poi/src/java/org/apache/poi/hssf/model/LinkTable.java

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   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
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   distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.poi.hssf.model;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.record.CRNCountRecord;
import org.apache.poi.hssf.record.CRNRecord;
import org.apache.poi.hssf.record.CountryRecord;
import org.apache.poi.hssf.record.ExternSheetRecord;
import org.apache.poi.hssf.record.ExternalNameRecord;
import org.apache.poi.hssf.record.NameCommentRecord;
import org.apache.poi.hssf.record.NameRecord;
import org.apache.poi.hssf.record.Record;
import org.apache.poi.hssf.record.SupBookRecord;
import org.apache.poi.ss.formula.ptg.Area3DPtg;
import org.apache.poi.ss.formula.ptg.ErrPtg;
import org.apache.poi.ss.formula.ptg.NameXPtg;
import org.apache.poi.ss.formula.ptg.Ptg;
import org.apache.poi.ss.formula.ptg.Ref3DPtg;

/**
 * Link Table (OOO pdf reference: 4.10.3 ) <p/>
 *
 * The main data of all types of references is stored in the Link Table inside the Workbook Globals
 * Substream (4.2.5). The Link Table itself is optional and occurs only if there are any
 * references in the document.
 *  <p/>
 *
 *  In BIFF8 the Link Table consists of
 *  <ul>
 *  <li>zero or more EXTERNALBOOK Blocks<p/>
 *  	each consisting of
 *  	<ul>
 *  	<li>exactly one EXTERNALBOOK (0x01AE) record</li>
 *  	<li>zero or more EXTERNALNAME (0x0023) records</li>
 *  	<li>zero or more CRN Blocks<p/>
 *			each consisting of
 *  		<ul>
 *  		<li>exactly one XCT (0x0059)record</li>
 *  		<li>zero or more CRN (0x005A) records (documentation says one or more)</li>
 *  		</ul>
 *  	</li>
 *  	</ul>
 *  </li>
 *  <li>zero or one EXTERNSHEET (0x0017) record</li>
 *  <li>zero or more DEFINEDNAME (0x0018) records</li>
 *  </ul>
 */
final class LinkTable {

	// TODO make this class into a record aggregate
	private static final class CRNBlock {

		private final CRNCountRecord _countRecord;
		private final CRNRecord[] _crns;

		public CRNBlock(RecordStream rs) {
			_countRecord = (CRNCountRecord) rs.getNext();
			int nCRNs = _countRecord.getNumberOfCRNs();
			CRNRecord[] crns = new CRNRecord[nCRNs];
			for (int i = 0; i < crns.length; i++) {
				crns[i] = (CRNRecord) rs.getNext();
			}
			_crns = crns;
		}
		public CRNRecord[] getCrns() {
			return _crns.clone();
		}
	}

	private static final class ExternalBookBlock {
		private final SupBookRecord _externalBookRecord;
		private ExternalNameRecord[] _externalNameRecords;
		private final CRNBlock[] _crnBlocks;

		public ExternalBookBlock(RecordStream rs) {
			_externalBookRecord = (SupBookRecord) rs.getNext();
			List<Object> temp = new ArrayList<Object>();
			while(rs.peekNextClass() == ExternalNameRecord.class) {
			   temp.add(rs.getNext());
			}
			_externalNameRecords = new ExternalNameRecord[temp.size()];
			temp.toArray(_externalNameRecords);

			temp.clear();

			while(rs.peekNextClass() == CRNCountRecord.class) {
				temp.add(new CRNBlock(rs));
			}
			_crnBlocks = new CRNBlock[temp.size()];
			temp.toArray(_crnBlocks);
		}

        /**
         * Create a new block for internal references. It is called when constructing a new LinkTable.
         *
         * @see org.apache.poi.hssf.model.LinkTable#LinkTable(int, WorkbookRecordList)
         */
        public ExternalBookBlock(int numberOfSheets) {
			_externalBookRecord = SupBookRecord.createInternalReferences((short)numberOfSheets);
			_externalNameRecords = new ExternalNameRecord[0];
			_crnBlocks = new CRNBlock[0];
		}

