import {Component} from '@angular/core';
import {Car} from "../core/model/car";
import {MatSnackBar} from "@angular/material/snack-bar";

const CAR: Car = {
    id: 1,
    brand: 'Toyota',
    model: 'Yaris',
    power: 12,
    numberOfSeats: 5
};

@Component({
    selector: 'app-promises-example',
    templateUrl: './promises-example.component.html',
    styleUrls: ['./promises-example.component.scss']
})
export class PromisesExampleComponent {
    car?: Car;
    isLoading: boolean = false;
    isLoaded: boolean = false;
    numberOfLoadings: number = 0;

    constructor(
        private snackBar: MatSnackBar
    ) {
    }

    // ******************************************
    // Mode Promise avec les then/catch/finally
    // ******************************************
    showCarViaAPromise(): void {
        this.loadCarViaAPromise();
    }

    private loadCarViaAPromise(): void {
        this.isLoading = true;
        this.isLoaded = false;

        this.findViaPromise()
            .then(car => {
                this.car = car;
                this.isLoaded = true;
            })
            .catch(error => {
                this.snackBar.open(`Error while loading car. Cause : ${error}`);
            })
            .finally(() => {
                this.isLoading = false;
                this.numberOfLoadings++;
            });
    }

    private findViaPromise(): Promise<Car> {
        return new Promise<Car>((resolve, reject) => {
            if (this.numberOfLoadings % 2 === 0) {
                setTimeout(() => {
                    resolve(CAR);
                }, 2000);
            } else {
                reject('It\'s an odd call number.');
            }
        });
    }

    // ******************************************
    // Mode async/await
    // ******************************************
    showCarViaAsyncAwaitProcess(): void {
        this.loadCarViaAsyncAwaitProcess();
    }

    private async loadCarViaAsyncAwaitProcess(): Promise<void> {
        this.isLoading = true;
        this.isLoaded = false;

        try {
            this.car = await this.findViaAsyncAwaitProcess();
            this.isLoaded = true;
        } catch (error) {
            this.snackBar.open(`Error while loading car. Cause : ${error}`);
        }

        this.numberOfLoadings++;
        this.isLoading = false;
    }

    private async findViaAsyncAwaitProcess(): Promise<Car> {
        if (this.numberOfLoadings % 2 !== 0) {
            throw 'It\'s an odd call number.';
        }
        await new Promise(resolve => setTimeout(resolve, 2000));
        return CAR;
    }
}