/*******************************************************************************
 * Copyright (c) 2006, 2008 Oracle. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0, which accompanies this distribution
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 * 
 * Contributors:
 *     Oracle - initial API and implementation
 ******************************************************************************/
package org.eclipse.jpt.db.internal;

import java.text.Collator;

import org.eclipse.datatools.connectivity.sqm.core.rte.ICatalogObject;
import org.eclipse.datatools.connectivity.sqm.core.rte.ICatalogObjectListener;
import org.eclipse.datatools.modelbase.dbdefinition.PredefinedDataTypeDefinition;
import org.eclipse.datatools.modelbase.sql.datatypes.DataType;
import org.eclipse.datatools.modelbase.sql.datatypes.PredefinedDataType;
import org.eclipse.jpt.utility.internal.ClassTools;
import org.eclipse.jpt.utility.internal.JavaType;
import org.eclipse.jpt.utility.internal.NameTools;

/**
 *  Wrap a DTP Column
 */
public final class Column extends DTPWrapper implements Comparable<Column> {
	private final Table table;
	private final org.eclipse.datatools.modelbase.sql.tables.Column dtpColumn;
	private ICatalogObjectListener columnListener;

	// TODO Object is the default?
	private static final JavaType DEFAULT_JAVA_TYPE = new JavaType(java.lang.Object.class);

	private static final JavaType BLOB_JAVA_TYPE = new JavaType(java.sql.Blob.class);
	private static final JavaType BYTE_ARRAY_JAVA_TYPE = new JavaType(byte[].class);

	private static final JavaType CLOB_JAVA_TYPE = new JavaType(java.sql.Clob.class);
	private static final JavaType STRING_JAVA_TYPE = new JavaType(java.lang.String.class);

	private static final JavaType UTIL_DATE_JAVA_TYPE = new JavaType(java.util.Date.class);
	private static final JavaType SQL_DATE_JAVA_TYPE = new JavaType(java.sql.Date.class);
	private static final JavaType SQL_TIME_JAVA_TYPE = new JavaType(java.sql.Time.class);
	private static final JavaType SQL_TIMESTAMP_JAVA_TYPE = new JavaType(java.sql.Timestamp.class);

	private static final JavaType BIG_DECIMAL_JAVA_TYPE = new JavaType(java.math.BigDecimal.class);
	private static final JavaType LONG_JAVA_TYPE = new JavaType(long.class);


	// ********** constructors **********

	Column( Table table, org.eclipse.datatools.modelbase.sql.tables.Column dtpColumn) {
		super();
		this.table = table;
		this.dtpColumn = dtpColumn;
		this.initialize();
	}

	// ********** behavior **********

	private void initialize() {
		if( this.connectionIsOnline()) {
			this.columnListener = this.buildColumnListener();
			this.addCatalogObjectListener(( ICatalogObject) this.dtpColumn, this.columnListener);
		}
	}
	
	@Override
	protected boolean connectionIsOnline() {
		return this.table.connectionIsOnline();
	}
	
	private ICatalogObjectListener buildColumnListener() {
       return new ICatalogObjectListener() {
    	    public void notifyChanged( final ICatalogObject column, final int eventType) { 
//				TODO
//    			if( column == Column.this.dtpColumn) {	    	    	
//    				Column.this.table.columnChanged( Column.this, eventType);
//    			}
    	    }
        };
    }
	
	@Override
	protected void dispose() {
		
		this.removeCatalogObjectListener(( ICatalogObject) this.dtpColumn, this.columnListener);
	}
	
	// ********** queries **********

	@Override
	public String getName() {
		return this.dtpColumn.getName();
	}

	boolean isCaseSensitive() {
		return this.table.isCaseSensitive();
	}

	public String dataTypeName() {
		DataType dataType = this.dtpColumn.getDataType();
		return (dataType == null) ? null : dataType.getName();
	}

	public String javaFieldName() {
		String jName = this.getName();
		if ( ! this.isCaseSensitive()) {
			jName = jName.toLowerCase();
		}
		return NameTools.convertToJavaIdentifier(jName);
	}

	public boolean matchesJavaFieldName(String javaFieldName) {
		return this.isCaseSensitive() ?
			this.getName().equals(javaFieldName)
		:
			this.getName().equalsIgnoreCase(javaFieldName);
	}

