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

import java.io.IOException;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.*;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.io.SerializedString;

import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
import com.fasterxml.jackson.databind.introspect.AnnotatedMember;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitable;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonObjectFormatVisitor;
import com.fasterxml.jackson.databind.jsonschema.SchemaAware;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.databind.ser.ContainerSerializer;
import com.fasterxml.jackson.databind.ser.ContextualSerializer;
import com.fasterxml.jackson.databind.util.EnumValues;

/**
 * Specialized serializer for {@link EnumMap}s. Somewhat tricky to
 * implement because actual Enum value type may not be available;
 * and if not, it can only be gotten from actual instance.
 */
@JacksonStdImpl
public class EnumMapSerializer
    extends ContainerSerializer, ?>>
    implements ContextualSerializer
{
    protected final boolean _staticTyping;

    /**
     * Property for which this serializer is being used, if any;
     * null for root values.
     */
    protected final BeanProperty _property;
    
    /**
     * If we know enumeration used as key, this will contain
     * value set to use for serialization
     */
    protected final EnumValues _keyEnums;

    protected final JavaType _valueType;
    
    /**
     * Value serializer to use, if it can be statically determined
     */
    protected final JsonSerializer _valueSerializer;

    /**
     * Type serializer used for values, if any.
     */
    protected final TypeSerializer _valueTypeSerializer;

    /*
    /**********************************************************
    /* Life-cycle
    /**********************************************************
     */
    
    public EnumMapSerializer(JavaType valueType, boolean staticTyping, EnumValues keyEnums,
            TypeSerializer vts, JsonSerializer valueSerializer)
    {
        super(EnumMap.class, false);
        _property = null; // not yet known
        _staticTyping = staticTyping || (valueType != null && valueType.isFinal());
        _valueType = valueType;
        _keyEnums = keyEnums;
        _valueTypeSerializer = vts;
        _valueSerializer = valueSerializer;
    }

    /**
     * Constructor called when a contextual instance is created.
     */
    @SuppressWarnings("unchecked")
    public EnumMapSerializer(EnumMapSerializer src, BeanProperty property,
            JsonSerializer ser)
    {
        super(src);
        _property = property;
        _staticTyping = src._staticTyping;
        _valueType = src._valueType;
        _keyEnums = src._keyEnums;
        _valueTypeSerializer = src._valueTypeSerializer;
        _valueSerializer = (JsonSerializer) ser;
    }
    
    @Override
    public EnumMapSerializer _withValueTypeSerializer(TypeSerializer vts) {
        return new EnumMapSerializer(_valueType, _staticTyping, _keyEnums, vts,  _valueSerializer);
    }

    public EnumMapSerializer withValueSerializer(BeanProperty prop, JsonSerializer ser) {
        if (_property == prop && ser == _valueSerializer) {
            return this;
        }
        return new EnumMapSerializer(this, prop, ser);
    }

    @Override
    public JsonSerializer createContextual(SerializerProvider provider,
            BeanProperty property)
        throws JsonMappingException
    {
        /* 29-Sep-2012, tatu: Actually, we need to do much more contextual
         *    checking here since we finally know for sure the property,
         *    and it may have overrides
         */
        JsonSerializer ser = null;
        // First: if we have a property, may have property-annotation overrides
        if (property != null) {
            AnnotatedMember m = property.getMember();
            if (m != null) {
                Object serDef = provider.getAnnotationIntrospector().findContentSerializer(m);
                if (serDef != null) {
                    ser = provider.serializerInstance(m, serDef);
                }
            }
        }
        if (ser == null) {
            ser = _valueSerializer;
        }
        // #124: May have a content converter
        ser = findConvertingContentSerializer(provider, property, ser);
        if (ser == null) {
            if (_staticTyping) {
                return withValueSerializer(property, provider.findValueSerializer(_valueType, property));
            }
        } else {
            ser = provider.handleSecondaryContextualization(ser, property);
        }
        if (ser != _valueSerializer) {
            return withValueSerializer(property, ser);
        }
        return this;
    }
    
