/* Copyright (c) 2001-2020, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 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.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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package org.hsqldb;

import org.hsqldb.HsqlNameManager.HsqlName;
import org.hsqldb.RangeGroup.RangeGroupSimple;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.HsqlList;
import org.hsqldb.lib.LongDeque;
import org.hsqldb.lib.OrderedHashSet;
import org.hsqldb.map.ValuePool;
import org.hsqldb.types.TimestampData;
import org.hsqldb.types.Type;

/**
 * Parser for DML statements
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.5.1
 * @since 1.9.0
 */
public class ParserDML extends ParserDQL {

    ParserDML(Session session, Scanner scanner) {
        super(session, scanner, null);
    }

    /**
     * Retrieves an INSERT Statement from this parse context.
     */
    StatementDMQL compileInsertStatement(RangeGroup[] rangeGroups) {

        boolean[]       insertColumnCheckList;
        boolean[]       updateColumnCheckList = null;
        int[]           insertColumnMap;
        int[]           updateColumnMap = ValuePool.emptyIntArray;
        int             colCount;
        Table           table;
        RangeVariable   targetRange;
        RangeVariable[] rangeVariables;
        boolean         overridingUser               = false;
        boolean         overridingSystem             = false;
        boolean         assignsToIdentityOrGenerated = false;
        Token           tableToken;
        boolean         hasColumnList = false;
        int             isSpecial     = StatementInsert.isNone;
        Expression      insertExpressions;
        Expression[]    updateExpressions = Expression.emptyArray;
        Expression[]    targets           = null;

        if (database.sqlSyntaxMys) {
            if (readIfThis(Tokens.REPLACE)) {
                isSpecial = StatementInsert.isReplace;
            }

            if (isSpecial == StatementInsert.isNone) {
                readThis(Tokens.INSERT);

                if (readIfThis(Tokens.IGNORE)) {
                    isSpecial = StatementInsert.isIgnore;
                }
            }

            readIfThis(Tokens.INTO);
        } else {
            readThis(Tokens.INSERT);
            readThis(Tokens.INTO);
        }

        tableToken  = getRecordedToken();
        targetRange = readRangeVariableForDataChange(StatementTypes.INSERT);

        targetRange.resolveRangeTableTypes(session, RangeVariable.emptyArray);

        rangeVariables        = new RangeVariable[]{ targetRange };
        table                 = targetRange.getTable();
        insertColumnCheckList = null;
        insertColumnMap       = table.getColumnMap();
        colCount              = table.getColumnCount();

        int   position  = getPosition();
        Table baseTable = table.isTriggerInsertable() ? table
                                                      : table.getBaseTable();

        switch (token.tokenType) {

            case Tokens.DEFAULT : {
                read();
                readThis(Tokens.VALUES);

                insertExpressions = new Expression(OpTypes.ROW,
                                                   new Expression[]{});
                insertExpressions = new Expression(OpTypes.VALUELIST,
                                                   new Expression[]{
                                                       insertExpressions });
                insertColumnCheckList = table.getNewColumnCheckList();

                StatementDMQL cs = new StatementInsert(session, table,
                                                       rangeVariables,
                                                       insertColumnMap,
                                                       insertExpressions,
                                                       insertColumnCheckList,
                                                       updateExpressions,
                                                       updateColumnCheckList,
                                                       updateColumnMap, null,
                                                       isSpecial,
                                                       compileContext);

                return cs;
            }
            case Tokens.OPENBRACKET : {
                int brackets = readOpenBrackets();

                if (brackets == 1) {
                    boolean isQuery = false;

                    switch (token.tokenType) {

                        case Tokens.WITH :
                        case Tokens.SELECT :
                        case Tokens.TABLE : {
                            rewind(position);

                            isQuery = true;

                            break;
                        }
                        default :
                    }

                    if (isQuery) {
                        break;
                    }

                    OrderedHashSet columnNames = new OrderedHashSet();
                    boolean        withPrefix  = database.sqlSyntaxOra;

                    readSimpleColumnNames(columnNames, targetRange,
                                          withPrefix);
                    readThis(Tokens.CLOSEBRACKET);

                    colCount        = columnNames.size();
                    insertColumnMap = table.getColumnIndexes(columnNames);
                    hasColumnList   = true;
                } else {
                    rewind(position);
                }

                break;
            }
            default :
        }

        if (token.tokenType == Tokens.OVERRIDING) {
            read();

            if (token.tokenType == Tokens.USER) {
                read();

                overridingUser = true;
            } else if (token.tokenType == Tokens.SYSTEM) {
                read();

                overridingSystem = true;
            } else {
                throw unexpectedToken();
            }

            readThis(Tokens.VALUE);
        }

        switch (token.tokenType) {

            case Tokens.VALUE : {
                if (!database.sqlSyntaxMys) {
                    throw unexpectedToken();
                }
            }

            // fall through
            case Tokens.VALUES : {
                read();

                insertColumnCheckList =
                    table.getColumnCheckList(insertColumnMap);
                insertExpressions = XreadContextuallyTypedTable(colCount);

                HsqlList unresolved =
                    insertExpressions.resolveColumnReferences(session,
                        RangeGroup.emptyGroup, rangeGroups, null);

                ExpressionColumn.checkColumnsResolved(unresolved);
                insertExpressions.resolveTypes(session, null);
                setParameterTypes(insertExpressions, table, insertColumnMap);

                if (table != baseTable) {
                    int[] baseColumnMap = table.getBaseTableColumnMap();
                    int[] newColumnMap  = new int[insertColumnMap.length];

