/********************************************************************************
 * 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 {Observable} from "rxjs";
import {filter, ignoreElements, map, retry, switchMap} from "rxjs/operators";
import {StatementsApiService} from "../../../../core/api/statements";
import {catchErrorTo, endWithObservable} from "../../../../util/rxjs";
import {setErrorAction} from "../../../root/actions";
import {EErrorCode} from "../../../root/model";
import {addCommentAction, deleteCommentAction, fetchCommentsAction, updateStatementEntityAction} from "../../actions";

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

    public fetch$ = createEffect(() => this.actions.pipe(
        ofType(fetchCommentsAction),
        filter((action) => action.statementId != null),
        switchMap((action) => this.fetchComments(action.statementId))
    ));

    public add$ = createEffect(() => this.actions.pipe(
        ofType(addCommentAction),
        filter((action) => action.statementId != null && action.text != null),
        switchMap((action) => this.addComment(action.statementId, action.text))
    ));

    public delete$ = createEffect(() => this.actions.pipe(
        ofType(deleteCommentAction),
        filter((action) => action.statementId != null && action.commentId != null),
        switchMap((action) => this.deleteComment(action.statementId, action.commentId))
    ));

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

    }

    public fetchComments(statementId: number): Observable<Action> {
        return this.statementsApiService.getComments(statementId).pipe(
            map((comments) => updateStatementEntityAction({statementId, entity: {comments}})),
            retry(2),
            catchErrorTo(setErrorAction({error: EErrorCode.UNEXPECTED})),
        );
    }

    public addComment(statementId: number, comment: string): Observable<Action> {
        return this.statementsApiService.putComment(statementId, comment).pipe(
            ignoreElements(),
            retry(2),
            catchErrorTo(setErrorAction({error: EErrorCode.UNEXPECTED})),
            endWithObservable(() => this.fetchComments(statementId))
        );
    }

    public deleteComment(statementId: number, commentId: number): Observable<Action> {
        return this.statementsApiService.deleteComment(statementId, commentId).pipe(
            ignoreElements(),
            retry(2),
            catchErrorTo(setErrorAction({error: EErrorCode.UNEXPECTED})),
            endWithObservable(() => this.fetchComments(statementId))
        );
    }

}