/****************************************************************************
 * tools/cfgdefine.c
 *
 *   Copyright (C) 2007-2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 *   Modified by Denis Ciocca <denis.ciocca@st.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name NuttX 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.
 *
 ****************************************************************************/

#include <stdio.h>
#include <string.h>
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "cfgdefine.h"
#include <stdbool.h>

#define CUTOM_MACRO_LIST	6

char line[LINESIZE + 1];

static struct custom_macro {
	char name[45];
} custom_macro[] = {
	{ .name = "CONFIG_ST_HAL_INEMO_GBIAS_THRESOLD_ACCEL" },
	{ .name = "CONFIG_ST_HAL_INEMO_GBIAS_THRESOLD_MAGN" },
	{ .name = "CONFIG_ST_HAL_INEMO_GBIAS_THRESOLD_GYRO" },
	{ .name = "CONFIG_ST_HAL_ACCEL_ROT_MATRIX" },
	{ .name = "CONFIG_ST_HAL_MAGN_ROT_MATRIX" },
	{ .name = "CONFIG_ST_HAL_GYRO_ROT_MATRIX" },
};

/* Skip over any spaces */
static char *skip_space(char *ptr)
{
	while (*ptr && isspace((int)*ptr)) ptr++;

	return ptr;
}

/* Find the end of a variable string */
static char *find_name_end(char *ptr)
{
	while (*ptr && (isalnum((int)*ptr) || *ptr == '_')) ptr++;

	return ptr;
}

/* Find the end of a value string */
static char *find_value_end(char *ptr)
{
	while (*ptr && !isspace((int)*ptr)) {
		if (*ptr == '"') {
			do ptr++; while (*ptr && *ptr != '"');
			if (*ptr) ptr++;
		} else
			do ptr++; while (*ptr && !isspace((int)*ptr) && *ptr != '"');

	}

	return ptr;
}

/* Read the next line from the configuration file */
static char *read_line(FILE *stream)
{
	char *ptr;

	for (;;) {
		line[LINESIZE] = '\0';

		if (!fgets(line, LINESIZE, stream))
			return NULL;
		else {
			ptr = skip_space(line);
			if (*ptr && *ptr != '#' && *ptr != '\n')
				return ptr;
			else if ((*ptr == '#') && (*(ptr+1) == '\n'))
				printf("\n");
		}
	}

	return NULL;
}

static void dequote_custom_values(char *var, char *value)
{
	int i, n, ret;
	char *t1;

	if (!var)
		return;

	for (i = 0; i < CUTOM_MACRO_LIST; i++) {
		ret = strncmp(custom_macro[i].name, var, strlen(custom_macro[i].name));
		if (ret == 0) {
			for (n = 1; n < strlen(value) - 1; n++)
				value[n - 1] = value[n];

			value[n - 1] = '\0';
			return;
		}
	}

	return;
}

/* Parse the line from the configuration file into a variable name
 * string and a value string.
 */
static void parse_line(char *ptr, char **varname, char **varval)
{
	/* Skip over any leading spaces */
	ptr = skip_space(ptr);

	/* The first no-space is the beginning of the variable name */
	*varname = skip_space(ptr);
	*varval = NULL;

	/* Parse to the end of the variable name */
	ptr = find_name_end(ptr);

	/* An equal sign is expected next, perhaps after some white space */
	if (*ptr && *ptr != '=') {
		/* Some else follows the variable name.  Terminate the variable
		* name and skip over any spaces.
		*/

		*ptr = '\0';
		ptr = skip_space(ptr + 1);
	}

	/* Verify that the equal sign is present */
	if (*ptr == '=') {
		/* Make sure that the variable name is terminated (this was already
		* done if the name was followed by white space.
		*/

		*ptr = '\0';

		/* The variable value should follow =, perhaps separated by some
		* white space.
		*/

		ptr = skip_space(ptr + 1);
		if (*ptr) {
			/* Yes.. a variable follows.  Save the pointer to the start
			* of the variable string.
			*/

			*varval = ptr;

			/* Find the end of the variable string and make sure that it
			* is terminated.
			*/

			ptr = find_value_end(ptr);
			*ptr = '\0';
		}
	}
}

void generate_definitions(FILE *stream)
{
	char *varname;
	char *varval;
	char *ptr;

	/* Loop until the entire file has been parsed. */
	do {
		/* Read the next line from the file */
		ptr = read_line(stream);
		if (ptr) {
			/* Parse the line into a variable and a value field */
			parse_line(ptr, &varname, &varval);

			dequote_custom_values(varname, varval);

			/* Was a variable name found? */
			if (varname) {
				/* If no value was provided or if the special value 'n' was provided,
				* then undefine the configuration variable.
				*/

				if (!varval || strcmp(varval, "n") == 0)
					printf("#undef %s\n", varname);
				else if (strcmp(varval, "y") == 0)
					printf("#define %s 1\n", varname);
				else
					printf("#define %s %s\n", varname, varval);
			}
		}
	} while (ptr);
}