/**
 * mds — A micro-display server
 * Copyright © 2014, 2015, 2016, 2017  Mattias Andrée (maandree@kth.se)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "callables.h"

#include <stdlib.h>
#include <string.h>



/**
 * Map, by index, from argument count, to list of callable's names
 */
static char ***restrict names = NULL;

/**
 * If `callable_list[callabes[i][j]]` and `callable_include_stack_list[callabes[i][j]]`
 * describe the callable named by `named[i][j]` with either `i` parameters, or the
 * number of parameters specified by the suffix in `named[i][j]`
 */
static size_t **restrict callables = NULL;

/**
 * Map the the number of elements in the, by index, corresponding element in `names`
 */
static size_t *restrict bucket_sizes = NULL;

/**
 * List of callables
 */
static mds_kbdc_tree_t **restrict callable_list = NULL;

/**
 * List of callables' include-stacks
 */
static mds_kbdc_include_stack_t **restrict callable_include_stack_list = NULL;

/**
 * The number of buckets in `names` and `bucket_sizes`
 */
static size_t buckets = 0;

/**
 * The index of the next item in `callable_list` and `callable_include_stack_list`
 */
static size_t list_ptr = 0;



/**
 * Destroy the callable storage
 */
void
callables_terminate(void)
{
	size_t i, j, n;
	char **bucket;
	for (i = 0; i < buckets; i++) {
		bucket = names[i];
		for (j = 0, n = bucket_sizes[i]; j < n; j++)
			free(bucket[j]);
		free(bucket);
		free(callables[i]);
	}
	for (i = 0; i < list_ptr; i++)
		mds_kbdc_include_stack_free(callable_include_stack_list[i]);
	free(callables), callables = NULL;
	free(names), names = NULL;
	free(bucket_sizes), bucket_sizes = NULL;
	free(callable_list), callable_list = NULL;
	free(callable_include_stack_list), callable_include_stack_list = NULL;
	buckets = list_ptr = 0;
}


/**
 * Store a callable
 * 
 * @param   name                    The name of the callable
 * @param   arg_count               The number of arguments the callable takes
 *                                  if `name` is suffixless, otherwise zero
 * @param   callable                The callable
 * @param   callable_include_stack  The include-stack for the callable
 * @return                          Zero on success, -1 on error
 */
int
callables_set(const char *restrict name, size_t arg_count, mds_kbdc_tree_t *restrict callable,
              mds_kbdc_include_stack_t *restrict callable_include_stack)
{
#define _yrealloc(var, elements, type) (yrealloc(tmp_##var, var, elements, type))

	char *dupname = NULL;
	char ***tmp_names = NULL;
	size_t **tmp_callables = NULL;
	size_t *tmp_bucket_sizes = NULL;
	char **old_names = NULL;
	size_t *old_callables = NULL;
	mds_kbdc_tree_t **tmp_callable_list = NULL;
	mds_kbdc_include_stack_t **tmp_callable_include_stack_list = NULL;
	int saved_errno;

	fail_if (xstrdup(dupname, name));

	if (arg_count >= buckets) {
		fail_if (_yrealloc(names,        arg_count + 1, char**));
		fail_if (_yrealloc(callables,    arg_count + 1, size_t*));
		fail_if (_yrealloc(bucket_sizes, arg_count + 1, size_t));
		memset(names        + buckets, 0, (arg_count + 1 - buckets) * sizeof(char**));
		memset(callables    + buckets, 0, (arg_count + 1 - buckets) * sizeof(size_t*));
		memset(bucket_sizes + buckets, 0, (arg_count + 1 - buckets) * sizeof(size_t));
		buckets = arg_count + 1;
	}

	fail_if (xxrealloc(old_names,     names[arg_count],     bucket_sizes[arg_count] + 1, char*));
	fail_if (xxrealloc(old_callables, callables[arg_count], bucket_sizes[arg_count] + 1, size_t));

	names[arg_count][bucket_sizes[arg_count]] = dupname, dupname = NULL;
	callables[arg_count][bucket_sizes[arg_count]] = list_ptr;
	bucket_sizes[arg_count]++;

	fail_if (_yrealloc(callable_list, list_ptr + 1, mds_kbdc_tree_t*));
	fail_if (_yrealloc(callable_include_stack_list, list_ptr + 1, mds_kbdc_include_stack_t*));

	callable_list[list_ptr] = callable;
	callable_include_stack_list[list_ptr] = callable_include_stack;
	list_ptr++;

	return 0;
fail:
	saved_errno = errno;
	free(dupname);
	if (old_names)
		names[arg_count] = old_names;
	if (old_callables)
		callables[arg_count] = old_callables;
	return errno = saved_errno, -1;
#undef _yrealloc
}


/**
 * Get a stored callable
 * 
 * @param  name                    The name of the callable
 * @param  arg_count               The number of arguments the callable takes
 *                                 if `name` is suffixless, otherwise zero
 * @param  callable                Output parameter for the callable, `NULL` if not found
 * @param  callable_include_stack  Output parameter for the include-stack for the callable
 */
void
callables_get(const char *restrict name, size_t arg_count, mds_kbdc_tree_t **restrict callable,
              mds_kbdc_include_stack_t **restrict callable_include_stack)
{
	char **restrict names_;
	size_t i, n;

	*callable = NULL;
	*callable_include_stack = NULL;

	if (arg_count >= buckets)
		return;

	names_ = names[arg_count];
	for (i = 0, n = bucket_sizes[arg_count]; i < n; i++) {
		if (strcmp(names_[i], name))
			continue;
		i = callables[arg_count][i];
		*callable = callable_list[i];
		*callable_include_stack = callable_include_stack_list[i];
		return;
	}
}