package com.fasterxml.jackson.databind.deser.std;

import java.io.IOException;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
import com.fasterxml.jackson.databind.node.*;
import com.fasterxml.jackson.databind.util.RawValue;

Deserializer that can build instances of JsonNode from any JSON content, using appropriate JsonNode type. /**
 * Deserializer that can build instances of {@link JsonNode} from any
 * JSON content, using appropriate {@link JsonNode} type.
 */
@SuppressWarnings("serial")
public class JsonNodeDeserializer
    extends BaseNodeDeserializer<JsonNode>
{
    
Singleton instance of generic deserializer for JsonNode. Only used for types other than JSON Object and Array. /**
     * Singleton instance of generic deserializer for {@link JsonNode}.
     * Only used for types other than JSON Object and Array.
     */
    private final static JsonNodeDeserializer instance = new JsonNodeDeserializer();

    protected JsonNodeDeserializer() {
        // `null` means that explicit "merge" is honored and may or may not work, but
        // that per-type and global defaults do not enable merging. This because
        // some node types (Object, Array) do support, others don't.
        super(JsonNode.class, null);
    }

    
Factory method for accessing deserializer for specific node type
/**
     * Factory method for accessing deserializer for specific node type
     */
    public static JsonDeserializer<? extends JsonNode> getDeserializer(Class<?> nodeClass)
    {
        if (nodeClass == ObjectNode.class) {
            return ObjectDeserializer.getInstance();
        }
        if (nodeClass == ArrayNode.class) {
            return ArrayDeserializer.getInstance();
        }
        // For others, generic one works fine
        return instance;
    }
    
    /*
    /**********************************************************
    /* Actual deserializer implementations
    /**********************************************************
     */

    @Override
    public JsonNode getNullValue(DeserializationContext ctxt) {
        return NullNode.getInstance();
    }

    
Implementation that will produce types of any JSON nodes; not just one
deserializer is registered to handle (in case of more specialized handler).
Overridden by typed sub-classes for more thorough checking
/**
     * Implementation that will produce types of any JSON nodes; not just one
     * deserializer is registered to handle (in case of more specialized handler).
     * Overridden by typed sub-classes for more thorough checking
     */
    @Override
    public JsonNode deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
    {
        switch (p.getCurrentTokenId()) {
        case JsonTokenId.ID_START_OBJECT:
            return deserializeObject(p, ctxt, ctxt.getNodeFactory());
        case JsonTokenId.ID_START_ARRAY:
            return deserializeArray(p, ctxt, ctxt.getNodeFactory());
        default:
        }
        return deserializeAny(p, ctxt, ctxt.getNodeFactory());
    }

    /*
    /**********************************************************
    /* Specific instances for more accurate types
    /**********************************************************
     */

    final static class ObjectDeserializer
        extends BaseNodeDeserializer<ObjectNode>
    {
        private static final long serialVersionUID = 1L;

        protected final static ObjectDeserializer _instance = new ObjectDeserializer();

        protected ObjectDeserializer() { super(ObjectNode.class, true); }

        public static ObjectDeserializer getInstance() { return _instance; }

        @Override
        public ObjectNode deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
        {
            if (p.isExpectedStartObjectToken()) {
                return deserializeObject(p, ctxt, ctxt.getNodeFactory());
            }
            if (p.hasToken(JsonToken.FIELD_NAME)) {
                return deserializeObjectAtName(p, ctxt, ctxt.getNodeFactory());
            }
            // 23-Sep-2015, tatu: Ugh. We may also be given END_OBJECT (similar to FIELD_NAME),
            //    if caller has advanced to the first token of Object, but for empty Object
            if (p.hasToken(JsonToken.END_OBJECT)) {
                return ctxt.getNodeFactory().objectNode();
            }
            return (ObjectNode) ctxt.handleUnexpectedToken(ObjectNode.class, p);
         }

