/*
 * The contents of this file are subject to the terms 
 * of the Common Development and Distribution License 
 * (the "License").  You may not use this file except 
 * in compliance with the License.
 * 
 * You can obtain a copy of the license at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt or 
 * https://glassfish.dev.java.net/public/CDDLv1.0.html. 
 * See the License for the specific language governing 
 * permissions and limitations under the License.
 * 
 * When distributing Covered Code, include this CDDL 
 * HEADER in each file and include the License file at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable, 
 * add the following below this CDDL HEADER, with the 
 * fields enclosed by brackets "[]" replaced with your 
 * own identifying information: Portions Copyright [yyyy] 
 * [name of copyright owner]
 */
// Copyright (c) 1998, 2006, Oracle. All rights reserved.  
package oracle.toplink.essentials.platform.database;

import java.io.*;
import java.util.*;
import oracle.toplink.essentials.exceptions.*;
import oracle.toplink.essentials.expressions.*;
import oracle.toplink.essentials.internal.expressions.*;
import oracle.toplink.essentials.internal.helper.*;
import oracle.toplink.essentials.internal.databaseaccess.*;
import oracle.toplink.essentials.queryframework.*;
import oracle.toplink.essentials.internal.sessions.AbstractSession;

/**
 * <p><b>Purpose</b>: Provides SQL Server specific behaviour.
 * <p><b>Responsibilities</b>:<ul>
 * <li> Native SQL for byte[], Date, Time, & Timestamp.
 * </ul>
 *
 * @since TOPLink/Java 1.0
 */
public class SQLServerPlatform extends oracle.toplink.essentials.platform.database.DatabasePlatform {

    /**
     * INTERNAL:
     * If using native SQL then print a byte[] as '0xFF...'
     */
    protected void appendByteArray(byte[] bytes, Writer writer) throws IOException {
        if (usesNativeSQL() && (!usesByteArrayBinding())) {
            writer.write("0x");
            Helper.writeHexString(bytes, writer);
        } else {
            super.appendByteArray(bytes, writer);
        }
    }

    /**
     * INTERNAL:
     * Answer a platform correct string representation of a Date, suitable for SQL generation.
     * Native format: 'yyyy-mm-dd
     */
    protected void appendDate(java.sql.Date date, Writer writer) throws IOException {
        if (usesNativeSQL()) {
            writer.write("'");
            writer.write(Helper.printDate(date));
            writer.write("'");
        } else {
            super.appendDate(date, writer);
        }
    }

    /**
     * INTERNAL:
     * Write a timestamp in Sybase specific format ( yyyy-mm-dd-hh.mm.ss.fff)
     */
    protected void appendSybaseTimestamp(java.sql.Timestamp timestamp, Writer writer) throws IOException {
        writer.write("'");
        writer.write(Helper.printTimestampWithoutNanos(timestamp));
        writer.write(':');

        // Must truncate the nanos to three decimal places,
        // it is actually a complex algorithm...
        String nanoString = Integer.toString(timestamp.getNanos());
        int numberOfZeros = 0;
        for (int num = Math.min(9 - nanoString.length(), 3); num > 0; num--) {
            writer.write('0');
            numberOfZeros++;
        }
        if ((nanoString.length() + numberOfZeros) > 3) {
            nanoString = nanoString.substring(0, (3 - numberOfZeros));
        }
        writer.write(nanoString);
        writer.write("'");
    }

    /**
     * INTERNAL:
     * Write a timestamp in Sybase specific format ( yyyy-mm-dd-hh.mm.ss.fff)
     */
    protected void appendSybaseCalendar(Calendar calendar, Writer writer) throws IOException {
        writer.write("'");
        writer.write(Helper.printCalendar(calendar));
        writer.write("'");
    }

