package speiger.src.collections.PACKAGE.sets;

import java.util.Arrays;
import java.util.Collection;
#if TYPE_OBJECT
import java.util.Comparator;
import java.util.function.Consumer;
#endif
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.Set;
#if PRIMITIVES
import java.util.function.JAVA_PREDICATE;
#endif
import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
import speiger.src.collections.PACKAGE.collections.COLLECTION;
import speiger.src.collections.PACKAGE.collections.ITERATOR;

import speiger.src.collections.PACKAGE.functions.consumer.BI_OBJECT_CONSUMER;
import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
#if !TYPE_OBJECT
import speiger.src.collections.PACKAGE.functions.COMPARATOR;
import speiger.src.collections.PACKAGE.functions.CONSUMER;
import speiger.src.collections.objects.utils.ObjectArrays;
#endif
import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR;
import speiger.src.collections.PACKAGE.utils.ARRAYS;


/**
 * A Type Specific ArraySet implementation.
 * That is based around the idea of {@link java.util.List#indexOf(Object)} for no duplication.
 * Unless a array constructor is used the ArraySet does not allow for duplication.
 * This implementation does not shrink the backing array
 * @Type(T)
 */
public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE implements SORTED_SET KEY_GENERIC_TYPE
{
	/** The Backing Array */
	protected transient KEY_TYPE[] data;
	/** The amount of elements stored in the array*/
	protected int size = 0;
	
	/**
	 * Default Constructor
	 */
	public ARRAY_SET() {
		data = EMPTY_KEY_ARRAY;
	}
	
	/**
	 * Minimum Capacity Constructor
	 * @param capacity the minimum capacity of the internal array
	 * @throws NegativeArraySizeException if the capacity is negative
	 */
	public ARRAY_SET(int capacity) {
		data = NEW_KEY_ARRAY(capacity);
	}
	
	/**
	 * Constructur using initial Array
	 * @param array the array that should be used for set.
	 */
	public ARRAY_SET(KEY_TYPE[] array) {
		this(array, array.length);
	}
	
	/**
	 * Constructur using initial Array
	 * @param array the array that should be used for set.
	 * @param length the amount of elements present within the array
	 * @throws NegativeArraySizeException if the length is negative
	 */
	public ARRAY_SET(KEY_TYPE[] array, int length) {
		data = Arrays.copyOf(array, length);
		size = length;
	}
	
	/**
	 * A Helper constructor that allows to create a Set with exactly the same values as the provided collection.
	 * @param c the elements that should be added to the set.
	 * @note this slowly checks every element to remove duplicates
	 */
	@Primitive
	public ARRAY_SET(Collection<? extends CLASS_TYPE> c) {
		this(c.size());
		addAll(c);
	}
	
	/**
	 * A Helper constructor that allows to create a Set with exactly the same values as the provided collection.
	 * @param c the elements that should be added to the set.
	 * @note this slowly checks every element to remove duplicates
	 */
	public ARRAY_SET(COLLECTION KEY_GENERIC_TYPE c) {
		this(c.size());
		addAll(c);
	}
	
	/**
	 * A Helper constructor that fast copies the element out of a set into the ArraySet.
	 * Since it is assumed that there is no duplication in the first place
	 * @param s the set the element should be taken from
	 */
	@Primitive
	public ARRAY_SET(Set<? extends CLASS_TYPE> s) {
		this(s.size());
		for(CLASS_TYPE e : s)
			data[size++] = OBJ_TO_KEY(e);
	}
	
	/**
	 * A Helper constructor that fast copies the element out of a set into the ArraySet.
	 * Since it is assumed that there is no duplication in the first place
	 * @param s the set the element should be taken from
	 */
	public ARRAY_SET(SET KEY_GENERIC_TYPE s) {
		this(s.size());
		for(ITERATOR KEY_GENERIC_TYPE iter = s.iterator();iter.hasNext();data[size++] = iter.NEXT());
	}
	
