package com.ctc.wstx.dtd;

import java.io.IOException;
import java.io.Writer;

import javax.xml.stream.XMLStreamException;

import com.ctc.wstx.exc.WstxIOException;

Simple utility class used by DTDReader when writing out flattened external DTD subset file. Writing functionality encapsulated here since it's specific to one mode of operation (flattening). 
 Note, too, that underlying IOExceptions are generally wrapped as XMLStreamExceptions. This is needed to reduce amount of work caller has to do for wrapping. It will still be possible to unwrap these exceptions further up the call stack if need be. /**
 * Simple utility class used by {@link DTDReader} when writing out
 * flattened external DTD subset file. Writing functionality encapsulated
 * here since it's specific to one mode of operation (flattening).
 *<p>
 * Note, too, that underlying {@link IOException}s are generally wrapped
 * as {@link XMLStreamException}s. This is needed to reduce amount of
 * work caller has to do for wrapping. It will still be possible to
 * unwrap these exceptions further up the call stack if need be.
 */
final class DTDWriter
{
    /*
    //////////////////////////////////////////////////
    // Configuration
    //////////////////////////////////////////////////
     */

    final Writer mWriter;

    final boolean mIncludeComments;

    final boolean mIncludeConditionals;

    final boolean mIncludePEs;

    /*
    //////////////////////////////////////////////////
    // Output status
    //////////////////////////////////////////////////
     */

    
Counter that indicates whether flattened output should be written to
(non-null) mWriter; values above zero indicate output is enabled,
zero and below that output is disabled.
Only enabled if mWriter is not
null; will be temporarily disabled during processing of content
that is not to be included (PE reference; or comments / conditional
sections if comment/cs output is suppressed)
/**
     * Counter that indicates whether flattened output should be written to
     * (non-null) mWriter; values above zero indicate output is enabled,
     * zero and below that output is disabled.
     * Only enabled if mWriter is not
     * null; will be temporarily disabled during processing of content
     * that is not to be included (PE reference; or comments / conditional
     * sections if comment/cs output is suppressed)
     */
    int mIsFlattening = 0;

    
Pointer to first character in the current input buffer that
has not yet been written to flatten writer.
/**
     * Pointer to first character in the current input buffer that
     * has not yet been written to flatten writer.
     */
    int mFlattenStart = 0;

    /*
    //////////////////////////////////////////////////
    // Life-cycle
    //////////////////////////////////////////////////
     */

    public DTDWriter(Writer out, boolean inclComments, boolean inclCond,
                     boolean inclPEs)
    {
        mWriter = out;
        mIncludeComments = inclComments;
        mIncludeConditionals = inclCond;
        mIncludePEs = inclPEs;

        mIsFlattening = 1; // starts enabled
    }

    /*
    //////////////////////////////////////////////////
    // Public API, accessors, state change
    //////////////////////////////////////////////////
     */

    public boolean includeComments() {
        return mIncludeComments;
    }

    public boolean includeConditionals() {
        return mIncludeConditionals;
    }

    public boolean includeParamEntities() {
        return mIncludePEs;
    }

    public void disableOutput()
    {
        --mIsFlattening;
    }

    public void enableOutput(int newStart)
    {
        ++mIsFlattening;
        mFlattenStart = newStart;
    }

    public void setFlattenStart(int ptr) {
        mFlattenStart = ptr;
    }

    public int getFlattenStart() {
        return mFlattenStart;
    }
    
    /*
    //////////////////////////////////////////////////
    // Public API, output methods:
    //////////////////////////////////////////////////
     */

    public void flush(char[] buf, int upUntil)
        throws XMLStreamException
    {
        if (mFlattenStart < upUntil) {
            if (mIsFlattening > 0) {
                try {
                    mWriter.write(buf, mFlattenStart, upUntil - mFlattenStart);
                } catch (IOException ioe) {
                    throw new WstxIOException(ioe);
                }
            }
            mFlattenStart = upUntil;
        }
    }

    
Method called when explicit output has to be done for flatten output:
this is usually done when there's need to do speculative checks
before it's known if some chars are output (when suppressing comments
or conditional sections)
/**
     * Method called when explicit output has to be done for flatten output:
     * this is usually done when there's need to do speculative checks
     * before it's known if some chars are output (when suppressing comments
     * or conditional sections)
     */
    public void output(String output)
        throws XMLStreamException
    {
        if (mIsFlattening > 0) {
            try {
                mWriter.write(output);
            } catch (IOException ioe) {
                throw new WstxIOException(ioe);
            }
        }
    }

    public void output(char c)
        throws XMLStreamException
    {
        if (mIsFlattening > 0) {
            try {
                mWriter.write(c);
            } catch (IOException ioe) {
                throw new WstxIOException(ioe);
            }
        }
    }
}