                    ArrayUtil.projectRow(baseColumnMap, insertColumnMap,
                                         newColumnMap);

                    insertColumnMap = newColumnMap;
                }

                Expression[] rowList = insertExpressions.nodes;

                for (int j = 0; j < rowList.length; j++) {
                    Expression[] rowArgs = rowList[j].nodes;

                    for (int i = 0; i < rowArgs.length; i++) {
                        Expression e = rowArgs[i];
                        ColumnSchema column =
                            baseTable.getColumn(insertColumnMap[i]);

                        if (column.isIdentity()) {
                            assignsToIdentityOrGenerated = true;

                            if (e.getType() != OpTypes.DEFAULT) {
                                if (overridingUser) {
                                    rowArgs[i] =
                                        new ExpressionColumn(OpTypes.DEFAULT);
                                } else if (overridingSystem) {

                                    // user value allowed
                                } else {
                                    if (baseTable.identitySequence
                                            .isAlways()) {
                                        throw Error.error(ErrorCode.X_42542);
                                    }
                                }
                            }
                        } else if (column.hasDefault()) {

                            //
                        } else if (column.isGenerated()
                                   || column.isSystemPeriod()) {
                            assignsToIdentityOrGenerated = true;

                            if (e.getType() != OpTypes.DEFAULT) {
                                if (overridingUser) {
                                    rowArgs[i] =
                                        new ExpressionColumn(OpTypes.DEFAULT);
                                } else {
                                    throw Error.error(ErrorCode.X_42543);
                                }
                            }
                        } else {

                            // no explicit default
                        }

                        if (e.isUnresolvedParam()) {
                            e.setAttributesAsColumn(column);
                        }
                    }
                }

                if (!assignsToIdentityOrGenerated
                        && (overridingUser || overridingSystem)) {
                    throw unexpectedToken(Tokens.T_OVERRIDING);
                }

                if (!hasColumnList) {
                    tableToken.setWithColumnList();
                }

                if (database.sqlSyntaxMys
                        && isSpecial == StatementInsert.isNone
                        && readIfThis(Tokens.ON)) {
                    readThis(Tokens.DUPLICATE);
                    readThis(Tokens.KEY);
                    readThis(Tokens.UPDATE);

                    OrderedHashSet targetSet    = new OrderedHashSet();
                    LongDeque      colIndexList = new LongDeque();
                    HsqlArrayList  exprList     = new HsqlArrayList();
                    RangeGroup rangeGroup =
                        new RangeGroupSimple(rangeVariables, false);
                    RangeVariable valueRange =
                        new RangeVariable(targetRange.getTable(), 2);

                    isSpecial = StatementInsert.isUpdate;

                    readOnDuplicateClauseList(rangeVariables, targetSet,
                                              colIndexList, exprList);

                    updateColumnMap = new int[colIndexList.size()];

                    colIndexList.toArray(updateColumnMap);

                    targets = new Expression[targetSet.size()];

                    targetSet.toArray(targets);

                    for (int i = 0; i < targets.length; i++) {
                        resolveReferencesAndTypes(rangeGroup, rangeGroups,
                                                  targets[i]);
                    }

                    updateColumnCheckList =
                        table.getColumnCheckList(updateColumnMap);
                    updateExpressions = new Expression[exprList.size()];

                    exprList.toArray(updateExpressions);
                    resolveUpdateExpressions(table, rangeGroup,
                                             updateColumnMap,
                                             updateExpressions, rangeGroups,
                                             valueRange);
                }

                StatementDMQL cs = new StatementInsert(session, table,
                                                       rangeVariables,
                                                       insertColumnMap,
                                                       insertExpressions,
                                                       insertColumnCheckList,
                                                       updateExpressions,
                                                       updateColumnCheckList,
                                                       updateColumnMap,
                                                       targets, isSpecial,
                                                       compileContext);

                return cs;
            }
            case Tokens.OPENBRACKET :
            case Tokens.WITH :
            case Tokens.SELECT :
            case Tokens.TABLE : {
                break;
            }
            default : {
                throw unexpectedToken();
            }
        }

        insertColumnCheckList = table.getColumnCheckList(insertColumnMap);

        if (table != baseTable) {
            int[] baseColumnMap = table.getBaseTableColumnMap();
            int[] newColumnMap  = new int[insertColumnMap.length];

            ArrayUtil.projectRow(baseColumnMap, insertColumnMap, newColumnMap);

            insertColumnMap = newColumnMap;
        }

        int enforcedDefaultIndex = baseTable.getIdentityColumnIndex();
        int overrideIndex        = -1;

        if (enforcedDefaultIndex != -1
                && ArrayUtil.find(insertColumnMap, enforcedDefaultIndex)
                   > -1) {
            if (baseTable.identitySequence.isAlways()) {
                if (!overridingUser && !overridingSystem) {
                    throw Error.error(ErrorCode.X_42543);
                }
            }

            if (overridingUser) {
                overrideIndex = enforcedDefaultIndex;
            }
        } else if (overridingUser || overridingSystem) {
            throw unexpectedToken(Tokens.T_OVERRIDING);
        }

        Type[] types = new Type[insertColumnMap.length];

        ArrayUtil.projectRow(baseTable.getColumnTypes(), insertColumnMap,
                             types);
        compileContext.setOuterRanges(rangeGroups);

        QueryExpression queryExpression = XreadQueryExpression();

        queryExpression.setReturningResult();
        queryExpression.resolve(session, rangeGroups, types);

        if (colCount != queryExpression.getColumnCount()) {
            throw Error.error(ErrorCode.X_42546);
        }

        if (!hasColumnList) {
            tableToken.setWithColumnList();
        }

        if (database.sqlSyntaxMys && isSpecial == StatementInsert.isNone
                && readIfThis(Tokens.ON)) {
            readThis(Tokens.DUPLICATE);
            readThis(Tokens.KEY);
            readThis(Tokens.UPDATE);

