import Stack;
import SimpleInput;
import SimpleOutput;

/**
 * A class to be used for conducting tests on stacks.
 *
 * @author Samuel A. Rebelsky
 * @version 1.0 of April 1999
 */
public class StackTester {
  // +--------+--------------------------------------------------
  // | Fields |
  // +--------+

  /** The stack we're testing. */
  protected Stack stack;
  /** Where to write output. */
  protected SimpleOutput output;
  /** Where to read input. */
  protected SimpleInput input;


  // +--------------+--------------------------------------------
  // | Constructors |
  // +--------------+

  /**
   * Build a new tester.
   */
  public StackTester(Stack s, SimpleInput in, SimpleOutput out) {
    this.stack = s;
    this.input = in;
    this.output = out;
  } // StackTester(Stack, SimpleInput, SimpleOutput)


  // +---------+-------------------------------------------------
  // | Methods |
  // +---------+

  /**
   * Run the tester.
   */
  public void run() {
    boolean done = false;	// Are we done yet?
    String command;		// The command.

    // Keep going until we're done.  (Duh.)
    while (!done) {
      // Describe the stack.
      output.println("Stack: " + stack.toString());
      output.println("Full: " + stack.isFull());
      output.println("Empty: " + stack.isEmpty());
      output.println();
      // Ask the user what to do
      output.println("What do you want to do? ");
      output.println("  [Q]uit.");
      output.println("  [A]dd an element.");
      output.println("  [P]eek at the top of the stack.");
      output.println("  [R]emove an element.");
      output.print("command: ");
      // Get a response.
      command = input.readString();
      // Respond to the request.
      if (command.equals("Q")) { 
        done = true;
      }
      else if (command.equals("A")) {
        output.print("String to add: ");
        stack.add(input.readString());
      }
      else if (command.equals("P")) {
        output.println("Top: " + stack.peek().toString());
      }
      else if (command.equals("R")) {
        output.println("Removed: " + stack.remove().toString());
      }
      else {
        output.println("Unknown command: '" + command + "'");
      }
    } // while not done
  } // run()
} // class StackTester