/*
	* Copyright (C) 2002-2019 Sebastiano Vigna
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	*     http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
package it.unimi.dsi.fastutil.objects;
import it.unimi.dsi.fastutil.bytes.ByteCollection;
import it.unimi.dsi.fastutil.bytes.AbstractByteCollection;
import it.unimi.dsi.fastutil.bytes.ByteIterator;
import it.unimi.dsi.fastutil.objects.AbstractObjectSet;
import java.util.Iterator;
import java.util.Map;
An abstract class providing basic methods for maps implementing a
type-specific interface.
 Optional operations just throw an UnsupportedOperationException. Generic versions of accessors delegate to the corresponding type-specific counterparts following the interface rules (they take care of returning null on a missing key). 
 As a further help, this class provides a BasicEntry inner class that implements a type-specific version of Entry; it is particularly useful for those classes that do not implement their own entries (e.g., most immutable maps). /**
 * An abstract class providing basic methods for maps implementing a
 * type-specific interface.
 *
 * <p>
 * Optional operations just throw an {@link UnsupportedOperationException}.
 * Generic versions of accessors delegate to the corresponding type-specific
 * counterparts following the interface rules (they take care of returning
 * {@code null} on a missing key).
 *
 * <p>
 * As a further help, this class provides a {@link BasicEntry BasicEntry} inner
 * class that implements a type-specific version of {@link java.util.Map.Entry};
 * it is particularly useful for those classes that do not implement their own
 * entries (e.g., most immutable maps).
 */
public abstract class AbstractReference2ByteMap<K> extends AbstractReference2ByteFunction<K>
		implements
			Reference2ByteMap<K>,
			java.io.Serializable {
	private static final long serialVersionUID = -4940583368468432370L;
	protected AbstractReference2ByteMap() {
	}
	@Override
	public boolean containsValue(final byte v) {
		return values().contains(v);
	}
	@Override
	public boolean containsKey(final Object k) {
		final ObjectIterator<Reference2ByteMap.Entry<K>> i = reference2ByteEntrySet().iterator();
		while (i.hasNext())
			if (i.next().getKey() == k)
				return true;
		return false;
	}
	@Override
	public boolean isEmpty() {
		return size() == 0;
	}
	
This class provides a basic but complete type-specific entry class for all
those maps implementations that do not have entries on their own (e.g., most
immutable maps).
 This class does not implement 
setValue(), as the modification would not be reflected in the base map. /**
	 * This class provides a basic but complete type-specific entry class for all
	 * those maps implementations that do not have entries on their own (e.g., most
	 * immutable maps).
	 *
	 * <p>
	 * This class does not implement {@link java.util.Map.Entry#setValue(Object)
	 * setValue()}, as the modification would not be reflected in the base map.
	 */
	public static class BasicEntry<K> implements Reference2ByteMap.Entry<K> {
		protected K key;
		protected byte value;
		public BasicEntry() {
		}
		public BasicEntry(final K key, final Byte value) {
			this.key = (key);
			this.value = (value).byteValue();
		}
		public BasicEntry(final K key, final byte value) {
			this.key = key;
			this.value = value;
		}
		@Override
		public K getKey() {
			return key;
		}
		@Override
		public byte getByteValue() {
			return value;
		}
		@Override
		public byte setValue(final byte value) {
			throw new UnsupportedOperationException();
		}
		@SuppressWarnings("unchecked")
		@Override
		public boolean equals(final Object o) {
			if (!(o instanceof Map.Entry))
				return false;
			if (o instanceof Reference2ByteMap.Entry) {
				final Reference2ByteMap.Entry<K> e = (Reference2ByteMap.Entry<K>) o;
				return ((key) == (e.getKey())) && ((value) == (e.getByteValue()));
			}
			final Map.Entry<?, ?> e = (Map.Entry<?, ?>) o;
			final Object key = e.getKey();
			final Object value = e.getValue();
			if (value == null || !(value instanceof Byte))
				return false;
			return ((this.key) == ((key))) && ((this.value) == (((Byte) (value)).byteValue()));
		}
		@Override
		public int hashCode() {
			return (System.identityHashCode(key)) ^ (value);
		}
		@Override
		public String toString() {
			return key + "->" + value;
		}
	}
	