            OrderedHashSet targetSet    = new OrderedHashSet();
            LongDeque      colIndexList = new LongDeque();
            HsqlArrayList  exprList     = new HsqlArrayList();
            RangeGroup rangeGroup = new RangeGroupSimple(rangeVariables,
                false);
            RangeVariable valueRange =
                new RangeVariable(targetRange.getTable(), 2);

            isSpecial = StatementInsert.isUpdate;

            readOnDuplicateClauseList(rangeVariables, targetSet, colIndexList,
                                      exprList);

            updateColumnMap = new int[colIndexList.size()];

            colIndexList.toArray(updateColumnMap);

            targets = new Expression[targetSet.size()];

            targetSet.toArray(targets);

            for (int i = 0; i < targets.length; i++) {
                resolveReferencesAndTypes(rangeGroup, rangeGroups, targets[i]);
            }

            updateColumnCheckList = table.getColumnCheckList(updateColumnMap);
            updateExpressions     = new Expression[exprList.size()];

            exprList.toArray(updateExpressions);
            resolveUpdateExpressions(table, rangeGroup, updateColumnMap,
                                     updateExpressions, rangeGroups,
                                     valueRange);
        }

        StatementDMQL cs = new StatementInsert(session, table, rangeVariables,
                                               insertColumnMap,
                                               insertColumnCheckList,
                                               queryExpression,
                                               updateExpressions,
                                               updateColumnCheckList,
                                               updateColumnMap, targets,
                                               isSpecial, overrideIndex,
                                               compileContext);

        return cs;
    }

    private static void setParameterTypes(Expression tableExpression,
                                          Table table, int[] columnMap) {

        for (int i = 0; i < tableExpression.nodes.length; i++) {
            Expression[] list = tableExpression.nodes[i].nodes;

            for (int j = 0; j < list.length; j++) {
                if (list[j].isUnresolvedParam()) {
                    list[j].setAttributesAsColumn(
                        table.getColumn(columnMap[j]));
                }
            }
        }
    }

    Statement compileTruncateStatement() {

        boolean         isTable         = false;
        boolean         withCommit      = false;
        boolean         noCheck         = false;
        boolean         restartIdentity = false;
        HsqlName        objectName      = null;
        RangeVariable[] rangeVariables  = null;
        Table           table           = null;
        HsqlName[]      writeTableNames = null;
        RangeVariable   targetRange     = null;
        TimestampData   timestamp       = null;

        readThis(Tokens.TRUNCATE);

        if (token.tokenType == Tokens.TABLE) {
            readThis(Tokens.TABLE);

            targetRange =
                readRangeVariableForDataChange(StatementTypes.TRUNCATE);
            rangeVariables = new RangeVariable[]{ targetRange };
            table          = rangeVariables[0].getTable();
            objectName     = table.getName();
            isTable        = true;
        } else {
            readThis(Tokens.SCHEMA);

            objectName = readSchemaName();
        }

        switch (token.tokenType) {

            case Tokens.CONTINUE : {
                read();
                readThis(Tokens.IDENTITY);

                break;
            }
            case Tokens.RESTART : {
                read();
                readThis(Tokens.IDENTITY);

                restartIdentity = true;

                break;
            }
            case Tokens.VERSIONING : {
                if (!isTable) {
                    throw unexpectedToken();
                }

                if (!table.isSystemVersioned()) {
                    throw unexpectedToken();
                }

                read();
                readThis(Tokens.TO);

                if (readIfThis(Tokens.TIMESTAMP)) {
                    String s = readQuotedString();

                    timestamp =
                        (TimestampData) Type.SQL_TIMESTAMP_WITH_TIME_ZONE
                            .convertToType(session, s,
                                           Type.SQL_VARCHAR_DEFAULT);
                } else {
                    readThis(Tokens.CURRENT_TIMESTAMP);

                    timestamp = session.getTransactionUTC();
                }

                break;
            }
            default :
        }

        if (!isTable) {
            checkIsThis(Tokens.AND);
        }

        if (readIfThis(Tokens.AND)) {
            readThis(Tokens.COMMIT);

            withCommit = true;

            if (readIfThis(Tokens.NO)) {
                readThis(Tokens.CHECK);

                noCheck = true;
            }
        }

        if (isTable) {
            writeTableNames = new HsqlName[]{ table.getName() };
        } else {
            writeTableNames =
                session.database.schemaManager.getCatalogAndBaseTableNames();
        }

        if (withCommit || timestamp != null) {
            Object[] args = new Object[] {
                objectName, Boolean.valueOf(restartIdentity),
                Boolean.valueOf(noCheck), timestamp
            };

            return new StatementCommand(StatementTypes.TRUNCATE, args, null,
                                        writeTableNames);
        }

        Statement cs = new StatementDML(session, table, targetRange,
                                        rangeVariables, compileContext,
                                        restartIdentity,
                                        StatementTypes.TRUNCATE, null);

        return cs;
    }

    /**
     * Creates a DELETE-type Statement from this parse context.
     */
    Statement compileDeleteStatement(RangeGroup[] rangeGroups) {

        Expression      condition       = null;
        boolean         restartIdentity = false;
        RangeVariable   targetRange;
        RangeVariable[] rangeVariables;
        RangeGroup      rangeGroup;
        Table           table;

        readThis(Tokens.DELETE);

        if (database.sqlSyntaxOra) {
            readIfThis(Tokens.FROM);
        } else {
            readThis(Tokens.FROM);
        }

        targetRange =
            readRangeVariableForDataChange(StatementTypes.DELETE_WHERE);
        rangeVariables = new RangeVariable[]{ targetRange };
        rangeGroup     = new RangeGroupSimple(rangeVariables, false);
        table          = rangeVariables[0].getTable();

        compileContext.setOuterRanges(rangeGroups);

        if (token.tokenType == Tokens.WHERE) {
            read();

            condition = XreadAndResolveBooleanValueExpression(rangeGroups,
                    rangeGroup);
        }

