#include <string.h>					// Defines strlen().
#include "player.h"					// Definition of player task.
#include <iostream>
using namespace std;

//--------------------------------------------------------------------------------------------------------------------
// Passes the message to the next task in the chain of tasks.
//--------------------------------------------------------------------------------------------------------------------
void Player::SendMessage( char *m ) {
    message   = m;
    gameOver += 1;					// Message has gone to another player, so note it.
    osacquire acq( cout );
    cout << "Player " << id << " received message '";
    if ( message != NULL ) {
	cout << message;
	perturbMessage();
	cout << "' and changed it to '" << message;
    } else {
	cout << "NULL";
    }
    cout << "' on pass " << gameOver << endl;
} 

//--------------------------------------------------------------------------------------------------------------------
// Blocks itself waiting for messages until the game is over.
//--------------------------------------------------------------------------------------------------------------------
void Player::main() {
    // Wait until get identity of next task in the chain.
    osacquire( cout ) << "Player " << id << " about to block waiting for initialization info" << endl;
    _Accept( SetPlayer );
    osacquire( cout ) << "Player " << id << " awake after waiting for initialization info" << endl;
  
    for ( ; gameOver <= 11 ; ) {			// Is the game over yet?
	osacquire( cout ) << "Player " << id << " about to block waiting for message" << endl;
	_Accept(SendMessage);				// Receive and perturb the message. Pass it along if not done.
	osacquire( cout ) << "Player " << id << " about to block waiting for message" << endl;
      
	if ( message != NULL && gameOver <= 11 ) {
	    osacquire( cout ) << "Player " << id << " send message to next player" << endl;
	    nextPlayer->SendMessage(message);
	    osacquire( cout ) << "Player " << id << " sent message to next player" << endl;
	} 
    } 

    if ( id < 4 ) {						// Wake up blocked tasks.
	osacquire( cout ) << "Player " << id << " send empty message to next player" << endl;
	nextPlayer->SendMessage( NULL );
	osacquire( cout ) << "Player " << id << " sent empty message to next player" << endl;
    }

    osacquire( cout ) << "Player " << id << " terminating" << endl;
}

//--------------------------------------------------------------------------------------------------------------------
// Randomly perturbs the message.
//--------------------------------------------------------------------------------------------------------------------
void Player::perturbMessage() {
    const char  lowEndRange     = ' ';			// Low end of valid character range for message (ASCII 32).
    const char  highEndRange    = '~';			// High end of valid character range for message (ASCII 126).
    const char  amountPerturb   = highEndRange-lowEndRange;
    const int   indexRange      = strlen(message);	// Number of characters in the string.
    int         index;					// Index of character to change.

    if ( indexRange > 0 ) {
	index          = random() % indexRange;
	message[index] = (char) (lowEndRange + (random() % amountPerturb) + 1);
    } // if
} // Player::perturbMessage