        /**
         * Create a new block for registering add-in functions
         *
         * @see org.apache.poi.hssf.model.LinkTable#addNameXPtg(String)
         */
        public ExternalBookBlock() {
            _externalBookRecord = SupBookRecord.createAddInFunctions();
            _externalNameRecords = new ExternalNameRecord[0];
            _crnBlocks = new CRNBlock[0];
        }

		public SupBookRecord getExternalBookRecord() {
			return _externalBookRecord;
		}

		public String getNameText(int definedNameIndex) {
			return _externalNameRecords[definedNameIndex].getText();
		}
		
		public int getNameIx(int definedNameIndex) {
		   return _externalNameRecords[definedNameIndex].getIx();
		}

		/**
		 * Performs case-insensitive search
		 * @return -1 if not found
		 */
		public int getIndexOfName(String name) {
			for (int i = 0; i < _externalNameRecords.length; i++) {
				if(_externalNameRecords[i].getText().equalsIgnoreCase(name)) {
					return i;
				}
			}
			return -1;
		}

        public int getNumberOfNames() {
            return _externalNameRecords.length;
        }

        public int addExternalName(ExternalNameRecord rec){
            ExternalNameRecord[] tmp = new ExternalNameRecord[_externalNameRecords.length + 1];
            System.arraycopy(_externalNameRecords, 0, tmp, 0, _externalNameRecords.length);
            tmp[tmp.length - 1] = rec;
            _externalNameRecords = tmp;
            return _externalNameRecords.length - 1;
        }
    }

    private ExternalBookBlock[] _externalBookBlocks;
	private final ExternSheetRecord _externSheetRecord;
	private final List<NameRecord> _definedNames;
	private final int _recordCount;
	private final WorkbookRecordList _workbookRecordList; // TODO - would be nice to remove this

	public LinkTable(List<Record> inputList, int startIndex, WorkbookRecordList workbookRecordList, Map<String, NameCommentRecord> commentRecords) {

		_workbookRecordList = workbookRecordList;
		RecordStream rs = new RecordStream(inputList, startIndex);

		List<ExternalBookBlock> temp = new ArrayList<ExternalBookBlock>();
		while(rs.peekNextClass() == SupBookRecord.class) {
		   temp.add(new ExternalBookBlock(rs));
		}

		_externalBookBlocks = new ExternalBookBlock[temp.size()];
		temp.toArray(_externalBookBlocks);
		temp.clear();

		if (_externalBookBlocks.length > 0) {
			// If any ExternalBookBlock present, there is always 1 of ExternSheetRecord
			if (rs.peekNextClass() != ExternSheetRecord.class) {
				// not quite - if written by google docs
				_externSheetRecord = null;
			} else {
				_externSheetRecord = readExtSheetRecord(rs);
			}
		} else {
			_externSheetRecord = null;
		}

		_definedNames = new ArrayList<NameRecord>();
		// collect zero or more DEFINEDNAMEs id=0x18,
		//  with their comments if present
		while(true) {
		  Class nextClass = rs.peekNextClass();
		  if (nextClass == NameRecord.class) {
		    NameRecord nr = (NameRecord)rs.getNext();
		    _definedNames.add(nr);
		  }
		  else if (nextClass == NameCommentRecord.class) {
		    NameCommentRecord ncr = (NameCommentRecord)rs.getNext();
		    commentRecords.put(ncr.getNameText(), ncr);
		  }
		  else {
		    break;
		  }
		}

		_recordCount = rs.getCountRead();
		_workbookRecordList.getRecords().addAll(inputList.subList(startIndex, startIndex + _recordCount));
	}

	private static ExternSheetRecord readExtSheetRecord(RecordStream rs) {
		List<ExternSheetRecord> temp = new ArrayList<ExternSheetRecord>(2);
		while(rs.peekNextClass() == ExternSheetRecord.class) {
			temp.add((ExternSheetRecord) rs.getNext());
		}

		int nItems = temp.size();
		if (nItems < 1) {
			throw new RuntimeException("Expected an EXTERNSHEET record but got ("
					+ rs.peekNextClass().getName() + ")");
		}
		if (nItems == 1) {
			// this is the normal case. There should be just one ExternSheetRecord
			return temp.get(0);
		}
		// Some apps generate multiple ExternSheetRecords (see bug 45698).
		// It seems like the best thing to do might be to combine these into one
		ExternSheetRecord[] esrs = new ExternSheetRecord[nItems];
		temp.toArray(esrs);
		return ExternSheetRecord.combine(esrs);
	}

	public LinkTable(int numberOfSheets, WorkbookRecordList workbookRecordList) {
		_workbookRecordList = workbookRecordList;
		_definedNames = new ArrayList<NameRecord>();
		_externalBookBlocks = new ExternalBookBlock[] {
				new ExternalBookBlock(numberOfSheets),
		};
		_externSheetRecord = new ExternSheetRecord();
		_recordCount = 2;