        SortAndSlice sortAndSlice = null;

        if (token.tokenType == Tokens.LIMIT) {
            sortAndSlice = XreadOrderByExpression();
        }

        Table baseTable = table.isTriggerDeletable() ? table
                                                     : table.getBaseTable();

        if (table != baseTable) {
            QuerySpecification baseSelect =
                table.getQueryExpression().getMainSelect();

            if (condition != null) {
                condition = condition.replaceColumnReferences(session,
                        rangeVariables[0], baseSelect.exprColumns);
            }

            condition =
                ExpressionLogical.andExpressions(baseSelect.queryCondition,
                                                 condition);
            rangeVariables = baseSelect.rangeVariables;

            ArrayUtil.fillArray(rangeVariables[0].usedColumns, true);
        }

        if (condition != null) {
            rangeVariables[0].addJoinCondition(condition);

            RangeVariableResolver resolver = new RangeVariableResolver(session,
                rangeVariables, null, compileContext, false);

            resolver.processConditions();

            rangeVariables = resolver.rangeVariables;
        }

        for (int i = 0; i < rangeVariables.length; i++) {
            rangeVariables[i].resolveRangeTableTypes(session,
                    RangeVariable.emptyArray);
        }

        Statement cs = new StatementDML(session, table, targetRange,
                                        rangeVariables, compileContext,
                                        restartIdentity,
                                        StatementTypes.DELETE_WHERE,
                                        sortAndSlice);

        return cs;
    }

    /**
     * Creates an UPDATE-type Statement from this parse context.
     */
    StatementDMQL compileUpdateStatement(RangeGroup[] rangeGroups) {

        read();

        Expression[]    updateExpressions;
        int[]           columnMap;
        boolean[]       columnCheckList;
        OrderedHashSet  targetSet    = new OrderedHashSet();
        LongDeque       colIndexList = new LongDeque();
        HsqlArrayList   exprList     = new HsqlArrayList();
        RangeVariable   targetRange;
        RangeVariable[] rangeVariables;
        RangeGroup      rangeGroup;
        Table           table;
        Table           baseTable;

        targetRange =
            readRangeVariableForDataChange(StatementTypes.UPDATE_WHERE);
        rangeVariables = new RangeVariable[]{ targetRange };
        rangeGroup     = new RangeGroupSimple(rangeVariables, false);
        table          = rangeVariables[0].rangeTable;
        baseTable      = table.isTriggerUpdatable() ? table
                                                    : table.getBaseTable();

        readThis(Tokens.SET);
        readSetClauseList(rangeGroups, rangeVariables, targetSet,
                          colIndexList, exprList);

        columnMap = new int[colIndexList.size()];

        colIndexList.toArray(columnMap);

        Expression[] targets = new Expression[targetSet.size()];

        targetSet.toArray(targets);

        for (int i = 0; i < targets.length; i++) {
            resolveReferencesAndTypes(rangeGroup, rangeGroups, targets[i]);
        }

        columnCheckList   = table.getColumnCheckList(columnMap);
        updateExpressions = new Expression[exprList.size()];

        exprList.toArray(updateExpressions);

        Expression condition = null;

        if (token.tokenType == Tokens.WHERE) {
            read();

            condition = XreadAndResolveBooleanValueExpression(rangeGroups,
                    rangeGroup);
        }

        SortAndSlice sortAndSlice = null;

        if (token.tokenType == Tokens.LIMIT) {
            sortAndSlice = XreadOrderByExpression();
        }

        resolveUpdateExpressions(table, rangeGroup, columnMap,
                                 updateExpressions, rangeGroups, null);

        if (table != baseTable) {
            QuerySpecification baseSelect =
                table.getQueryExpression().getMainSelect();

            if (condition != null) {
                condition = condition.replaceColumnReferences(session,
                        rangeVariables[0], baseSelect.exprColumns);
            }

            for (int i = 0; i < updateExpressions.length; i++) {
                updateExpressions[i] =
                    updateExpressions[i].replaceColumnReferences(session,
                        rangeVariables[0], baseSelect.exprColumns);
            }

            condition =
                ExpressionLogical.andExpressions(baseSelect.queryCondition,
                                                 condition);
            rangeVariables = baseSelect.rangeVariables;

            ArrayUtil.fillArray(rangeVariables[0].usedColumns, true);
        }

        if (condition != null) {
            rangeVariables[0].addJoinCondition(condition);

            RangeVariableResolver resolver = new RangeVariableResolver(session,
                rangeVariables, null, compileContext, false);

            resolver.processConditions();

            rangeVariables = resolver.rangeVariables;
        }

        for (int i = 0; i < rangeVariables.length; i++) {
            rangeVariables[i].resolveRangeTableTypes(session,
                    RangeVariable.emptyArray);
        }

        if (table != baseTable) {
            int[] baseColumnMap = table.getBaseTableColumnMap();
            int[] newColumnMap  = new int[columnMap.length];

            ArrayUtil.projectRow(baseColumnMap, columnMap, newColumnMap);

            columnMap = newColumnMap;

            for (int i = 0; i < columnMap.length; i++) {
                if (baseTable.colGenerated[columnMap[i]]) {
                    throw Error.error(ErrorCode.X_42513);
                }
            }
        }

