#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define TYPE_REQUEST 0
#define TYPE_RESPONSE 1

#define TOKEN_OPTION 0

#define RTSP_ERROR_SUCCESS 0
#define RTSP_ERROR_NO_MEMORY -1
#define RTSP_ERROR_MALFORMED -2

#define SEQ_INVALID -1

#define FLAG_ALLOCATED_OPTION_FIELDS 0x1
#define FLAG_ALLOCATED_MESSAGE_BUFFER 0x2
#define FLAG_ALLOCATED_OPTION_ITEMS 0x4

/* Linked List to store the options */
typedef struct _OPTION_ITEM {
	char flags;
	char *option;
	char *content;
	struct _OPTION_ITEM *next;
} OPTION_ITEM, *POPTION_ITEM;

/* RTSP Message *
* In this implementation, a flag indicates the message type:
* TYPE_REQUEST = 0
* TYPE_RESPONSE = 1 */
typedef struct _RTSP_MESSAGE {
	char type;
	char flags;
	int sequenceNumber;
	char *protocol;
	POPTION_ITEM options;
	char *payload;

	char* messageBuffer;

	union {
		struct {
			/* Request fields */
			char *command;
			char *target;
		} request;
		struct {
			/* Response fields */
			char *statusString;
			int statusCode;
		} response;
	} message;
} RTSP_MESSAGE, *PRTSP_MESSAGE;

int parseRtspMessage(PRTSP_MESSAGE msg, char *rtspMessage);
void freeMessage(PRTSP_MESSAGE msg);
void createRtspResponse(PRTSP_MESSAGE msg, char* messageBuffer, int flags, char *protocol, int statusCode, char *statusString, int sequenceNumber, POPTION_ITEM optionsHead, char *payload);
void createRtspRequest(PRTSP_MESSAGE msg, char* messageBuffer, int flags, char *command, char *target, char *protocol, int sequenceNumber, POPTION_ITEM optionsHead, char *payload);
char *getOptionContent(POPTION_ITEM optionsHead, char *option);
void insertOption(POPTION_ITEM *optionsHead, POPTION_ITEM opt);
void freeOptionList(POPTION_ITEM optionsHead);
char *serializeRtspMessage(PRTSP_MESSAGE msg, int *serializedLength);