/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
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 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.tools.ant.taskdefs.condition;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.ProjectComponent;
import org.apache.tools.ant.types.Reference;
import org.apache.tools.ant.types.EnumeratedAttribute;
import org.apache.tools.ant.types.JDBCConnection;

/**
 * Condition to check database metadata for objects. Its attribute(s) are:
 *   schema - 
 *   connectionRef - 
 *
 * @author <a href="mailto:thierry.lach@bbdodetroit.com">Thierry Lach</a>
 * @since Ant 1.6
 */
public class JDBCCondition extends ProjectComponent implements Condition {

    private Connection connection = null;
    private JDBCConnection jdbc = null;
    private String catalog = null;
    private String schema = null;
    private String table = null;
    private String name = null;
    private String type = null;
    // private boolean unique = false;

    public static String SCHEMA = "schema";
    public static String CATALOG = "catalog";
    public static String TABLE = "table";
    public static String VIEW = "view";
    public static String COLUMN = "column";
    public static String INDEX = "index";

    public boolean eval() throws BuildException {
        boolean result = false;
	validateArguments();
	this.connection = this.jdbc.getConnectionInstance();
        if (this.connection == null) {
            throw new BuildException("Unable to connect to database");
        }
	try {
	    result = checkMetaData();
	}
	catch (SQLException e) {
	    result = false;
	}
	return result;
    }

    // public void setUnique(boolean unique) {
        // this.unique = unique;
    // }

    // public boolean getUnique() {
        // return this.unique;
    // }

    public void setTable(String table) {
        this.table = table;
    }

    public String getTable() {
        return this.table;
    }

    public void setCatalog(String catalog) {
        this.catalog = catalog;
    }

    public String getCatalog() {
        return this.catalog;
    }

    public void setSchema(String schema) {
        this.schema = schema;
    }

    public String getSchema() {
        return this.schema;
    }

    public void setType(ObjectType type) {
        this.type = type.getValue();
    }

    public String getType() {
        return this.type;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return this.name;
    }

    public void setConnectionRef(Reference r) {
        // this.connectionRef = r;
	this.jdbc = new JDBCConnection(getProject());
	this.jdbc.setConnectionRef(r);
    }

    // public Reference getConnectionRef() {
        // return this.connection.getConnectionRef();
    // }

    private boolean checkResultSet(ResultSet rs, int col) throws BuildException {
        boolean result = false;

	try {
	    String val;
	    while( (!result) && rs.next()) {
                val = rs.getString(col);
	        if (val.equalsIgnoreCase(name)) {
		    result = true;
		}
	    }
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to fetch metadata resultset", e);
	}

	try {
	    rs.close();
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to close metadata resultset", e);
	}

	return result;
    }

    private boolean checkCatalog(DatabaseMetaData dbmd) throws BuildException {
        ResultSet rs = null;

	try {
            rs = dbmd.getCatalogs();
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to get metadata resultset", e);
	}
	return checkResultSet(rs, 1);

    }

    private boolean checkSchema(DatabaseMetaData dbmd) throws BuildException {
        ResultSet rs = null;

	try {
            rs = dbmd.getSchemas();
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to get metadata resultset", e);
	}
	return checkResultSet(rs, 1);
    }

    private boolean checkColumn(DatabaseMetaData dbmd) throws BuildException {
        ResultSet rs = null;
	boolean result = false;

	try {
            rs = dbmd.getColumns(this.catalog,
	                         this.schema,
				 this.table,
				 this.name);
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to get metadata resultset", e);
	}

	return checkResultSet(rs, 4);
    }

    private boolean checkIndex(DatabaseMetaData dbmd) throws BuildException {
        ResultSet rs = null;

	try {
            rs = dbmd.getIndexInfo(this.catalog,
	                           this.schema,
				   this.table,
				   false,
				   false);
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to get metadata resultset", e);
	}

	return checkResultSet(rs, 6);
    }

    private boolean checkTableOrView(DatabaseMetaData dbmd, String passedType)
    throws BuildException {
        ResultSet rs = null;
	boolean result = false;
        String[] typelist = new String[] { passedType };

	try {
            rs = dbmd.getTables(this.catalog,
	                        this.schema,
				this.name,
				typelist);
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to get metadata resultset", e);
	}

	return checkResultSet(rs, 3);
    }

    private boolean checkMetaData() throws SQLException {
        boolean result = false;
        DatabaseMetaData dbmd = null;

        try {
	   dbmd = connection.getMetaData();
	}
	catch (SQLException e) {
	    throw new BuildException("Unable to get database metadata", e);
	}

	log("  Looking for " + type + " '" + this.name + "'", Project.MSG_DEBUG);
	if (SCHEMA.equals(type)) {
	    result = checkSchema(dbmd);
	}
	if (TABLE.equals(type)) {
	    result = checkTableOrView(dbmd, TABLE.toUpperCase());
	}
	if (VIEW.equals(type)) {
	    result = checkTableOrView(dbmd, VIEW.toUpperCase());
	}
	if (INDEX.equals(type)) {
	    result = checkIndex(dbmd);
	}
	if (COLUMN.equals(type)) {
	    result = checkColumn(dbmd);
	}
	if (result) {
	    log("  Found " + type + " '" + this.name + "'", Project.MSG_DEBUG);
	}
	else {
	    log("  Did not find " + type + " '" + this.name + "'", Project.MSG_DEBUG);
	}

	return result;
    }

    private void requireType() throws BuildException {
        if (this.type == null) {
            throw new BuildException("Type not supplied");
        }
    }

    private void requireConnection() throws BuildException {
        if (this.jdbc == null) {
            throw new BuildException("Connection not supplied");
        }
    }

    private void requireName() throws BuildException {
        if (this.name == null) {
            throw new BuildException("Name not supplied");
        }
    }

    private void requireTable() throws BuildException {
        if (this.table == null) {
            throw new BuildException("Table not supplied");
        }
    }

    private void validateArguments() throws BuildException {

        requireType();
	requireConnection();
	requireName();

	if (SCHEMA.equals(type)) { }

	else if (TABLE.equals(type)) { }

	else if (VIEW.equals(type)) { }

	else if (INDEX.equals(type)) {
	    requireTable();
	}
	else if (COLUMN.equals(type)) {
	    requireTable();
	}

    }

    /**
     * The type of object to check for, one of the list
     * "schema", "catalog", "table", "view", "column", "index".
     */
    public static class ObjectType extends EnumeratedAttribute {
        public String[] getValues() {
            return new String[] {SCHEMA, CATALOG, TABLE, VIEW, COLUMN, INDEX};
        }
    }

}