	/**
	 * Return a Java type declaration that is reasonably
	 * similar to the column's data type and suitable for use as a
	 * primary key field.
	 */
	public String primaryKeyJavaTypeDeclaration() {
		return this.primaryKeyJavaType().declaration();
	}

	/**
	 * Return a Java type that is reasonably
	 * similar to the column's data type and suitable for use as a
	 * primary key field.
	 */
	public JavaType primaryKeyJavaType() {
		return this.jpaSpecCompliantPrimaryKeyJavaType(this.javaType());
	}

	/**
	 * The JPA spec [2.1.4] says only the following types are allowed in
	 * primary key fields:
	 *     [variable] primitives
	 *     [variable] primitive wrappers
	 *     java.lang.String
	 *     java.util.Date
	 *     java.sql.Date
	 */
	private JavaType jpaSpecCompliantPrimaryKeyJavaType(JavaType javaType) {
		if (javaType.isVariablePrimitive()
				|| javaType.isVariablePrimitiveWrapper()
				|| javaType.equals(STRING_JAVA_TYPE)
				|| javaType.equals(UTIL_DATE_JAVA_TYPE)
				|| javaType.equals(SQL_DATE_JAVA_TYPE)) {
			return javaType;
		}
		if (javaType.equals(BIG_DECIMAL_JAVA_TYPE)) {
			return LONG_JAVA_TYPE;  // ??
		}
		if (javaType.equals(SQL_TIME_JAVA_TYPE)) {
			return UTIL_DATE_JAVA_TYPE;  // ???
		}
		if (javaType.equals(SQL_TIMESTAMP_JAVA_TYPE)) {
			return UTIL_DATE_JAVA_TYPE;  // ???
		}
		// all the other typical types are pretty much un-mappable - return String(?)
		return STRING_JAVA_TYPE;
	}

	/**
	 * Return a Java type declaration that is reasonably
	 * similar to the column's data type.
	 */
	public String javaTypeDeclaration() {
		return this.javaType().declaration();
	}

	/**
	 * Return a Java type that is reasonably
	 * similar to the column's data type.
	 */
	public JavaType javaType() {
		DataType dataType = this.dtpColumn.getDataType();
		return (dataType instanceof PredefinedDataType) ?
			this.jpaSpecCompliantJavaType(this.javaType((PredefinedDataType) dataType))
		:
			DEFAULT_JAVA_TYPE;
	}

	private JavaType javaType(PredefinedDataType dataType) {
		// this is just a bit hacky: moving from a type declaration to a class name to a type declaration...
		String dtpJavaClassName = this.predefinedDataTypeDefinition(dataType).getJavaClassName();
		return new JavaType(ClassTools.classNameForTypeDeclaration(dtpJavaClassName));
	}

	private PredefinedDataTypeDefinition predefinedDataTypeDefinition(PredefinedDataType dataType) {
		return this.database().dtpDefinition().getPredefinedDataTypeDefinition(dataType.getName());
	}

	/**
	 * The JDBC spec says JDBC drivers should be able to map BLOBs and CLOBs
	 * directly, but the JPA spec does not allow them.
	 */
	private JavaType jpaSpecCompliantJavaType(JavaType javaType) {
		if (javaType.equals(BLOB_JAVA_TYPE)) {
			return BYTE_ARRAY_JAVA_TYPE;
		}
		if (javaType.equals(CLOB_JAVA_TYPE)) {
			return STRING_JAVA_TYPE;
		}
		return javaType;
	}

	public boolean isLob() {
		DataType dataType = this.dtpColumn.getDataType();
		return (dataType instanceof PredefinedDataType) ?
			DTPTools.dataTypeIsLob(((PredefinedDataType) dataType).getPrimitiveType())
		:
			false;
	}

	boolean wraps( org.eclipse.datatools.modelbase.sql.tables.Column column) {
		return this.dtpColumn == column;
	}

	public Database database() {
		return this.table.database();
	}

	// ********** Comparable implementation **********
	
	public int compareTo( Column column) {
		return Collator.getInstance().compare( this.getName(), column.getName());
	}
}