        
Variant needed to support both root-level `updateValue()` and merging.
Since:
2.9/**
         * Variant needed to support both root-level `updateValue()` and merging.
         *
         * @since 2.9
         */
        @Override
        public ObjectNode deserialize(JsonParser p, DeserializationContext ctxt,
                ObjectNode node) throws IOException
        {
            if (p.isExpectedStartObjectToken() || p.hasToken(JsonToken.FIELD_NAME)) {
                return (ObjectNode) updateObject(p, ctxt, (ObjectNode) node);
            }
            return (ObjectNode) ctxt.handleUnexpectedToken(ObjectNode.class, p);
        }
    }

    final static class ArrayDeserializer
        extends BaseNodeDeserializer<ArrayNode>
    {
        private static final long serialVersionUID = 1L;

        protected final static ArrayDeserializer _instance = new ArrayDeserializer();

        protected ArrayDeserializer() { super(ArrayNode.class, true); }

        public static ArrayDeserializer getInstance() { return _instance; }

        @Override
        public ArrayNode deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
        {
            if (p.isExpectedStartArrayToken()) {
                return deserializeArray(p, ctxt, ctxt.getNodeFactory());
            }
            return (ArrayNode) ctxt.handleUnexpectedToken(ArrayNode.class, p);
        }

        
Variant needed to support both root-level `updateValue()` and merging.
Since:
2.9/**
         * Variant needed to support both root-level `updateValue()` and merging.
         *
         * @since 2.9
         */
        @Override
        public ArrayNode deserialize(JsonParser p, DeserializationContext ctxt,
                ArrayNode node) throws IOException
        {
            if (p.isExpectedStartArrayToken()) {
                return (ArrayNode) updateArray(p, ctxt, (ArrayNode) node);
            }
            return (ArrayNode) ctxt.handleUnexpectedToken(ArrayNode.class, p);
        }
    }
}

Base class for all actual JsonNode deserializer implementations /**
 * Base class for all actual {@link JsonNode} deserializer
 * implementations
 */
@SuppressWarnings("serial")
abstract class BaseNodeDeserializer<T extends JsonNode>
    extends StdDeserializer<T>
{
    protected final Boolean _supportsUpdates;

    public BaseNodeDeserializer(Class<T> vc, Boolean supportsUpdates) {
        super(vc);
        _supportsUpdates = supportsUpdates;
    }

    @Override
    public Object deserializeWithType(JsonParser p, DeserializationContext ctxt,
            TypeDeserializer typeDeserializer)
        throws IOException
    {
        // Output can be as JSON Object, Array or scalar: no way to know a priori:
        return typeDeserializer.deserializeTypedFromAny(p, ctxt);
    }

    /* 07-Nov-2014, tatu: When investigating [databind#604], realized that it makes
     *   sense to also mark this is cachable, since lookup not exactly free, and
     *   since it's not uncommon to "read anything"
     */
    @Override
    public boolean isCachable() { return true; }

    @Override // since 2.9
    public Boolean supportsUpdate(DeserializationConfig config) {
        return _supportsUpdates;
    }

    /*
    /**********************************************************
    /* Overridable methods
    /**********************************************************
     */

    
Method called when there is a duplicate value for a field.
By default we don't care, and the last value is used.
Can be overridden to provide alternate handling, such as throwing
an exception, or choosing different strategy for combining values
or choosing which one to keep.
Params:
fieldName – Name of the field for which duplicate value was found
objectNode – Object node that contains values
oldValue – Value that existed for the object node before newValue
  was added
newValue – Newly added value just added to the object node/**
     * Method called when there is a duplicate value for a field.
     * By default we don't care, and the last value is used.
     * Can be overridden to provide alternate handling, such as throwing
     * an exception, or choosing different strategy for combining values
     * or choosing which one to keep.
     *
     * @param fieldName Name of the field for which duplicate value was found
     * @param objectNode Object node that contains values
     * @param oldValue Value that existed for the object node before newValue
     *   was added
     * @param newValue Newly added value just added to the object node
     */
    protected void _handleDuplicateField(JsonParser p, DeserializationContext ctxt,
            JsonNodeFactory nodeFactory,
            String fieldName, ObjectNode objectNode,
            JsonNode oldValue, JsonNode newValue)
        throws JsonProcessingException
    {
        // [databind#237]: Report an error if asked to do so:
        if (ctxt.isEnabled(DeserializationFeature.FAIL_ON_READING_DUP_TREE_KEY)) {
            ctxt.reportInputMismatch(JsonNode.class,
                    "Duplicate field '%s' for ObjectNode: not allowed when FAIL_ON_READING_DUP_TREE_KEY enabled",
                    fieldName);
        }
    }

    /*
    /**********************************************************
    /* Helper methods
    /**********************************************************
     */

