#include "enum.hfa"
#include "fstream.hfa"
#include <string.h>

#pragma GCC visibility push(default)

forall( E | Serial( E ) ) {
    E fromInt( unsigned i ) {
        E upper = upperBound();
        E lower = lowerBound();
        // It is okay to overflow as overflow will be theoretically caught by the other bound
		if ( i < fromInstance( lower ) || i > fromInstance( upper ) )
			abort( "call to fromInt has index %d outside enumeration range %d-%d",
				   i, fromInstance( lower ), fromInstance( upper ) );
        return fromInt_unsafe( i );
    }

    E succ( E e ) {
        E upper = upperBound();
		if ( fromInstance( e ) >= fromInstance( upper ) )
			abort( "call to succ() exceeds enumeration upper bound of %d", fromInstance( upper ) );
        return succ_unsafe(e);
    }

    E pred( E e ) {
        E lower = lowerBound();
		if ( fromInstance(e) <= fromInstance(lower ) )
			abort( "call to pred() exceeds enumeration lower bound of %d", fromInstance( lower ) );
        return pred_unsafe(e);
    }

    int Countof( __attribute__((unused)) E e ) {
        E upper = upperBound();
        E lower = lowerBound();
		return fromInstance( upper ) + fromInstance( lower ) + 1;
    }
}

forall( istype & | istream( istype ), E | CfaEnum( E ) )
istype & ?|?( istype & is, E & e ) {
//	fprintf( stderr, "here0\n" );
	if ( eof( is ) ) throwResume ExceptionInst( missing_data );

	// Match input enumerator string to enumerator labels.
	int N = Countof( e ), lnths[N], max = 0;
//	printf( "N %d\n", N );
//	for ( s; E : i; 0~@ ) {
	int i = 0;
	for ( s; E ) {
		lnths[i] = strlen( label( s ) );
		if ( lnths[i] > max ) max = lnths[i];
//		fprintf( stderr, "%s %d %d\n", label( s ), lnths[i], max );
		i += 1;
	} // for

	int win = -1;
	char ch, curr = '\0', prev = '\0';

	fmt( is, " " );										// skip optional whitespace
	for ( c; max ) {
		int args = fmt( is, "%c", &ch );				// read character
		if ( eof( is ) ) {
//			fprintf( stderr, "Eof1\n" );
			if ( c == 0 ) return is;					// no characters read ?
			clear( is );								// => reset EOF => detect again on next read
//			fprintf( stderr, "Eof2\n" );
			goto W;
		}
		if ( args != 1 ) throwResume ExceptionInst( missing_data );
//		printf( "read '%c'\n", ch );
		for ( i; N ) {
//			printf( "%d %d %d\n", c, i, lnths[i] );
			if ( c < lnths[i] ) {						// eligible for this checking round ?
				char match = label( fromInt( i ) )[c];	// optimization
//				printf( "%c '%c'\n", match, ch );
				if ( (match == ch) && (c == 0 || curr == label( fromInt( i ) )[c - 1]) ) {
//					printf( "match %d %d %d '%c' '%c' '%c' '%c' 'c'\n", c, i, lnths[i], match, ch, prev, label( fromInt( i ) )[c - 1] );
					win = c;
					prev = curr;
					curr = ch;
					break;
				} // if
			} // if
		} else {
//			fprintf( stderr, "finished win: %d ch: '%c' curr: '%c' prev: '%c'\n", win, ch, curr, prev );
			ungetc( ch, is );
			if ( win == -1 ) throwResume ExceptionInst( missing_data );
			goto W;										// break does not work
		} // for
//		printf( "\n" );
//	} else {
//		fprintf( stderr, "finished2 %d\n", win );
 	} // for
  W :;
	for ( i; N ) {										// scan for winner, must succeed
		if ( win == lnths[i] - 1 ) {
			char match = label( fromInt( i ) )[win];	// optimization
//			printf( "finished1 win: %d i: %d lnth: %d match: '%c' curr: '%c' prev: '%c'\n", win, i, lnths[i], match, curr, prev );
			if ( (match == curr) && (win == 0 || prev == label( fromInt( i ) )[win - 1]) ) {
				e = fromInt( i );
				break;
			}
		} // if
	} else {
//		fprintf( stderr, "finished3 %d\n", win );
		throwResume ExceptionInst( missing_data );
	} // for
	return is;
}

forall( ostype & | ostream( ostype ), E | CfaEnum( E ) ) {
	ostype & ?|?( ostype & os, E e ) {
		return os | label( e );
	}
	OSTYPE_VOID_IMPL( E )
}