        StatementDMQL cs = new StatementDML(session, targets, table,
                                            targetRange, rangeVariables,
                                            columnMap, updateExpressions,
                                            columnCheckList, compileContext,
                                            sortAndSlice);

        return cs;
    }

    Expression XreadAndResolveBooleanValueExpression(RangeGroup[] rangeGroups,
            RangeGroup rangeGroup) {

        Expression condition = XreadBooleanValueExpression();
        HsqlList unresolved = condition.resolveColumnReferences(session,
            rangeGroup, rangeGroups, null);

        ExpressionColumn.checkColumnsResolved(unresolved);
        condition.resolveTypes(session, null);

        if (condition.isUnresolvedParam()) {
            condition.dataType = Type.SQL_BOOLEAN;
        }

        if (condition.getDataType() != Type.SQL_BOOLEAN) {
            throw Error.error(ErrorCode.X_42568);
        }

        return condition;
    }

    void resolveUpdateExpressions(Table targetTable, RangeGroup rangeGroup,
                                  int[] columnMap,
                                  Expression[] colExpressions,
                                  RangeGroup[] rangeGroups,
                                  RangeVariable valuesRange) {

        HsqlList unresolved           = null;
        int      enforcedDefaultIndex = -1;

        if (targetTable.hasIdentityColumn()
                && targetTable.identitySequence.isAlways()) {
            enforcedDefaultIndex = targetTable.getIdentityColumnIndex();
        }

        for (int i = 0, ix = 0; i < columnMap.length; ix++) {
            Expression expr = colExpressions[ix];
            Expression e;

            // no generated column can be updated
            if (targetTable.colGenerated[columnMap[i]]) {
                throw Error.error(ErrorCode.X_42513);
            }

            if (expr.getType() == OpTypes.ROW) {
                Expression[] elements = expr.nodes;

                for (int j = 0; j < elements.length; j++, i++) {
                    e = elements[j];

                    if (enforcedDefaultIndex == columnMap[i]) {
                        if (e.getType() != OpTypes.DEFAULT) {
                            throw Error.error(ErrorCode.X_42541);
                        }
                    }

                    if (e.isUnresolvedParam()) {
                        e.setAttributesAsColumn(
                            targetTable.getColumn(columnMap[i]));
                    } else if (e.getType() == OpTypes.DEFAULT) {

                        //
                    } else {
                        unresolved = expr.resolveColumnReferences(session,
                                rangeGroup, rangeGroups, null);

                        ExpressionColumn.checkColumnsResolved(unresolved);

                        unresolved = null;

                        e.resolveTypes(session, null);
                    }
                }
            } else if (expr.getType() == OpTypes.ROW_SUBQUERY) {
                unresolved = expr.resolveColumnReferences(session, rangeGroup,
                        rangeGroups, null);

                ExpressionColumn.checkColumnsResolved(unresolved);
                expr.resolveTypes(session, null);

                int count = expr.table.queryExpression.getColumnCount();

                for (int j = 0; j < count; j++, i++) {
                    if (enforcedDefaultIndex == columnMap[i]) {
                        throw Error.error(ErrorCode.X_42541);
                    }
                }
            } else {
                e = expr;

                if (enforcedDefaultIndex == columnMap[i]) {
                    if (e.getType() != OpTypes.DEFAULT) {
                        throw Error.error(ErrorCode.X_42541);
                    }
                }

                if (e.isUnresolvedParam()) {
                    e.setAttributesAsColumn(
                        targetTable.getColumn(columnMap[i]));
                } else if (e.getType() == OpTypes.DEFAULT) {

                    //
                } else {
                    unresolved = expr.resolveColumnReferences(session,
                            rangeGroup, rangeGroups, null);

                    if (valuesRange != null && unresolved != null) {
                        for (int j = unresolved.size() - 1; j >= 0; j--) {
                            ExpressionColumn col =
                                (ExpressionColumn) unresolved.get(j);

                            col.resolveColumnReference(valuesRange, false);

                            if (col.rangeVariable != null) {
                                unresolved.remove(j);
                            }
                        }
                    }

                    ExpressionColumn.checkColumnsResolved(unresolved);
                    e.resolveTypes(session, null);
                }

                i++;
            }
        }
    }

    void readSetClauseList(RangeGroup[] rangeGroups,
                           RangeVariable[] rangeVars, OrderedHashSet targets,
                           LongDeque colIndexList, HsqlArrayList expressions) {

        while (true) {
            int degree;

            if (token.tokenType == Tokens.OPENBRACKET) {
                read();

                int oldCount = targets.size();

                readTargetSpecificationList(targets, rangeVars, colIndexList);

                degree = targets.size() - oldCount;

                readThis(Tokens.CLOSEBRACKET);
            } else {
                Expression target = XreadTargetSpecification(rangeVars,
                    colIndexList);

                if (!targets.add(target)) {
                    ColumnSchema col = target.getColumn();

                    throw Error.error(ErrorCode.X_42579, col.getName().name);
                }

                degree = 1;
            }

            readThis(Tokens.EQUALS_OP);

            int position = getPosition();
            int brackets = readOpenBrackets();

            if (token.tokenType == Tokens.SELECT) {
                rewind(position);
                compileContext.setOuterRanges(rangeGroups);

                TableDerived td = XreadSubqueryTableBody(OpTypes.ROW_SUBQUERY);
                QueryExpression qe = td.getQueryExpression();

                qe.setReturningResult();

                if (degree != qe.getColumnCount()) {
                    throw Error.error(ErrorCode.X_42546);
                }

                Expression e = new Expression(OpTypes.ROW_SUBQUERY, td);

                expressions.add(e);

                if (token.tokenType == Tokens.COMMA) {
                    read();

                    continue;
                }

                break;
            }

            if (brackets > 0) {
                rewind(position);
            }

            if (degree > 1) {
                readThis(Tokens.OPENBRACKET);

