/* ElectionClient.java
**
** Java application that accepts the name of an "election file" as its first
** run argument and uses its contents as input in simulating the process of
** establishing a ballot of candidates and then counting votes cast for
** them.  An integer imposing a limit on the number of candidates for whom
** votes can be cast may be provided (optionally) as the second run argument.
** (Otherwise, a default limit applies.)
** 
** The first line in an election file contains the title of the election
** (typically identifying the office for which the candidates are vying),
** and the second line contains the names of the candidates as a CSV string.
** Each subsequent line contains a name and represents a vote cast for the
** candidate with that name.  An exception to this is that a blank line
** indicates that the election has closed, meaning that any subsequent 
** votes are considered to have been cast afterwards (and thus should not 
** be counted). 
**
** CMPS 134 Fall 2019 Prog. Assg. #7
** Authors: P.M.J & R.W.M. & ...
**
** Collaboration:
**
** Known defects: ...
*/
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;

public class ElectionClient {

   private static Scanner keyboard;  // to read input entered by user
   private static Scanner input;     // to read data from input file

   public static void main(String[] args) throws FileNotFoundException {
      System.out.print("Election Client ...");

      // Establish a Scanner to read from the file with the specified name.
      String fileName = getFirstArg(args);
      input = new Scanner(new File(fileName));  

      // Read first line to get election title
      String title = input.nextLine().trim();

      // Read second line to get election candidate list
      String candidateList = input.nextLine().trim();

      // Declare variable
      Election election;

      // Construct object based on optional run argument
      if(args.length > 1) {
         int candLimit = Integer.parseInt(args[1]);
         System.out.printf(" (limited to %d candidates)", candLimit);
         election = new Election(candLimit);
      } else {
         election = new Election();
      }
      System.out.println();

      // Add candidates to the election
      addCandidates(election, candidateList);

      printElectionStatus(title, election);

      // Open voting 
      election.openVoting();
      System.out.println("Voting Opened ..................");

      printElectionStatus(title, election);

      // Now process the votes.
      while (input.hasNextLine()) {
         try {
            String vote = input.nextLine().trim();
            if(vote.length() == 0) {
               election.closeVoting();   // Close voting
               System.out.println("Voting Closed ..................");
            }
            else {
               election.castVote(vote);
            }
            printElectionStatus(title, election);
         } catch (Exception e) {
            System.out.println(e + "\nContinuing ...\n");
         }
      }

      // Print final results
      System.out.println("Final Results:");
      printElectionStatus(title, election);
      System.out.println("\nDone!");
   }

   private static final String COLON = ":";
   private static final String BLANK = " ";

   /* Prints the given title followed by the current status of the given
   ** election.
   */
   private static void printElectionStatus(String title, Election election) {
      System.out.println(title + COLON + BLANK + election.toString());
   }

   /* If the given array has at least one element, the first such element
   ** (i.e., the one at location zero) is returned.  Otherwise, the user
   ** is prompted to enter a string (intended to be the name of a file
   ** to be used as input) and the response is returned.
   */
   private static String getFirstArg(String args[]) {
      String result = "";
      if(args.length > 0) {
         result = args[0];
      } else {
         result = getStringFromUser("Enter name of input file: ",
                                    new Scanner(System.in));
      }
      return result;
   }

   /* Prints the given prompt and reads/returns a line of data read
   ** using the given Scanner.
   */
   private static String getStringFromUser(String prompt, Scanner keyboard) {
      System.out.print(prompt);
      return keyboard.nextLine();
   }

   /* Adds each of the candidates appearing in the given list to the
   ** given election.  The given list is assumed to be in CSV form
   ** (i.e., the names of the candidates are separated by commas).
   */
   private static void addCandidates(Election election, String list) {
      Scanner scanner = new Scanner(list);
      scanner.useDelimiter(",");
      while(scanner.hasNext()) {
         String candidate = scanner.next().trim();
         try {
            election.addCandidate(candidate);
         } catch (Exception e) {
            System.out.println(e + "\nContinuing ...\n");
         }
      }
   }
}