	@Override
	public boolean add(KEY_TYPE o) {
		int index = findIndex(o);
		if(index == -1) {
			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
			data[size++] = o;
			return true;
		}
		return false;
	}
	
	@Override
	public boolean addAndMoveToFirst(KEY_TYPE o) {
		int index = findIndex(o);
		if(index == -1) {
			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
			System.arraycopy(data, 0, data, 1, size++);
			data[0] = o;
			return true;
		}
		else if(index != 0) {
			o = data[index];
			System.arraycopy(data, 0, data, 1, index);
			data[0] = o;
		}
		return false;
	}

	@Override
	public boolean addAndMoveToLast(KEY_TYPE o) {
		int index = findIndex(o);
		if(index == -1) {
			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
			data[size++] = o;
			return true;
		}
		else if(index != size - 1) {
			o = data[index];
			System.arraycopy(data, index+1, data, index, size - index);
			data[size-1] = o;
		}
		return false;
	}

	@Override
	public boolean moveToFirst(KEY_TYPE o) {
		int index = findIndex(o);
		if(index > 0) {
			o = data[index];
			System.arraycopy(data, 0, data, 1, index);
			data[0] = o;
			return true;
		}
		return false;
	}

	@Override
	public boolean moveToLast(KEY_TYPE o) {
		int index = findIndex(o);
		if(index != -1 && index != size - 1) {
			o = data[index];
			System.arraycopy(data, index+1, data, index, size - index - 1);
			data[size-1] = o;
			return true;
		}
		return false;
	}
	
#if !TYPE_OBJECT
	@Override
	public boolean contains(KEY_TYPE e) {
		return findIndex(e) != -1;
	}
	
#else
	@Override
	public boolean contains(Object e) {
		return findIndex(e) != -1;
	}
	
#endif
	@Override
	public KEY_TYPE FIRST_KEY() {
		if(size == 0) throw new NoSuchElementException();
		return data[0];
	}
	
	@Override
	public KEY_TYPE LAST_KEY() {
		if(size == 0) throw new NoSuchElementException();
		return data[size - 1];
	}
	
	@Override
	public boolean removeAll(COLLECTION KEY_GENERIC_TYPE c) {
		int j = 0;
		for(int i = 0;i<size;i++) {
			if(!c.contains(data[i])) 
				data[j++] = data[i];
		}
		boolean result = j != size;
#if TYPE_OBJECT
		Arrays.fill(data, j, size, null);
#endif
		size = j;
		return result;
	}
	
	@Override
	public boolean retainAll(COLLECTION KEY_GENERIC_TYPE c) {
		int j = 0;
		for(int i = 0;i<size;i++) {
			if(c.contains(data[i])) 
				data[j++] = data[i];
		}
		boolean result = j != size;
#if TYPE_OBJECT
		Arrays.fill(data, j, size, null);
#endif
		size = j;
		return result;
	}
	
	@Override
	@Primitive
	public boolean removeAll(Collection<?> c) {
		int j = 0;
		for(int i = 0;i<size;i++) {
			if(!c.contains(KEY_TO_OBJ(data[i])))
				data[j++] = data[i];
		}
		boolean result = j != size;
#if TYPE_OBJECT
		Arrays.fill(data, j, size, null);
#endif
		size = j;
		return result;
	}
	
	@Override
	@Primitive
	public boolean retainAll(Collection<?> c) {
		int j = 0;
		for(int i = 0;i<size;i++) {
			if(c.contains(KEY_TO_OBJ(data[i])))
				data[j++] = data[i];
		}
		boolean result = j != size;
#if TYPE_OBJECT
		Arrays.fill(data, j, size, null);
#endif
		size = j;
		return result;
	}
	
#if !TYPE_OBJECT
	@Override
	public boolean remove(KEY_TYPE o) {
		int index = findIndex(o);
		if(index != -1) {
			size--;
			if(index != size) System.arraycopy(data, index+1, data, index, size - index);
#if TYPE_OBJECT
			data[size] = EMPTY_KEY_VALUE;
#endif
			return true;
		}
		return false;
	}
	
