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/*

 * Created on 16-feb-2004

 *

 * To change the template for this generated file go to

 * Window>Preferences>Java>Code Generation>Code and Comments

 */

package com.iver.cit.gvsig.fmap.drivers.dbf;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.ByteOrder;

import java.util.Calendar;

import java.util.Date;

import com.iver.utiles.bigfile.BigByteBuffer;

/**

 * Class to represent the header of a Dbase III file. Creation date: (5/15/2001

 * 5:15:30 PM)

 */

public class DbaseFileHeader {

    // Constant for the size of a record

    private int FILE_DESCRIPTOR_SIZE = 32;

    // type of the file, must be 03h

    private int myFileType = 0x03;

    // Date the file was last updated.

    private Date myUpdateDate = new Date();

    // Number of records in the datafile

    private int myNumRecords = 0;

    // Length of the header structure

    private int myHeaderLength;

    // Length of the records

    private int myRecordLength;

    // Number of fields in the record.

    private int myNumFields;

    // collection of header records.

    private DbaseFieldDescriptor[] myFieldDescriptions;

    /**

     * DbaseFileHreader constructor comment.

     */

    public DbaseFileHeader() {

        super();

    }

    /**

     * Add a column to this DbaseFileHeader. The type is one of (C N L or D)

     * character, number, logical(true/false), or date. The Field length is

     * the total length in bytes reserved for this column. The decimal count

     * only applies to numbers(N), and floating point values (F), and refers

     * to the number of characters to reserve after the decimal point.

     *

     * @param inFieldName DOCUMENT ME!

     * @param inFieldType DOCUMENT ME!

     * @param inFieldLength DOCUMENT ME!

     * @param inDecimalCount DOCUMENT ME!

     *

     * @throws Exception DOCUMENT ME!

     */

    public void addColumn(String inFieldName, char inFieldType,

        int inFieldLength, int inDecimalCount) throws Exception {

        if (inFieldLength <= 0) {

            inFieldLength = 1;

        }

        if (myFieldDescriptions == null) {

            myFieldDescriptions = new DbaseFieldDescriptor[0];

        }

        int tempLength = 1; // the length is used for the offset, and there is a * for deleted as the first byte

        DbaseFieldDescriptor[] tempFieldDescriptors = new DbaseFieldDescriptor[myFieldDescriptions.length +

            1];

        for (int i = 0; i < myFieldDescriptions.length; i++) {

            myFieldDescriptions[i].myFieldDataAddress = tempLength;

            tempLength = tempLength + myFieldDescriptions[i].myFieldLength;

            tempFieldDescriptors[i] = myFieldDescriptions[i];

        }

        tempFieldDescriptors[myFieldDescriptions.length] = new DbaseFieldDescriptor();

        tempFieldDescriptors[myFieldDescriptions.length].myFieldLength = inFieldLength;

        tempFieldDescriptors[myFieldDescriptions.length].myDecimalCount = inDecimalCount;

        tempFieldDescriptors[myFieldDescriptions.length].myFieldDataAddress = tempLength;

        // set the field name

        String tempFieldName = inFieldName;

        if (tempFieldName == null) {

            tempFieldName = "NoName";

        }

        if (tempFieldName.length() > 11) {

            tempFieldName = tempFieldName.substring(0, 11);

            warn("FieldName " + inFieldName +

                " is longer than 11 characters, truncating to " +

                tempFieldName);

        }

        tempFieldDescriptors[myFieldDescriptions.length].myFieldName = tempFieldName;

        // the field type

        if ((inFieldType == 'C') || (inFieldType == 'c')) {

            tempFieldDescriptors[myFieldDescriptions.length].myFieldType = 'C';

            if (inFieldLength > 254) {

                warn("Field Length for " + inFieldName + " set to " +

                    inFieldLength +

                    " Which is longer than 254, not consistent with dbase III");

