/**
 * @file shell_ext.c
 * @author Letter (NevermindZZT@gmail.com)
 * @brief shell extensions
 * @version 1.0.0
 * @date 2019-01-05
 * 
 * @Copyright (c) 2019 Letter
 * 
 */

#include "shell.h"
#include "shell_ext.h"


/**
 * @brief 判断数字进制
 * 
 * @param string 参数字符串
 * @return NUM_Type 进制
 */
static NUM_Type shellExtNumType(char *string)
{
    char *p = string;
    NUM_Type type = NUM_TYPE_INT;

    if ((*p == '0') && ((*(p + 1) == 'x') || (*(p + 1) == 'X')))
    {
        type = NUM_TYPE_HEX;
    }
    else if ((*p == '0') && ((*(p + 1) == 'b') || (*(p + 1) == 'B')))
    {
        type = NUM_TYPE_BIN;
    }
    else if (*p == '0')
    {
        type = NUM_TYPE_OCT;
    }
    else
    {
        while (*p++)
        {
            if (*p == '.' && *(p + 1) != 0)
            {
                type = NUM_TYPE_FLOAT;
                break;
            }
        }
    }

    return type;
}


/**
 * @brief 字符转数字
 * 
 * @param code 字符
 * @return char 数字
 */
static char shellExtToNum(char code)
{
    if ((code >= '0') && (code <= '9'))
    {
        return code -'0';
    }
    else if ((code >= 'a') && (code <= 'f'))
    {
        return code - 'a' + 10;
    }
    else if ((code >= 'A') && (code <= 'F'))
    {
        return code - 'A' + 10;
    }
    else
    {
        return 0;
    }
}


/**
 * @brief 解析字符参数
 * 
 * @param string 字符串参数
 * @return char 解析出的字符
 */
static char shellExtParseChar(char *string)
{
    char *p = string + 1;
    char value = 0;

    if (*p == '\\')
    {
        switch (*(p + 1))
        {
        case 'b':
            value = '\b';
            break;
        case 'r':
            value = '\r';
            break;
        case 'n':
            value = '\n';
            break;
        case 't':
            value = '\t';
            break;
        case '0':
            value = 0;
            break;
        default:
            value = *(p + 1);
            break;
        }
    }
    else
    {
        value = *p;
    }
    return value;
}


/**
 * @brief 解析字符串参数
 * 
 * @param string 字符串参数
 * @return char* 解析出的字符串
 */
static char* shellExtParseString(char *string)
{
    char *p = string;
    unsigned short index = 0;

    if (*string == '\"')
    {
        p = ++string;
    }

    while (*p)
    {
        if (*p == '\\')
        {
            *(string + index) = shellExtParseChar(p - 1);
            p++;
        }
        else if (*p == '\"')
        {
            *(string + index) = 0;
        }
        else
        {
            *(string + index) = *p;
        }
        p++;
        index ++;
    }
    *(string + index) = 0;
    return string;
}


/**
 * @brief 解析数字参数
 * 
 * @param string 字符串参数
 * @return unsigned int 解析出的数字
 */
static unsigned int shellExtParseNumber(char *string)
{
    NUM_Type type = NUM_TYPE_INT;
    char radix = 10;
    char *p = string;
    char offset = 0;
    signed char sign = 1;
    unsigned int valueInt = 0;

    if (*string == '-')
    {
        sign = -1;
    }

    type = shellExtNumType(string + ((sign == -1) ? 1 : 0));

    switch ((char)type)
    {
    case NUM_TYPE_HEX:
        radix = 16;
        offset = 2;
        break;
    
    case NUM_TYPE_OCT:
        radix = 8;
        offset = 1;
        break;

    case NUM_TYPE_BIN:
        radix = 2;
        offset = 2;
        break;
    
    default:
        break;
    }

    p = string + offset + ((sign == -1) ? 1 : 0);

    if (type != NUM_TYPE_FLOAT)
    {
        while (*p)
        {
            valueInt = valueInt * radix + shellExtToNum(*p);
            p++;
        }
        return valueInt * sign;
    }

    return 0;
}


/**
 * @brief 解析参数
 * 
 * @param string 参数
 * @return unsigned int 解析结果
 */
unsigned int shellExtParsePara(char *string)
{
    if (*string == '\'' && *(string + 1))
    {
        return (unsigned int)shellExtParseChar(string);
    }
    else if (*string == '-' || (*string >= '0' && *string <= '9'))
    {
        return (unsigned int)shellExtParseNumber(string);
    }
    else if (*string)
    {
        return (unsigned int)shellExtParseString(string);
    }
    return 0;
}


/**
 * @brief 执行命令
 * 
 * @param function 执行命令的函数
 * @param argc 参数个数
 * @param argv 参数
 * @return int 返回值
 */
int shellExtRun(shellFunction function, int argc, char *argv[])
{
    switch (argc)
    {
    case 1:
        function();
        break;
    case 2:
        function(shellExtParsePara(argv[1]));
        break;
    case 3:
        function(shellExtParsePara(argv[1]), shellExtParsePara(argv[2]));
        break;
    case 4:
        function(shellExtParsePara(argv[1]), shellExtParsePara(argv[2]),
                 shellExtParsePara(argv[3]));
        break;
    case 5:
        function(shellExtParsePara(argv[1]), shellExtParsePara(argv[2]),
                 shellExtParsePara(argv[3]), shellExtParsePara(argv[4]));
        break;
    case 6:
        function(shellExtParsePara(argv[1]), shellExtParsePara(argv[2]),
                 shellExtParsePara(argv[3]), shellExtParsePara(argv[4]),
                 shellExtParsePara(argv[5]));
        break;
    case 7:
        function(shellExtParsePara(argv[1]), shellExtParsePara(argv[2]),
                 shellExtParsePara(argv[3]), shellExtParsePara(argv[4]),
                 shellExtParsePara(argv[5]), shellExtParsePara(argv[6]));
        break;
    case 8:
        function(shellExtParsePara(argv[1]), shellExtParsePara(argv[2]),
                 shellExtParsePara(argv[3]), shellExtParsePara(argv[4]),
                 shellExtParsePara(argv[5]), shellExtParsePara(argv[6]),
                 shellExtParsePara(argv[7]));
        break;
    default:
        return -1;
        // break;
    }
    return 0;
}