#else
	@Override
	public boolean remove(Object o) {
		int index = findIndex(o);
		if(index != -1) {
			size--;
			if(index != size) System.arraycopy(data, index+1, data, index, size - index);
#if TYPE_OBJECT
			data[size] = EMPTY_KEY_VALUE;
#endif
			return true;
		}
		return false;
	}
	
#endif
	@Override
	public KEY_TYPE POLL_FIRST_KEY() {
		if(size == 0) throw new NoSuchElementException();
		KEY_TYPE result = data[0];
		System.arraycopy(data, 1, data, 0, --size);
#if TYPE_OBJECT
		data[size] = EMPTY_KEY_VALUE;
#endif
		return result;
	}
	
	@Override
	public KEY_TYPE POLL_LAST_KEY() {
		if(size == 0) throw new NoSuchElementException();
		size--;
#if TYPE_OBJECT
		KEY_TYPE result = data[size];
		data[size] = EMPTY_KEY_VALUE;
		return result;
#else
		return data[size];
#endif
	}
#if PRIMITIVES
	@Override
	public boolean remIf(JAVA_PREDICATE KEY_GENERIC_TYPE filter) {
		Objects.requireNonNull(filter);
		boolean modified = false;
		int j = 0;
		for(int i = 0;i<size;i++) {
			if(!filter.test(data[i])) data[j++] = data[i];
			else modified = true;
		}
		size = j;
		return modified;
	}
	
#endif
	@Override
	public void forEach(CONSUMER KEY_SUPER_GENERIC_TYPE action) {
		Objects.requireNonNull(action);
		for(int i = 0;i<size;action.accept(data[i++]));
	}
	
	@Override
	public <E> void forEach(E input, BI_OBJECT_CONSUMER KEY_VALUE_SPECIAL_GENERIC_TYPE action) {
		Objects.requireNonNull(action);
		for(int i = 0;i<size;i++)
			action.accept(data[i], input);		
	}
	
	@Override
	public boolean matchesAny(PREDICATE KEY_GENERIC_TYPE filter) {
		Objects.requireNonNull(filter);
		for(int i = 0;i<size;i++) {
			if(filter.TEST_VALUE(data[i])) return true;
		}
		return false;
	}
	
	@Override
	public boolean matchesNone(PREDICATE KEY_GENERIC_TYPE filter) {
		Objects.requireNonNull(filter);
		for(int i = 0;i<size;i++) {
			if(filter.TEST_VALUE(data[i])) return false;
		}
		return true;
	}
	
	@Override
	public boolean matchesAll(PREDICATE KEY_GENERIC_TYPE filter) {
		Objects.requireNonNull(filter);
		for(int i = 0;i<size;i++) {
			if(!filter.TEST_VALUE(data[i])) return false;
		}
		return true;
	}
	
	@Override
	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
		Objects.requireNonNull(filter);
		for(int i = 0;i<size;i++) {
			if(filter.TEST_VALUE(data[i])) return data[i];
		}
		return EMPTY_VALUE;
	}
	
#if !TYPE_OBJECT
	protected int findIndex(KEY_TYPE o) {
		for(int i = size-1;i>=0;i--)
			if(KEY_EQUALS(data[i], o)) return i;
		return -1;
	}
	
#endif
	protected int findIndex(Object o) {
		for(int i = size-1;i>=0;i--)
			if(EQUALS_KEY_TYPE(data[i], o)) return i;
		return -1;
	}
	
	@Override
	public BI_ITERATOR KEY_GENERIC_TYPE iterator() {
		return new SetIterator(0);
	}
	
	@Override
	public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) {
		int index = findIndex(fromElement);
		if(index != -1) return new SetIterator(index);
		throw new NoSuchElementException();
	}
	
	@Override
	public SORTED_SET KEY_GENERIC_TYPE subSet(KEY_TYPE fromElement, KEY_TYPE toElement) {
		int fromIndex = findIndex(fromElement);
		int toIndex = findIndex(toElement);
		if(fromIndex == -1 || toIndex == -1) throw new NoSuchElementException();
		return new SubSet(fromIndex, toIndex - fromIndex + 1);
	}