            }

        } else if ((inFieldType == 'S') || (inFieldType == 's')) {

            tempFieldDescriptors[myFieldDescriptions.length].myFieldType = 'C';

            warn("Field type for " + inFieldName +

                " set to S which is flat out wrong people!, I am setting this to C, in the hopes you meant character.");

            if (inFieldLength > 254) {

                warn("Field Length for " + inFieldName + " set to " +

                    inFieldLength +

                    " Which is longer than 254, not consistent with dbase III");

            }

            tempFieldDescriptors[myFieldDescriptions.length].myFieldLength = 8;

        } else if ((inFieldType == 'D') || (inFieldType == 'd')) {

            tempFieldDescriptors[myFieldDescriptions.length].myFieldType = 'D';

            if (inFieldLength != 8) {

                warn("Field Length for " + inFieldName + " set to " +

                    inFieldLength + " Setting to 8 digets YYYYMMDD");

            }

            tempFieldDescriptors[myFieldDescriptions.length].myFieldLength = 8;

        } else if ((inFieldType == 'F') || (inFieldType == 'f')) {

            tempFieldDescriptors[myFieldDescriptions.length].myFieldType = 'F';

            if (inFieldLength > 20) {

                warn("Field Length for " + inFieldName + " set to " +

                    inFieldLength +

                    " Preserving length, but should be set to Max of 20 not valid for dbase IV, and UP specification, not present in dbaseIII.");

            }

        } else if ((inFieldType == 'N') || (inFieldType == 'n')) {

            tempFieldDescriptors[myFieldDescriptions.length].myFieldType = 'N';

            if (inFieldLength > 18) {

                warn("Field Length for " + inFieldName + " set to " +

                    inFieldLength +

                    " Preserving length, but should be set to Max of 18 for dbase III specification.");

            }

            if (inDecimalCount < 0) {

                warn("Field Decimal Position for " + inFieldName + " set to " +

                    inDecimalCount +

                    " Setting to 0 no decimal data will be saved.");

                tempFieldDescriptors[myFieldDescriptions.length].myDecimalCount = 0;

            }

            if (inDecimalCount > (inFieldLength - 1)) {

                warn("Field Decimal Position for " + inFieldName + " set to " +

                    inDecimalCount + " Setting to " + (inFieldLength - 1) +

                    " no non decimal data will be saved.");

                tempFieldDescriptors[myFieldDescriptions.length].myDecimalCount = inFieldLength -

                    1;

            }

        } else if ((inFieldType == 'L') || (inFieldType == 'l')) {

            tempFieldDescriptors[myFieldDescriptions.length].myFieldType = 'L';

            if (inFieldLength != 1) {

                warn("Field Length for " + inFieldName + " set to " +

                    inFieldLength +

                    " Setting to length of 1 for logical fields.");

            }

            tempFieldDescriptors[myFieldDescriptions.length].myFieldLength = 1;

        } else {

            throw new Exception("Undefined field type " + inFieldType +

                " For column " + inFieldName);

        }

        // the length of a record

        tempLength = tempLength +

            tempFieldDescriptors[myFieldDescriptions.length].myFieldLength;

        // set the new fields.

        myFieldDescriptions = tempFieldDescriptors;

        myHeaderLength = 33 + (32 * myFieldDescriptions.length);

        myNumFields = myFieldDescriptions.length;

        myRecordLength = tempLength;

    }

    /**

     * Remove a column from this DbaseFileHeader.

     *

     * @param inFieldName DOCUMENT ME!

     *

     * @return index of the removed column, -1 if no found

     */

    public int removeColumn(String inFieldName) {

        int retCol = -1;

        int tempLength = 1;

        DbaseFieldDescriptor[] tempFieldDescriptors = new DbaseFieldDescriptor[myFieldDescriptions.length -

            1];

        for (int i = 0, j = 0; i < myFieldDescriptions.length; i++) {

            if (!inFieldName.equalsIgnoreCase(

                        myFieldDescriptions[i].myFieldName.trim())) {

                // if this is the last field and we still haven't found the

                // named field

                if ((i == j) && (i == (myFieldDescriptions.length - 1))) {

                    System.err.println("Could not find a field named '" +

                        inFieldName + "' for removal");

                    return retCol;