    
Method called to deserialize Object node instance when there is no existing
node to modify.
/**
     * Method called to deserialize Object node instance when there is no existing
     * node to modify.
     */
    protected final ObjectNode deserializeObject(JsonParser p, DeserializationContext ctxt,
            final JsonNodeFactory nodeFactory) throws IOException
    {
        final ObjectNode node = nodeFactory.objectNode();
        String key = p.nextFieldName();
        for (; key != null; key = p.nextFieldName()) {
            JsonNode value;
            JsonToken t = p.nextToken();
            if (t == null) { // can this ever occur?
                t = JsonToken.NOT_AVAILABLE; // can this ever occur?
            }
            switch (t.id()) {
            case JsonTokenId.ID_START_OBJECT:
                value = deserializeObject(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_START_ARRAY:
                value = deserializeArray(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_EMBEDDED_OBJECT:
                value = _fromEmbedded(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_STRING:
                value = nodeFactory.textNode(p.getText());
                break;
            case JsonTokenId.ID_NUMBER_INT:
                value = _fromInt(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_TRUE:
                value = nodeFactory.booleanNode(true);
                break;
            case JsonTokenId.ID_FALSE:
                value = nodeFactory.booleanNode(false);
                break;
            case JsonTokenId.ID_NULL:
                value = nodeFactory.nullNode();
                break;
            default:
                value = deserializeAny(p, ctxt, nodeFactory);
            }
            JsonNode old = node.replace(key, value);
            if (old != null) {
                _handleDuplicateField(p, ctxt, nodeFactory,
                        key, node, old, value);
            }
        }
        return node;
    }

    
Alternate deserialization method used when parser already points to first
FIELD_NAME and not START_OBJECT.
Since:
2.9/**
     * Alternate deserialization method used when parser already points to first
     * FIELD_NAME and not START_OBJECT.
     *
     * @since 2.9
     */
    protected final ObjectNode deserializeObjectAtName(JsonParser p, DeserializationContext ctxt,
            final JsonNodeFactory nodeFactory) throws IOException
    {
        final ObjectNode node = nodeFactory.objectNode();
        String key = p.getCurrentName();
        for (; key != null; key = p.nextFieldName()) {
            JsonNode value;
            JsonToken t = p.nextToken();
            if (t == null) { // can this ever occur?
                t = JsonToken.NOT_AVAILABLE; // can this ever occur?
            }
            switch (t.id()) {
            case JsonTokenId.ID_START_OBJECT:
                value = deserializeObject(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_START_ARRAY:
                value = deserializeArray(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_EMBEDDED_OBJECT:
                value = _fromEmbedded(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_STRING:
                value = nodeFactory.textNode(p.getText());
                break;
            case JsonTokenId.ID_NUMBER_INT:
                value = _fromInt(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_TRUE:
                value = nodeFactory.booleanNode(true);
                break;
            case JsonTokenId.ID_FALSE:
                value = nodeFactory.booleanNode(false);
                break;
            case JsonTokenId.ID_NULL:
                value = nodeFactory.nullNode();
                break;
            default:
                value = deserializeAny(p, ctxt, nodeFactory);
            }
            JsonNode old = node.replace(key, value);
            if (old != null) {
                _handleDuplicateField(p, ctxt, nodeFactory,
                        key, node, old, value);
            }
        }
        return node;
    }
    
    
Alternate deserialization method that is to update existing ObjectNode if possible. 
Since:
2.9/**
     * Alternate deserialization method that is to update existing {@link ObjectNode}
     * if possible.
     *
     * @since 2.9
     */
    protected final JsonNode updateObject(JsonParser p, DeserializationContext ctxt,
        final ObjectNode node) throws IOException
    {
        String key;
        if (p.isExpectedStartObjectToken()) {
            key = p.nextFieldName();
        } else {
            if (!p.hasToken(JsonToken.FIELD_NAME)) {
                return deserialize(p, ctxt);
            }
            key = p.getCurrentName();
        }
        for (; key != null; key = p.nextFieldName()) {
            // If not, fall through to regular handling
            JsonToken t = p.nextToken();