	@Override
	public SORTED_SET KEY_GENERIC_TYPE headSet(KEY_TYPE toElement) {
		int toIndex = findIndex(toElement);
		if(toIndex == -1) throw new NoSuchElementException();
		return new SubSet(0, toIndex+1);
	}

	@Override
	public SORTED_SET KEY_GENERIC_TYPE tailSet(KEY_TYPE fromElement) {
		int fromIndex = findIndex(fromElement);
		if(fromIndex == -1) throw new NoSuchElementException();
		return new SubSet(fromIndex, size - fromIndex);
	}
	
	@Override
	public COMPARATOR KEY_GENERIC_TYPE comparator() {
		return null;
	}
	
	@Override
	public void clear() {
		size = 0;
	}
	
	@Override
	public int size() {
		return size;
	}
	
#if !TYPE_OBJECT
	@Override
	public KEY_TYPE[] TO_ARRAY(KEY_TYPE[] a) {
		if(a == null || a.length < size()) return Arrays.copyOf(data, size());
		System.arraycopy(data, 0, a, 0, size());
		return a;
	}
	
#endif
	@Override
	@Deprecated
	public Object[] toArray() {
		Object[] obj = new Object[size()];
		for(int i = 0;i<size();i++)
			obj[i] = KEY_TO_OBJ(data[i]);
		return obj;
	}
	
	@Override
	@Primitive
	public <E> E[] toArray(E[] a) {
		if(a == null) a = (E[])new Object[size()];
		else if(a.length < size()) a = (E[])ObjectArrays.newArray(a.getClass().getComponentType(), size());
		for(int i = 0;i<size();i++)
			a[i] = (E)KEY_TO_OBJ(data[i]);
		return a;
	}
	
	private class SubSet extends ABSTRACT_SET KEY_GENERIC_TYPE implements SORTED_SET KEY_GENERIC_TYPE {
		int offset;
		int length;
		
		SubSet(int offset, int length) {
			this.offset = offset;
			this.length = length;
		}
		
		int end() { return offset+length; }

		@Override
		public boolean add(KEY_TYPE o) {
			int index = findIndex(o);
			if(index == -1) {
				if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
				if(end() != size) System.arraycopy(data, end(), data, end()+1, size-(offset+length));
				data[end()] = o;
				size++;
				length++;
				return true;
			}
			return false;
		}

		@Override
		public boolean addAndMoveToFirst(KEY_TYPE o) {
			int index = findIndex(o);
			if(index == -1) {
				if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
				System.arraycopy(data, offset, data, offset+1, size-offset);
				data[offset] = o;
				size++;
				length++;
				return true;
			}
			else if(index != 0) {
				o = data[index];
				System.arraycopy(data, offset, data, offset+1, index-offset);
				data[offset] = o;
			}
			return false;
		}
		
		@Override
		public boolean addAndMoveToLast(KEY_TYPE o) {
			int index = findIndex(o);
			if(index == -1) {
				if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
				System.arraycopy(data, end()+1, data, end(), size-end());
				data[end()] = o;
				size++;
				length++;
				return true;
			}
			else if(index != 0) {
				o = data[index];
				System.arraycopy(data, offset+1, data, offset, index-offset);
				data[offset+length] = o;
			}
			return false;
		}
		
		@Override
		public boolean moveToFirst(KEY_TYPE o) {
			int index = findIndex(o);
			if(index > offset) {
				o = data[index];
				System.arraycopy(data, offset, data, offset+1, index-offset);
				data[offset] = o;
				return true;
			}
			return false;
		}
		
		@Override
		public boolean moveToLast(KEY_TYPE o) {
			int index = findIndex(o);
			if(index != -1 && index < end()-1) {
				o = data[index];
				System.arraycopy(data, index+1, data, index, end()-index-1);
				data[end()-1] = o;
				return true;
			}
			return false;
		}
		