    /**
     * INTERNAL:
     * Answer a platform correct string representation of a Time, suitable for SQL generation.
     * The time is printed in the ODBC platform independent format {t'hh:mm:ss'}.
     */
    protected void appendTime(java.sql.Time time, Writer writer) throws IOException {
        if (usesNativeSQL()) {
            writer.write("'");
            writer.write(Helper.printTime(time));
            writer.write("'");
        } else {
            super.appendTime(time, writer);
        }
    }

    /**
     * INTERNAL:
     * Answer a platform correct string representation of a Timestamp, suitable for SQL generation.
     * The date is printed in the ODBC platform independent format {d'YYYY-MM-DD'}.
     */
    protected void appendTimestamp(java.sql.Timestamp timestamp, Writer writer) throws IOException {
        if (usesNativeSQL()) {
            appendSybaseTimestamp(timestamp, writer);
        } else {
            super.appendTimestamp(timestamp, writer);
        }
    }

    /**
     * INTERNAL:
     * Answer a platform correct string representation of a Calendar, suitable for SQL generation.
     * The date is printed in the ODBC platform independent format {d'YYYY-MM-DD'}.
     */
    protected void appendCalendar(Calendar calendar, Writer writer) throws IOException {
        if (usesNativeSQL()) {
            appendSybaseCalendar(calendar, writer);
        } else {
            super.appendCalendar(calendar, writer);
        }
    }

    protected Hashtable buildFieldTypes() {
        Hashtable fieldTypeMapping;

        fieldTypeMapping = new Hashtable();
        fieldTypeMapping.put(Boolean.class, new FieldTypeDefinition("BIT default 0", false));

        fieldTypeMapping.put(Integer.class, new FieldTypeDefinition("INTEGER", false));
        fieldTypeMapping.put(Long.class, new FieldTypeDefinition("NUMERIC", 19));
        fieldTypeMapping.put(Float.class, new FieldTypeDefinition("FLOAT(16)", false));
        fieldTypeMapping.put(Double.class, new FieldTypeDefinition("FLOAT(32)", false));
        fieldTypeMapping.put(Short.class, new FieldTypeDefinition("SMALLINT", false));
        fieldTypeMapping.put(Byte.class, new FieldTypeDefinition("SMALLINT", false));
        fieldTypeMapping.put(java.math.BigInteger.class, new FieldTypeDefinition("NUMERIC", 28));
        fieldTypeMapping.put(java.math.BigDecimal.class, new FieldTypeDefinition("NUMERIC", 28).setLimits(28, -19, 19));
        fieldTypeMapping.put(Number.class, new FieldTypeDefinition("NUMERIC", 28).setLimits(28, -19, 19));

        fieldTypeMapping.put(String.class, new FieldTypeDefinition("VARCHAR", 255));
        fieldTypeMapping.put(Character.class, new FieldTypeDefinition("CHAR", 1));
        
        fieldTypeMapping.put(Byte[].class, new FieldTypeDefinition("IMAGE", false));
        fieldTypeMapping.put(Character[].class, new FieldTypeDefinition("TEXT", false));
        fieldTypeMapping.put(byte[].class, new FieldTypeDefinition("IMAGE", false));
        fieldTypeMapping.put(char[].class, new FieldTypeDefinition("TEXT", false));
        fieldTypeMapping.put(java.sql.Blob.class, new FieldTypeDefinition("IMAGE", false));
        fieldTypeMapping.put(java.sql.Clob.class, new FieldTypeDefinition("TEXT", false));
        
        fieldTypeMapping.put(java.sql.Date.class, new FieldTypeDefinition("DATETIME", false));
        fieldTypeMapping.put(java.sql.Time.class, new FieldTypeDefinition("DATETIME", false));
        fieldTypeMapping.put(java.sql.Timestamp.class, new FieldTypeDefinition("DATETIME", false));

        return fieldTypeMapping;
    }

    /**
     * INTERNAL:
     * Build the identity query for native sequencing.
     */
    public ValueReadQuery buildSelectQueryForNativeSequence() {
        ValueReadQuery selectQuery = new ValueReadQuery();
        StringWriter writer = new StringWriter();
        writer.write("SELECT @@IDENTITY");
        selectQuery.setSQLString(writer.toString());
        return selectQuery;
    }

