#include <fstream.hfa>									// sin/sout
#include <stdlib.hfa>									// convert
#include <string.h>
#include <coroutine.hfa>

ExceptionDecl( Schmilblick );

enum { DEATH_DECK_DIVISOR = 7 };

coroutine Player {
	PRNG & prng;
	unsigned int id;									// identity of the player
	Player * partner[2];								// task on the left and right
	unsigned int deck;									// size of the deck currently in play
}; // Player

void players( unsigned int num );
void ?{}( Player & player, PRNG & prng, unsigned int id );
void start( Player & player, Player & lp, Player & rp ); // supply partners
void play( Player & player,  unsigned int deck );
void drink( Player & player );

enum { RIGHT = 0, LEFT = 1 };

enum {
	MinCardsTaken = 1,									// minimum number of cards allowed to draw
	MaxCardsTaken = 8									// maximum number of cards allowed to draw
};

static unsigned int NumPlayersRemaining;				// number of players currently in the game
static unsigned int rounds;								// count rounds during Schmilblick

static unsigned int MakePlay( Player & player, unsigned int RemainingCards ) with( player ) {
	unsigned int took = min( RemainingCards, (typeof(RemainingCards))prng( prng, MinCardsTaken, MaxCardsTaken ) ); // cards drawn
	unsigned int passing = RemainingCards - took;		// remaining cards in the deck to be passed
	return passing;
} // Player::MakePlay

void main( Player & player ) with( player ) {
	try {
		suspend;										// return immediately after establishing starter
		poll();

		for ( ;; ) {
		  if ( partner[LEFT] == &player ) {				// stop when only one player
		  		sout | id;
				break;
			} // exit

			bool die = (deck % DEATH_DECK_DIVISOR) == 0; // check before making a play
			deck = MakePlay( player, deck );			// make a play
		  if ( deck == 0 ) break;						// stop when no cards left

			if ( die ) {
				partner[LEFT]->partner[RIGHT] = partner[RIGHT]; // unlink node
				partner[RIGHT]->partner[LEFT] = partner[LEFT];
				NumPlayersRemaining -= 1;
			} else if ( prng( prng, 10 ) == 0 ) {
				try {
					drink( *partner[RIGHT] );			// have a drink
					poll();
				} catchResume( Schmilblick * ) {		// stop cycle
				} // try
			} // if
			play( *partner[deck & 1], deck );			// odd goes left, even goes right
		} // for
	} catchResume( Schmilblick * ) {
		drink( *partner[RIGHT] );						// have a drink
	} // try
} // Player::main

void ?{}( Player & player, PRNG & prng, unsigned int id ) with( player ) {
	&player.prng = &prng;  player.id = id;
} // Player::Player

void start( Player & player, Player & lp, Player & rp ) with( player ) { // obtain the partner identifier
	partner[LEFT] = &lp;
	partner[RIGHT] = &rp;
	resume( player );									// establish main as starter for termination
} // Player::start

void players( unsigned int num ) {
	NumPlayersRemaining = num;
} // Player::players

void play( Player & player, unsigned int deck ) with( player ) { // send the deck to the partner
	player.deck = deck;
	resume( player );
	poll();
} // Player::play

void drink( Player & player ) with( player ) {			// cause partner to drink
	resumeAt( player, ExceptionInst( Schmilblick ) );
	resume( player );
} // Player::drink

static unsigned int rightOf( unsigned int me, unsigned int total ) {
	return ( me + 1 ) % total;
} // rightOf

static unsigned int leftOf( unsigned int me, unsigned int total ) {
	return ( me != 0 ) ? me - 1 : total - 1;
} // leftOf

// convert(...) throws out_of_range or invalid_argument
ExceptionDecl( cmd_error );

int main( int argc, char * argv[] ) {
	enum {
		MinNoPlayers = 2,								// minimum players in the game
		MaxNoPlayers = 10,								// maximum players in the game
		MinNoCards = 10,								// minimum cards in the deck
		MaxNoCards = 200,								// maximum cards in the deck
		DefaultGames = 50,								// default games to play
	};
	intmax_t numGames = DefaultGames;					// games to play
	intmax_t numPlayers = 0; bool playersSet = false;	// players for a particular game
	intmax_t numCards = 0; bool cardsSet = false;		// cards in the deck for a game
	intmax_t seed = 2423;									// random-number seed

	try {
		switch ( argc ) {
		  case 5:
			if ( strcmp( argv[4], "d" ) != 0 ) {		// default ?
				seed = convert( argv[4] ); if ( seed < 1 ) throw ExceptionInst( cmd_error ); // invalid ?
			} // if
			// FALL THROUGH
		  case 4:
			if ( strcmp( argv[3], "d" ) != 0 ) {		// default ?
				numCards = convert( argv[3] ); if ( numCards < 1 ) throw ExceptionInst( cmd_error ); // invalid ?
				cardsSet = true;
			} // if
			// FALL THROUGH
		  case 3:
			if ( strcmp( argv[2], "d" ) != 0 ) {		// default ?
				numPlayers = convert( argv[2] ); if ( numPlayers < 2 ) throw ExceptionInst( cmd_error ); // invalid ?
				playersSet = true;
			} // if
			// FALL THROUGH
		  case 2:
			if ( strcmp( argv[1], "d" ) != 0 ) {		// default ?
				numGames = convert( argv[1] ); if ( numGames < 0 ) throw ExceptionInst( cmd_error ); // invalid ?
			} // if
			// FALL THROUGH
		  case 1:										// defaults
			break;
		  default:										// wrong number of options
			throw ExceptionInst( cmd_error );
		} // switch
	} catch( exception_t * ) {							// catch any
		exit | "Usage: " | argv[0]
			 | " [ games (>=0) | 'd' (default " | DefaultGames
			 | ") [ players (>=2) | 'd' (random " | MinNoPlayers | "-" | MaxNoPlayers
			 | ") [ cards (>0) | 'd' (random " | MinNoCards | "-" | MaxNoCards
			 | ") [ seed (>0) | 'd' (random) ] ] ] ]";
	} // try

	PRNG mprng, pprng;
	if ( seed != 0 ) {									// specified on command line ?
		set_seed( mprng, seed );  set_seed( pprng, seed );
	} // if
	sout | "start";
	for ( unsigned int game = 1; game <= (unsigned int)numGames; game += 1 ) {
		if ( ! playersSet ) numPlayers = prng( mprng, MinNoPlayers, MaxNoPlayers );
		if ( ! cardsSet ) numCards = prng( mprng, MinNoCards, MaxNoCards );
		{
			Player * players[numPlayers];

			players( numPlayers );						// set number of players in game

			for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) { // start the players
				players[i] = &(*malloc()){ pprng, i };
			} // for

			// Tell each player who its partner is.
			for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) {
				start( *players[i], *players[leftOf(i, numPlayers)], *players[rightOf(i, numPlayers)] );
			} // for

			play( *players[ prng( mprng, numPlayers ) ], numCards ); // dealer starts the game
			for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) { // delete players when the game is over
				delete( players[i] );
			} // for
		}
	} // for
	sout | "done";
} // main