SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.runtime.cldc.util;

import cc.squirreljme.runtime.cldc.debug.Debugging;
import java.util.AbstractMap;
import java.util.Set;

/**
 * An enumeration based map.
 *
 * @since 2021/03/13
 */
public final class EnumTypeMap<E extends Enum<E>, V>
    extends AbstractMap<E, V>
{
    /** The type of value to store. */
    protected final Class<E> type;
    
    /** The stored keys. */
    private final E[] _keys;
    
    /** Stored values. */
    private final Object[] _values;
    
    /**
     * Initializes the enum type map.
     * 
     * @param __type The type used.
     * @param __keys Enumeration keys.
     * @throws NullPointerException On null arguments.
     * @since 2021/03/13
     */
    public EnumTypeMap(Class<E> __type, E... __keys)
        throws NullPointerException
    {
        if (__type == null)
            throw new NullPointerException("NARG");
        
        this.type = __type;
        this._keys = __keys.clone();
        this._values = new Object[__keys.length];
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/03/13
     */
    @Override
    public boolean containsKey(Object __key)
    {
        // Not this type, so it will never exist
        if (__key == null || !this.type.isInstance(__key))
            return false;
        
        // Has the key been set?
        for (E key : this._keys)
            if (key == __key)
                return true;
        
        // Does not exist otherwise
        return false;
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/03/13
     */
    @Override
    public Set<Entry<E, V>> entrySet()
    {
        return new __ArrayEntrySet__<E, V>(this._keys, this._values);
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/03/13
     * @param __key
     */
    @SuppressWarnings("unchecked")
    @Override
    public V get(Object __key)
    {
        if (!this.type.isInstance(__key))
            return null;
        
        Enum<?> key = (Enum<?>)__key;
        
        return (V)this._values[key.ordinal()];
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/03/13
     */
    @SuppressWarnings("unchecked")
    @Override
    public V put(E __key, V __value)
    {
        /* {@squirreljme.error ZZ1i Cannot store key into map.} */ 
        if (!this.type.isInstance(__key))
            throw new IllegalArgumentException("ZZ1i");
        
        Object[] values = this._values;
        Object old = values[__key.ordinal()];
        values[__key.ordinal()] = __value;
        return (V)old;
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/03/13
     */
    @SuppressWarnings("unchecked")
    @Override
    public V remove(Object __key)
    {
        if (!this.type.isInstance(__key))
            return null;
        
        Enum<?> key = (Enum<?>)__key;
        
        Object[] values = this._values;
        Object old = values[key.ordinal()];
        values[key.ordinal()] = null;
        return (V)old;
    }
    
    /**
     * {@inheritDoc}
     * @since 2021/03/13
     */
    @Override
    public int size()
    {
        return this._values.length;
    }
}