    /**
     * INTERNAL:
     * Used for batch writing and sp defs.
     */
    public String getBatchDelimiterString() {
        return "";
    }

    /**
     * INTERNAL:
     * This method is used to print the required output parameter token for the
     * specific platform.  Used when stored procedures are created.
     */
    public String getCreationInOutputProcedureToken() {
        return getInOutputProcedureToken();
    }

    /**
     * INTERNAL:
     * This method is used to print the required output parameter token for the
     * specific platform.  Used when stored procedures are created.
     */
    public String getCreationOutputProcedureToken() {
        return "OUTPUT";
    }

    /**
     * INTERNAL:
     * This method is used to print the output parameter token when stored
     * procedures are called
     */
    public String getInOutputProcedureToken() {
        return "OUT";
    }

    /**
     * INTERNAL:
     * returns the maximum number of characters that can be used in a field
     * name on this platform.
     */
    public int getMaxFieldNameSize() {
        return 22;
    }

    /**
     * INTERNAL:
     * Return the catalog information through using the native SQL catalog selects.
     * This is required because many JDBC driver do not support meta-data.
     * Willcards can be passed as arguments.
     */
    public Vector getNativeTableInfo(String table, String creator, AbstractSession session) {
        // need to filter only tables / views
        String query = "SELECT * FROM sysobjects WHERE table_type <> 'SYSTEM_TABLE'";
        if (table != null) {
            if (table.indexOf('%') != -1) {
                query = query + " AND table_name LIKE " + table;
            } else {
                query = query + " AND table_name = " + table;
            }
        }
        if (creator != null) {
            if (creator.indexOf('%') != -1) {
                query = query + " AND table_owner LIKE " + creator;
            } else {
                query = query + " AND table_owner = " + creator;
            }
        }
        return session.executeSelectingCall(new SQLCall(query));
    }

    /**
     * INTERNAL:
     * This method is used to print the output parameter token when stored
     * procedures are called
     */
    public String getOutputProcedureToken() {
        return "";
    }

    /**
     * INTERNAL:
     * Used for sp defs.
     */
    public String getProcedureArgumentString() {
        return "@";
    }
    
    /**
     * INTERNAL:
     */
    public String getSelectForUpdateString() {
        return " FOR UPDATE";
    }

    /**
     * INTERNAL:
     * Used for sp calls.
     */
    public String getProcedureCallHeader() {
        return "EXECUTE ";
    }
    
    /**
     * INTERNAL:
     */
    public String getStoredProcedureParameterPrefix() {
        return "@";
    }

    /**
     * INTERNAL:
     * This method returns the delimiter between stored procedures in multiple stored procedure calls.
     */
    public String getStoredProcedureTerminationToken() {
        return " go";
    }

    /**
     * INTERNAL:
     * This method returns the query to select the timestamp
     * from the server for SQLServer.
     */
    public ValueReadQuery getTimestampQuery() {
        if (timestampQuery == null) {
            timestampQuery = new ValueReadQuery();
            timestampQuery.setSQLString("SELECT GETDATE()");
        }
        return timestampQuery;
    }

