Parses the encoding profiles in CASC encoding files.

parseEncodingProfile.cpp

#include <string.h>
#include <stdint.h>

void *memAlloc(size_t count)
{
    char* ptr = new char[count] {};
    return ptr;
}
void memFree(void* ptr) { free(ptr); }

bool isWhitespace(int value)
{
    bool result;

    result = value == ' ' || value == '\t' || value == '\v' || value == '\r' || value == '\f' || value == '\n';
    return result;
}

int parseEncodingProfile(char *encodingProfile, char **encodingMode, char ***params, unsigned int *nParams)
{
    char *it;

    for (it = encodingProfile; ; ++it)
    {
        if (!isWhitespace(*it))
            break;
    }

    for (*encodingMode = it; *it; ++it)
    {
        if (*it == ':'  || isWhitespace(*it))
            break;
    }

    char *encodingModeEnd = it;
    
    while (isWhitespace(*it))
    {
        ++it;
    }

    if (*it != '\0')
    {
        if (*it != ':')
            return 0;

        *encodingModeEnd = '\0';

        do
        {
            ++it;
        } while (isWhitespace(*it));

        if (*it == '{')
        {
            do
            {
                ++it;
            } while (isWhitespace(*it));

            *nParams = 1;
            
            if (!*it)
                return 0;

            char *paramsStart = it;

            int state = 1;
            do
            {
                if (!isWhitespace(*it))
                {
                    if (!state)
                        return 0;

                    if (*it == '{')
                    {
                        state++;
                    }
                    else
                    {
                        if (*it == '}')
                        {
                            --state;
                        }
                        else
                        {
                            if (*it == ',' && state == 1)
                                ++*nParams;
                        }
                    }
                }
            } while (*++it);

            if (state)
                return 0;

            char **paramArray = (char **)memAlloc(4 * (*nParams) | -((uint64_t)*nParams >> 30 != 0));

            if (*params)
                memFree(*params);
            *params = paramArray;

            int paramIndex = 0;
            **params = paramsStart;
            for (int state = 1; *paramsStart; ++paramsStart)
            {
                if (*paramsStart != ' ' && *paramsStart != '\t' && *paramsStart != '\v' && *paramsStart != '\r' && *paramsStart != '\f' && *paramsStart != '\n')
                {
                    if (!state)
                        return 0;

                    if (*paramsStart == '{')
                    {
                        ++state;
                    }
                    else if (*paramsStart == '}')
                    {
                        --state;

                        if (!state)
                        {
                            char *paramsEnd;
                            for (paramsEnd = paramsStart; paramsEnd > (*params)[paramIndex]; --paramsEnd)
                            {
                                char ch = *(paramsEnd - 1);
                                if (ch != ' ' && ch != '\t' && ch != '\v' && ch != '\r' && ch != '\f' && ch != '\n')
                                    break;
                            }
                            *paramsEnd = '\0';
                        }
                    }
                    else if (*paramsStart == ',' && state == 1)
                    {
                        char *paramsEnd = paramsStart;
                        if (paramsStart > (*params)[paramIndex])
                        {
                            do
                            {
                                if (!isWhitespace(*(paramsEnd - 1)))
                                    break;
                                --paramsEnd;
                            } while (paramsEnd > (*params)[paramIndex]);
                        }
                        *paramsEnd = '\0';
                        ++paramIndex;
                        for (; *paramsStart; ++paramsStart)
                        {
                            if (!isWhitespace(paramsStart[1]))
                                break;
                        }
                        (*params)[paramIndex] = paramsStart + 1;
                    }
                }
            }

            if (paramIndex + 1 != *nParams)
                abort();
        }
        else
        {
            *nParams = 1;

            char **paramArray = (char **)memAlloc(4);
            
            if (*params)
                memFree(*params);
            *params = paramArray;
            
            **params = it;

            for (it = &it[strlen(it)]; it > **params; --it)
            {
                char ch = *(it - 1);
                if (ch != ' ' && ch != '\t' && ch != '\v' && ch != '\r' && ch != '\f' && ch != '\n')
                    break;
            }

            *it = '\0';
        }

        if (*nParams == 1 && !***params)
        {
            *nParams = 0;

            if (*params)
                memFree(*params);
            *params = 0;
        }
    }
    return 1;
}