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/*
 * Copyright 2019 the original author or authors.
 *
 * Licensed under the Apache, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at  http://www.gnu.org/licenses/lgpl-3.0.html
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.jn.easyjson.jackson.serializer;

import com.fasterxml.jackson.annotation.JsonValue;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.jn.easyjson.core.codec.dialect.PropertyCodecConfiguration;
import com.jn.easyjson.jackson.Jacksons;
import com.jn.langx.util.Strings;
import com.jn.langx.util.collection.Pipeline;
import com.jn.langx.util.enums.Enums;
import com.jn.langx.util.function.Predicate;
import com.jn.langx.util.reflect.Reflects;

import java.io.IOException;
import java.lang.reflect.Field;
import java.util.Collection;

import static com.jn.easyjson.jackson.JacksonConstants.ENABLE_CUSTOM_CONFIGURATION;
import static com.jn.easyjson.jackson.JacksonConstants.SERIALIZE_ENUM_USING_FIELD_ATTR_KEY;

public class EnumSerializer extends JsonSerializer {

    @Override
    public void serialize(T e, JsonGenerator gen, SerializerProvider sp) throws IOException {
        if (e == null) {
            gen.writeNull();
            return;
        }
        Boolean usingIndex = null;
        Boolean usingToString = null;
        if (Jacksons.getBooleanAttr(sp, ENABLE_CUSTOM_CONFIGURATION)) {
            PropertyCodecConfiguration propertyCodecConfiguration = Jacksons.getPropertyCodecConfiguration(gen);
            if (propertyCodecConfiguration != null) {
                usingIndex = propertyCodecConfiguration.getEnumUsingIndex();
                usingToString = propertyCodecConfiguration.getEnumUsingToString();
            }
        }
        if (usingIndex == null) {
            usingIndex = sp.isEnabled(SerializationFeature.WRITE_ENUMS_USING_INDEX);
        }
        if (usingToString == null) {
            usingToString = sp.isEnabled(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
        }
        String usingField = (String) sp.getAttribute(SERIALIZE_ENUM_USING_FIELD_ATTR_KEY);

        if (usingIndex) {
            gen.writeNumber(e.ordinal());
            return;
        }

        if (usingToString) {
            gen.writeString(e.toString());
            return;
        }

        if(Strings.isEmpty(usingField)){
            Collection fields = Reflects.getAllDeclaredFields(e.getClass(), false);
            Field field = Pipeline.of(fields)
                    .findFirst(new Predicate() {
                        @Override
                        public boolean test(Field field) {
                            return Reflects.hasAnnotation(field, JsonValue.class);
                        }
                    });
            if (field != null) {
                usingField = field.getName();
            }
        }

        if (Strings.isNotEmpty(usingField)) {
            usingField = usingField.trim();
            try {
                Field field = e.getClass().getDeclaredField(usingField);
                field.setAccessible(true);
                Class fieldClazz = field.getType();
                if (fieldClazz.isArray() || fieldClazz.isAnonymousClass() || fieldClazz.isAnnotation() || fieldClazz.isSynthetic()) {
                    throw new UnsupportedOperationException();
                }
                if (fieldClazz == String.class) {
                    gen.writeString(field.get(e).toString());
                    return;
                }
                if (fieldClazz == Character.class) {
                    gen.writeRaw((Character) field.get(e));
                    return;
                }
                if (fieldClazz == Boolean.class) {
                    gen.writeBoolean((Boolean) field.get(e));
                    return;
                }
                if (Number.class.isAssignableFrom(fieldClazz)) {
                    gen.writeNumber(((Number) field.get(e)).toString());
                    return;
                }
            } catch (NoSuchFieldException e1) {
                // ignore it
            } catch (IllegalAccessException e1) {
                // ignore it
            }
        }
        gen.writeString(Enums.getName(e));
    }

}