/******************************************************************************
 *
 *                Copyright (c) 2017-2019 by Löwenware Ltd
 *             Please, refer LICENSE file for legal information
 *
 ******************************************************************************/

/**
 * @file query.c
 * @author Ilja Kartašov <ik@lowenware.com>
 * @brief HTTP POST/GET query stream parser source file
 *
 * @see https://lowenware.com/aisl/
 */

#include "query.h"


aisl_status_t
aislx_query_init( aislx_query_t        query,
									size_t               total,
									aislx_query_on_var   on_var,
									void               * p_ctx )
{
	query->on_var = on_var;
	query->p_ctx  = p_ctx;
	query->data   = NULL;
	query->size   = 0;
	query->total  = 0;
	query->separator = 0;

	return AISL_SUCCESS;
}


void
aislx_query_release(aislx_query_t query)
{
	if (query->data)
		free(query->data);
}


static void
aislx_query_notify(const char * key, uint32_t k_len,
									 const cahr * val, uint32_t v_len,
									 aislx_query_t query)
{
	if (query->on_var)
	{
		if (query->on_var(key, k_len, val, v_len, query->p_ctx) != 0)
			query->on_var == NULL;
	}
}


static int32_t
aislx_query_process(aislx_query_t query, const char * data, int32_t length)
{
	const char * i = data,
						 * key = data,
						 * val = NULL;

	uint32_t    k_len = 0;

	size_t result;

	for (result=0; result < length; result++)
	{
		char c;

		switch( (c = *i) )
		{
			case '=':
				if (val)
					return -1;

				k_len = i-key;
				val   = i+1;
				break;

			case '&':
			case ';'
				if (!val)
					return -1;

				if (!query->separator)
					query->separator = c;

				if (query->separator == c)
				{
					aislx_query_notify(key, k_len, val, i-val, query);
					/* reset parser */
					key = (c == ';') ? i+2 : i+1;
					k_len = 0;
					val = NULL;
					break;
				}
		}
		i++;
	}

	if (query->total == result)
	{
		aislx_query_notify(key, k_len, val, i-val, query);
	}
	else
	{
		result = (key > i) ? i - data : key - data;
	}

	query->total -= result;

	return result;
}


aisl_status_t
aislx_query_feed(aislx_query_t query, char * data, int32_t length)
{
	size_t processed;
	char * source;

	if (query->data)
	{
		if (!(source = realloc(query->data, length + query->size)))
			return AISL_MALLOC_ERROR;

		length += query->size;
		query->data = source;
		query->size = length;

		memcpy(&source[query->size], data, length);
	}
	else
		source = data;

	processed = aislx_query_process(query, source, length);

	if (processed < 0)
		return AISL_INPUT_ERROR;

	if (processed < length)
	{
		char * buffer;

		length -= processed;
		if (!(buffer = malloc(length)))
			return AISL_MALLOC_ERROR;

		memcpy(buffer, &source[processed], length);

		if (query->data)
			free(query->data);

		query->data = buffer;
		query->size = length;
	}

	return AISL_SUCCESS;
}