#if !TYPE_OBJECT
		@Override
		public boolean contains(KEY_TYPE e) {
			return findIndex(e) != -1;
		}
		
#endif
		@Override
		public boolean contains(Object e) {
			return findIndex(e) != -1;
		}
		
		@Override
		public KEY_TYPE FIRST_KEY() {
			if(length == 0) throw new NoSuchElementException();
			return data[offset];
		}
		
		@Override
		public KEY_TYPE LAST_KEY() {
			if(length == 0) throw new NoSuchElementException();
			return data[end()-1];
		}
		
#if !TYPE_OBJECT
		@Override
		public boolean remove(KEY_TYPE o) {
			int index = findIndex(o);
			if(index != -1) {
				size--;
				length--;
				if(index != size) System.arraycopy(data, index+1, data, index, size - index);
				return true;
			}
			return false;
		}
		
#endif
		@Override
		public boolean remove(Object o) {
			int index = findIndex(o);
			if(index != -1) {
				size--;
				length--;
				if(index != size) System.arraycopy(data, index+1, data, index, size - index);
#if TYPE_OBJECT
				data[size] = EMPTY_KEY_VALUE;
#endif
				return true;
			}
			return false;
		}
		
		@Override
		public KEY_TYPE POLL_FIRST_KEY() {
			if(length == 0) throw new NoSuchElementException();
			size--;
			length--;
			KEY_TYPE result = data[offset];
			System.arraycopy(data, offset+1, data, offset, size-offset);
#if TYPE_OBJECT
			data[size] = EMPTY_KEY_VALUE;
#endif
			return result;
		}
		
		@Override
		public KEY_TYPE POLL_LAST_KEY() {
			if(length == 0) throw new NoSuchElementException();
			KEY_TYPE result = data[offset+length];
			size--;
			length--;
			System.arraycopy(data, end()+1, data, end(), size-end());
#if TYPE_OBJECT
			data[size] = EMPTY_KEY_VALUE;
#endif
			return result;
		}
		
		@Override
		public COMPARATOR KEY_GENERIC_TYPE comparator() {
			return null;
		}

		@Override
		public BI_ITERATOR KEY_GENERIC_TYPE iterator() {
			return new SetIterator(offset);
		}

		@Override
		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) {
			int index = findIndex(fromElement);
			if(index != -1) return new SetIterator(index);
			throw new NoSuchElementException();
		}

		@Override
		public SORTED_SET KEY_GENERIC_TYPE subSet(KEY_TYPE fromElement, KEY_TYPE toElement) {
			int fromIndex = findIndex(fromElement);
			int toIndex = findIndex(toElement);
			if(fromIndex == -1 || toIndex == -1) throw new NoSuchElementException();
			return new SubSet(fromIndex, toIndex - fromIndex + 1);
		}

		@Override
		public SORTED_SET KEY_GENERIC_TYPE headSet(KEY_TYPE toElement) {
			int toIndex = findIndex(toElement);
			if(toIndex == -1) throw new NoSuchElementException();
			return new SubSet(0, toIndex+1);
		}

		@Override
		public SORTED_SET KEY_GENERIC_TYPE tailSet(KEY_TYPE fromElement) {
			int fromIndex = findIndex(fromElement);
			if(fromIndex == -1) throw new NoSuchElementException();
			return new SubSet(fromIndex, size - fromIndex);
		}
		
		@Override
		public int size() {
			return length;
		}
		
#if !TYPE_OBJECT
		@Override
		public KEY_TYPE[] TO_ARRAY(KEY_TYPE[] a) {
			if(a == null || a.length < size()) return Arrays.copyOfRange(data, offset, end());
			System.arraycopy(data, offset, a, 0, size());
			return a;
		}
		
#endif
		@Override
		@Deprecated
		public Object[] toArray() {
			Object[] obj = new Object[size()];
			for(int i = 0;i<size();i++)
				obj[i] = KEY_TO_OBJ(data[offset+i]);
			return obj;
		}
		