            // First: see if we can merge things:
            JsonNode old = node.get(key);
            if (old != null) {
                if (old instanceof ObjectNode) {
                    JsonNode newValue = updateObject(p, ctxt, (ObjectNode) old);
                    if (newValue != old) {
                        node.set(key, newValue);
                    }
                    continue;
                }
                if (old instanceof ArrayNode) {
                    JsonNode newValue = updateArray(p, ctxt, (ArrayNode) old);
                    if (newValue != old) {
                        node.set(key, newValue);
                    }
                    continue;
                }
            }
            if (t == null) { // can this ever occur?
                t = JsonToken.NOT_AVAILABLE;
            }
            JsonNode value;
            JsonNodeFactory nodeFactory = ctxt.getNodeFactory();
            switch (t.id()) {
            case JsonTokenId.ID_START_OBJECT:
                value = deserializeObject(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_START_ARRAY:
                value = deserializeArray(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_EMBEDDED_OBJECT:
                value = _fromEmbedded(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_STRING:
                value = nodeFactory.textNode(p.getText());
                break;
            case JsonTokenId.ID_NUMBER_INT:
                value = _fromInt(p, ctxt, nodeFactory);
                break;
            case JsonTokenId.ID_TRUE:
                value = nodeFactory.booleanNode(true);
                break;
            case JsonTokenId.ID_FALSE:
                value = nodeFactory.booleanNode(false);
                break;
            case JsonTokenId.ID_NULL:
                value = nodeFactory.nullNode();
                break;
            default:
                value = deserializeAny(p, ctxt, nodeFactory);
            }
            if (old != null) {
                _handleDuplicateField(p, ctxt, nodeFactory,
                        key, node, old, value);
            }
            node.set(key, value);
        }
        return node;
    }

    protected final ArrayNode deserializeArray(JsonParser p, DeserializationContext ctxt,
            final JsonNodeFactory nodeFactory) throws IOException
    {
        ArrayNode node = nodeFactory.arrayNode();
        while (true) {
            JsonToken t = p.nextToken();
            switch (t.id()) {
            case JsonTokenId.ID_START_OBJECT:
                node.add(deserializeObject(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_START_ARRAY:
                node.add(deserializeArray(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_END_ARRAY:
                return node;
            case JsonTokenId.ID_EMBEDDED_OBJECT:
                node.add(_fromEmbedded(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_STRING:
                node.add(nodeFactory.textNode(p.getText()));
                break;
            case JsonTokenId.ID_NUMBER_INT:
                node.add(_fromInt(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_TRUE:
                node.add(nodeFactory.booleanNode(true));
                break;
            case JsonTokenId.ID_FALSE:
                node.add(nodeFactory.booleanNode(false));
                break;
            case JsonTokenId.ID_NULL:
                node.add(nodeFactory.nullNode());
                break;
            default:
                node.add(deserializeAny(p, ctxt, nodeFactory));
                break;
            }
        }
    }

    
Alternate deserialization method that is to update existing ObjectNode if possible. 
Since:
2.9/**
     * Alternate deserialization method that is to update existing {@link ObjectNode}
     * if possible.
     *
     * @since 2.9
     */
    protected final JsonNode updateArray(JsonParser p, DeserializationContext ctxt,
        final ArrayNode node) throws IOException
    {
        final JsonNodeFactory nodeFactory = ctxt.getNodeFactory();
        while (true) {
            JsonToken t = p.nextToken();
            switch (t.id()) {
            case JsonTokenId.ID_START_OBJECT:
                node.add(deserializeObject(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_START_ARRAY:
                node.add(deserializeArray(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_END_ARRAY:
                return node;
            case JsonTokenId.ID_EMBEDDED_OBJECT:
                node.add(_fromEmbedded(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_STRING:
                node.add(nodeFactory.textNode(p.getText()));
                break;
            case JsonTokenId.ID_NUMBER_INT:
                node.add(_fromInt(p, ctxt, nodeFactory));
                break;
            case JsonTokenId.ID_TRUE:
                node.add(nodeFactory.booleanNode(true));
                break;
            case JsonTokenId.ID_FALSE:
                node.add(nodeFactory.booleanNode(false));
                break;
            case JsonTokenId.ID_NULL:
                node.add(nodeFactory.nullNode());
                break;
            default:
                node.add(deserializeAny(p, ctxt, nodeFactory));
                break;
            }
        }
    }
    
