/*
 * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.mdsal.binding.dom.codec.impl;

import static java.util.Objects.requireNonNull;

import java.util.concurrent.ExecutionException;
import org.opendaylight.mdsal.binding.spec.reflect.BindingReflections;
import org.opendaylight.yangtools.concepts.IllegalArgumentCodec;
import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.BitsTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.EnumTypeDefinition;

/**
 * Value codec, which serializes / deserializes values from DOM simple values.
 */
// FIXME: IllegalArgumentCodec is perhaps not appropriate here due to null behavior
abstract class ValueTypeCodec implements IllegalArgumentCodec<Object, Object> {
    /**
     * Marker interface for codecs, which functionality will not be affected by schema change (introduction of new YANG
     * modules) they may have one static instance generated when first time needed.
     */
    // FIXME: IllegalArgumentCodec is perhaps not appropriate here due to null behavior
    interface SchemaUnawareCodec extends IllegalArgumentCodec<Object, Object> {

    }

    /**
     * No-op Codec, Java YANG Binding uses same types as NormalizedNode model for base YANG types, representing numbers,
     * binary, strings and empty.
     */
    public static final SchemaUnawareCodec NOOP_CODEC = new SchemaUnawareCodec() {
        @Override
        public Object serialize(final Object input) {
            return input;
        }

        @Override
        public Object deserialize(final Object input) {
            return input;
        }
    };

    public static SchemaUnawareCodec getCodecFor(final Class<?> typeClz, final TypeDefinition<?> def) {
        if (BindingReflections.isBindingClass(typeClz)) {
            return getCachedSchemaUnawareCodec(typeClz, def);
        }
        return NOOP_CODEC;
    }

    private static SchemaUnawareCodec getCachedSchemaUnawareCodec(final Class<?> typeClz, final TypeDefinition<?> def) {
        // FIXME: extract this only when really needed
        var rootType = requireNonNull(def);
        while (true) {
            final var base = rootType.getBaseType();
            if (base != null) {
                rootType = base;
            } else {
                break;
            }
        }

        try {
            if (rootType instanceof EnumTypeDefinition) {
                return EnumerationCodec.of(typeClz, (EnumTypeDefinition) rootType);
            } else if (rootType instanceof BitsTypeDefinition) {
                return BitsCodec.of(typeClz, (BitsTypeDefinition) rootType);
            } else {
                return EncapsulatedValueCodec.of(typeClz, def);
            }
        } catch (ExecutionException e) {
            throw new IllegalStateException(e);
        }
    }

    @SuppressWarnings("rawtypes")
    static ValueTypeCodec encapsulatedValueCodecFor(final Class<?> typeClz, final TypeDefinition<?> typeDef,
             final IllegalArgumentCodec delegate) {
        return new CompositeValueCodec(getCachedSchemaUnawareCodec(typeClz, typeDef), delegate);
    }
}