		@Override
		@Primitive
		public <E> E[] toArray(E[] a) {
			if(a == null) a = (E[])new Object[size()];
			else if(a.length < size()) a = (E[])ObjectArrays.newArray(a.getClass().getComponentType(), size());
			for(int i = 0;i<size();i++)
				a[i] = (E)KEY_TO_OBJ(data[offset+i]);
			return a;
		}
		
#if !TYPE_OBJECT
		protected int findIndex(KEY_TYPE o) {
			for(int i = length-1;i>=0;i--)
				if(KEY_EQUALS(data[offset+i], o)) return i + offset;
			return -1;
		}
		
#endif
		protected int findIndex(Object o) {
			for(int i = length-1;i>=0;i--)
				if(EQUALS_KEY_TYPE(data[offset+i], o)) return i + offset;
			return -1;
		}
		
		private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
			int index;
			int lastReturned = -1;
			
			public SetIterator(int index) {
				this.index = index;
			}
			
			@Override
			public boolean hasNext() {
				return index < size();
			}
			
			@Override
			public KEY_TYPE NEXT() {
				lastReturned = index;
				return data[index++];
			}
			
			@Override
			public boolean hasPrevious() {
				return index > 0;
			}
			
			@Override
			public KEY_TYPE PREVIOUS() {
				lastReturned = index;
				return data[index--];
			}
			
			@Override
			public int nextIndex() {
				return index;
			}
			
			@Override
			public int previousIndex() {
				return index-1;
			}
			
			@Override
			public void remove() {
				if(lastReturned == -1)
					throw new IllegalStateException();
				SubSet.this.remove(data[lastReturned]);
				if(lastReturned < index)
					index--;
				lastReturned = -1;
			}
			
		#if TYPE_OBJECT
			@Override
			public void set(Object e) { throw new UnsupportedOperationException(); }
			
			@Override
			public void add(Object e) { throw new UnsupportedOperationException(); }
			
		#else
			@Override
			public void set(KEY_TYPE e) { throw new UnsupportedOperationException(); }
		
			@Override
			public void add(KEY_TYPE e) { throw new UnsupportedOperationException(); }
			
		#endif
			@Override
			public int skip(int amount) {
				if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
				int steps = Math.min(amount, (size() - 1) - index);
				index += steps;
				return steps;
			}
			
			@Override
			public int back(int amount) {
				if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
				int steps = Math.min(amount, index);
				index -= steps;
				return steps;
			}
		}
	}
	
	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
		int index;
		int lastReturned = -1;
		
		public SetIterator(int index) {
			this.index = index;
		}
		
		@Override
		public boolean hasNext() {
			return index < size();
		}
		
		@Override
		public KEY_TYPE NEXT() {
			lastReturned = index;
			return data[index++];
		}
		
		@Override
		public boolean hasPrevious() {
			return index > 0;
		}
		
		@Override
		public KEY_TYPE PREVIOUS() {
			lastReturned = index;
			return data[index--];
		}
		
		@Override
		public int nextIndex() {
			return index;
		}
		
		@Override
		public int previousIndex() {
			return index-1;
		}
		
		@Override
		public void remove() {
			if(lastReturned == -1)
				throw new IllegalStateException();
			ARRAY_SET.this.remove(data[lastReturned]);
			if(lastReturned < index)
				index--;
			lastReturned = -1;
		}
		
#if TYPE_OBJECT
		@Override
		public void set(Object e) { throw new UnsupportedOperationException(); }
		
		@Override
		public void add(Object e) { throw new UnsupportedOperationException(); }
		
#else
		@Override
		public void set(KEY_TYPE e) { throw new UnsupportedOperationException(); }

		@Override
		public void add(KEY_TYPE e) { throw new UnsupportedOperationException(); }
		
#endif
		@Override
		public int skip(int amount) {
			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
			int steps = Math.min(amount, (size() - 1) - index);
			index += steps;
			return steps;
		}
		
		@Override
		public int back(int amount) {
			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
			int steps = Math.min(amount, index);
			index -= steps;
			return steps;
		}
	}
}