SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package net.multiphasicapps.jsr353;

import com.oracle.json.JsonException;
import com.oracle.json.stream.JsonLocation;
import com.oracle.json.stream.JsonParser;
import com.oracle.json.stream.JsonParsingException;
import java.io.IOException;
import java.io.Reader;
import java.util.NoSuchElementException;

/**
 * This is an event based parser which decodes JSON input data.
 *
 * @since 2014/08/01
 */
public class ImplParser
    extends BaseDecoder
    implements JsonParser
{
    /** Current event. */
    private Event _e;
    
    /** Has been closed. */
    private boolean _closed;
    
    /**
     * Reads JSON data from the specified stream.
     *
     * @param __r Stream to read from.
     * @since 2014/08/01
     */
    public ImplParser(Reader __r)
    {
        super(new ReaderInput(__r));
    }
    
    /**
     * Reads JSON data from an input.
     *
     * @param __i Input mechanism to use.
     * @since 2014/08/08
     */
    public ImplParser(BaseDecoder.Input __i)
    {
        super(__i);
    }
    
    /**
     * Closes the parser and releases resources associated with it, the input
     * source is also closed.
     *
     * @throws JsonException If an {@link IOException}, it will be wrapped,
     * otherwise it is unspecified.
     * @since 2014/08/01
     */
    @Override
    public void close()
    {
        synchronized (this.lock)
        {
            // Ignore if closed
            if (this._closed)
                return;    
            
            // Close and set super close (it does the work)
            this._closed = true;
            super.close();
        }
    }
    
    /**
     * When the event is {@link Event#VALUE_NUMBER}, this returns the integer
     * value of it as if {@code new BigDecimal(getString()).intValue()} were
     * called. It is possible that information may be lost.
     *
     * @return The integer value.
     * @throws IllegalStateException If the state is not
     * {@link Event#VALUE_NUMBER}.
     * @since 2014/08/01
     */
    @Override
    public int getInt()
    {
        return this.__getNumber().intValue();
    }
    
    /**
     * Returns information on the parser's current state within the JSON
     * stream, said information is only valid in the current state. If the
     * state is modified, the values here are invalid.
     *
     * @return A non-{@code null} location matching the current parser state.
     * @since 2014/08/01
     */
    @Override
    public JsonLocation getLocation()
    {
        synchronized (this.lock)
        {
            // Cannot be closed
            if (this._closed)
                throw new IllegalStateException("Parser has been closed.");
            
            // Input has the potential location
            return this.input.getLocation();
        }
    }
    
    /**
     * When the event is {@link Event#VALUE_NUMBER}, this returns the long
     * value of it as if {@code new BigDecimal(getString()).longValue()} were
     * called. It is possible that information may be lost.
     *
     * @return The long value.
     * @throws IllegalStateException If the state is not
     * {@link Event#VALUE_NUMBER}.
     * @since 2014/08/01
     */
    @Override
    public long getLong()
    {
        return this.__getNumber().longValue();
    }
    
    /**
     * Returns either the key name or a value if the parser is in the 
     * {@link Event#VALUE_NUMBER}, {@link Event#VALUE_STRING}, or
     * {@link Event#KEY_NAME} states.
     *
     * @throws IllegalStateException If the state is not
     * {@link Event#VALUE_NUMBER}, {@link Event#VALUE_STRING}, or
     * {@link Event#KEY_NAME}.
     * @since 2014/08/01
     */
    @Override
    public String getString()
    {
        synchronized (this.lock)
        {
            // Cannot be closed
            if (this._closed)
                throw new IllegalStateException(
                    "Parser has been closed.");
            
            // Invalid state
            if (this._e != Event.VALUE_NUMBER &&
                this._e != Event.VALUE_STRING && this._e != Event.KEY_NAME)
                throw new IllegalStateException(String.format(
                    "Invalid state: %1$s.", this._e));
            
            throw new RuntimeException("TODO -- ImplParser::getString() " +
                "is not implemented.");
        }
    }
    
    /**
     * Returns {@code true} if there are more states to parse, otherwise
     * {@code false} will be returned at the end.
     *
     * @throws JsonException A standard error, {@link IOException} may be
     * wrapped if it occurs.
     * @throws JsonParsingException Invalid JSON data was detected.
     * @since 2014/08/01
     */
    @Override
    public boolean hasNext()
    {
        synchronized (this.lock)
        {
            // Cannot be closed
            if (this._closed)
                throw new IllegalStateException(
                    "Parser has been closed.");
            
            // Check
            throw new RuntimeException("TODO -- ImplParser::hasNext() " +
                "is not implemented.");
        }
    }
    
    /**
     * Returns true if the specified numeric value is an integer (that is, it
     * has no fractional values).
     *
     * @return {@code true} if this number is integral.
     * @throws IllegalStateException If the state is not
     * {@link Event#VALUE_NUMBER}.
     * @since 2014/08/01
     */
    @Override
    public boolean isIntegralNumber()
    {
        return new ImplValueNumber(this.__getNumber()).isIntegral();
    }
    
    /**
     * Advances to the next state returning the type of data read.
     *
     * This relies on {@link #hasNext()} to obtain the next token to be read
     * so that duplicate code is reduced.
     *
     * @throws JsonException A standard error, {@link IOException} may be
     * wrapped if it occurs.
     * @throws JsonParsingException Invalid JSON data was detected.
     * @throws NoSuchElementException If there is nothing left.
     * @since 2014/08/01
     */
    @Override
    public Event next()
    {
        synchronized (this.lock)
        {
            // Cannot be closed
            if (this._closed)
                throw new IllegalStateException(
                    "Parser has been closed.");
            
            throw new RuntimeException("TODO -- ImplParser::next() is not " +
                "implemented.");
        }
    }
    
    /**
     * When the event is {@link Event#VALUE_NUMBER}, this returns the decimal
     * value of it as if {@code new BigDecimal(getString())} were called.
     *
     * @return The decimal number the value is set to.
     * @throws IllegalStateException If the state is not
     * {@link Event#VALUE_NUMBER}.
     * @since 2014/08/01
     */
    private Number __getNumber()
    {
        synchronized (this.lock)
        {
            // Cannot be closed
            if (this._closed)
                throw new IllegalStateException("Parser has been closed.");
            
            // Invalid state
            if (this._e != Event.VALUE_NUMBER)
                throw new IllegalStateException(String.format(
                    "Invalid state: %1$s.", this._e));
            
            return ImplValueNumber.__parseNumber(this.getString());
        }
    }
    
}