                Expression e = readRow();

                readThis(Tokens.CLOSEBRACKET);

                int rowDegree = e.getType() == OpTypes.ROW ? e.nodes.length
                                                           : 1;

                if (degree != rowDegree) {
                    throw Error.error(ErrorCode.X_42546);
                }

                expressions.add(e);
            } else {
                Expression e = XreadValueExpressionWithContext();

                expressions.add(e);
            }

            if (token.tokenType == Tokens.COMMA) {
                read();

                continue;
            }

            break;
        }
    }

    void readOnDuplicateClauseList(RangeVariable[] rangeVars,
                                   OrderedHashSet targets,
                                   LongDeque colIndexList,
                                   HsqlArrayList expressions) {

        while (true) {
            Expression target = XreadTargetSpecification(rangeVars,
                colIndexList);

            if (!targets.add(target)) {
                ColumnSchema col = target.getColumn();

                throw Error.error(ErrorCode.X_42579, col.getName().name);
            }

            readThis(Tokens.EQUALS_OP);

            Expression e = XreadValueExpressionOnDuplicate();

            expressions.add(e);

            if (token.tokenType == Tokens.COMMA) {
                read();

                continue;
            }

            break;
        }
    }

    void readGetClauseList(RangeVariable[] rangeVars, OrderedHashSet targets,
                           LongDeque colIndexList, HsqlArrayList expressions) {

        while (true) {
            Expression target = XreadTargetSpecification(rangeVars,
                colIndexList);

            if (!targets.add(target)) {
                ColumnSchema col = target.getColumn();

                throw Error.error(ErrorCode.X_42579, col.getName().name);
            }

            readThis(Tokens.EQUALS_OP);

            switch (token.tokenType) {

                case Tokens.ROW_COUNT :
                case Tokens.MORE :
                    int columnIndex =
                        ExpressionColumn.diagnosticsList.getIndex(
                            token.tokenString);
                    Expression e =
                        new ExpressionColumn(OpTypes.DIAGNOSTICS_VARIABLE,
                                             columnIndex);

                    expressions.add(e);
                    read();
                    break;

                default :
            }

            if (token.tokenType == Tokens.COMMA) {
                read();

                continue;
            }

            break;
        }
    }

    /**
     * Retrieves a MERGE Statement from this parse context.
     */
    StatementDMQL compileMergeStatement(RangeGroup[] rangeGroups) {

        boolean[]     insertColumnCheckList;
        int[]         insertColumnMap = null;
        int[]         updateColumnMap = null;
        int[]         baseUpdateColumnMap;
        Table         table;
        RangeVariable targetRange;
        RangeVariable sourceRange;
        Expression    mergeCondition;
        Expression[]  targets           = null;
        HsqlArrayList updateList        = new HsqlArrayList();
        Expression[]  updateExpressions = Expression.emptyArray;
        HsqlArrayList insertList        = new HsqlArrayList();
        Expression    insertExpression  = null;

        read();
        readThis(Tokens.INTO);

        targetRange = readRangeVariableForDataChange(StatementTypes.MERGE);
        table       = targetRange.rangeTable;

        readThis(Tokens.USING);
        compileContext.setOuterRanges(rangeGroups);

        sourceRange = readTableOrSubquery();

        RangeVariable[] targetRanges = new RangeVariable[]{ targetRange };
        RangeGroup      rangeGroup = new RangeGroupSimple(targetRanges, false);

        sourceRange.resolveRangeTable(session, rangeGroup, rangeGroups);
        sourceRange.resolveRangeTableTypes(session, targetRanges);
        compileContext.setOuterRanges(RangeGroup.emptyArray);

        RangeVariable[] fullRangeVars   = new RangeVariable[] {
            sourceRange, targetRange
        };
        RangeVariable[] sourceRangeVars = new RangeVariable[]{ sourceRange };
        RangeVariable[] targetRangeVars = new RangeVariable[]{ targetRange };
        RangeGroup fullRangeGroup = new RangeGroupSimple(fullRangeVars, false);
        RangeGroup sourceRangeGroup = new RangeGroupSimple(sourceRangeVars,
            false);

        // parse ON search conditions
        readThis(Tokens.ON);

        mergeCondition = XreadAndResolveBooleanValueExpression(rangeGroups,
                fullRangeGroup);

        // parse WHEN clause(s) and convert lists to arrays
        insertColumnMap       = table.getColumnMap();
        insertColumnCheckList = table.getNewColumnCheckList();

        OrderedHashSet updateTargetSet    = new OrderedHashSet();
        OrderedHashSet insertColNames     = new OrderedHashSet();
        LongDeque      updateColIndexList = new LongDeque();
        Expression[]   conditions         = new Expression[3];
        boolean        deleteFirst        = false;

        readMergeWhen(rangeGroups, fullRangeGroup, updateColIndexList,
                      insertColNames, updateTargetSet, insertList, updateList,
                      targetRangeVars, sourceRange, conditions);