                }

                tempFieldDescriptors[j] = myFieldDescriptions[i];

                tempFieldDescriptors[j].myFieldDataAddress = tempLength;

                tempLength += tempFieldDescriptors[j].myFieldLength;

                // only increment j on non-matching fields

                j++;

            } else {

                retCol = i;

            }

        }

        // set the new fields.

        myFieldDescriptions = tempFieldDescriptors;

        myHeaderLength = 33 + (32 * myFieldDescriptions.length);

        myNumFields = myFieldDescriptions.length;

        myRecordLength = tempLength;

        return retCol;

    }

    /**

     * DOCUMENT ME!

     *

     * @param inWarn DOCUMENT ME!

     */

    private void warn(String inWarn) {

        //TODO Descomentar esto cuando tenga la clase warning support

        //            warnings.warn(inWarn);

    }

    /**

     * Return the Field Descriptor for the given field.

     *

     * @param inIndex DOCUMENT ME!

     *

     * @return DOCUMENT ME!

     */

    public DbaseFieldDescriptor getFieldDescription(int inIndex) {

        return myFieldDescriptions[inIndex];

    }

    // Retrieve the length of the field at the given index

    public int getFieldLength(int inIndex) {

        return myFieldDescriptions[inIndex].myFieldLength;

    }

    // Retrieve the location of the decimal point within the field.

    public int getFieldDecimalCount(int inIndex) {

        return myFieldDescriptions[inIndex].myDecimalCount;

    }

    // Retrieve the Name of the field at the given index

    public String getFieldName(int inIndex) {

        return myFieldDescriptions[inIndex].myFieldName;

    }

    // Retrieve the type of field at the given index

    public char getFieldType(int inIndex) {

        return myFieldDescriptions[inIndex].myFieldType;

    }

    /**

     * Return the date this file was last updated.

     *

     * @return DOCUMENT ME!

     */

    public Date getLastUpdateDate() {

        return myUpdateDate;

    }

    /**

     * Return the number of fields in the records.

     *

     * @return DOCUMENT ME!

     */

    public int getNumFields() {

        return myNumFields;

    }

    /**

     * Return the number of records in the file

     *

     * @return DOCUMENT ME!

     */

    public int getNumRecords() {

        return myNumRecords;

    }

    /**

     * Return the length of the records in bytes.

     *

     * @return DOCUMENT ME!

     */

    public int getRecordLength() {

        return myRecordLength;

    }

    /**

     * Return the length of the header

     *

     * @return DOCUMENT ME!

     */

    public int getHeaderLength() {

        return myHeaderLength;

    }

    /**

     * Read the header data from the DBF file.

     *

     * @param in DOCUMENT ME!

     *

     * @throws IOException DOCUMENT ME!

     */

    public void readHeader(BigByteBuffer in) throws IOException {

        // type of file.

        myFileType = in.get();

        if (myFileType != 0x03) {

            throw new IOException("Unsupported DBF file Type " +

                Integer.toHexString(myFileType));

        }

        // parse the update date information.

        int tempUpdateYear = (int) in.get();

        int tempUpdateMonth = (int) in.get();

        int tempUpdateDay = (int) in.get();

        tempUpdateYear = tempUpdateYear + 1900;

        Calendar c = Calendar.getInstance();

        c.set(Calendar.YEAR, tempUpdateYear);

        c.set(Calendar.MONTH, tempUpdateMonth - 1);

        c.set(Calendar.DATE, tempUpdateDay);

        myUpdateDate = c.getTime();

        // read the number of records.

        in.order(ByteOrder.LITTLE_ENDIAN);

        myNumRecords = in.getInt();

        // read the length of the header structure.

        myHeaderLength = in.getShort();

        // read the length of a record

        myRecordLength = in.getShort();

        in.order(ByteOrder.BIG_ENDIAN);

        // skip the reserved bytes in the header.

        in.position(in.position() + 20);

        // calculate the number of Fields in the header

        myNumFields = (myHeaderLength - FILE_DESCRIPTOR_SIZE - 1) / FILE_DESCRIPTOR_SIZE;