		// tell _workbookRecordList about the 2 new records

		SupBookRecord supbook = _externalBookBlocks[0].getExternalBookRecord();

		int idx = findFirstRecordLocBySid(CountryRecord.sid);
		if(idx < 0) {
			throw new RuntimeException("CountryRecord not found");
		}
		_workbookRecordList.add(idx+1, _externSheetRecord);
		_workbookRecordList.add(idx+1, supbook);
	}

	/**
	 * TODO - would not be required if calling code used RecordStream or similar
	 */
	public int getRecordCount() {
		return _recordCount;
	}


	/**
	 * @param builtInCode a BUILTIN_~ constant from {@link NameRecord}
	 * @param sheetNumber 1-based sheet number
	 */
	public NameRecord getSpecificBuiltinRecord(byte builtInCode, int sheetNumber) {

		Iterator iterator = _definedNames.iterator();
		while (iterator.hasNext()) {
			NameRecord record = ( NameRecord ) iterator.next();

			//print areas are one based
			if (record.getBuiltInName() == builtInCode && record.getSheetNumber() == sheetNumber) {
				return record;
			}
		}

		return null;
	}

	public void removeBuiltinRecord(byte name, int sheetIndex) {
		//the name array is smaller so searching through it should be faster than
		//using the findFirstXXXX methods
		NameRecord record = getSpecificBuiltinRecord(name, sheetIndex);
		if (record != null) {
			_definedNames.remove(record);
		}
		// TODO - do we need "Workbook.records.remove(...);" similar to that in Workbook.removeName(int namenum) {}?
	}

	public int getNumNames() {
		return _definedNames.size();
	}

	public NameRecord getNameRecord(int index) {
		return _definedNames.get(index);
	}

	public void addName(NameRecord name) {
		_definedNames.add(name);

		// TODO - this is messy
		// Not the most efficient way but the other way was causing too many bugs
		int idx = findFirstRecordLocBySid(ExternSheetRecord.sid);
		if (idx == -1) idx = findFirstRecordLocBySid(SupBookRecord.sid);
		if (idx == -1) idx = findFirstRecordLocBySid(CountryRecord.sid);
		int countNames = _definedNames.size();
		_workbookRecordList.add(idx+countNames, name);
	}

	public void removeName(int namenum) {
		_definedNames.remove(namenum);
	}

	/**
	 * checks if the given name is already included in the linkTable
	 */
	public boolean nameAlreadyExists(NameRecord name)
	{
		// Check to ensure no other names have the same case-insensitive name
		for ( int i = getNumNames()-1; i >=0; i-- ) {
			NameRecord rec = getNameRecord(i);
			if (rec != name) {
				if (isDuplicatedNames(name, rec))
					return true;
			}
		}
		return false;
	}

	private static boolean isDuplicatedNames(NameRecord firstName, NameRecord lastName) {
		return lastName.getNameText().equalsIgnoreCase(firstName.getNameText())
			&& isSameSheetNames(firstName, lastName);
	}
	private static boolean isSameSheetNames(NameRecord firstName, NameRecord lastName) {
		return lastName.getSheetNumber() == firstName.getSheetNumber();
	}

	public String[] getExternalBookAndSheetName(int extRefIndex) {
		int ebIx = _externSheetRecord.getExtbookIndexFromRefIndex(extRefIndex);
		SupBookRecord ebr = _externalBookBlocks[ebIx].getExternalBookRecord();
		if (!ebr.isExternalReferences()) {
			return null;
		}
		// Sheet name only applies if not a global reference
		int shIx = _externSheetRecord.getFirstSheetIndexFromRefIndex(extRefIndex);
		String usSheetName = null;
		if(shIx >= 0) {
		   usSheetName = ebr.getSheetNames()[shIx];
		}
		return new String[] {
				ebr.getURL(),
				usSheetName,
		};
	}