        // conditions[0], [1] and [2] are null (no action) or TRUE if there is no merge condition for the action
        if (conditions[2] != null) {
            deleteFirst = true;
        }

        if (token.tokenType == Tokens.WHEN) {
            readMergeWhen(rangeGroups, fullRangeGroup, updateColIndexList,
                          insertColNames, updateTargetSet, insertList,
                          updateList, targetRangeVars, sourceRange,
                          conditions);
        }

        if (conditions[1] == null && conditions[2] != null) {
            deleteFirst = true;
        }

        if (token.tokenType == Tokens.WHEN) {
            readMergeWhen(rangeGroups, fullRangeGroup, updateColIndexList,
                          insertColNames, updateTargetSet, insertList,
                          updateList, targetRangeVars, sourceRange,
                          conditions);
        }

        if (conditions[1] == null && conditions[2] != null) {
            deleteFirst = true;
        }

        if (insertList.size() > 0) {
            int colCount = insertColNames.size();

            if (colCount != 0) {
                insertColumnMap = table.getColumnIndexes(insertColNames);
                insertColumnCheckList =
                    table.getColumnCheckList(insertColumnMap);
            }

            insertExpression = (Expression) insertList.get(0);

            setParameterTypes(insertExpression, table, insertColumnMap);

            if (conditions[0] == null) {
                conditions[0] = Expression.EXPR_TRUE;
            }
        }

        if (updateList.size() > 0) {
            targets = new Expression[updateTargetSet.size()];

            updateTargetSet.toArray(targets);

            for (int i = 0; i < targets.length; i++) {
                resolveReferencesAndTypes(rangeGroup, rangeGroups, targets[i]);
            }

            updateExpressions = new Expression[updateList.size()];

            updateList.toArray(updateExpressions);

            updateColumnMap = new int[updateColIndexList.size()];

            updateColIndexList.toArray(updateColumnMap);

            if (conditions[1] == null) {
                conditions[1] = Expression.EXPR_TRUE;
            }
        }

        if (updateExpressions.length != 0) {
            Table baseTable = table.isTriggerUpdatable() ? table
                                                         : table.getBaseTable();

            baseUpdateColumnMap = updateColumnMap;

            if (table != baseTable) {
                baseUpdateColumnMap = new int[updateColumnMap.length];

                ArrayUtil.projectRow(table.getBaseTableColumnMap(),
                                     updateColumnMap, baseUpdateColumnMap);
            }

            resolveUpdateExpressions(table, fullRangeGroup, updateColumnMap,
                                     updateExpressions, rangeGroups, null);
        }

        HsqlList unresolved = null;

        unresolved = mergeCondition.resolveColumnReferences(session,
                fullRangeGroup, rangeGroups, null);

        ExpressionColumn.checkColumnsResolved(unresolved);
        mergeCondition.resolveTypes(session, null);

        if (mergeCondition.isUnresolvedParam()) {
            mergeCondition.dataType = Type.SQL_BOOLEAN;
        }

        if (mergeCondition.getDataType() != Type.SQL_BOOLEAN) {
            throw Error.error(ErrorCode.X_42568);
        }

        fullRangeVars[1].addJoinCondition(mergeCondition);

        RangeVariableResolver resolver = new RangeVariableResolver(session,
            fullRangeVars, null, compileContext, false);

        resolver.processConditions();

        fullRangeVars = resolver.rangeVariables;

        for (int i = 0; i < fullRangeVars.length; i++) {
            fullRangeVars[i].resolveRangeTableTypes(session,
                    RangeVariable.emptyArray);
        }

        if (insertExpression != null) {
            unresolved = insertExpression.resolveColumnReferences(session,
                    sourceRangeGroup, RangeGroup.emptyArray, null);
            unresolved = Expression.resolveColumnSet(session,
                    RangeVariable.emptyArray, rangeGroups, unresolved);

            ExpressionColumn.checkColumnsResolved(unresolved);
            insertExpression.resolveTypes(session, null);
        }

        StatementDMQL cs = new StatementDML(session, targets, sourceRange,
                                            targetRange, fullRangeVars,
                                            insertColumnMap, updateColumnMap,
                                            insertColumnCheckList,
                                            mergeCondition, insertExpression,
                                            updateExpressions, deleteFirst,
                                            conditions[0], conditions[1],
                                            conditions[2], compileContext);

        return cs;
    }

    /**
     * Parses a WHEN clause from a MERGE statement. This can be either a
     * WHEN MATCHED or WHEN NOT MATCHED clause, or both, and the appropriate
     * values will be updated.
     *
     * If the var that is to hold the data is not null, then we already
     * encountered this type of clause, which is only allowed once, and at least
     * one is required.
     */
    private void readMergeWhen(RangeGroup[] rangeGroups,
                               RangeGroup rangeGroup,
                               LongDeque updateColIndexList,
                               OrderedHashSet insertColumnNames,
                               OrderedHashSet updateTargetSet,
                               HsqlArrayList insertExpressions,
                               HsqlArrayList updateExpressions,
                               RangeVariable[] targetRangeVars,
                               RangeVariable sourceRangeVar,
                               Expression[] conditions) {

        Table      table       = targetRangeVars[0].rangeTable;
        int        columnCount = table.getColumnCount();
        Expression condition   = null;

        readThis(Tokens.WHEN);

        if (token.tokenType == Tokens.MATCHED) {
            read();

            if (readIfThis(Tokens.AND)) {
                condition = XreadAndResolveBooleanValueExpression(rangeGroups,
                        rangeGroup);
            }

            readThis(Tokens.THEN);

            if (readIfThis(Tokens.UPDATE)) {
                if (updateExpressions.size() != 0) {
                    throw Error.error(ErrorCode.X_42547);
                }

                conditions[1] = condition;

                readThis(Tokens.SET);
                readSetClauseList(rangeGroups, targetRangeVars,
                                  updateTargetSet, updateColIndexList,
                                  updateExpressions);
            } else {
                if (conditions[2] != null) {
                    throw Error.error(ErrorCode.X_42547);
                }

                if (condition == null) {
                    condition = Expression.EXPR_TRUE;
                }

                conditions[2] = condition;

                readThis(Tokens.DELETE);
            }
        } else if (token.tokenType == Tokens.NOT) {
            if (insertExpressions.size() != 0) {
                throw Error.error(ErrorCode.X_42548);
            }

            read();
            readThis(Tokens.MATCHED);

            if (readIfThis(Tokens.AND)) {
                condition = XreadAndResolveBooleanValueExpression(rangeGroups,
                        rangeGroup);
            }

            conditions[0] = condition;

            readThis(Tokens.THEN);
            readThis(Tokens.INSERT);

