/*-
 * ========================LICENSE_START=================================
 * O-RAN-SC
 * %%
 * Copyright (C) 2019 Nordix Foundation
 * %%
 * 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.
 * ========================LICENSE_END===================================
 */

import { HttpErrorResponse } from '@angular/common/http';
import { CollectionViewer, DataSource } from '@angular/cdk/collections';
import { Injectable } from '@angular/core';
import { BehaviorSubject } from 'rxjs/BehaviorSubject';
import { of } from 'rxjs/observable/of';
import { Observable } from 'rxjs/Observable';
import { catchError, finalize, map } from 'rxjs/operators';

import { PolicyType, PolicyTypes, PolicyTypeSchema } from '../interfaces/policy.types';
import { PolicyService } from '../services/policy/policy.service';
import { NotificationService } from '../services/ui/notification.service';

@Injectable({
    providedIn: 'root'
})

export class PolicyTypeDataSource extends DataSource<PolicyTypeSchema> {

    policyTypes: PolicyTypeSchema[] = [];

    policyTypeSubject = new BehaviorSubject<PolicyTypeSchema[]>([]);

    private loadingSubject = new BehaviorSubject<boolean>(false);

    public rowCount = 1; // hide footer during intial load

    constructor(public policySvc: PolicyService,
        private notificationService: NotificationService) {
        super();
    }

    public getPolicyTypes() {
        this.policyTypes = [] as PolicyTypeSchema[];
        this.policySvc.getPolicyTypes()
            .pipe(
                catchError((httpError: HttpErrorResponse) => {
                    this.notificationService.error('Failed to get policy types: ' + httpError.error);
                    return of([]);
                }),
                finalize(() => this.loadingSubject.next(false))
            )
            .subscribe((policyType: PolicyTypes) => {
                this.rowCount = policyType.policytype_ids.length;
                if (policyType.policytype_ids.length != 0) {
                    policyType.policytype_ids.forEach(policyTypeId => {
                        var policyTypeSchema = {} as PolicyTypeSchema
                        if (policyTypeId === "") {
                            policyTypeSchema.id = '';
                            policyTypeSchema.name = '';
                            policyTypeSchema.schemaObject = '{}';
                            this.policyTypes.push(policyTypeSchema);
                        }
                        else {
                            this.policySvc.getPolicyType(policyTypeId)
                                .pipe(
                                    catchError((httpError: HttpErrorResponse) => {
                                        this.notificationService.error('Failed to get policy type: ' + httpError.error);
                                        return of([]);
                                    }),
                                    finalize(() => this.loadingSubject.next(false))
                                )
                                .subscribe((policyType: PolicyType) => {
                                    policyTypeSchema.id = policyTypeId;
                                    policyTypeSchema.schemaObject = policyType.policy_schema;
                                    policyTypeSchema.name = policyType.policy_schema.title;
                                    this.policyTypes.push(policyTypeSchema);
                                })
                        }
                        this.policyTypeSubject.next(this.policyTypes);
                    })
                }
            })
    }

    connect(collectionViewer: CollectionViewer): Observable<PolicyTypeSchema[]> {
        return of(this.policyTypeSubject.getValue());
    }

    disconnect(collectionViewer: CollectionViewer): void {
        this.policyTypeSubject.complete();
    }
}