/*
 *  © 2012 Francisco G. Paletta, © 2020 Gregor Baues. All rights reserved.
 *  
 *  This is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  It is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
 */

#include "Arduino.h"
#include "HttpRequest.h"
#include "NetworkInterface.h"
#include "DIAG.h"

// public interface to the parsed request
// static ParsedRequest req;

HttpRequest::HttpRequest()
{
	resetRequest();
	req.method = method;
	req.uri = uri;
	req.version = version;
	req.paramCount = &paramCount;
	/**
	 * @todo add list of parameters
	 * 
	 */
}

ParsedRequest HttpRequest::getParsedRequest()
{
	return req;
}

void HttpRequest::resetRequest()
{

	freeParamMem(firstParam);
	freeCookieMem(firstCookie);

	parseStatus = HTTP_PARSE_INIT;
	method[0] = '\0';
	uri[0] = '\0';
	version[0] = '\0';
	firstParam = NULL;
	firstCookie = NULL;
	paramCount = 0;
	cookieCount = 0;
	tmpParamName[0] = '\0';
	tmpParamValue[0] = '\0';
	tmpAttribName[0] = '\0';
	tmpAttribValue[0] = '\0';
	tmpCookieName[0] = '\0';
	tmpCookieValue[0] = '\0';
	dataBlockLength = 0;
	dataCount = 0;
}

void HttpRequest::freeParamMem(Params *paramNode)
{
	if (paramNode != NULL)
	{
		freeParamMem(paramNode->next);
		delete paramNode;
	}
}

void HttpRequest::freeCookieMem(Cookies *cookieNode)
{
	if (cookieNode != NULL)
	{
		freeCookieMem(cookieNode->next);
		delete cookieNode;
	}
}

void HttpRequest::parseRequest(char c)
{

	char cStr[2];
	cStr[0] = c;
	cStr[1] = '\0';
	switch (parseStatus)
	{

	case HTTP_METHOD:
		if (c == ' ')
			parseStatus = HTTP_URI;
		else if (strlen(method) < HTTP_REQ_METHOD_LENGTH - 1)
			strcat(method, cStr);
		break;

	case HTTP_URI:
		// DIAG(F("HTTP_URI: %c\n"), c);
		if (c == ' ')
			parseStatus = HTTP_VERSION;
		else if (c == '?') 
			parseStatus = HTTP_GET_NAME;
		else if (strlen(uri) < HTTP_REQ_URI_LENGTH - 1)
			strcat(uri, cStr);
		break;

	case HTTP_GET_NAME:
		// DIAG(F("HTTP_GET_NAME: %c\n"), c);
		if (c == ' ')
			parseStatus = HTTP_VERSION;
		else if (c != '=')
		{
			if (strlen(tmpParamName) < HTTP_REQ_PARAM_NAME_LENGTH - 1)
				strcat(tmpParamName, cStr);
		}
		else
			parseStatus = HTTP_GET_VALUE;
		break;

	case HTTP_GET_VALUE:
		// DIAG(F("HTTP_GET_VALUE: %c\n"), c);
		if (c == '&')
		{
			addParam();
			parseStatus = HTTP_GET_NAME;
		}
		else if (c == ' ')
		{
			addParam();
			parseStatus = HTTP_VERSION;
		}
		else if (strlen(tmpParamValue) < HTTP_REQ_PARAM_VALUE_LENGTH - 1)
			strcat(tmpParamValue, cStr);
		break;

	case HTTP_VERSION:
		// DIAG(F("HTTP_VERSION: %c\n"), c);
		if (c == '\n')
			parseStatus = HTTP_NEW_LINE;
		else if (c != '\r' && strlen(version) < HTTP_REQ_VERSION_LENGTH - 1)
			strcat(version, cStr);
		break;

	case HTTP_NEW_LINE:
		// DIAG(F("HTTP_NEW_LINE: %c\n"), c);
		if (c != '\r' && c != '\n')
		{
			parseStatus = HTTP_ATTRIB_NAME;
			tmpAttribName[0] = '\0';
			tmpAttribValue[0] = '\0';
		}
		else
		{
			if (strcmp(method, "POST") == 0 && dataBlockLength > 0)
				parseStatus = HTTP_POST_NAME;
			else
				// DIAG(F("HTTP_REQUEST_END: %c\n"), c);
				parseStatus = HTTP_REQUEST_END;
			break;
		}
		break;

	case HTTP_ATTRIB_NAME:
		// DIAG(F("HTTP_ATTRIB_NAME: %c\n"), c);
		if (c == '\n')
			parseStatus = HTTP_NEW_LINE;
		else if (c != ':' && c != ' ' && c != '\r')
		{
			if (strlen(tmpAttribName) < HTTP_REQ_ATTRIB_NAME_LENGTH - 1)
				strcat(tmpAttribName, cStr);
		}
		else if (c == ' ')
		{
			if (strcmp(tmpAttribName, "Cookie") == 0)
				parseStatus = HTTP_COOKIE_NAME;
			else
				parseStatus = HTTP_ATTRIB_VALUE;
		}
		break;

	case HTTP_ATTRIB_VALUE:
		// DIAG(F("HTTP_ATTRIB_VALUE: %c\n"), c);
		if (c == '\n')
		{
			addAttrib();
			parseStatus = HTTP_NEW_LINE;
		}
		else if (c != '\r')
			if (strlen(tmpAttribValue) < HTTP_REQ_ATTRIB_VALUE_LENGTH - 1)
				strcat(tmpAttribValue, cStr);
		break;

