {
         pw.println(cand);
      }
      pw.close();
   }


   // helper methods
   // --------------

   /* If there exists a candidate with the given name, the index of
   ** that candidate within candidates[] is returned.  Otherwise, -1
   ** is returned.
   */
   private int indexOf(String name) {
      return -2;   // STUB
   }


   /* Adjusts the candidates[] array to remain in decsending order of
   ** votes received, under the assumption that the candidate at the
   ** given location may need to move up.
   */
   private void adjustCandidates(int k) {
      // STUB
   }

   /* Swaps the elements at locations k-1 and k of candidates[].
   */
   private void swapWithPredecessor(int k) {
      Candidate temp = candidates[k];
      candidates[k] = candidates[k-1];
      candidates[k-1] = temp;
   }

   // static inner class
   // ------------------

   /* An instance of this "static inner" class is an ordered pair 
   ** whose components are a String (e.g., representing the name of a
   ** candidate) and a count (representing # of votes received by that
   ** candidate).
   */
   private static class Candidate {

      // instance variables
      // ------------------
      public String name;
      public int voteCount;

      // constructor
      // -----------

      /* Establishes this Candidate object to have the name and vote count
      ** indicated by the given string, which is assumed to be either of
      ** the form <name>:<number> or just <name>.  In the former case,
      ** the vote count is explicitly indicated; in the former, it is 
      ** implicitly zero.
      ** E.g., "Lincoln:23456" or "Lincoln"
      */
      public Candidate(String descriptor) { 
         int posOfColon = descriptor.indexOf(':');
         if (posOfColon == -1) {   // no colon, so only name is given
            this.name = descriptor;
            this.voteCount = 0;
         }
         else {  // colon is present, so both name and vote count are given
            this.name = descriptor.substring(0,posOfColon).trim();
            String voteCountStr = descriptor.substring(posOfColon+1).trim();
            this.voteCount = Integer.parseInt(voteCountStr);
         }
      }


      // observer
      // --------

      /* Returns a string displaying this Candidate's name and vote
      ** count, separated by a colon.
      */
      public String toString() { return name + ':' + voteCount; }
  
   }  // end of static inner Candidate class

}