/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.dialect;

import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;

import org.hibernate.MappingException;
import org.hibernate.internal.util.StringHelper;

/**
 * This class maps a type to names.  Associations may be marked with a capacity. Calling the get()
 * method with a type and actual size n will return  the associated name with smallest capacity >= n,
 * if available and an unmarked default type otherwise.
 * Eg, setting
 * <pre>
 *	names.put( type,        "TEXT" );
 *	names.put( type,   255, "VARCHAR($l)" );
 *	names.put( type, 65534, "LONGVARCHAR($l)" );
 * </pre>
 * will give you back the following:
 * <pre>
 *  names.get( type )         // --> "TEXT" (default)
 *  names.get( type,    100 ) // --> "VARCHAR(100)" (100 is in [0:255])
 *  names.get( type,   1000 ) // --> "LONGVARCHAR(1000)" (1000 is in [256:65534])
 *  names.get( type, 100000 ) // --> "TEXT" (default)
 * </pre>
 * On the other hand, simply putting
 * <pre>
 *	names.put( type, "VARCHAR($l)" );
 * </pre>
 * would result in
 * <pre>
 *  names.get( type )        // --> "VARCHAR($l)" (will cause trouble)
 *  names.get( type, 100 )   // --> "VARCHAR(100)"
 *  names.get( type, 10000 ) // --> "VARCHAR(10000)"
 * </pre>
 *
 * @author Christoph Beck
 */
public class TypeNames {
	/**
	 * Holds default type mappings for a typeCode.  This is the non-sized mapping
	 */
	private Map<Integer, String> defaults = new HashMap<Integer, String>();

	/**
	 * Holds the weighted mappings for a typeCode.  The nested map is a TreeMap to sort its contents
	 * based on the key (the weighting) to ensure proper iteration ordering during {@link #get(int, long, int, int)}
	 */
	private Map<Integer, Map<Long, String>> weighted = new HashMap<Integer, Map<Long, String>>();

	/**
	 * get default type name for specified type
	 *
	 * @param typeCode the type key
	 *
	 * @return the default type name associated with specified key
	 *
	 * @throws MappingException Indicates that no registrations were made for that typeCode
	 */
	public String get(int typeCode) throws MappingException {
		final String result = defaults.get( typeCode );
		if ( result == null ) {
			throw new MappingException( "No Dialect mapping for JDBC type: " + typeCode );
		}
		return result;
	}

	/**
	 * get type name for specified type and size
	 *
	 * @param typeCode the type key
	 * @param size the SQL length
	 * @param scale the SQL scale
	 * @param precision the SQL precision
	 *
	 * @return the associated name with smallest capacity >= size, if available and the default type name otherwise
	 *
	 * @throws MappingException Indicates that no registrations were made for that typeCode
	 */
	public String get(int typeCode, long size, int precision, int scale) throws MappingException {
		final Map<Long, String> map = weighted.get( typeCode );
		if ( map != null && map.size() > 0 ) {
			// iterate entries ordered by capacity to find first fit
			for ( Map.Entry<Long, String> entry: map.entrySet() ) {
				if ( size <= entry.getKey() ) {
					return replace( entry.getValue(), size, precision, scale );
				}
			}
		}

		// if we get here one of 2 things happened:
		//		1) There was no weighted registration for that typeCode
		//		2) There was no weighting whose max capacity was big enough to contain size
		return replace( get( typeCode ), size, precision, scale );
	}

	private static String replace(String type, long size, int precision, int scale) {
		type = StringHelper.replaceOnce( type, "$s", Integer.toString( scale ) );
		type = StringHelper.replaceOnce( type, "$l", Long.toString( size ) );
		return StringHelper.replaceOnce( type, "$p", Integer.toString( precision ) );
	}

	/**
	 * Register a weighted typeCode mapping
	 *
	 * @param typeCode the JDBC type code
	 * @param capacity The capacity for this weighting
	 * @param value The mapping (type name)
	 */
	public void put(int typeCode, long capacity, String value) {
		Map<Long, String> map = weighted.get( typeCode );
		if ( map == null ) {
			// add new ordered map
			map = new TreeMap<Long, String>();
			weighted.put( typeCode, map );
		}
		map.put( capacity, value );
	}

	/**
	 * Register a default (non-weighted) typeCode mapping
	 *
	 * @param typeCode the type key
	 * @param value The mapping (type name)
	 */
	public void put(int typeCode, String value) {
		defaults.put( typeCode, value );
	}

	/**
	 * Check whether or not the provided typeName exists.
	 *
	 * @param typeName the type name.
	 *
	 * @return true if the given string has been registered as a type.
	 */
	public boolean containsTypeName(final String typeName) {
		return this.defaults.containsValue( typeName );
	}
}