#ifndef MESSAGE_H_
#define MESSAGE_H_

#include <stdbool.h>
#include <stdint.h>

#define MAX_MESSAGE_LENGTH 277

// Message structure
typedef struct message_t message_t;
// and handle type
typedef message_t *message_handle_t;

typedef void (*observer_func)(void);

#ifdef TEST //This is a test build
// Makes private functions reachable by the tester
#define unit_static
// Calls all observer functions attached to this message.
unit_static void message_state_changed(message_handle_t message_handle);
#else
#define unit_static static
#endif

// Initializes a message structure and returns the message handle. User must provide the length of
// the message without the null termination character (strlen);
message_handle_t message_init(const char *message, int message_length, uint16_t received_from);

// Frees a message structure.
void message_free(message_handle_t message_handle);

// Adds an new receiver to the message.
void message_add_sent_to(message_handle_t message_handle, uint16_t sent_to);

// Returns the message.
char *message_get(message_handle_t message_handle, int *message_length);

// Returns true if the message has been previously sent to this node, false otherwise.
bool message_sent_to(message_handle_t message_handle, uint16_t node);

// Attaches an observer function to the message.
void message_attach_observer(message_handle_t message_handle, observer_func observer);

#endif //MESSAGE_H_