package calculator;
   
   import calculator.command.CLICommand;
   import calculator.command.EvalCommand;
   import calculator.command.ExitCommand;
   import calculator.command.HelpCommand;
   
   import java.util.HashMap;
   import java.util.Map;
  import java.util.Scanner;
  
  import calculator.atoms.Real;
  import calculator.operations.*;
  
  /**
   * A very simple calculator in Java
   * University of Mons - UMONS
   * Software Engineering Lab
   * Faculty of Sciences
   *
   * @author tommens
   */
  public class Main {
  
  	/**
  	 * This is the main method of the application.
  	 * It provides examples of how to use it to construct and evaluate arithmetic
  	 * expressions.
  	 *
  	 * @param args Command-line parameters are not used in this version
  	 */
  	public static void main(String[] args) {
  		// Commands registration
          Map<String, CLICommand> commands = new HashMap<>();
          commands.put("help", new HelpCommand());
          commands.put("exit", new ExitCommand());
          commands.put("eval", new EvalCommand());
  
  		Scanner scanner = new Scanner(System.in);
  		System.out.println("Welcome to the Calculator! Type 'help' for assistance.");
  		
  		boolean running = true;
          while (running) {
              System.out.print("calc> ");
              String input = scanner.nextLine().trim();  // Trim input to handle extra spaces
              
              if (input.isEmpty()) continue;
              
              String[] parts = input.split(" ", 2);  // Split to get command (first word)
              String commandName = parts[0].toLowerCase(); // Command names are case-insensitive
              String arguments = parts.length > 1 ? parts[1] : "";  // The rest of the input is considered as arguments
              
              CLICommand command = commands.get(commandName);  // = null if command not found (or not eval at the beginning of the input)
              
              if (command != null) {
                  running = command.execute(arguments);
              } else {
                  CLICommand defaultEval = commands.get("eval");
                  running = defaultEval.execute(input);
              }
          }
          scanner.close();
  	}
  
  }