/*!
 * @license
 * Copyright © 2005-2025 Hyland Software, Inc. and its affiliates. All rights reserved.
 *
 * 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 { Injectable } from '@angular/core';
import { Agent, AgentsApi } from '@alfresco/js-api';
import { BehaviorSubject, from, Observable, of } from 'rxjs';
import { map, switchMap } from 'rxjs/operators';
import { AlfrescoApiService } from '../../services';

@Injectable({
    providedIn: 'root'
})
export class AgentService {
    private _agentsApi: AgentsApi;
    private agents = new BehaviorSubject<Agent[]>([]);

    get agentsApi(): AgentsApi {
        this._agentsApi = this._agentsApi ?? new AgentsApi(this.apiService.getInstance());
        return this._agentsApi;
    }

    agents$ = this.agents.asObservable();

    constructor(private apiService: AlfrescoApiService) {}

    /**
     * Gets all agents from cache. If cache is empty, fetches agents from backend.
     *
     * @returns Agent[] list containing agents.
     */
    getAgents(): Observable<Agent[]> {
        return this.agents$.pipe(
            switchMap((agentsList) => {
                if (agentsList.length) {
                    return of(agentsList);
                }
                return from(this.agentsApi.getAgents()).pipe(
                    map((paging) => {
                        const agentEntries = paging.list.entries.map((agentEntry) => agentEntry.entry);
                        this.agents.next(agentEntries);
                        return agentEntries;
                    })
                );
            })
        );
    }
}