    /**
     * INTERNAL:
     * Initialize any platform-specific operators
     */
    protected void initializePlatformOperators() {
        super.initializePlatformOperators();
        addOperator(operatorOuterJoin());
        addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.Today, "GETDATE"));
        // GETDATE retuens both date and time. It is not the perfect match for ExpressionOperator.currentDate
        // However, there is no known function on sql server that returns just the date
        addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.currentDate, "GETDATE"));
        addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.Length, "CHAR_LENGTH"));
        addOperator(ExpressionOperator.simpleThreeArgumentFunction(ExpressionOperator.Substring, "SUBSTRING"));
        addOperator(ExpressionOperator.addDate());
        addOperator(ExpressionOperator.dateName());
        addOperator(ExpressionOperator.datePart());
        addOperator(ExpressionOperator.dateDifference());
        addOperator(ExpressionOperator.difference());
        addOperator(ExpressionOperator.charIndex());
        addOperator(ExpressionOperator.charLength());
        addOperator(ExpressionOperator.reverse());
        addOperator(ExpressionOperator.replicate());
        addOperator(ExpressionOperator.right());
        addOperator(ExpressionOperator.cot());
        addOperator(ExpressionOperator.sybaseAtan2Operator());
        addOperator(ExpressionOperator.sybaseAddMonthsOperator());
        addOperator(ExpressionOperator.sybaseInStringOperator());
        // bug 3061144
        addOperator(ExpressionOperator.simpleTwoArgumentFunction(ExpressionOperator.Nvl, "ISNULL"));
        // CR### TO_NUMBER, TO_CHAR, TO_DATE is CONVERT(type, ?)
        addOperator(ExpressionOperator.sybaseToNumberOperator());
        addOperator(ExpressionOperator.sybaseToDateToStringOperator());
        addOperator(ExpressionOperator.sybaseToDateOperator());
        addOperator(ExpressionOperator.sybaseToCharOperator());
        addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.Ceil, "CEILING"));
        addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.Length, "LEN"));
        addOperator(modOperator());
    }

    public boolean isSQLServer() {
        return true;
    }

    /**
     * INTERNAL:
     * Builds a table of maximum numeric values keyed on java class. This is used for type testing but
     * might also be useful to end users attempting to sanitize values.
     * <p><b>NOTE</b>: BigInteger & BigDecimal maximums are dependent upon their precision & Scale
     */
    public Hashtable maximumNumericValues() {
        Hashtable values = new Hashtable();

        values.put(Integer.class, new Integer(Integer.MAX_VALUE));
        values.put(Long.class, new Long(Long.MAX_VALUE));
        values.put(Double.class, new Double(0));
        values.put(Short.class, new Short(Short.MAX_VALUE));
        values.put(Byte.class, new Byte(Byte.MAX_VALUE));
        values.put(Float.class, new Float(0));
        values.put(java.math.BigInteger.class, new java.math.BigInteger("9999999999999999999999999999"));
        values.put(java.math.BigDecimal.class, new java.math.BigDecimal("999999999.9999999999999999999"));
        return values;
    }

    /**
     * INTERNAL:
     * Builds a table of minimum numeric values keyed on java class. This is used for type testing but
     * might also be useful to end users attempting to sanitize values.
     * <p><b>NOTE</b>: BigInteger & BigDecimal minimums are dependent upon their precision & Scale
     */
    public Hashtable minimumNumericValues() {
        Hashtable values = new Hashtable();

        values.put(Integer.class, new Integer(Integer.MIN_VALUE));
        values.put(Long.class, new Long(Long.MIN_VALUE));
        values.put(Double.class, new Double((double)-9));
        values.put(Short.class, new Short(Short.MIN_VALUE));
        values.put(Byte.class, new Byte(Byte.MIN_VALUE));
        values.put(Float.class, new Float((float)-9));
        values.put(java.math.BigInteger.class, new java.math.BigInteger("-9999999999999999999999999999"));
        values.put(java.math.BigDecimal.class, new java.math.BigDecimal("-999999999.9999999999999999999"));
        return values;
    }

    /**
     * INTERNAL:
     * Override the default MOD operator.
     */
    public ExpressionOperator modOperator() {
        ExpressionOperator result = new ExpressionOperator();
        result.setSelector(ExpressionOperator.Mod);
        Vector v = new Vector();
        v.addElement(" % ");
        result.printsAs(v);
        result.bePostfix();
        result.setNodeClass(oracle.toplink.essentials.internal.expressions.FunctionExpression.class);
        return result;
    }

