import { Injectable } from '@angular/core';
import { Apollo } from 'apollo-angular';
import { jsonToGraphQLQuery } from 'json-to-graphql-query';
import gql from 'graphql-tag';
import { Utils } from './utils';
import { throwError } from 'rxjs';
import { catchError } from 'rxjs/operators';
import { LoaderService } from '../components/generic/loader/loader.service';

@Injectable({
	providedIn: 'root',
})
export class GraphQLService {
	constructor(private readonly apollo: Apollo, private loader: LoaderService) {}

	//  fetch data from graphQL server
	query(query, variables = {}) {
		try {
			return this.apollo.query({ query, variables }).pipe(
				catchError(error => {
					// Utils.showError('GraphQLService.watchQuery()', error);
					return throwError(error);
				})
			);
		} catch (error) {
			Utils.showError('GraphQLService.query()', error);
		}
	}

	// mutate data to graphql server. i.e. edit, delete, create
	mutate(mutation, variables = {}) {
		try {
			return this.apollo.mutate({ mutation, variables }).pipe(
                catchError(error => {
					//  Utils.addLog("error", 'GraphQLService.mutate()', error);
                    return throwError(error);
				})
			);
		} catch (error) {
			Utils.addLog("error", 'GraphQLService.mutate()', error);
		}
	}

	subscribe(query) {
		try {
			query = { subscription: query };
			query = jsonToGraphQLQuery(query, { pretty: true });
			return this.apollo.subscribe(query);
		} catch (error) {
			Utils.showError('subscribe() ', error);
		}
	}

	// upload files to graphql server.
	upload(query, variables) {
		try {
			return this.apollo.mutate({
				mutation: gql(query),
				variables,
				context: {
					useMultipart: true,
				},
			});
		} catch (error) {
			Utils.showError('upload()', error);
		}
	}
}