/*
 * Copyright 2018 NEM
 *
 * Licensed 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 { Observable } from 'rxjs';
import { map, mergeMap } from 'rxjs/operators';
import { NamespaceRepository } from '../infrastructure/NamespaceRepository';
import { NamespaceId } from '../model/namespace/NamespaceId';
import { NamespaceInfo } from '../model/namespace/NamespaceInfo';
import { NamespaceName } from '../model/namespace/NamespaceName';
import { Namespace } from './Namespace';

/**
 * Namespace service
 */
export class NamespaceService {
    /**
     * Constructor
     * @param namespaceRepository
     */
    constructor(private readonly namespaceRepository: NamespaceRepository) {}

    /**
     * Get namespace info and name from namespace Id
     * @param id
     * @returns {Observable<Namespace>}
     */
    namespace(id: NamespaceId): Observable<Namespace> {
        return this.namespaceRepository.getNamespace(id).pipe(
            mergeMap((namespaceInfo: NamespaceInfo) =>
                this.namespaceRepository.getNamespacesNames(namespaceInfo.levels).pipe(
                    map((names) =>
                        Object.assign(
                            {
                                __proto__: Object.getPrototypeOf(namespaceInfo),
                            },
                            namespaceInfo,
                            {
                                name: this.extractFullNamespace(namespaceInfo, names),
                            },
                        ),
                    ),
                ),
            ),
        );
    }

    private extractFullNamespace(namespace: NamespaceInfo, namespaceNames: NamespaceName[]): string {
        return namespace.levels
            .map((level) => {
                const namespaceName = namespaceNames.find((name) => name.namespaceId.equals(level));
                if (namespace === undefined) {
                    throw new Error('Not found');
                }
                return namespaceName;
            })
            .map((namespaceName: NamespaceName) => namespaceName.name)
            .join('.');
    }
}