    /**
     * INTERNAL:
     * Create the outer join operator for this platform.
     */
    protected ExpressionOperator operatorOuterJoin() {
        ExpressionOperator result = new ExpressionOperator();
        result.setSelector(ExpressionOperator.EqualOuterJoin);
        Vector v = new Vector();
        v.addElement(" =* ");
        result.printsAs(v);
        result.bePostfix();
        result.setNodeClass(RelationExpression.class);
        return result;
    }

    /**
     * INTERNAL:
     * Append the receiver's field 'identity' constraint clause to a writer.
     */
    public void printFieldIdentityClause(Writer writer) throws ValidationException {
        try {
            writer.write(" IDENTITY");
        } catch (IOException ioException) {
            throw ValidationException.fileError(ioException);
        }
    }

    /**
     * INTERNAL:
     * Append the receiver's field 'NULL' constraint clause to a writer.
     */
    public void printFieldNullClause(Writer writer) throws ValidationException {
        try {
            writer.write(" NULL");
        } catch (IOException ioException) {
            throw ValidationException.fileError(ioException);
        }
    }

    /**
     * INTERNAL:
     * Used for sp calls.
     */
    public boolean requiresProcedureCallBrackets() {
        return false;
    }

    /**
     * INTERNAL:
     * Used for sp calls.  Sybase must print output after output params.
     */
    public boolean requiresProcedureCallOuputToken() {
        return true;
    }

    /**
     * INTERNAL:
     * This is required in the construction of the stored procedures with
     * output parameters
     */
    public boolean shouldPrintInOutputTokenBeforeType() {
        return false;
    }

    /**
     * INTERNAL:
     * Some database require outer joins to be given in the where clause, others require it in the from clause.
     */
    public boolean shouldPrintOuterJoinInWhereClause() {
        return false;
    }

    /**
     * INTERNAL:
     * This is required in the construction of the stored procedures with
     * output parameters
     */
    public boolean shouldPrintOutputTokenBeforeType() {
        return false;
    }

    /**
     * INTERNAL:
     * If native sequencing is being used on Sybase then the values must be
     * retrieved after the insert.
     * This method is to be used *ONLY* by sequencing classes
     */
    public boolean shouldNativeSequenceAcquireValueAfterInsert() {
        return true;
    }

    /**
     * INTERNAL:
     * JDBC defines and outer join syntax, many drivers do not support this. So we normally avoid it.
     */
    public boolean shouldUseJDBCOuterJoinSyntax() {
        return false;
    }

    /**
     * INTERNAL:
     * Return true if the receiver uses host sequence numbers, generated on the database.
     * Sybase does through IDENTITY field types.
     */
    public boolean supportsNativeSequenceNumbers() {
        return true;
    }

    /**
     * INTERNAL:
     */
    public boolean supportsLocalTempTables() {
        return true;
    }
     
    /**
     * INTERNAL:
     */
    protected String getCreateTempTableSqlPrefix() {
        return "CREATE TABLE ";
    }          

    /**
     * INTERNAL:
     */
    public DatabaseTable getTempTableForTable(DatabaseTable table) {
        return new DatabaseTable("#" + table.getName(), table.getTableQualifier());
    }          

    /**
     * INTERNAL:
     */
    public void writeUpdateOriginalFromTempTableSql(Writer writer, DatabaseTable table,
                                                    Collection pkFields,
                                                    Collection assignedFields) throws IOException 
    {
        writer.write("UPDATE ");
        String tableName = table.getQualifiedName();
        writer.write(tableName);
        String tempTableName = getTempTableForTable(table).getQualifiedName();
        writeAutoAssignmentSetClause(writer, null, tempTableName, assignedFields);
        writer.write(" FROM ");
        writer.write(tableName);
        writer.write(", ");
        writer.write(tempTableName);
        writeAutoJoinWhereClause(writer, tableName, tempTableName, pkFields);
    }          
}
