/*
 * Squidex Headless CMS
 *
 * @license
 * Copyright (c) Squidex UG (haftungsbeschränkt). All rights reserved.
 */

import { Injectable } from '@angular/core';
import { defined, DialogService, shareSubscribed, State, Types } from '@app/framework';
import { Observable, of } from 'rxjs';
import { catchError, tap } from 'rxjs/operators';
import { AppDto, AppsService, CreateAppDto, UpdateAppDto } from './../services/apps.service';

interface Snapshot {
    // All apps, loaded once.
    apps: ReadonlyArray<AppDto>;

    // The selected app.
    selectedApp: AppDto | null;
}

@Injectable()
export class AppsState extends State<Snapshot> {
    public apps =
        this.project(s => s.apps);

    public selectedAppOrNull =
        this.project(s => s.selectedApp);

    public selectedApp =
        this.selectedAppOrNull.pipe(defined());

    public get appName() {
        return this.snapshot.selectedApp?.name || '';
    }

    public get appDisplayName() {
        return this.snapshot.selectedApp?.displayName || '';
    }

    constructor(
        private readonly appsService: AppsService,
        private readonly dialogs: DialogService
    ) {
        super({ apps: [], selectedApp: null });
    }

    public reloadSelected() {
        return this.loadApp(this.appName).pipe(
            shareSubscribed(this.dialogs));
    }

    public select(name: string | null): Observable<AppDto | null> {
        return this.loadApp(name, true).pipe(
            tap(selectedApp => {
                this.next(s => {
                    return { ...s, selectedApp };
                });
            }));
    }

    public loadApp(name: string | null, cached = false) {
        if (!name) {
            return of(null);
        }

        if (cached) {
            const found = this.snapshot.apps.find(x => x.name === name);

            if (found) {
                return of(found);
            }
        }

        return this.appsService.getApp(name).pipe(
            tap(app => {
                this.replaceApp(app, app);
            }),
            catchError(() => of(null)));
    }

    public load(): Observable<any> {
        return this.appsService.getApps().pipe(
            tap(apps => {
                this.next(s => {
                    return { ...s, apps };
                });
            }),
            shareSubscribed(this.dialogs));
    }

    public create(request: CreateAppDto): Observable<AppDto> {
        return this.appsService.postApp(request).pipe(
            tap(created => {
                this.next(s => {
                    const apps = [...s.apps, created].sortedByString(x => x.displayName);

                    return { ...s, apps };
                });
            }),
            shareSubscribed(this.dialogs, { silent: true }));
    }

    public update(app: AppDto, request: UpdateAppDto): Observable<AppDto> {
        return this.appsService.putApp(app, request, app.version).pipe(
            tap(updated => {
                this.replaceApp(updated, app);
            }),
            shareSubscribed(this.dialogs, { silent: true }));
    }

    public removeImage(app: AppDto): Observable<AppDto> {
        return this.appsService.deleteAppImage(app, app.version).pipe(
            tap(updated => {
                this.replaceApp(updated, app);
            }),
            shareSubscribed(this.dialogs, { silent: true }));
    }

    public uploadImage(app: AppDto, file: File): Observable<number | AppDto> {
        return this.appsService.postAppImage(app, file, app.version).pipe(
            tap(updated => {
                if (Types.is(updated, AppDto)) {
                    this.replaceApp(updated, app);
                }
            }),
            shareSubscribed(this.dialogs));
    }

    public delete(app: AppDto): Observable<any> {
        return this.appsService.deleteApp(app).pipe(
            tap(() => {
                this.next(s => {
                    const apps = s.apps.filter(x => x.name !== app.name);

                    const selectedApp =
                        s.selectedApp &&
                        s.selectedApp.id === app.id ?
                        null :
                        s.selectedApp;

                    return { ...s, apps, selectedApp };
                });
            }),
            shareSubscribed(this.dialogs));
    }

    private replaceApp(updated: AppDto, app: AppDto) {
        this.next(s => {
            const apps = s.apps.replaceBy('id', updated);

            const selectedApp =
                s.selectedApp &&
                s.selectedApp.id === app.id ?
                updated :
                s.selectedApp;

            return { ...s, apps, selectedApp };
        });
    }
}