import { NgModule, Optional, SkipSelf, Type, PLATFORM_ID } from '@angular/core';
import { CommonModule } from '@angular/common';
import { Title } from '@angular/platform-browser';

import { LocalDatabase, LOCAL_STORAGE_PREFIX } from '@ngx-pwa/local-storage';

// Shared Components
import { PromptDialogComponent } from '../shared/components/prompt-dialog/prompt-dialog.component';
import { ChoiceDialogComponent } from '../shared/components/choice-dialog/choice-dialog.component';
import { ProjectionDialogComponent } from 'app/shared/components/projection-dialog/projection-dialog.component';

import { OperatorService } from './core-services/operator.service';
import { OnAfterAppsLoaded } from './onAfterAppsLoaded';
import { StoragelockService } from './local-storage/storagelock.service';
import { customLocalDatabaseFactory } from './local-storage/custom-indexeddb-database';

export const ServicesToLoadOnAppsLoaded: Type<OnAfterAppsLoaded>[] = [OperatorService];

/**
 * Global Core Module.
 */
@NgModule({
    imports: [CommonModule],
    providers: [
        Title,
        // Use our own localStorage wrapper.
        {
            provide: LocalDatabase,
            useFactory: customLocalDatabaseFactory,
            deps: [PLATFORM_ID, StoragelockService, [new Optional(), LOCAL_STORAGE_PREFIX]]
        }
    ],
    entryComponents: [PromptDialogComponent, ChoiceDialogComponent, ProjectionDialogComponent]
})
export class CoreModule {
    /** make sure CoreModule is imported only by one NgModule, the AppModule */
    public constructor(
        @Optional()
        @SkipSelf()
        parentModule: CoreModule
    ) {
        if (parentModule) {
            throw new Error('CoreModule is already loaded. Import only in AppModule');
        }
    }
}