/*

   Derby - Class org.apache.derby.impl.sql.execute.FKInfo

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to you under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package org.apache.derby.impl.sql.execute;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.StreamCorruptedException;
import java.util.Vector;
import org.apache.derby.catalog.UUID;
import org.apache.derby.shared.common.error.StandardException;
import org.apache.derby.shared.common.util.ArrayUtil;
import org.apache.derby.iapi.services.io.FormatIdUtil;
import org.apache.derby.iapi.services.io.Formatable;
import org.apache.derby.iapi.services.io.StoredFormatIds;
import org.apache.derby.iapi.services.monitor.Monitor;
import org.apache.derby.iapi.types.RowLocation;
import org.apache.derby.shared.common.sanity.SanityManager;

/**
 * This is a simple class used to store the run time information
 * about a foreign key.  Used by DML to figure out what to
 * check.
 *
 */
public class FKInfo implements Formatable 
{
	/********************************************************
	**
	**	This class implements Formatable. That means that it
	**	can write itself to and from a formatted stream. If
	**	you add more fields to this class, make sure that you
	**	also write/read them with the writeExternal()/readExternal()
	**	methods.
	**
    **  If, between releases, you add more fields to this class,
	**	then you should bump the version number emitted by the getTypeFormatId()
	**	method.  OR, since this is something that is used
	**	in stored prepared statements, it is ok to change it
	**	if you make sure that stored prepared statements are
	**	invalidated across releases.
	**
	********************************************************/

	public static final int FOREIGN_KEY = 1;
	public static final int REFERENCED_KEY = 2;

	/*
	** See the constructor for the meaning of these fields
	*/
    String              schemaName;
    String              tableName;
    int                 type;
    UUID                refUUID; // index index conglomerate uuid
    long                refConglomNumber;
    UUID                refConstraintID;
    boolean             refConstraintIsDeferrable;
    int                 stmtType;
    RowLocation         rowLocation;

    // These arrays all have the same cardinality, either 1 (foreign key), or
    // the number of FKs referencing this referenced key
    String[]            fkConstraintNames;
    private UUID[]      fkUUIDs; // the index conglomerate uuids
    long[]              fkConglomNumbers;
    UUID[]              fkIds; // the constraint uuids
    boolean[]           fkIsSelfReferencing;
    int[]               colArray;
    int[]               raRules;
    boolean[]           deferrable;

	/**
	 * Niladic constructor for Formattable
	 */
	public FKInfo() {}

	/**
     * Constructor for FKInfo
	 *
	 * @param fkConstraintNames the foreign key constraint names
     * @param schemaName the name of the schema of the table being modified
	 * @param tableName	the name of the table being modified
	 * @param stmtType	the type of the statement: e.g. StatementType.INSERT
	 * @param type either FKInfo.REFERENCED_KEY or FKInfo.FOREIGN_KEY
     * @param refUUID UUID of the referenced constraint's supporting index
     * @param refConglomNumber conglomerate number of the referenced key
     * @param refConstraintID UUID of the referenced constraint
     * @param refConstraintIsDeferrable {@code true} iff the referenced key
     *                                  constraint is deferrable
	 * @param fkUUIDs an array of fkUUIDs of backing indexes.  if
	 *			FOREIGN_KEY, then just one element, the backing
     *          index of the referenced keys.  if REFERENCED_KEY,
	 *			then all the foreign keys
	 * @param fkConglomNumbers array of conglomerate numbers, corresponds
	 *			to fkUUIDs
	 * @param fkIsSelfReferencing array of conglomerate booleans indicating
     *          whether the foreign key references a key in the same table
	 * @param colArray map of columns to the base row that DML
	 * 			is changing.  1 based.  Note that this maps the
	 *			constraint index to a row in the target table of
     *          the current DML operation.
	 * @param rowLocation a row location template for the target table
	 *			used to pass in a template row to tc.openScan()
     * @param raRules referential action rules
     * @param deferrable the corresponding constraint is deferrable
     * @param fkIds the foreign key constraints' uuids.
	 */
	public FKInfo(
					String[]			fkConstraintNames,
                    String              schemaName,
                    String              tableName,
					int					stmtType,
					int					type,
					UUID				refUUID,
					long				refConglomNumber,
                    UUID                refConstraintID,
                    boolean             refConstraintIsDeferrable,
					UUID[]				fkUUIDs,
					long[]				fkConglomNumbers,
					boolean[]			fkIsSelfReferencing,
					int[]				colArray,
					RowLocation			rowLocation,
                    int[]               raRules,
                    boolean[]           deferrable,
                    UUID[]              fkIds
					)
	{
        this.fkConstraintNames = ArrayUtil.copy(fkConstraintNames);
		this.tableName = tableName;
        this.schemaName = schemaName;
		this.stmtType = stmtType;
		this.type = type;
		this.refUUID = refUUID;
		this.refConglomNumber = refConglomNumber;
        this.refConstraintID = refConstraintID;
        this.refConstraintIsDeferrable = refConstraintIsDeferrable;
        this.fkUUIDs = ArrayUtil.copy(fkUUIDs);
        this.fkConglomNumbers = ArrayUtil.copy(fkConglomNumbers);
        this.fkIsSelfReferencing = ArrayUtil.copy(fkIsSelfReferencing);
        this.colArray = ArrayUtil.copy(colArray);
		this.rowLocation = rowLocation;
        this.raRules = ArrayUtil.copy(raRules);
        this.deferrable = ArrayUtil.copy(deferrable);
        this.fkIds = ArrayUtil.copy(fkIds);