            // parse INSERT statement
            // optional column list
            int brackets = readOpenBrackets();

            if (brackets == 1) {
                boolean withPrefix = database.sqlSyntaxOra;

                readSimpleColumnNames(insertColumnNames, targetRangeVars[0],
                                      withPrefix);

                columnCount = insertColumnNames.size();

                readThis(Tokens.CLOSEBRACKET);

                brackets = 0;
            }

            readThis(Tokens.VALUES);

            Expression e = XreadContextuallyTypedTable(columnCount);

            if (e.nodes.length != 1) {
                throw Error.error(ErrorCode.X_21000);
            }

            insertExpressions.add(e);
        } else {
            throw unexpectedToken();
        }
    }

    /**
     * Retrieves a CALL Statement from this parse context.
     */

    // to do call argument name and type resolution
    StatementDMQL compileCallStatement(RangeGroup[] rangeGroups,
                                       boolean isStrictlyProcedure) {

        read();

        if (isIdentifier()) {
            RoutineSchema routineSchema =
                (RoutineSchema) database.schemaManager.findSchemaObject(
                    session, token.tokenString, token.namePrefix,
                    token.namePrePrefix, SchemaObject.PROCEDURE);

            if (routineSchema == null && token.namePrefix == null) {
                String schema = session.getSchemaName(null);
                ReferenceObject synonym =
                    database.schemaManager.findSynonym(token.tokenString,
                                                       schema,
                                                       SchemaObject.ROUTINE);

                if (synonym != null) {
                    HsqlName name = synonym.getTarget();

                    routineSchema =
                        (RoutineSchema) database.schemaManager
                            .findSchemaObject(name.name, name.schema.name,
                                              name.type);
                }
            }

            if (routineSchema != null) {
                read();

                return compileProcedureCall(rangeGroups, routineSchema);
            }
        }

        if (isStrictlyProcedure) {
            throw Error.error(ErrorCode.X_42501, token.tokenString);
        }

        Expression expression = XreadValueExpression();
        HsqlList unresolved = expression.resolveColumnReferences(session,
            RangeGroup.emptyGroup, rangeGroups, null);

        ExpressionColumn.checkColumnsResolved(unresolved);
        expression.resolveTypes(session, null);

        StatementDMQL cs = new StatementProcedure(session, expression,
            compileContext);

        return cs;
    }

    StatementDMQL compileProcedureCall(RangeGroup[] rangeGroups,
                                       RoutineSchema routineSchema) {

        HsqlArrayList list    = new HsqlArrayList();
        boolean       bracket = true;

        if (database.sqlSyntaxOra) {
            bracket = readIfThis(Tokens.OPENBRACKET);
        } else {
            readThis(Tokens.OPENBRACKET);
        }

        if (bracket) {
            if (token.tokenType == Tokens.CLOSEBRACKET) {
                read();
            } else {
                while (true) {
                    Expression e = XreadValueExpression();

                    list.add(e);

                    if (token.tokenType == Tokens.COMMA) {
                        read();
                    } else {
                        readThis(Tokens.CLOSEBRACKET);

                        break;
                    }
                }
            }
        }

        Expression[] arguments = new Expression[list.size()];

        list.toArray(arguments);

        Routine routine = routineSchema.getSpecificRoutine(arguments.length);

        compileContext.addProcedureCall(routine);

        HsqlList unresolved = null;

        for (int i = 0; i < arguments.length; i++) {
            Expression e = arguments[i];

            if (e.isUnresolvedParam()) {
                e.setAttributesAsColumn(routine.getParameter(i));
            } else {
                int paramMode = routine.getParameter(i).getParameterMode();

                unresolved = arguments[i].resolveColumnReferences(session,
                        RangeGroup.emptyGroup, rangeGroups, unresolved);

                if (paramMode != SchemaObject.ParameterModes.PARAM_IN) {
                    if (e.getType() != OpTypes.VARIABLE) {
                        throw Error.error(ErrorCode.X_42603);
                    }
                }
            }
        }

        ExpressionColumn.checkColumnsResolved(unresolved);

        for (int i = 0; i < arguments.length; i++) {
            arguments[i].resolveTypes(session, null);

            if (!routine.getParameter(i).getDataType().canBeAssignedFrom(
                    arguments[i].getDataType())) {
                throw Error.error(ErrorCode.X_42561);
            }
        }

        StatementDMQL cs = new StatementProcedure(session, routine, arguments,
            compileContext);

        return cs;
    }

    void resolveReferencesAndTypes(RangeGroup rangeGroup,
                                   RangeGroup[] rangeGroups, Expression e) {

        HsqlList unresolved = e.resolveColumnReferences(session, rangeGroup,
            rangeGroup.getRangeVariables().length, rangeGroups, null, false);

        ExpressionColumn.checkColumnsResolved(unresolved);
        e.resolveTypes(session, null);
    }

    /**
     * Used in ROUTINE statements. Accepts NEXT VALUE FOR SEQUENCE as source
     */
    void resolveOuterReferencesAndTypes(RangeGroup[] rangeGroups,
                                        Expression e) {

        HsqlList unresolved = e.resolveColumnReferences(session,
            RangeGroup.emptyGroup, rangeGroups, null);

        ExpressionColumn.checkColumnsResolved(unresolved);
        e.resolveTypes(session, null);
    }
}
