import { FilterService } from '../filtering';
import { SearchService } from '../search';
import { SortingService } from '../sorting';
import { EntitiesService, ListingService } from './services';
import { forwardRef, Provider, Type } from '@angular/core';
import { ListingComponent } from './listing-component.directive';
import { IListable } from './models';
import { Id } from './models/trackable';

export const DefaultListingServices: readonly Provider[] = [FilterService, SearchService, SortingService, ListingService] as const;

export interface IListingServiceFactoryOptions<T extends IListable<PrimaryKey>, PrimaryKey extends Id = T['id']> {
    readonly entitiesService?: Type<EntitiesService<T, T>>;
    readonly component: Type<unknown>;
}

function getEntitiesService<T extends IListable<PrimaryKey>, PrimaryKey extends Id = T['id']>(
    service?: Type<EntitiesService<T, T>>,
): Provider {
    if (service) {
        return {
            provide: EntitiesService,
            useExisting: service,
        };
    }

    return EntitiesService;
}

function getOptions<T extends IListable<PrimaryKey>, PrimaryKey extends Id = T['id']>(
    options?: IListingServiceFactoryOptions<T> | Type<unknown>,
) {
    if (typeof options === 'function') {
        return {
            component: options,
        };
    }

    return options;
}

function getComponent(component: Type<unknown>) {
    return {
        provide: ListingComponent,
        useExisting: forwardRef(() => component),
    };
}

/**
 * This is equivalent to
 * @example <code>[FilterService, SearchService, SortingService, ListingService, EntitiesService]</code>
 */
export function listingProvidersFactory(): Provider[];
/**
 * This is equivalent to
 * @example <code>[{provide: ListingComponent, useExisting: forwardRef(() => component)}, EntitiesService, FilterService, SearchService, SortingService, ListingService]</code>
 */
export function listingProvidersFactory(component: Type<unknown>): Provider[];
/**
 * This is equivalent to
 * @example <code>[{provide: EntitiesService, useExisting: entitiesService}, {provide: ListingComponent, useExisting: forwardRef(() => component)}, FilterService, SearchService, SortingService, ListingService]</code>
 */
export function listingProvidersFactory<T extends IListable<PrimaryKey>, PrimaryKey extends Id = T['id']>(
    options: IListingServiceFactoryOptions<T>,
): Provider[];
export function listingProvidersFactory<T extends IListable<PrimaryKey>, PrimaryKey extends Id = T['id']>(
    args?: IListingServiceFactoryOptions<T> | Type<unknown>,
): Provider[] {
    const options = getOptions(args);
    const services = [...DefaultListingServices];

    const entitiesService = getEntitiesService(options?.entitiesService);
    services.push(entitiesService);

    if (options?.component) {
        services.push(getComponent(options.component));
    }

    return services;
}