#include <stdio.h>
#include <string.h>
#include "spinix.h"
#include "varsubs.h"

static char retvalstr[16];

//******************************************************************************
// Copyright (c) 2013 Dave Hein
// See end of file for terms of use.
//******************************************************************************
char *varsubs_FindVar(char *str)
{
    char *ptr = (char *)spinix_environ_vars;
    while (*ptr)
    {
        if (!strcmp(str, ptr + 1))
        {
            if (*ptr != varsubs_ALIAS_FLAG)
            {
                return ptr;
            }
        }
        ptr += strlen(ptr) + 1;
        ptr += strlen(ptr) + 1;
    }
    return 0;
}

char *varsubs_FindAlias(char *str)
{
    char *ptr = (char *)spinix_environ_vars;
    while (*ptr)
    {
        if (!strcmp(str, ptr + 1))
        {
            if (*ptr == varsubs_ALIAS_FLAG)
            {
                return ptr;
            }
        }
        ptr += strlen(ptr) + 1;
        ptr += strlen(ptr) + 1;
    }
    return 0;
}

char *varsubs_FindEnd(void)
{
    char *ptr = (char *)spinix_environ_vars;
    while (*ptr)
    {
        ptr += strlen(ptr) + 1;
        ptr += strlen(ptr) + 1;
    }
    return ptr;
}

char *varsubs_RemoveEntry(char *ptr1)
{
    int i, len;
    char *ptr2 = ptr1 + strlen(ptr1) + 1;
    ptr2 += strlen(ptr2) + 1;
    while (*ptr2)
    {
        for (i = 0; i < 2; i++)
        {
            len = strlen(ptr2) + 1;
            memmove (ptr1, ptr2, len);
            ptr1 += len;
            ptr2 += len;
        }
    }
    *ptr1 = 0;
    return ptr1;
}

void varsubs_RemoveVar(char *name)
{
    char *ptr;
    if ((ptr = varsubs_FindVar(name)))
    {
        ptr = varsubs_RemoveEntry(ptr);
    }
}

void varsubs_SaveVar(char *name, char *value, int type)
{
    char *ptr;
    int space, len1, len2;
    // Check if variable already exists
    if ((ptr = varsubs_FindVar(name)))
    {
        type = *ptr;
        ptr = varsubs_RemoveEntry(ptr);
    }
    else
    {
        ptr = varsubs_FindEnd();
    }
    // Check if space is available
    space = spinix_environ_vars_end - (int)ptr + 1;
    len1 = strlen(name) + 1;
    len2 = strlen(value) + 1;
    if ((space < len1 + len2 + 2))
    {
        printf("Not enough variable space\n");
        return;
    }
    else if ((space < len1 + len2 + 82))
    {
        printf("space = %d, need = %d\n", space, len1 + len2 + 2);
    }
    // Add variable
    *ptr++ = type;
    memmove (ptr, name, len1);
    ptr += len1;
    memmove (ptr, value, len2);
    ptr += len2;
    *ptr = 0;
}

char *varsubs_GetVarVal(char *name)
{
    char *ptr;
    if (!strcmp(name, "?"))
    {
        sprintf(retvalstr, "%d", *(int *)spinix_return_value);
        return retvalstr;
    }
    if ((ptr = varsubs_FindVar(name)))
    {
        return ptr + strlen(ptr) + 1;
    }
    return "";
}

char *varsubs_Val(char *ptr)
{
    if (*ptr != '$') return ptr;
    return varsubs_GetVarVal(ptr + 1);
}

int varsubs_NumVal(char *ptr)
{
    if (*ptr == '$')
    {
        if (!strcmp(ptr, "$?"))
        {
            return *(int *)spinix_return_value;
        }
        ptr = varsubs_GetVarVal(ptr + 1);
    }
    return atol(ptr);
}

#if 0
char *varsubs_FindChar(char *str, int val)
{
    while (*str && *str != val) str++;
    return str;
}

char *varsubs_SkipChar(char *str, int val)
{
    while (*str && *str == val) str++;
    return str;
}
#endif

/*
+-----------------------------------------------------------------------------+
|                       TERMS OF USE: MIT License                             |
+-----------------------------------------------------------------------------+
|Permission is hereby granted, free of charge, to any person obtaining a copy |
|of this software and associated documentation files (the "Software"), to deal|
|in the Software without restriction, including without limitation the rights |
|to use, copy, modify, merge, publish, distribute, sublicense, and/or sell    |
|copies of the Software, and to permit persons to whom the Software is        |
|furnished to do so, subject to the following conditions:                     |
|                                                                             |
|The above copyright notice and this permission notice shall be included in   |
|all copies or substantial portions of the Software.                          |
|                                                                             |
|THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR   |
|IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,     |
|FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE  |
|AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER       |
|LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,|
|OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE|
|SOFTWARE.                                                                    |
+-----------------------------------------------------------------------------+
*/