package gov.nasa.gsfc.spdf.cdfj;
import java.util.*;
import java.nio.*;
/**
 * Abstract base class for GenericReader.
 * Provides methods to access CDF properties, global attributes, variable
 * properties and attributes.
 */
public abstract class MetaData {
    CDFImpl thisCDF;
    /**
     * Returns ByteOrder.LITTLE_ENDIAN, or ByteOrder.BIG_ENDIAN depending
     * the CDF encoding
     * @return 
     */
    public final ByteOrder getByteOrder() {
        return thisCDF.getByteOrder();
    }

    /**
     * Returns whether the arrays are stored in row major order in the source
     * @return 
     */
    public final boolean rowMajority() {
        return thisCDF.rowMajority();
    }

    /**
     * Returns names of variables in the CDF
     * @return 
     */
    public final String [] getVariableNames() {
        return thisCDF.getVariableNames();
    }

    /**
     * returns variable names of a given VAR_TYPE in a String[]
     * @param type
     * @return 
     */
    public final String [] getVariableNames(String type) {
        return thisCDF.getVariableNames(type);
    }

    /**
     * Returns names of global attributes.
     * @return 
     */
    public final String [] globalAttributeNames() {
        return thisCDF.globalAttributeNames();
    }

    /**
     * Returns names of variable attributes.
     * @param name
     * @return 
     */
    public final String [] variableAttributeNames(String name) {
        return thisCDF.variableAttributeNames(name);
    }

    /**
     * Returns value of the first entry for the named global attribute.
     * <p>
     * For a  character string attribute, a String[] is returned
     * For a  numeric attribute, a long[] is returned for long type;
     * double[] is returned for all other numeric types.
     * <p>
     * This method is deprecated. Use {@link #getGlobalAttribute(String atr)
     * getGlobalAttribute(String atr)} method to extract all entries.
     * @param atr
     * @return 
     */
    public final Object getAttribute( String atr) {
        return thisCDF.getAttribute(atr);
    }

    /**
     * Returns number of entries for the named global attribute.
     * @param atr
     * @return 
     * @throws gov.nasa.gsfc.spdf.cdfj.CDFException.ReaderError 
     */
    public final int globalAttributeEntryCount(String atr) throws
        CDFException.ReaderError {
        return getGlobalAttribute(atr).getEntryCount();
    }

    /**
     * Returns value of the named attribute for specified variable.For a  character string attribute, a Vector of String is returned.For a  numeric attribute, a Vector of size 1 is returned.The 
 single element of the Vector is a long[] if attribute's type is long;
 For all other numeric types, the element is a double[].
     * @param varName
     * @param aname
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final Object getAttribute( String varName,
        String aname) throws CDFException.ReaderError {
        return thisCDF.getAttribute(varName, aname);
    }

    /**
     * Returns list of {@link AttributeEntry AttributeEntry} objects for
     * the named attribute for the named variable.
     * @param varName
     * @param aname
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final Vector<AttributeEntry> getAttributeEntries(
         String varName, String aname) throws CDFException.ReaderError {
        return thisCDF.getAttributeEntries(varName, aname);
    }

    /**
     * Returns list of {@link AttributeEntry AttributeEntry} objects for the
     * named global attribute.
     * @param aname
     * @return 
     * @throws gov.nasa.gsfc.spdf.cdfj.CDFException.ReaderError 
     */
    public final Vector<AttributeEntry> getAttributeEntries(
         String aname) throws CDFException.ReaderError {
        try {
            return thisCDF.getAttributeEntries(aname);
        } catch (Throwable th) {
            throw new CDFException.ReaderError(th.getMessage());
        }
    }

    /**
     * Returns {@link GlobalAttribute GlobalAttribute} object for
     * the named global attribute.
     * @param atr
     * @return 
     * @throws gov.nasa.gsfc.spdf.cdfj.CDFException.ReaderError 
     */
    public final GlobalAttribute getGlobalAttribute( String atr)
        throws CDFException.ReaderError {
        try {
            return thisCDF.getGlobalAttribute(atr);
        } catch (Throwable th) {
            throw new CDFException.ReaderError(th.getMessage());
        }
    }

    /**
     * Returns an indication of the record varying property of a variable.
     * @param varName
     * @return false if variable has a constant value for this CDF.
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean recordVariance( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).recordVariance();
    }

    /**
     * Returns whether the values of the variable are represented in a
     * compressed form in the CDF.For variables declared to be compressed, CDF specification allows
 the values to be stored in uncompressed form if the latter results in
 a smaller size.
     * @param varName
     * @return
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean isCompressed( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).isCompressed();
    }

    /**
     * Returns CDF type of the variable.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int getType( String varName) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getType();
    }

    /**
     * Returns size of a data item for the given variable.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int getDataItemSize( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getDataItemSize();
    }

    /**
     * Returns given variable's number property.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int getNumber( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getNumber();
    }

    /**
     * Returns given variable's 'number of elements' property.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int getNumberOfElements( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getNumberOfElements();
    }

    /**
     * Returns 'number of values' property of the given variable.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int getNumberOfValues( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getNumberOfValues();
    }

    /**
     * Returns 'pad value' property of the given variable.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final Object getPadValue( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getPadValue();
    }

    /**
     * Returns 'pad value' property of the given variable subject to the given
     * precision  preservation constraint.
     * @param varName
     * @param preservePrecision
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final Object getPadValue( String varName,
        boolean preservePrecision) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        Variable var = thisCDF.getVariable(varName);
        return var.getPadValue(preservePrecision);
    }

    /**
     * Returns dimensions the given variable.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int[] getDimensions( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getDimensions();
    }

