/*
 * Copyright (C) 2012 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.crsh.lang.impl.groovy;

import groovy.lang.Closure;
import groovy.lang.MissingMethodException;
import org.codehaus.groovy.runtime.InvokerInvocationException;
import org.crsh.command.CommandContext;
import org.crsh.command.InvocationContext;
import org.crsh.command.RuntimeContext;
import org.crsh.lang.impl.groovy.closure.PipeLineClosure;
import org.crsh.shell.impl.command.CRaSH;
import org.crsh.shell.impl.command.spi.Command;
import org.crsh.shell.impl.command.spi.CommandException;
import org.crsh.util.SafeCallable;

/**
 * @author Julien Viet
 */
public class Helper {

  public static Object invokeMethod(RuntimeContext context, String name, Object args, MissingMethodException ex) {
    if (context instanceof InvocationContext<?>) {
      SafeCallable executed = Helper.resolveMethodInvocation((InvocationContext)context, name, args);
      if (executed != null) {
        return executed.call();
      }
    }

    //
    Object o = context.getSession().get(name);
    if (o instanceof Closure) {
      Closure closure = (Closure)o;
      if (args instanceof Object[]) {
        Object[] array = (Object[])args;
        if (array.length == 0) {
          return closure.call();
        } else {
          return closure.call(array);
        }
      } else {
        return closure.call(args);
      }
    } else {
      throw ex;
    }
  }

  public static PipeLineClosure resolveProperty(final InvocationContext context, final String property) {
    CRaSH crash = (CRaSH)context.getSession().get("crash");
    if (crash != null) {
      try {
        Command<?> cmd = crash.getCommand(property);
        if (cmd != null) {
          return new PipeLineClosure(context, property, cmd);
        } else {
          return null;
        }
      } catch (CommandException e) {
        throw new InvokerInvocationException(e);
      }
    } else {
      return null;
    }
  }

  public static SafeCallable resolveMethodInvocation(final InvocationContext context, final String name, final Object args) {
    CRaSH crash = (CRaSH)context.getSession().get("crash");
    if (crash != null) {
      final Command<?> cmd;
      try {
        cmd = crash.getCommand(name);
      }
      catch (CommandException ce) {
        throw new InvokerInvocationException(ce);
      }
      if (cmd != null) {
        return new SafeCallable() {
          @Override
          public Object call() {
            PipeLineClosure closure = new PipeLineClosure(context, name, cmd);
            return closure.call((Object[])args);
          }
        };
      }
    }
    return null;
  }
}