/*******************************************************************************
 * Copyright (c) 2004, 2007 Boeing.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Boeing - initial API and implementation
 *******************************************************************************/
package org.eclipse.osee.ote.core.environment.console;

import java.lang.ref.WeakReference;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public abstract class ConsoleShell {
   private static final Pattern CMD_PATTERN = Pattern.compile("^(\\S+)\\s*((-[a-zA-Z]\\S*\\s*)*)\\s*((\\S+(\\s+|$))*)");

   private final WeakReference<ICommandManager> manager;
   private volatile ConsoleCommand lastCmd;
   private volatile String lastSwitches;
   private volatile String lastArgs;
   private boolean saveLastCmdFlag = true;

   public ConsoleShell(ICommandManager manager) {
      this.manager = new WeakReference<>(manager);
   }

   public abstract void println(String string);

   public abstract void print(String string);

   public abstract void println();

   public ICommandManager getCommandManager() {
      return manager.get();
   }

   public void runLast() {
      lastCmd.execute(this, lastSwitches, lastArgs);
   }

   public final void parseAndExecuteCmd(String line) throws Throwable {
      final Matcher matcher = CMD_PATTERN.matcher(line);
      if (matcher.matches()) {
         String cmdName = matcher.group(1);
         String switches = matcher.group(2);
         String args = matcher.group(4);
         final ConsoleCommand cmd = getCommandManager().getCommand(cmdName);
         if (cmd != null) {
            cmd.execute(this, switches, args);
            if (saveLastCmdFlag) {
               lastCmd = cmd;
               lastSwitches = switches;
               lastArgs = args;
            } else {
               // we do not save the last command as instructed but we reset the flag
               saveLastCmdFlag = true;
            }
         } else {
            println(cmdName + " is not recognized as a command");
         }
      } else {
         println("invalid command format");
      }
   }

   /**
    * Prevents the currently running command from being saved as the last executed command. This is useful for commands
    * that process the last executed command but do not want themselves to become the last command executed
    */
   public void setSaveLastCmdFlag(boolean save) {
      saveLastCmdFlag = save;
   }

   public void printStackTrace(Throwable t) {
      println(t.toString() + ":");
      StackTraceElement[] elements = t.getStackTrace();
      for (int i = 0; i < elements.length; i++) {
         println("   " + elements[i].toString());
      }
      t = t.getCause();
      while (t != null) {
         println("Caused by: " + t.toString());
         elements = t.getStackTrace();
         for (int i = 0; i < elements.length; i++) {
            println("   " + elements[i].toString());
         }
         t = t.getCause();
      }
   }
}