		if (SanityManager.DEBUG)
		{
			if (fkUUIDs.length != fkConglomNumbers.length)
			{
				SanityManager.THROWASSERT("number of ForeignKey UUIDS ("+fkUUIDs.length+
										") doesn't match the number of conglomerate numbers"+
										" ("+fkConglomNumbers.length+")");
			}
			if (type == FOREIGN_KEY)
			{
				SanityManager.ASSERT(fkUUIDs.length == 1, "unexpected number of fkUUIDs for a foreign key, should only have the uuid of the key it references");
			}
			else if (type == REFERENCED_KEY)
			{
				SanityManager.ASSERT(fkUUIDs.length >= 1, "too few fkUUIDs for a referenced key, expect at least one foreign key");
			}
			else
			{
				SanityManager.THROWASSERT("bad type: "+type);
			}
		}
	}

	/**
	 * Comb through the FKInfo structures and pick out the
	 * ones that have columns that intersect with the input
	 * columns.
	 *
 	 * @param fkInfo	        array of fkinfos
	 * @param cols	            array of columns
     * @param addAllTypeIsFK    take all with type == FOREIGN_KEY
	 *
	 * @return array of relevant fkinfos
	 */
	public static FKInfo[] chooseRelevantFKInfos
	(	
		FKInfo[] 	fkInfo, 
		int[] 		cols,
		boolean		addAllTypeIsFK)
	{
		if (fkInfo == null)
		{
			return (FKInfo[])null;
		}

		Vector<FKInfo> newfksVector = new Vector<FKInfo>();
		FKInfo[] newfks = null;

		/*
		** For each FKInfo
		*/
		for (int i = 0; i < fkInfo.length; i++)
		{
			if (addAllTypeIsFK && 
				(fkInfo[i].type == FOREIGN_KEY))
			{
				newfksVector.addElement(fkInfo[i]);
				continue;
			}
				
			int fkcollen = fkInfo[i].colArray.length;
			for (int fkCols = 0; fkCols < fkcollen; fkCols++)
			{
				for (int chcol = 0; chcol < cols.length; chcol++)
				{
					/*
					** If any column intersects, the FKInfo is
					** relevant.
					*/
					if (fkInfo[i].colArray[fkCols] == cols[chcol])
					{
						newfksVector.addElement(fkInfo[i]);
						
						// go to the next fk
						fkCols = fkcollen;
						break;
					}
				}
			}
		}

		
		/*
		** Now convert the vector into an array.
		*/
		int size = newfksVector.size();
		if (size > 0)
		{
			newfks = new FKInfo[size];
			for (int i = 0; i < size; i++)
			{
                newfks[i] = newfksVector.elementAt(i);
			}
		}
		return newfks;
	}
		
	//////////////////////////////////////////////
	//
	// FORMATABLE
	//
	//////////////////////////////////////////////
	/**
	 * Write this object out
	 *
	 * @param out write bytes here
	 *
 	 * @exception IOException thrown on error
	 */
	public void writeExternal(ObjectOutput out) throws IOException
	{
		/*
		** Row locations cannot be written unless they
		** have a valid value.  So we'll just write out
		** the format id, and create a new RowLocation
		** when we read it back in.
		*/
		FormatIdUtil.writeFormatIdInteger(out, rowLocation.getTypeFormatId());

        out.writeObject(schemaName);
		out.writeObject(tableName);
		out.writeInt(type);
		out.writeInt(stmtType);
		out.writeObject(refUUID);
		out.writeLong(refConglomNumber);
        out.writeObject(refConstraintID);
        out.writeBoolean(refConstraintIsDeferrable);

