/*
 * (C) Copyright 2009-2016 CompuLab, Ltd.
 *
 * Authors: Nikita Kiryanov <nikita@compulab.co.il>
 *          Igor Grinberg <grinberg@compulab.co.il>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <linux/string.h>
#include <eeprom_field.h>

static void __eeprom_field_print_bin(const struct eeprom_field *field,
                                     char *delimiter, bool reverse)
{
        int i;
        int from = reverse ? field->size - 1 : 0;
        int to = reverse ? 0 : field->size - 1;

        printf(PRINT_FIELD_SEGMENT, field->name);
        for (i = from; i != to; reverse ? i-- : i++)
                printf("%02x%s", field->buf[i], delimiter);

        printf("%02x\n", field->buf[i]);
}

static int __eeprom_field_update_bin(struct eeprom_field *field,
                                     const char *value, bool reverse)
{
        int len = strlen(value);
        int k, j, i = reverse ? len - 1 : 0;
        unsigned char byte;
        char *endptr;

        /* each two characters in the string fit in one byte */
        if (len > field->size * 2)
                return -1;

        memset(field->buf, 0, field->size);

        /* i - string iterator, j - buf iterator */
        for (j = 0; j < field->size; j++) {
                byte = 0;
                char tmp[3] = { 0, 0, 0 };

                if ((reverse && i < 0) || (!reverse && i >= len))
                        break;

                for (k = 0; k < 2; k++) {
                        if (reverse && i == 0) {
                                tmp[k] = value[i];
                                break;
                        }

                        tmp[k] = value[reverse ? i - 1 + k : i + k];
                }

                byte = simple_strtoul(tmp, &endptr, 0);
                if (*endptr != '\0' || byte < 0)
                        return -1;

                field->buf[j] = byte;
                i = reverse ? i - 2 : i + 2;
        }

        return 0;
}

static int __eeprom_field_update_bin_delim(struct eeprom_field *field,
                                           char *value, char *delimiter)
{
        int count = 0;
        int i, val;
        const char *tmp = value;
        char *tok;
        char *endptr;

        tmp = strstr(tmp, delimiter);
        while (tmp != NULL) {
                count++;
                tmp++;
                tmp = strstr(tmp, delimiter);
        }

        if (count > field->size)
                return -1;

        tok = strtok(value, delimiter);
        for (i = 0; tok && i < field->size; i++) {
                val = simple_strtoul(tok, &endptr, 0);
                if (*endptr != '\0')
                        return -1;

                /* here we assume that each tok is no more than byte long */
                field->buf[i] = (unsigned char)val;
                tok = strtok(NULL, delimiter);
        }

        return 0;
}

/**
 * eeprom_field_print_bin() - print a field which contains binary data
 *
 * Treat the field data as simple binary data, and print it as two digit
 * hexadecimal values.
 * Sample output:
 *      Field Name       0102030405060708090a
 *
 * @field:      an initialized field to print
 */
void eeprom_field_print_bin(const struct eeprom_field *field)
{
        __eeprom_field_print_bin(field, "", false);
}

/**
 * eeprom_field_update_bin() - Update field with new data in binary form
 *
 * @field:      an initialized field
 * @value:      a string of values (i.e. "10b234a")
 */
int eeprom_field_update_bin(struct eeprom_field *field, char *value)
{
        return __eeprom_field_update_bin(field, value, false);
}

/**
 * eeprom_field_update_reserved() - Update reserved field with new data in
 *                                  binary form
 *
 * @field:      an initialized field
 * @value:      a space delimited string of byte values (i.e. "1 02 3 0x4")
 */
int eeprom_field_update_reserved(struct eeprom_field *field, char *value)
{
        return __eeprom_field_update_bin_delim(field, value, " ");
}

/**
 * eeprom_field_print_bin_rev() - print a field which contains binary data in
 *                                reverse order
 *
 * Treat the field data as simple binary data, and print it in reverse order
 * as two digit hexadecimal values.
 *
 * Data in field:
 *                      0102030405060708090a
 * Sample output:
 *      Field Name      0a090807060504030201
 *
 * @field:      an initialized field to print
 */
void eeprom_field_print_bin_rev(const struct eeprom_field *field)
{
        __eeprom_field_print_bin(field, "", true);
}

/**
 * eeprom_field_update_bin_rev() - Update field with new data in binary form,
 *                                 storing it in reverse
 *
 * This function takes a string of byte values, and stores them
 * in the field in the reverse order. i.e. if the input string was "1234",
 * "3412" will be written to the field.
 *
 * @field:      an initialized field
 * @value:      a string of byte values
 */
int eeprom_field_update_bin_rev(struct eeprom_field *field, char *value)
{
        return __eeprom_field_update_bin(field, value, true);
}

/**
 * eeprom_field_print_mac_addr() - print a field which contains a mac address
 *
 * Treat the field data as simple binary data, and print it formatted as a MAC
 * address.
 * Sample output:
 *      Field Name     01:02:03:04:05:06
 *
 * @field:      an initialized field to print
 */
void eeprom_field_print_mac(const struct eeprom_field *field)
{
        __eeprom_field_print_bin(field, ":", false);
}

/**
 * eeprom_field_update_mac() - Update a mac address field which contains binary
 *                             data
 *
 * @field:      an initialized field
 * @value:      a colon delimited string of byte values (i.e. "1:02:3:ff")
 */
int eeprom_field_update_mac(struct eeprom_field *field, char *value)
{
        return __eeprom_field_update_bin_delim(field, value, ":");
}

/**
 * eeprom_field_print_ascii() - print a field which contains ASCII data
 * @field:      an initialized field to print
 */
void eeprom_field_print_ascii(const struct eeprom_field *field)
{
        char format[8];

        sprintf(format, "%%.%ds\n", field->size);
        printf(PRINT_FIELD_SEGMENT, field->name);
        printf(format, field->buf);
}

/**
 * eeprom_field_update_ascii() - Update field with new data in ASCII form
 * @field:      an initialized field
 * @value:      the new string data
 *
 * Returns 0 on success, -1 of failure (new string too long).
 */
int eeprom_field_update_ascii(struct eeprom_field *field, char *value)
{
        if (strlen(value) >= field->size) {
                printf("%s: new data too long\n", field->name);
                return -1;
        }

        strncpy((char *)field->buf, value, field->size - 1);
        field->buf[field->size - 1] = '\0';

        return 0;
}

/**
 * eeprom_field_print_reserved() - print the "Reserved fields" field
 *
 * Print a notice that the following field_size bytes are reserved.
 *
 * Sample output:
 *      Reserved fields              (64 bytes)
 *
 * @field:      an initialized field to print
 */
void eeprom_field_print_reserved(const struct eeprom_field *field)
{
        printf(PRINT_FIELD_SEGMENT, "Reserved fields\t");
        printf("(%d bytes)\n", field->size);
}