	case HTTP_POST_NAME:
		dataCount++;
		if (c != '=')
		{
			if (strlen(tmpParamName) < HTTP_REQ_PARAM_NAME_LENGTH - 1)
				strcat(tmpParamName, cStr);
		}
		else
			parseStatus = HTTP_POST_VALUE;
		if (dataCount > dataBlockLength)
		{
			addParam();
			// DIAG(F("HTTP_REQUEST_END: %c\n"), c);
			parseStatus = HTTP_REQUEST_END;
		}
		break;

	case HTTP_POST_VALUE:
		dataCount++;
		if (c == '&')
		{
			addParam();
			parseStatus = HTTP_POST_NAME;
		}
		else if (strlen(tmpParamValue) < HTTP_REQ_PARAM_VALUE_LENGTH - 1)
			strcat(tmpParamValue, cStr);
		if (dataCount > dataBlockLength)
		{
			addParam();
			// DIAG(F("HTTP_REQUEST_END: %c\n"), c);
			parseStatus = HTTP_REQUEST_END;
		}
		break;

	case HTTP_COOKIE_NAME:
		if (c == '\n')
			parseStatus = HTTP_NEW_LINE;
		else if (c != '=')
		{
			if (c != ' ' && strlen(tmpCookieName) < HTTP_REQ_COOKIE_NAME_LENGTH - 1)
				strcat(tmpCookieName, cStr);
		}
		else
			parseStatus = HTTP_COOKIE_VALUE;
		break;

	case HTTP_COOKIE_VALUE:
		if (c == ';')
		{
			addCookie();
			parseStatus = HTTP_COOKIE_NAME;
		}
		else if (c == '\n')
		{
			addCookie();
			parseStatus = HTTP_NEW_LINE;
		}
		else if (c != '\r' && c != ' ' && strlen(tmpCookieValue) < HTTP_REQ_COOKIE_VALUE_LENGTH - 1)
			strcat(tmpCookieValue, cStr);
		break;
	}
}

bool HttpRequest::endOfRequest()
{
	if (parseStatus == HTTP_REQUEST_END)
		return true;
	else
		return false;
}

void HttpRequest::addParam()
{

	Params **cursor;

	cursor = &firstParam;
	while ((*cursor) != NULL)
	{
		if (strcmp((*cursor)->name, tmpParamName) == 0)
			break;
		cursor = &((*cursor)->next);
	}
	if ((*cursor) == NULL)
	{
		// DIAG(F("New Param: %s\n"), tmpParamName);
		(*cursor) = new Params;
		strcpy((*cursor)->name, tmpParamName);
		strcpy((*cursor)->value, tmpParamValue);
		(*cursor)->next = NULL;
		paramCount++;
	}

	tmpParamName[0] = '\0';
	tmpParamValue[0] = '\0';
}

void HttpRequest::addCookie()
{

	Cookies **cursor;

	cursor = &firstCookie;
	while ((*cursor) != NULL)
	{
		if (strcmp((*cursor)->name, tmpCookieName) == 0)
			break;
		cursor = &((*cursor)->next);
	}
	if ((*cursor) == NULL)
	{
		(*cursor) = new Cookies;
		strcpy((*cursor)->name, tmpCookieName);
		strcpy((*cursor)->value, tmpCookieValue);
		(*cursor)->next = NULL;
		cookieCount++;
	}

	tmpCookieName[0] = '\0';
	tmpCookieValue[0] = '\0';
}

void HttpRequest::addAttrib()
{

	if (strcmp(tmpAttribName, "Content-Length") == 0)
		dataBlockLength = atoi(tmpAttribValue);

	tmpAttribName[0] = '\0';
	tmpAttribValue[0] = '\0';
}

uint8_t HttpRequest::getParam(uint8_t paramNum, char *name, char *value)
{
	uint8_t i = 0;

	Params **cursor;

	cursor = &firstParam;
	while ((*cursor) != NULL)
	{
		i++;
		if (i == paramNum)
		{
			strcpy(name, (*cursor)->name);
			strcpy(value, (*cursor)->value);
			break;
		}
		cursor = &((*cursor)->next);
	}

	return i;
}

Params* HttpRequest::getParam(uint8_t paramNum)
{
	uint8_t i = 0;

	Params **cursor;

	cursor = &firstParam;
	while ((*cursor) != NULL)
	{
		i++;
		if (i == paramNum)
		{
			break;
		}
		cursor = &((*cursor)->next);
	}
	return *cursor;
}

uint8_t HttpRequest::getParam(char *name, char *value)
{

	uint8_t pos = 0, i = 0;
	Params **cursor;

	cursor = &firstParam;
	while ((*cursor) != NULL)
	{
		i++;
		if (strcmp((*cursor)->name, name) == 0)
		{
			strcpy(value, (*cursor)->value);
			pos = i;
			break;
		}
		cursor = &((*cursor)->next);
	}
	return pos;
}

uint8_t HttpRequest::getCookie(uint8_t cookieNum, char *name, char *value)
{
	uint8_t i = 0;

	Cookies **cursor;

	cursor = &firstCookie;
	while ((*cursor) != NULL)
	{
		i++;
		if (i == cookieNum)
		{
			strcpy(name, (*cursor)->name);
			strcpy(value, (*cursor)->value);
			break;
		}
		cursor = &((*cursor)->next);
	}
	return i;
}

uint8_t HttpRequest::getCookie(char *name, char *value)
{

	uint8_t pos = 0, i = 0;
	Cookies **cursor;

	cursor = &firstCookie;
	while ((*cursor) != NULL)
	{
		i++;
		if (strcmp((*cursor)->name, name) == 0)
		{
			strcpy(value, (*cursor)->value);
			pos = i;
			break;
		}
		cursor = &((*cursor)->next);
	}
	return pos;
}