This class provides a basic implementation for an Entry set which forwards
some queries to the map.
/**
	 * This class provides a basic implementation for an Entry set which forwards
	 * some queries to the map.
	 */
	public abstract static class BasicEntrySet<K> extends AbstractObjectSet<Entry<K>> {
		protected final Reference2ByteMap<K> map;
		public BasicEntrySet(final Reference2ByteMap<K> map) {
			this.map = map;
		}
		@SuppressWarnings("unchecked")
		@Override
		public boolean contains(final Object o) {
			if (!(o instanceof Map.Entry))
				return false;
			if (o instanceof Reference2ByteMap.Entry) {
				final Reference2ByteMap.Entry<K> e = (Reference2ByteMap.Entry<K>) o;
				final K k = e.getKey();
				return map.containsKey(k) && ((map.getByte(k)) == (e.getByteValue()));
			}
			final Map.Entry<?, ?> e = (Map.Entry<?, ?>) o;
			final Object k = e.getKey();
			final Object value = e.getValue();
			if (value == null || !(value instanceof Byte))
				return false;
			return map.containsKey(k) && ((map.getByte(k)) == (((Byte) (value)).byteValue()));
		}
		@SuppressWarnings("unchecked")
		@Override
		public boolean remove(final Object o) {
			if (!(o instanceof Map.Entry))
				return false;
			if (o instanceof Reference2ByteMap.Entry) {
				final Reference2ByteMap.Entry<K> e = (Reference2ByteMap.Entry<K>) o;
				return map.remove(e.getKey(), e.getByteValue());
			}
			Map.Entry<?, ?> e = (Map.Entry<?, ?>) o;
			final Object k = e.getKey();
			final Object value = e.getValue();
			if (value == null || !(value instanceof Byte))
				return false;
			final byte v = ((Byte) (value)).byteValue();
			return map.remove(k, v);
		}
		@Override
		public int size() {
			return map.size();
		}
	}
	
Returns a type-specific-set view of the keys of this map.
 The view is backed by the set returned by Map.entrySet(). Note that no attempt is made at caching the result of this method, as this
would require adding some attributes that lightweight implementations would
not need. Subclasses may easily override this policy by calling this method
and caching the result, but implementors are encouraged to write more
efficient ad-hoc implementations.
Returns:
a set view of the keys of this map; it may be safely cast to a
        type-specific interface./**
	 * Returns a type-specific-set view of the keys of this map.
	 *
	 * <p>
	 * The view is backed by the set returned by {@link Map#entrySet()}. Note that
	 * <em>no attempt is made at caching the result of this method</em>, as this
	 * would require adding some attributes that lightweight implementations would
	 * not need. Subclasses may easily override this policy by calling this method
	 * and caching the result, but implementors are encouraged to write more
	 * efficient ad-hoc implementations.
	 *
	 * @return a set view of the keys of this map; it may be safely cast to a
	 *         type-specific interface.
	 */
	@Override
	public ReferenceSet<K> keySet() {
		return new AbstractReferenceSet<K>() {
			@Override
			public boolean contains(final Object k) {
				return containsKey(k);
			}
			@Override
			public int size() {
				return AbstractReference2ByteMap.this.size();
			}
			@Override
			public void clear() {
				AbstractReference2ByteMap.this.clear();
			}
			@Override
			public ObjectIterator<K> iterator() {
				return new ObjectIterator<K>() {
					private final ObjectIterator<Reference2ByteMap.Entry<K>> i = Reference2ByteMaps
							.fastIterator(AbstractReference2ByteMap.this);
					@Override
					public K next() {
						return i.next().getKey();
					};
					@Override
					public boolean hasNext() {
						return i.hasNext();
					}
					@Override
					public void remove() {
						i.remove();
					}
				};
			}
		};
	}
	
