src/app/store/process/effects/complete-task.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 {Params, Router} from "@angular/router";
import {Actions, createEffect, ofType} from "@ngrx/effects";
import {Action} from "@ngrx/store";
import {concat, defer, EMPTY, Observable, of} from "rxjs";
import {exhaustMap, filter, map, switchMap} from "rxjs/operators";
import {EAPIProcessTaskDefinitionKey} from "../../../core/api";
import {IAPIProcessObject, IAPIProcessTask, ProcessApiService} from "../../../core/api/process";
import {ignoreError} from "../../../util/rxjs";
import {arrayJoin} from "../../../util/store";
import {completeTaskAction, deleteTaskAction} from "../actions";

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

    public readonly completeTask$ = createEffect(() => this.actions$.pipe(
        ofType(completeTaskAction),
        filter((action) => typeof action.statementId === "number" && typeof action.taskId === "string"),
        exhaustMap((action) => this.completeTask(action.statementId, action.taskId, action.variables, action.claimNext, action.endWith))
    ));

    public constructor(
        private readonly actions$: Actions,
        private readonly processApiService: ProcessApiService,
        private readonly router: Router
    ) {

    }

    public completeTask(
        statementId: number,
        taskId: string,
        variables: IAPIProcessObject,
        claimNext?: boolean | EAPIProcessTaskDefinitionKey,
        endWithActions?: Action[]
    ): Observable<Action> {
        return concat(
            this.processApiService.completeStatementTask(statementId, taskId, variables).pipe(
                switchMap(() => {
                    endWithActions = arrayJoin([deleteTaskAction({statementId, taskId})], endWithActions);
                    return claimNext == null ? of<IAPIProcessTask>(null) : this.claimNextTask(statementId);
                }),
                switchMap((task) => {
                    return this.navigateToStatement(statementId, task?.taskId);
                }),
                switchMap(() => EMPTY),
                ignoreError()
            ),
            defer(() => of(...endWithActions))
        );
    }

    public claimNextTask(statementId: number, key?: EAPIProcessTaskDefinitionKey): Observable<IAPIProcessTask> {
        return this.processApiService.getStatementTasks(statementId).pipe(
            map((taskList) => {
                return taskList
                    .filter((task) => task?.taskId != null)
                    .filter((task) => key == null || task.taskDefinitionKey === key)[0];
            }),
            switchMap((task) => {
                return task == null ? of(task) : this.processApiService.claimStatementTask(statementId, task.taskId);
            })
        );
    }

    public navigateToStatement(statementId: number, taskId?: string, queryParams: Params = {}): Observable<boolean> {
        return defer(() => {
            const route = statementId == null ? "/" : taskId == null ? "/details" : "/edit";
            if (statementId != null) {
                queryParams.id = statementId;
                if (taskId != null) {
                    queryParams.taskId = taskId;
                }
            }
            return this.router.navigate([route], {queryParams});
        });
    }

}