src/app/store/statements/effects/fetch-statements.effect.ts

/********************************************************************************
 * Copyright (c) 2020 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0
 *
 * SPDX-License-Identifier: EPL-2.0
 ********************************************************************************/

import {Injectable} from "@angular/core";
import {Actions, createEffect, ofType} from "@ngrx/effects";
import {Action} from "@ngrx/store";
import {EMPTY, Observable} from "rxjs";
import {catchError, filter, map, retry, startWith, switchMap} from "rxjs/operators";
import {StatementsApiService} from "../../../core";
import {addAttachmentsAction, addStatementsAction, fetchStatementDetailsAction, fetchStatementsAction} from "../actions";

@Injectable({providedIn: "root"})
export class FetchStatementsEffect {

    public readonly fetchStatements$ = createEffect(() => this.actions.pipe(
        ofType(fetchStatementsAction),
        switchMap(() => this.fetchStatements())
    ));

    public readonly fetchStatementDetails$ = createEffect(() => this.actions.pipe(
        ofType(fetchStatementDetailsAction),
        filter((action) => typeof action?.id === "number"),
        switchMap((action) => this.fetchStatementDetails(action.id))
    ));

    public constructor(
        private readonly actions: Actions,
        private readonly statementsApiService: StatementsApiService
    ) {

    }

    public fetchStatements(): Observable<Action> {
        return this.statementsApiService.getStatements().pipe(
            map((statements) => {
                return addStatementsAction({statements});
            }),
            retry(2),
            catchError(() => EMPTY)
        );
    }

    public fetchStatementDetails(id: number): Observable<Action> {
        return this.statementsApiService.getStatement(id).pipe(
            switchMap((statement) => {
                return this.fetchAttachments(statement.id).pipe(
                    startWith(addStatementsAction({statements: [statement]}))
                );
            }),
            retry(2),
            catchError(() => EMPTY)
        );
    }

    public fetchAttachments(statementId: number) {
        return this.statementsApiService.getAllAttachments(statementId).pipe(
            map((attachments) => {
                return addAttachmentsAction({statementId, attachments});
            }),
            retry(2),
            catchError(() => EMPTY)
        );
    }

}