		ArrayUtil.writeArray(out, fkConstraintNames);
		ArrayUtil.writeArray(out, fkUUIDs);
		ArrayUtil.writeLongArray(out, fkConglomNumbers);
		ArrayUtil.writeBooleanArray(out, fkIsSelfReferencing);
		ArrayUtil.writeIntArray(out, colArray);
		ArrayUtil.writeIntArray(out, raRules);
        ArrayUtil.writeBooleanArray(out, deferrable);
        ArrayUtil.writeArray(out, fkIds);
	}

	/**
	 * Read this object from a stream of stored objects.
	 *
	 * @param in read this.
	 *
	 * @exception IOException					thrown on error
	 * @exception ClassNotFoundException		thrown on error
	 */
	public void readExternal(ObjectInput in)
		throws IOException, ClassNotFoundException
	{
		try
		{
			/*
			** Create a new RowLocation from the format id.
			*/
			int formatid = FormatIdUtil.readFormatIdInteger(in);
			rowLocation = (RowLocation)Monitor.newInstanceFromIdentifier(formatid);
			if (SanityManager.DEBUG)
			{
				SanityManager.ASSERT(rowLocation != null, "row location is null in readExternal");
			}

            schemaName = (String) in.readObject();
			tableName = (String)in.readObject();
			type = in.readInt();
			stmtType = in.readInt();
			refUUID = (UUID)in.readObject();
			refConglomNumber = in.readLong();
            refConstraintID = (UUID)in.readObject();
            refConstraintIsDeferrable = in.readBoolean();

			fkConstraintNames = new String[ArrayUtil.readArrayLength(in)];
			ArrayUtil.readArrayItems(in, fkConstraintNames);

			fkUUIDs = new UUID[ArrayUtil.readArrayLength(in)];
			ArrayUtil.readArrayItems(in, fkUUIDs);

			fkConglomNumbers = ArrayUtil.readLongArray(in);
			fkIsSelfReferencing = ArrayUtil.readBooleanArray(in);
			colArray = ArrayUtil.readIntArray(in);
			raRules = ArrayUtil.readIntArray(in);
            deferrable = ArrayUtil.readBooleanArray(in);
            fkIds = new UUID[ArrayUtil.readArrayLength(in)];
            ArrayUtil.readArrayItems(in, fkIds);
		}
		catch (StandardException exception)
		{
			throw new StreamCorruptedException(exception.toString());
		}
	}
	
	/**
	 * Get the formatID which corresponds to this class.
	 *
	 *	@return	the formatID of this class
	 */
    public  int getTypeFormatId()   { return StoredFormatIds.FK_INFO_V01_ID; }

	//////////////////////////////////////////////////////////////
	//
	// Misc
	//
	//////////////////////////////////////////////////////////////
	public String toString()
	{
		if (SanityManager.DEBUG)
		{
            StringBuilder str = new StringBuilder();
			str.append("\nTableName:\t\t\t");
			str.append(tableName);

			str.append("\ntype:\t\t\t\t");
			str.append((type == FOREIGN_KEY) ? "FOREIGN_KEY" : "REFERENCED_KEY");

            str.append("\nReferenced Key Index UUID:\t\t"+refUUID);
			str.append("\nReferenced Key ConglomNum:\t"+refConglomNumber);
            str.append("\nReferenced Key Constraint is deferrable:\t" +
                       refConstraintIsDeferrable);

			str.append("\nForeign Key Names:\t\t(");
			for (int i = 0; i < fkUUIDs.length; i++)
			{
				if (i > 0)
					str.append(",");
			
				str.append(fkConstraintNames[i]);
			}
			str.append(")");

			str.append("\nForeign Key UUIDS:\t\t(");
			for (int i = 0; i < fkUUIDs.length; i++)
			{
				if (i > 0)
					str.append(",");
			
				str.append(fkUUIDs[i]);
			}
			str.append(")");

			str.append("\nForeign Key Conglom Nums:\t(");
			for (int i = 0; i < fkConglomNumbers.length; i++)
			{
				if (i > 0)
					str.append(",");
			
				str.append(fkConglomNumbers[i]);
			}
			str.append(")");
		
			str.append("\nForeign Key isSelfRef:\t\t(");
			for (int i = 0; i < fkIsSelfReferencing.length; i++)
			{
				if (i > 0)
					str.append(",");
			
				str.append(fkIsSelfReferencing[i]);
			}
			str.append(")");
		
			str.append("\ncolumn Array:\t\t\t(");
			for (int i = 0; i < colArray.length; i++)
			{
				if (i > 0)
					str.append(",");
			
				str.append(colArray[i]);
			}
			str.append(")\n");

            str.append("\nDeferrable array:\t\t\t(");
            for (int i = 0; i < deferrable.length; i++)
            {
                if (i > 0)
                    str.append(",");

                str.append(colArray[i]);
            }
            str.append(")\n");



            return str.toString();
		}
		else
		{
			return "";
		}
	}
}