    /**
     * Returns 'varys' property of the given variable.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean[] getVarys( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getVarys();
    }

    /**
     * Returns effective rank of this variable.Dimensions for which dimVarys is false do not count.
     * @param varName
     * @return
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int getEffectiveRank( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getEffectiveRank();
    }

    /**
     * Shows whether one or more records (in the range returned by
     * getRecordRange()) are missing. 
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean isMissingRecords( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).isMissingRecords();
    }

    /**
     * Returns record range for this variable
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int[] getRecordRange( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getRecordRange();
    }

    /**
     * returns whether conversion of this variable to type specified by
     * cl is supported while preserving precision.
     * @param varName
     * @param cl
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean isCompatible( String varName, Class cl) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        try {
            return thisCDF.getVariable(varName).isCompatible(cl);
        } catch (Throwable th) {
            throw new CDFException.ReaderError(th.getMessage());
        }
    }

    /**
     * Returns whether conversion of this variable to type specified by
     * cl is supported under the given precision preserving constraint.
     * @param varName
     * @param preserve
     * @param cl
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean isCompatible( String varName,
        Class cl, boolean preserve) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        Variable var = thisCDF.getVariable(varName);
        return var.isCompatible(cl, preserve);
    }

    /**
     * Return whether the missing record should be assigned the last 
     * seen value.If none has been seen, pad value is assigned.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean missingRecordValueIsPrevious(
        String varName) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        Variable var = thisCDF.getVariable(varName);
        return var.missingRecordValueIsPrevious();
    }

    /**
     * Return whether the missing record should be assigned the pad 
     * value.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean missingRecordValueIsPad(
        String varName) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        Variable var = thisCDF.getVariable(varName);
        return var.missingRecordValueIsPad();
    } 

    /**
     * Return element count for this variable's dimensions.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final Vector<Integer> getElementCount(
        String varName) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getElementCount();
    } 

    /**
     * Returns effective dimensions of the given variable.Dimensions for which dimVarys is false are ignored.
     * @param varName
     * @return
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final int[] getEffectiveDimensions(
        String varName) throws CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        Variable var = thisCDF.getVariable(varName);
        return var.getEffectiveDimensions();
    } 

    /**
     * Returns whether the given variable represents time.
     * @param varName
     * @return 
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final boolean isTimeType( String varName) throws
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError(
            "CDF does not hava a variable named " + varName);
        Variable var = thisCDF.getVariable(varName);
        int type = var.getType();
        boolean isTimeType = (CDFTimeType.EPOCH.getValue() == type);
        isTimeType |= (CDFTimeType.EPOCH16.getValue() == type);
        isTimeType |= (CDFTimeType.TT2000.getValue() == type);
        return isTimeType;
    }

    /**
     * Returns whether there is a variable with the given name.
     * @param varName
     * @return 
     */
    public final boolean existsVariable(String varName) {
        if (varName == null) return false;
        return (thisCDF.getVariable(varName) != null);
    }

    /**
     *
     * @param varName
     * @return
     * @throws CDFException.ReaderError
     */
    public abstract String userTimeVariableName(String varName) throws
        CDFException.ReaderError;

    /**
     * Returns the name of the time variable for the given variable.
     * @param    varName   variable name
     * @return  String
     * @throws   CDFException.ReaderError  if variable does not exist
     */
    public final String getTimeVariableName(String varName) throws Throwable {
        if (!existsVariable(varName)) throw new Throwable (
            "CDF does not hava a variable named " + varName);
        String tname = userTimeVariableName(varName);
        if (tname != null) return tname;
        // assume istp convention
        Variable var = thisCDF.getVariable(varName);
        String vname = var.getName();
        Vector v = (Vector)thisCDF.getAttribute(vname, "DEPEND_0");
        if (v.size() > 0) tname = (String)v.elementAt(0);
        if (tname == null) {
            if (!vname.equals("Epoch")) {
                if (thisCDF.getVariable("Epoch") != null) {
                    tname = "Epoch";
                    System.out.println("Variable " + vname + " has no DEPEND_0"+
                    " attribute. Variable named Epoch " +
                    "assumed to be the right time variable");
                } else {
                    throw new Throwable("Time variable not found for " + vname);
                }
            } else {
                throw new Throwable("Variable named Epoch has no DEPEND_0 " +
                "attribute.");
            }
        }
        return tname;
    }

    /**
     * Identifies the leap second table used in creating this CDF.Returns the id of the last leap second in the leap second table.
     * Leap second id is an integer = year*10000 + month*100 + day, where
 year, month and day refer to the day following the leap second. Until
 2015, leap second has been added at the end of December, or June. Thus
 leapSecondId is either (10000*year + 101), or (10000*year + 701).
     * @return 
     */
    public final int getLastLeapSecondId() {
        return thisCDF.lastLeapSecondId;
    }

    /**
     * Returns the blocking factor used to compress this variable.See the CDF User's Guide for details.
     * @param varName
     * @return 
     * @throws gov.nasa.gsfc.spdf.cdfj.CDFException.ReaderError 
     */
    public final int getBlockingFactor(String varName) throws 
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError (
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).getBlockingFactor();
    }
    /**
     * Returns whether a variable of type r-variable..See the CDF User's Guide for details.
     * @param varName
     * @return 
     * @throws gov.nasa.gsfc.spdf.cdfj.CDFException.ReaderError 
     */
    public final boolean isTypeR(String varName) throws 
        CDFException.ReaderError {
        if (!existsVariable(varName)) throw new CDFException.ReaderError (
            "CDF does not hava a variable named " + varName);
        return thisCDF.getVariable(varName).isTypeR();
    }
}