        // read all of the header records

        myFieldDescriptions = new DbaseFieldDescriptor[myNumFields];

        int fieldOffset = 0;

        for (int i = 0; i < myNumFields; i++) {

            myFieldDescriptions[i] = new DbaseFieldDescriptor();

            // read the field name

            byte[] buffer = new byte[11];

            in.get(buffer);

            myFieldDescriptions[i].myFieldName = new String(buffer);

            // read the field type

            myFieldDescriptions[i].myFieldType = (char) in.get();

            // read the field data address, offset from the start of the record.

            myFieldDescriptions[i].myFieldDataAddress = in.getInt();

            // read the field length in bytes

            int tempLength = (int) in.get();

            if (tempLength < 0) {

                tempLength = tempLength + 256;

            }

            myFieldDescriptions[i].myFieldLength = tempLength;

            // read the field decimal count in bytes

            myFieldDescriptions[i].myDecimalCount = (int) in.get();

            // NUEVO: Calculamos los offsets aqu? para no

            // tener que recalcular cada vez que nos piden

            // algo.            

            myFieldDescriptions[i].myFieldDataAddress = fieldOffset;

            fieldOffset += tempLength;

            // Fin NUEVO

            // read the reserved bytes.

            in.position(in.position() + 14);

        }

        // Last byte is a marker for the end of the field definitions.

        in.get();

    }

    /**

     * Set the number of records in the file

     *

     * @param inNumRecords DOCUMENT ME!

     */

    protected void setNumRecords(int inNumRecords) {

        myNumRecords = inNumRecords;

    }

    /*

     * Write the header data to the DBF file.

     *

     * @param out DOCUMENT ME!

     *

     * @throws Exception DOCUMENT ME!

     *

           public void writeHeader(LEDataOutputStream out) throws Exception {

               // write the output file type.

               out.writeByte(myFileType);

               // write the date stuff

               Calendar c = Calendar.getInstance();

               c.setTime(new Date());

               out.writeByte(c.get(Calendar.YEAR) - 1900);

               out.writeByte(c.get(Calendar.MONTH) + 1);

               out.writeByte(c.get(Calendar.DAY_OF_MONTH));

               // write the number of records in the datafile.

               out.writeInt(myNumRecords);

               // write the length of the header structure.

               out.writeShort(myHeaderLength);

               // write the length of a record

               out.writeShort(myRecordLength);

               // write the reserved bytes in the header

               for (int i = 0; i < 20; i++)

                   out.writeByte(0);

               // write all of the header records

               int tempOffset = 0;

               for (int i = 0; i < myFieldDescriptions.length; i++) {

                   // write the field name

                   for (int j = 0; j < 11; j++) {

                       if (myFieldDescriptions[i].myFieldName.length() > j) {

                           out.writeByte((int) myFieldDescriptions[i].myFieldName.charAt(

                                   j));

                       } else {

                           out.writeByte(0);

                       }

                   }

                   // write the field type

                   out.writeByte(myFieldDescriptions[i].myFieldType);

                   // write the field data address, offset from the start of the record.

                   out.writeInt(tempOffset);

                   tempOffset += myFieldDescriptions[i].myFieldLength;

                   // write the length of the field.

                   out.writeByte(myFieldDescriptions[i].myFieldLength);

                   // write the decimal count.

                   out.writeByte(myFieldDescriptions[i].myDecimalCount);

                   // write the reserved bytes.

                   for (int j = 0; j < 14; j++)

                       out.writeByte(0);

               }

               // write the end of the field definitions marker

               out.writeByte(0x0D);

           }

     */

    /**

     * Class for holding the information assicated with a record.

     */

    class DbaseFieldDescriptor {

        // Field Name

        String myFieldName;

        // Field Type (C N L D F or M)

        char myFieldType;

        // Field Data Address offset from the start of the record.

        int myFieldDataAddress;

        // Length of the data in bytes

        int myFieldLength;

        // Field decimal count in Binary, indicating where the decimal is

        int myDecimalCount;

    }

}