package io.gitlab.jfronny.gson.compile.processor.adapter.impl;

import com.squareup.javapoet.*;
import io.gitlab.jfronny.gson.compile.processor.Cl;
import io.gitlab.jfronny.gson.compile.processor.core.TypeHelper;
import io.gitlab.jfronny.gson.compile.processor.adapter.AdapterAdapter;

import javax.lang.model.element.*;
import javax.lang.model.type.DeclaredType;
import javax.tools.Diagnostic;
import java.util.List;
import java.util.Map;

public class DeclaredAdapter extends AdapterAdapter<DeclaredAdapter.Hydrated> {
    @Override
    public Hydrated instantiate() {
        return new Hydrated();
    }

    public class Hydrated extends AdapterAdapter<Hydrated>.Hydrated {
        private DeclaredType typeAdapterClass;

        @Override
        public boolean applies() {
            return typeAdapterClass != null;
        }

        @Override
        protected void afterHydrate() {
            this.typeAdapterClass = findTypeAdapterClass(annotations);
        }

        @Override
        protected String createAdapter(String typeAdapterName) {
            if (TypeHelper.isInstance(typeAdapterClass, Cl.TYPE_ADAPTER.toString(), typeUtils)) {
                klazz.addField(
                        FieldSpec.builder(TypeName.get(typeAdapterClass), typeAdapterName)
                                .addModifiers(Modifier.PRIVATE, Modifier.STATIC, Modifier.FINAL)
                                .initializer("new $T()", typeAdapterClass)
                                .build()
                );
            } else if (TypeHelper.isInstance(typeAdapterClass, Cl.TYPE_ADAPTER_FACTORY.toString(), typeUtils)) {
                TypeName typeAdapterType = ParameterizedTypeName.get(Cl.TYPE_ADAPTER, TypeName.get(type).box());
                CodeBlock.Builder block = CodeBlock.builder();
                block.add("new $T().create($T.HOLDER.getGson(), ", typeAdapterClass, Cl.CCORE);
                appendFieldTypeToken(false);
                block.add(")");
                klazz.addField(
                        FieldSpec.builder(typeAdapterType, typeAdapterName)
                                .addModifiers(Modifier.PRIVATE, Modifier.STATIC, Modifier.FINAL)
                                .initializer(block.build())
                                .build()
                );
            } else message.printMessage(Diagnostic.Kind.ERROR, "@JsonAdapter value must by TypeAdapter or TypeAdapterFactory reference.", sourceElement);
            return typeAdapterName;
        }

        private static DeclaredType findTypeAdapterClass(List<? extends AnnotationMirror> annotations) {
            for (AnnotationMirror annotation : annotations) {
                String typeName = annotation.getAnnotationType().toString();
                if (typeName.equals(Cl.JSON_ADAPTER.toString())) {
                    Map<? extends ExecutableElement, ? extends AnnotationValue> elements = annotation.getElementValues();
                    if (!elements.isEmpty()) {
                        AnnotationValue value = elements.values().iterator().next();
                        return (DeclaredType) value.getValue();
                    }
                }
            }
            return null;
        }
    }
}