    /*
    /**********************************************************
    /* Accessors
    /**********************************************************
     */
    
    @Override
    public JavaType getContentType() {
        return _valueType;
    }

    @Override
    public JsonSerializer getContentSerializer() {
        return _valueSerializer;
    }
    
    @Override
    public boolean isEmpty(EnumMap,?> value) {
        return (value == null) || value.isEmpty();
    }

    @Override
    public boolean hasSingleElement(EnumMap, ?> value) {
        return value.size() == 1;
    }
    
    /*
    /**********************************************************
    /* Serialization
    /**********************************************************
     */
    
    @Override
    public void serialize(EnumMap,?> value, JsonGenerator jgen, SerializerProvider provider)
        throws IOException, JsonGenerationException
    {
        jgen.writeStartObject();
        if (!value.isEmpty()) {
            serializeContents(value, jgen, provider);
        }        
        jgen.writeEndObject();
    }

    @Override
    public void serializeWithType(EnumMap,?> value, JsonGenerator jgen, SerializerProvider provider,
            TypeSerializer typeSer)
        throws IOException, JsonGenerationException
    {
        typeSer.writeTypePrefixForObject(value, jgen);
        if (!value.isEmpty()) {
            serializeContents(value, jgen, provider);
        }
        typeSer.writeTypeSuffixForObject(value, jgen);
    }
    
    protected void serializeContents(EnumMap,?> value, JsonGenerator jgen, SerializerProvider provider)
        throws IOException, JsonGenerationException
    {
        if (_valueSerializer != null) {
            serializeContentsUsing(value, jgen, provider, _valueSerializer);
            return;
        }
        JsonSerializer prevSerializer = null;
        Class prevClass = null;
        EnumValues keyEnums = _keyEnums;
        final boolean skipNulls = !provider.isEnabled(SerializationFeature.WRITE_NULL_MAP_VALUES);
        final TypeSerializer vts = _valueTypeSerializer;

        for (Map.Entry,?> entry : value.entrySet()) {
            final Object valueElem = entry.getValue();
            if (skipNulls && valueElem == null) { // [JACKSON-314] skip entries with null values?
                continue;
            }
            // First, serialize key
            Enum key = entry.getKey();
            if (keyEnums == null) {
                /* 15-Oct-2009, tatu: This is clumsy, but still the simplest efficient
                 * way to do it currently, as Serializers get cached. (it does assume we'll always use
                 * default serializer tho -- so ideally code should be rewritten)
                 */
                // ... and lovely two-step casting process too...
                StdSerializer ser = (StdSerializer) provider.findValueSerializer(
                        key.getDeclaringClass(), _property);
                keyEnums = ((EnumSerializer) ser).getEnumValues();
            }
            jgen.writeFieldName(keyEnums.serializedValueFor(key));
            if (valueElem == null) {
                provider.defaultSerializeNull(jgen);
                continue;
            }
            Class cc = valueElem.getClass();
            JsonSerializer currSerializer;
            if (cc == prevClass) {
                currSerializer = prevSerializer;
            } else {
                currSerializer = provider.findValueSerializer(cc, _property);
                prevSerializer = currSerializer;
                prevClass = cc;
            }
            try {
                if (vts == null) {
                    currSerializer.serialize(valueElem, jgen, provider);
                } else {
                    currSerializer.serializeWithType(valueElem, jgen, provider, vts);
                }
            } catch (Exception e) {
                // [JACKSON-55] Need to add reference information
                wrapAndThrow(provider, e, value, entry.getKey().name());
            }
        }
    }

    protected void serializeContentsUsing(EnumMap,?> value, JsonGenerator jgen, SerializerProvider provider,
            JsonSerializer valueSer)
        throws IOException, JsonGenerationException
    {
        EnumValues keyEnums = _keyEnums;
        final boolean skipNulls = !provider.isEnabled(SerializationFeature.WRITE_NULL_MAP_VALUES);
        final TypeSerializer vts = _valueTypeSerializer;
        