    protected final JsonNode deserializeAny(JsonParser p, DeserializationContext ctxt,
            final JsonNodeFactory nodeFactory) throws IOException
    {
        switch (p.getCurrentTokenId()) {
        case JsonTokenId.ID_END_OBJECT: // for empty JSON Objects we may point to this?
            return nodeFactory.objectNode();
        case JsonTokenId.ID_FIELD_NAME:
            return deserializeObjectAtName(p, ctxt, nodeFactory);
        case JsonTokenId.ID_EMBEDDED_OBJECT:
            return _fromEmbedded(p, ctxt, nodeFactory);
        case JsonTokenId.ID_STRING:
            return nodeFactory.textNode(p.getText());
        case JsonTokenId.ID_NUMBER_INT:
            return _fromInt(p, ctxt, nodeFactory);
        case JsonTokenId.ID_NUMBER_FLOAT:
            return _fromFloat(p, ctxt, nodeFactory);
        case JsonTokenId.ID_TRUE:
            return nodeFactory.booleanNode(true);
        case JsonTokenId.ID_FALSE:
            return nodeFactory.booleanNode(false);
        case JsonTokenId.ID_NULL:
            return nodeFactory.nullNode();

            /* Caller checks for these, should not get here ever
        case JsonTokenId.ID_START_OBJECT:
            return deserializeObject(p, ctxt, nodeFactory);
        case JsonTokenId.ID_START_ARRAY:
            return deserializeArray(p, ctxt, nodeFactory);
            */

            
            // These states cannot be mapped; input stream is
            // off by an event or two

        //case END_OBJECT:
        //case END_ARRAY:
        default:
        }
        return (JsonNode) ctxt.handleUnexpectedToken(handledType(), p);
    }

    protected final JsonNode _fromInt(JsonParser p, DeserializationContext ctxt,
            JsonNodeFactory nodeFactory) throws IOException
    {
        JsonParser.NumberType nt;
        int feats = ctxt.getDeserializationFeatures();
        if ((feats & F_MASK_INT_COERCIONS) != 0) {
            if (DeserializationFeature.USE_BIG_INTEGER_FOR_INTS.enabledIn(feats)) {
                nt = JsonParser.NumberType.BIG_INTEGER;
            } else if (DeserializationFeature.USE_LONG_FOR_INTS.enabledIn(feats)) {
                nt = JsonParser.NumberType.LONG;
            } else {
                nt = p.getNumberType();
            }
        } else {
            nt = p.getNumberType();
        }
        if (nt == JsonParser.NumberType.INT) {
            return nodeFactory.numberNode(p.getIntValue());
        }
        if (nt == JsonParser.NumberType.LONG) {
            return nodeFactory.numberNode(p.getLongValue());
        }
        return nodeFactory.numberNode(p.getBigIntegerValue());
    }

    protected final JsonNode _fromFloat(JsonParser p, DeserializationContext ctxt,
            final JsonNodeFactory nodeFactory) throws IOException
    {
        JsonParser.NumberType nt = p.getNumberType();
        if (nt == JsonParser.NumberType.BIG_DECIMAL) {
            return nodeFactory.numberNode(p.getDecimalValue());
        }
        if (ctxt.isEnabled(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS)) {
            // 20-May-2016, tatu: As per [databind#1028], need to be careful
            //   (note: JDK 1.8 would have `Double.isFinite()`)
            if (p.isNaN()) {
                return nodeFactory.numberNode(p.getDoubleValue());
            }
            return nodeFactory.numberNode(p.getDecimalValue());
        }
        if (nt == JsonParser.NumberType.FLOAT) {
            return nodeFactory.numberNode(p.getFloatValue());
        }
        return nodeFactory.numberNode(p.getDoubleValue());
    }

    protected final JsonNode _fromEmbedded(JsonParser p, DeserializationContext ctxt,
            JsonNodeFactory nodeFactory) throws IOException
    {
        Object ob = p.getEmbeddedObject();
        if (ob == null) { // should this occur?
            return nodeFactory.nullNode();
        }
        Class<?> type = ob.getClass();
        if (type == byte[].class) { // most common special case
            return nodeFactory.binaryNode((byte[]) ob);
        }
        // [databind#743]: Don't forget RawValue
        if (ob instanceof RawValue) {
            return nodeFactory.rawValueNode((RawValue) ob);
        }
        if (ob instanceof JsonNode) {
            // [databind#433]: but could also be a JsonNode hiding in there!
            return (JsonNode) ob;
        }
        // any other special handling needed?
        return nodeFactory.pojoNode(ob);
    }
}