/*
 * Copyright 2014 Goldman Sachs.
 *
 * 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 com.gs.collections.impl;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

/**
 * An unmodifiable view of a Map.
 */
public class UnmodifiableMap<K, V> implements Map<K, V>, Serializable
{
    private static final long serialVersionUID = 1L;

    protected final Map<K, V> delegate;

    public UnmodifiableMap(Map<K, V> delegate)
    {
        if (delegate == null)
        {
            throw new NullPointerException();
        }
        this.delegate = delegate;
    }

    public int size()
    {
        return this.delegate.size();
    }

    public boolean isEmpty()
    {
        return this.delegate.isEmpty();
    }

    public boolean containsKey(Object key)
    {
        return this.delegate.containsKey(key);
    }

    public boolean containsValue(Object value)
    {
        return this.delegate.containsValue(value);
    }

    public V get(Object key)
    {
        return this.delegate.get(key);
    }

    public V put(K key, V value)
    {
        throw new UnsupportedOperationException("Cannot call put() on " + this.getClass().getSimpleName());
    }

    public V remove(Object key)
    {
        throw new UnsupportedOperationException("Cannot call remove() on " + this.getClass().getSimpleName());
    }

    public void putAll(Map<? extends K, ? extends V> t)
    {
        throw new UnsupportedOperationException("Cannot call putAll() on " + this.getClass().getSimpleName());
    }

    public void clear()
    {
        throw new UnsupportedOperationException("Cannot call clear() on " + this.getClass().getSimpleName());
    }

    public Set<K> keySet()
    {
        return Collections.unmodifiableSet(this.delegate.keySet());
    }

    public Set<Map.Entry<K, V>> entrySet()
    {
        return Collections.unmodifiableMap(this.delegate).entrySet();
    }

    public Collection<V> values()
    {
        return Collections.unmodifiableCollection(this.delegate.values());
    }

    @Override
    public boolean equals(Object o)
    {
        return o == this || this.delegate.equals(o);
    }

    @Override
    public int hashCode()
    {
        return this.delegate.hashCode();
    }

    @Override
    public String toString()
    {
        return this.delegate.toString();
    }
}