package com.fasterxml.jackson.dataformat.cbor;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.io.CharTypes;
import com.fasterxml.jackson.core.io.ContentReference;
import com.fasterxml.jackson.core.json.DupDetector;

Replacement of JsonReadContext to support features needed by CBOR format. /**
 * Replacement of {@link com.fasterxml.jackson.core.json.JsonReadContext}
 * to support features needed by CBOR format.
 */
public final class CBORReadContext
    extends JsonStreamContext
{
    
Parent context for this context; null for root context.
/**
     * Parent context for this context; null for root context.
     */
    protected final CBORReadContext _parent;
    
    // // // Optional duplicate detection

    protected final DupDetector _dups;

    
For fixed-size Arrays, Objects, this indicates expected number of entries.
/**
     * For fixed-size Arrays, Objects, this indicates expected number of entries.
     */
    protected int _expEntryCount;
    
    // // // Location information (minus source reference)

    protected String _currentName;

    
Since:
2.9/**
     * @since 2.9
     */
    protected Object _currentValue;
    
    /*
    /**********************************************************
    /* Simple instance reuse slots
    /**********************************************************
     */

    protected CBORReadContext _child = null;

    /*
    /**********************************************************
    /* Instance construction, reuse
    /**********************************************************
     */

    public CBORReadContext(CBORReadContext parent, DupDetector dups,
            int type, int expEntryCount)
    {
        super();
        _parent = parent;
        _dups = dups;
        _type = type;
        _expEntryCount = expEntryCount;
        _index = -1;
    }

    protected void reset(int type, int expEntryCount)
    {
        _type = type;
        _expEntryCount = expEntryCount;
        _index = -1;
        _currentName = null;
        _currentValue = null;
        if (_dups != null) {
            _dups.reset();
        }
    }

    @Override
    public Object getCurrentValue() {
        return _currentValue;
    }

    @Override
    public void setCurrentValue(Object v) {
        _currentValue = v;
    }
    
    // // // Factory methods

    public static CBORReadContext createRootContext(DupDetector dups) {
        return new CBORReadContext(null, dups, TYPE_ROOT, -1);
    }

    public CBORReadContext createChildArrayContext(int expEntryCount)
    {
        CBORReadContext ctxt = _child;
        if (ctxt == null) {
            _child = ctxt = new CBORReadContext(this,
                    (_dups == null) ? null : _dups.child(),
                            TYPE_ARRAY, expEntryCount);
        } else {
            ctxt.reset(TYPE_ARRAY, expEntryCount);
        }
        return ctxt;
    }

    public CBORReadContext createChildObjectContext(int expEntryCount)
    {
        CBORReadContext ctxt = _child;
        if (ctxt == null) {
            _child = ctxt = new CBORReadContext(this,
                    (_dups == null) ? null : _dups.child(),
                    TYPE_OBJECT, expEntryCount);
            return ctxt;
        }
        ctxt.reset(TYPE_OBJECT, expEntryCount);
        return ctxt;
    }

    /*
    /**********************************************************
    /* Abstract method implementation
    /**********************************************************
     */

    @Override
    public String getCurrentName() { return _currentName; }

    @Override
    public CBORReadContext getParent() { return _parent; }

    /*
    /**********************************************************
    /* Extended API
    /**********************************************************
     */

    public boolean hasExpectedLength() { return (_expEntryCount >= 0); }
    public int getExpectedLength() { return _expEntryCount; }

    // @since 2.13
    public int getRemainingExpectedLength() {
        int diff = _expEntryCount - _index;
        // Negative values would occur when expected count is -1
        return Math.max(0, diff);
    }

    public boolean acceptsBreakMarker() {
        return (_expEntryCount < 0) && _type != TYPE_ROOT;
    }

    
Method called to increment the current entry count (Object property, Array
element or Root value) for this context level
and then see if more entries are accepted.
The only case where more entries are NOT expected is for fixed-count
Objects and Arrays that just reached the entry count.

Note that since the entry count is updated this is a state-changing method.
/**
     * Method called to increment the current entry count (Object property, Array
     * element or Root value) for this context level
     * and then see if more entries are accepted.
     * The only case where more entries are NOT expected is for fixed-count
     * Objects and Arrays that just reached the entry count.
     *<p>
     * Note that since the entry count is updated this is a state-changing method.
     */
    public boolean expectMoreValues() {
        if (++_index == _expEntryCount) {
            return false;
        }
        return true;
    }
    
    
Returns:
Location pointing to the point where the context
  start marker was found/**
     * @return Location pointing to the point where the context
     *   start marker was found
     */
    @Override
    public JsonLocation startLocation(ContentReference srcRef) {
        return new JsonLocation(srcRef, 1L, -1, -1);
    }

    @Override
    @Deprecated // since 2.13
    public JsonLocation getStartLocation(Object rawSrc) {
        return startLocation(ContentReference.rawReference(rawSrc));
    }

    /*
    /**********************************************************
    /* State changes
    /**********************************************************
     */

    public void setCurrentName(String name) throws JsonProcessingException
    {
        _currentName = name;
        if (_dups != null) {
            _checkDup(_dups, name);
        }
    }

    private void _checkDup(DupDetector dd, String name) throws JsonProcessingException
    {
        if (dd.isDup(name)) {
            // 04-MAy-2016, tatu: Would be great to pass JsonParser, alas, not available so:
            throw new JsonParseException(null,
                    "Duplicate field '"+name+"'", dd.findLocation());
        }
    }

    /*
    /**********************************************************
    /* Overridden standard methods
    /**********************************************************
     */

    
Overridden to provide developer readable "JsonPath" representation
of the context.
/**
     * Overridden to provide developer readable "JsonPath" representation
     * of the context.
     */
    @Override
    public String toString()
    {
        StringBuilder sb = new StringBuilder(64);
        switch (_type) {
        case TYPE_ROOT:
            sb.append("/");
            break;
        case TYPE_ARRAY:
            sb.append('[');
            sb.append(getCurrentIndex());
            sb.append(']');
            break;
        case TYPE_OBJECT:
            sb.append('{');
            if (_currentName != null) {
                sb.append('"');
                CharTypes.appendQuoted(sb, _currentName);
                sb.append('"');
            } else {
                sb.append('?');
            }
            sb.append('}');
            break;
        }
        return sb.toString();
    }
}