        for (Map.Entry,?> entry : value.entrySet()) {
            final Object valueElem = entry.getValue();
            if (skipNulls && valueElem == null) { // [JACKSON-314] skip entries with null values?
                continue;
            }
            Enum key = entry.getKey();
            if (keyEnums == null) {
                // clumsy, but has to do for now:
                StdSerializer ser = (StdSerializer) provider.findValueSerializer(key.getDeclaringClass(),
                        _property);
                keyEnums = ((EnumSerializer) ser).getEnumValues();
            }
            jgen.writeFieldName(keyEnums.serializedValueFor(key));
            if (valueElem == null) {
                provider.defaultSerializeNull(jgen);
                continue;
            }
            try {
                if (vts == null) {
                    valueSer.serialize(valueElem, jgen, provider);
                } else {
                    valueSer.serializeWithType(valueElem, jgen, provider, vts);
                }
            } catch (Exception e) {
                wrapAndThrow(provider, e, value, entry.getKey().name());
            }
        }
    }
    
    @SuppressWarnings({ "unchecked", "deprecation" })
    @Override
    public JsonNode getSchema(SerializerProvider provider, Type typeHint)
        throws JsonMappingException
    {
        ObjectNode o = createSchemaNode("object", true);
        if (typeHint instanceof ParameterizedType) {
            Type[] typeArgs = ((ParameterizedType) typeHint).getActualTypeArguments();
            if (typeArgs.length == 2) {
                JavaType enumType = provider.constructType(typeArgs[0]);
                JavaType valueType = provider.constructType(typeArgs[1]);
                ObjectNode propsNode = JsonNodeFactory.instance.objectNode();
                Class> enumClass = (Class>) enumType.getRawClass();
                for (Enum enumValue : enumClass.getEnumConstants()) {
                    JsonSerializer ser = provider.findValueSerializer(valueType.getRawClass(), _property);
                    JsonNode schemaNode = (ser instanceof SchemaAware) ?
                            ((SchemaAware) ser).getSchema(provider, null) :
                            	com.fasterxml.jackson.databind.jsonschema.JsonSchema.getDefaultSchemaNode();
                    propsNode.put(provider.getConfig().getAnnotationIntrospector().findEnumValue((Enum)enumValue), schemaNode);
                }
                o.put("properties", propsNode);
            }
        }
        return o;
    }

    /**
     * We consider possibility here that an EnumMap might actually just be serialized
     * as something like a Record, given that number of keys is bound, just like
     * with Objects/Records (and not unbounded like regular maps)
     */
    @Override
    public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint)
        throws JsonMappingException
    {
        if (visitor == null) {
            return;
        }
        JsonObjectFormatVisitor objectVisitor = visitor.expectObjectFormat(typeHint);
        if (objectVisitor == null) {
            return;
        }
        JavaType valueType = typeHint.containedType(1);
        JsonSerializer ser = _valueSerializer;
        if (ser == null && valueType != null) {
            ser = visitor.getProvider().findValueSerializer(valueType, _property);
        }
        if (valueType == null) {
            valueType = visitor.getProvider().constructType(Object.class);
        }
        EnumValues keyEnums = _keyEnums;
        if (keyEnums == null) {
            JavaType enumType = typeHint.containedType(0);
             if (enumType == null) {
                 throw new IllegalStateException("Can not resolve Enum type of EnumMap: "+typeHint);
             }
             JsonSerializer enumSer = visitor.getProvider().findValueSerializer(enumType, _property);
             if (!(enumSer instanceof EnumSerializer)) {
                 throw new IllegalStateException("Can not resolve Enum type of EnumMap: "+typeHint);
             }
             keyEnums = ((EnumSerializer) enumSer).getEnumValues();
        }
        for (Map.Entry entry : keyEnums.internalMap().entrySet()) {
            String name = entry.getValue().getValue();
            // should all have the same type, so:
            if (ser == null) {
                ser = visitor.getProvider().findValueSerializer(entry.getKey().getClass(), _property);
            }
            objectVisitor.property(name, (JsonFormatVisitable) ser, valueType);
        }
    }
}