	public int getExternalSheetIndex(String workbookName, String sheetName) {
		SupBookRecord ebrTarget = null;
		int externalBookIndex = -1;
		for (int i=0; i<_externalBookBlocks.length; i++) {
			SupBookRecord ebr = _externalBookBlocks[i].getExternalBookRecord();
			if (!ebr.isExternalReferences()) {
				continue;
			}
			if (workbookName.equals(ebr.getURL())) { // not sure if 'equals()' works when url has a directory
				ebrTarget = ebr;
				externalBookIndex = i;
				break;
			}
		}
		if (ebrTarget == null) {
			throw new RuntimeException("No external workbook with name '" + workbookName + "'");
		}
		int sheetIndex = getSheetIndex(ebrTarget.getSheetNames(), sheetName);

		int result = _externSheetRecord.getRefIxForSheet(externalBookIndex, sheetIndex);
		if (result < 0) {
			throw new RuntimeException("ExternSheetRecord does not contain combination ("
					+ externalBookIndex + ", " + sheetIndex + ")");
		}
		return result;
	}

	private static int getSheetIndex(String[] sheetNames, String sheetName) {
		for (int i = 0; i < sheetNames.length; i++) {
			if (sheetNames[i].equals(sheetName)) {
				return i;
			}

		}
		throw new RuntimeException("External workbook does not contain sheet '" + sheetName + "'");
	}

	/**
	 * @param extRefIndex as from a {@link Ref3DPtg} or {@link Area3DPtg}
	 * @return -1 if the reference is to an external book
	 */
	public int getIndexToInternalSheet(int extRefIndex) {
		return _externSheetRecord.getFirstSheetIndexFromRefIndex(extRefIndex);
	}
	
	public void updateIndexToInternalSheet(int extRefIndex, int offset) {
		_externSheetRecord.adjustIndex(extRefIndex, offset);
	}

	public int getSheetIndexFromExternSheetIndex(int extRefIndex) {
		if (extRefIndex >= _externSheetRecord.getNumOfRefs() || extRefIndex < 0) {
			return -1;
		}
		return _externSheetRecord.getFirstSheetIndexFromRefIndex(extRefIndex);
	}

	public int checkExternSheet(int sheetIndex) {
		int thisWbIndex = -1; // this is probably always zero
		for (int i=0; i<_externalBookBlocks.length; i++) {
			SupBookRecord ebr = _externalBookBlocks[i].getExternalBookRecord();
			if (ebr.isInternalReferences()) {
				thisWbIndex = i;
				break;
			}
		}
		if (thisWbIndex < 0) {
			throw new RuntimeException("Could not find 'internal references' EXTERNALBOOK");
		}

		//Trying to find reference to this sheet
		int i = _externSheetRecord.getRefIxForSheet(thisWbIndex, sheetIndex);
		if (i>=0) {
			return i;
		}
		//We haven't found reference to this sheet
		return _externSheetRecord.addRef(thisWbIndex, sheetIndex, sheetIndex);
	}

	/**
	 * copied from Workbook
	 */
	private int findFirstRecordLocBySid(short sid) {
		int index = 0;
		for (Iterator iterator = _workbookRecordList.iterator(); iterator.hasNext(); ) {
			Record record = ( Record ) iterator.next();

			if (record.getSid() == sid) {
				return index;
			}
			index ++;
		}
		return -1;
	}

	public String resolveNameXText(int refIndex, int definedNameIndex) {
		int extBookIndex = _externSheetRecord.getExtbookIndexFromRefIndex(refIndex);
		return _externalBookBlocks[extBookIndex].getNameText(definedNameIndex);
	}
	public int resolveNameXIx(int refIndex, int definedNameIndex) {
      int extBookIndex = _externSheetRecord.getExtbookIndexFromRefIndex(refIndex);
      return _externalBookBlocks[extBookIndex].getNameIx(definedNameIndex);
	}

	public NameXPtg getNameXPtg(String name) {
		// first find any external book block that contains the name:
		for (int i = 0; i < _externalBookBlocks.length; i++) {
			int definedNameIndex = _externalBookBlocks[i].getIndexOfName(name);
			if (definedNameIndex < 0) {
				continue;
			}
			// found it.
			int sheetRefIndex = findRefIndexFromExtBookIndex(i);
			if (sheetRefIndex >= 0) {
				return new NameXPtg(sheetRefIndex, definedNameIndex);
			}
		}
		return null;
	}

