package speiger.src.collections.PACKAGE.utils;

import speiger.src.collections.PACKAGE.collections.ITERATOR;

public class ITERATORS
{
	public static GENERIC_BRACES ArrayIterator KEY_GENERIC_TYPE wrap(KEY_TYPE[] a) {
		return wrap(a, 0, a.length);
	}
	
	public static GENERIC_BRACES ArrayIterator KEY_GENERIC_TYPE wrap(KEY_TYPE[] a, int start, int end) {
		return new ArrayIteratorBRACES(a, start, end);
	}
	
	public static GENERIC_BRACES int unwrap(KEY_TYPE[] a, ITERATOR KEY_GENERIC_TYPE i) {
		return unwrap(a, i, 0, a.length);
	}
	
	public static GENERIC_BRACES int unwrap(KEY_TYPE[] a, ITERATOR KEY_GENERIC_TYPE i, int offset) {
		return unwrap(a, i, offset, a.length);
	}
	
	public static GENERIC_BRACES int unwrap(KEY_TYPE[] a, ITERATOR KEY_GENERIC_TYPE i, int offset, int max) {
		if(max < 0) throw new IllegalStateException("The max size is smaller then 0");
		if(offset + max >= a.length) throw new IllegalStateException("largest array index exceeds array size");
		int index = 0;
		for(;index<max && i.hasNext();index++) a[index+offset] = i.NEXT();
		return index;
	}
	
#if !TYPE_OBJECT
	public static GENERIC_BRACES int unwrap(CLASS_TYPE[] a, ITERATOR KEY_GENERIC_TYPE i) {
		return unwrap(a, i, 0, a.length);
	}
	
	public static GENERIC_BRACES int unwrap(CLASS_TYPE[] a, ITERATOR KEY_GENERIC_TYPE i, int offset) {
		return unwrap(a, i, offset, a.length);
	}
	
	public static GENERIC_BRACES int unwrap(CLASS_TYPE[] a, ITERATOR KEY_GENERIC_TYPE i, int offset, int max) {
		if(max < 0) throw new IllegalStateException("The max size is smaller then 0");
		if(offset + max >= a.length) throw new IllegalStateException("largest array index exceeds array size");
		int index = 0;
		for(;index<max && i.hasNext();index++) a[index+offset] = KEY_TO_OBJ(i.NEXT());
		return index;
	}
	
#endif	
	private static class ArrayIterator KEY_GENERIC_TYPE implements ITERATOR KEY_GENERIC_TYPE
	{
		KEY_TYPE[] a;
		int from;
		int to;
		
		ArrayIterator(KEY_TYPE[] a, int from, int to) {
			this.a = a;
			this.from = from;
			this.to = to;
		}
		
		@Override
		public boolean hasNext() {
			return from < to;
		}
		
		@Override
		public KEY_TYPE NEXT() {
			return a[from++];
		}
		
		@Override
		public int skip(int amount) {
			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
			int left = Math.min(amount, to - from);
			from += left;
			return amount - left;
		}
	}
}