/* Copyright (c) 2008, Tim Post <tinkertim@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the original program's authors nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/* NOTES:
 * module_* functions are pretty much identical to builtin_* functions at this
 * point. On the surface, it would appear that making each function dual purpose
 * would be economical.
 *
 * These are kept separate because the structures (module_t and builtin_t) may
 * grow apart and become rather different, even though they're identical at this
 * point.
 *
 * To keep things easy to hack, everything is separated. In reality this only adds
 * 6 - 8 extra functions, but keeps each function very easy to read and modify. */

/* TODO:
 * Many of these could be unsigned, provided the modules and builtins themselves
 * can follow suit. Long term goal. */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "errors.h"
#include "cmds.h"
#include "module_aliases.h"

extern volatile unsigned int cli_interactive;

int module_is_restricted(int pos)
{
	/* Restriction Levels:
	 * -1 -> Available only in interactive mode
	 *  0 -> Available in any mode
	 *  1 -> Available only in non-interactive mode */

	module_t *mod = modules;
	mod += pos;
	/* We're interactive, and the module is OK to run */
	if (cli_interactive && mod->restricted <= 0)
		return 0;
	/* We're not interactive, and the module is OK to run */
	if (!cli_interactive && mod->restricted >= 0)
		return 0;

	/* Anything else is just a big fat no :) */
	return 1;
}

/* Checks if an entry function matching command exists in modules[], if so
 * its position in the array is returned */
int is_module(const char *command)
{
	module_t *mod;
	unsigned int i = 0;

	if (NULL == command)
		return -2;

	for (mod = modules; mod->name != NULL; mod++, i++) {
		if (!strcmp(mod->name, command))
			return i;
	}

	return -1;
}

/* Checks if a module is an alias (sharing an entry point with another
 * module). Returns 1 if so */
int is_module_alias(const char *command)
{
	unsigned int i = 0;

	if (NULL == command)
		return -1;

	for(i=0; mod_aliases[i] != NULL; i+=2) {
		if (!strcmp(mod_aliases[i], command))
			return 1;
	}

	return 0;
}

/* Returns the name of the module that an alias points to */
char *alias_for_module(const char *command)
{
	unsigned int i = 0;

	if (NULL == command)
		return (char *)NULL;

	for(i=0; mod_aliases[i] != NULL; i++) {
		if (!strcmp(mod_aliases[i], command))
			return (char *)mod_aliases[++i];
		i++;
	}

	return (char *)NULL;
}


/* Invokes the 'help' entry function for the module at position (int) module,
 * which wants an unsigned int to determine brief or extended display. */
int help_module(int module, unsigned int extended)
{
	module_t *mod = modules;

	mod += module;

	if (NULL != mod->help) {
		mod->help(extended);
		return CL_EOK;
	} else
		return CL_ENOENT;
}

/* Invokes the module entry point modules[module], passing argv[] as an argument
 * stack. */
int run_module(int module, char *argv[])
{
	module_t *mod = modules;

	mod += module;

	if (NULL != mod->entry)
		return ((int)mod->entry(argv));

	return CL_ENOENT;
}