    /**
     * Register an external name in this workbook
     *
     * @param name  the name to register
     * @return a NameXPtg describing this name 
     */
    public NameXPtg addNameXPtg(String name) {
        int extBlockIndex = -1;
        ExternalBookBlock extBlock = null;

        // find ExternalBlock for Add-In functions and remember its index
        for (int i = 0; i < _externalBookBlocks.length; i++) {
            SupBookRecord ebr = _externalBookBlocks[i].getExternalBookRecord();
            if (ebr.isAddInFunctions()) {
                extBlock = _externalBookBlocks[i];
                extBlockIndex = i;
                break;
            }
        }
        // An ExternalBlock for Add-In functions was not found. Create a new one.
        if (extBlock == null) {
            extBlock = new ExternalBookBlock();

            ExternalBookBlock[] tmp = new ExternalBookBlock[_externalBookBlocks.length + 1];
            System.arraycopy(_externalBookBlocks, 0, tmp, 0, _externalBookBlocks.length);
            tmp[tmp.length - 1] = extBlock;
            _externalBookBlocks = tmp;

            extBlockIndex = _externalBookBlocks.length - 1;

            // add the created SupBookRecord before ExternSheetRecord
            int idx = findFirstRecordLocBySid(ExternSheetRecord.sid);
            _workbookRecordList.add(idx, extBlock.getExternalBookRecord());

            // register the SupBookRecord in the ExternSheetRecord
            // -2 means that the scope of this name is Workbook and the reference applies to the entire workbook.
            _externSheetRecord.addRef(_externalBookBlocks.length - 1, -2, -2);
        }

        // create a ExternalNameRecord that will describe this name
        ExternalNameRecord extNameRecord = new ExternalNameRecord();
        extNameRecord.setText(name);
        // The docs don't explain why Excel set the formula to #REF!
        extNameRecord.setParsedExpression(new Ptg[]{ErrPtg.REF_INVALID});

        int nameIndex = extBlock.addExternalName(extNameRecord);
        int supLinkIndex = 0;
        // find the posistion of the Add-In SupBookRecord in the workbook stream,
        // the created ExternalNameRecord will be appended to it
        for (Iterator<Record> iterator = _workbookRecordList.iterator(); iterator.hasNext(); supLinkIndex++) {
            Record record = iterator.next();
            if (record instanceof SupBookRecord) {
                if (((SupBookRecord) record).isAddInFunctions()) break;
            }
        }
        int numberOfNames = extBlock.getNumberOfNames();
        // a new name is inserted in the end of the SupBookRecord, after the last name
        _workbookRecordList.add(supLinkIndex + numberOfNames, extNameRecord);
        int ix = _externSheetRecord.getRefIxForSheet(extBlockIndex, -2 /* the scope is workbook*/);
        return new NameXPtg(ix, nameIndex);
    }

    private int findRefIndexFromExtBookIndex(int extBookIndex) {
		return _externSheetRecord.findRefIndexFromExtBookIndex(extBookIndex);
	}
   
	/**
	 * Changes an external referenced file to another file.
	 * A formular in Excel which refers a cell in another file is saved in two parts: 
	 * The referenced file is stored in an reference table. the row/cell information is saved separate.
	 * This method invokation will only change the reference in the lookup-table itself.
	 * @param oldUrl The old URL to search for and which is to be replaced
	 * @param newUrl The URL replacement
	 * @return true if the oldUrl was found and replaced with newUrl. Otherwise false
	 */
	public boolean changeExternalReference(String oldUrl, String newUrl) {
		for(ExternalBookBlock ex : _externalBookBlocks) {
			SupBookRecord externalRecord = ex.getExternalBookRecord();
			if (externalRecord.isExternalReferences() 
				&& externalRecord.getURL().equals(oldUrl)) {
				
				externalRecord.setURL(newUrl);
				return true;
			}
		}
		return false;
	}

}