#import <Foundation/Foundation.h>
#import <stdio.h>

@interface PWGen : NSObject {

}

+returnUnique: aString;
+(BOOL)allElementsIn: (int*)anArray ofSize: (int)aLength are: (int)anInt;
+stringWithMapping: (int*)anArray ofSize: (int)anInt andCharacters: aString;
+makeList: (int)length withCharacters: availableCharacters;

@end

@implementation PWGen

+returnUnique: aString {
	int i;
	id newString = [NSMutableString string];
	id charSet = [[NSMutableCharacterSet alloc] init];
	for(i=0; i<[aString length]; i++) {
		char c = [aString characterAtIndex:i];
		if(![charSet characterIsMember: c]) {
			[charSet addCharactersInString:[NSString stringWithFormat:@"%c", c]];
			[newString appendFormat:@"%c", c];
		}
	}
	[charSet release];
	return newString;
}

+(BOOL)allElementsIn: (int*)anArray ofSize: (int)aLength are: (int)anInt {
	int i;
	for(i=0; i<aLength; i++) {
		if(anArray[i] != anInt) {
			return NO;
		}
	}
	return YES;
}

+stringWithMapping: (int*)anArray ofSize: (int)anInt andCharacters: aString {
	int i;
	id newString = [NSMutableString string];
	for(i=0; i<anInt; i++) {
		[newString appendFormat:@"%c", [aString characterAtIndex: anArray[i]]];
	}
	return newString;
}

+makeList: (int)length withCharacters: availableCharacters
{
	int max,i;
	id availChars = [[PWGen returnUnique: availableCharacters] retain];
	int newString[100]={0};

	max = [availChars length]-1;
	if(max < 0) {
		NSBeep();
		NSLog(@"Not enough characters.");
		return nil;
	}

	while(![PWGen allElementsIn: newString ofSize: length are: max]) {
		printf("%s\n", [[PWGen stringWithMapping: newString ofSize: length andCharacters: availChars] cString]);
		for(i=length-1; i>=0; i--) {
			if(newString[i] != max) {
				newString[i]++;
				break;
			} else {
				newString[i] = 0;
			}
		}
	}
	printf("%s\n",[[PWGen stringWithMapping: newString ofSize: length andCharacters: availChars] cString]);
	[availChars release];
	return nil;
}

@end

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	if(argc < 3) {
		printf("usage: %s length \"characters\"\n", argv[0]);
		return 0;
	}
	[PWGen makeList: atoi(argv[1]) withCharacters: [NSString stringWithCString: argv[2]]];
    [pool release];
    return 0;
}