Returns a type-specific-set view of the values of this map.
 The view is backed by the set returned by Map.entrySet(). Note that no attempt is made at caching the result of this method, as this
would require adding some attributes that lightweight implementations would
not need. Subclasses may easily override this policy by calling this method
and caching the result, but implementors are encouraged to write more
efficient ad-hoc implementations.
Returns:
a set view of the values of this map; it may be safely cast to a
        type-specific interface./**
	 * Returns a type-specific-set view of the values of this map.
	 *
	 * <p>
	 * The view is backed by the set returned by {@link Map#entrySet()}. Note that
	 * <em>no attempt is made at caching the result of this method</em>, as this
	 * would require adding some attributes that lightweight implementations would
	 * not need. Subclasses may easily override this policy by calling this method
	 * and caching the result, but implementors are encouraged to write more
	 * efficient ad-hoc implementations.
	 *
	 * @return a set view of the values of this map; it may be safely cast to a
	 *         type-specific interface.
	 */
	@Override
	public ByteCollection values() {
		return new AbstractByteCollection() {
			@Override
			public boolean contains(final byte k) {
				return containsValue(k);
			}
			@Override
			public int size() {
				return AbstractReference2ByteMap.this.size();
			}
			@Override
			public void clear() {
				AbstractReference2ByteMap.this.clear();
			}
			@Override
			public ByteIterator iterator() {
				return new ByteIterator() {
					private final ObjectIterator<Reference2ByteMap.Entry<K>> i = Reference2ByteMaps
							.fastIterator(AbstractReference2ByteMap.this);
					@Override
					public byte nextByte() {
						return i.next().getByteValue();
					}
					@Override
					public boolean hasNext() {
						return i.hasNext();
					}
				};
			}
		};
	}
	
{@inheritDoc} /** {@inheritDoc} */
	@SuppressWarnings({"unchecked", "deprecation"})
	@Override
	public void putAll(final Map<? extends K, ? extends Byte> m) {
		if (m instanceof Reference2ByteMap) {
			ObjectIterator<Reference2ByteMap.Entry<K>> i = Reference2ByteMaps.fastIterator((Reference2ByteMap<K>) m);
			while (i.hasNext()) {
				final Reference2ByteMap.Entry<? extends K> e = i.next();
				put(e.getKey(), e.getByteValue());
			}
		} else {
			int n = m.size();
			final Iterator<? extends Map.Entry<? extends K, ? extends Byte>> i = m.entrySet().iterator();
			Map.Entry<? extends K, ? extends Byte> e;
			while (n-- != 0) {
				e = i.next();
				put(e.getKey(), e.getValue());
			}
		}
	}
	
Returns a hash code for this map.
The hash code of a map is computed by summing the hash codes of its entries.
Returns:
a hash code for this map./**
	 * Returns a hash code for this map.
	 *
	 * The hash code of a map is computed by summing the hash codes of its entries.
	 *
	 * @return a hash code for this map.
	 */
	@Override
	public int hashCode() {
		int h = 0, n = size();
		final ObjectIterator<Reference2ByteMap.Entry<K>> i = Reference2ByteMaps.fastIterator(this);
		while (n-- != 0)
			h += i.next().hashCode();
		return h;
	}
	@Override
	public boolean equals(Object o) {
		if (o == this)
			return true;
		if (!(o instanceof Map))
			return false;
		final Map<?, ?> m = (Map<?, ?>) o;
		if (m.size() != size())
			return false;
		return reference2ByteEntrySet().containsAll(m.entrySet());
	}
	@Override
	public String toString() {
		final StringBuilder s = new StringBuilder();
		final ObjectIterator<Reference2ByteMap.Entry<K>> i = Reference2ByteMaps.fastIterator(this);
		int n = size();
		Reference2ByteMap.Entry<K> e;
		boolean first = true;
		s.append("{");
		while (n-- != 0) {
			if (first)
				first = false;
			else
				s.append(", ");
			e = i.next();
			if (this == e.getKey())
				s.append("(this map)");
			else
				s.append(String.valueOf(e.getKey()));
			s.append("=>");
			s.append(String.valueOf(e.getByteValue()));
		}
		s.append("}");
		return s.toString();
	}
}