/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, 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.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */

import StringBuilder from './StringBuilder';

/**
 * Properties generation entry point.
 */
export default class IgnitePropertiesGenerator {
    _collectProperties(bean) {
        const props = [];

        // Append properties for complex object.
        const processBean = (bean) => {
            const newProps = _.difference(this._collectProperties(bean), props);

            if (!_.isEmpty(newProps)) {
                props.push(...newProps);

                if (!_.isEmpty(_.last(props)))
                    props.push('');
            }
        };

        // Append properties from item.
        const processItem = (item) => {
            switch (item.clsName) {
                case 'PROPERTY':
                case 'PROPERTY_CHAR':
                case 'PROPERTY_INT':
                    props.push(..._.difference([`${item.value}=${item.hint}`], props));

                    break;
                case 'BEAN':
                case 'DATA_SOURCE':
                    processBean(item.value);

                    break;
                case 'ARRAY':
                case 'COLLECTION':
                    _.forEach(item.items, processBean);

                    break;
                case 'MAP':
                    // Generate properties for all objects in keys and values of map.
                    _.forEach(item.entries, (entry) => {
                        processBean(entry.name);
                        processBean(entry.value);
                    });

                    break;
                default:
                    // No-op.
            }
        };

        // Generate properties for object arguments.
        _.forEach(_.get(bean, 'arguments'), processItem);

        // Generate properties for object properties.
        _.forEach(_.get(bean, 'properties'), processItem);

        return props;
    }

    generate(cfg) {
        const lines = this._collectProperties(cfg);

        if (_.isEmpty(lines))
            return null;

        const sb = new StringBuilder();

        sb.append(`# ${sb.generatedBy()}`).emptyLine();

        _.forEach(lines, (line) => sb.append(line));

        return sb.asString();
    }
}