import 'reflect-metadata';

import {
    requiredMocks,
} from './../../../../test-mocks';
requiredMocks(jest);

import {
    ElementRef,
} from '@angular/core';

import {
    DomElementLocationService,
} from './dom-element-location.service';

const initDomElementLocationService = (
    window?: Window,
) => {
    return new DomElementLocationService(
        window,
    );
};

describe('getCenterPointOfElement', () => {
    // tslint:disable-next-line
    test('It returns the top of the element plus half the height', () => {
        const domElementLocationService =
            initDomElementLocationService();
        const elementRef = {
            nativeElement: {},
        } as ElementRef;
        elementRef.nativeElement.getBoundingClientRect =
            jest.fn().mockReturnValue({
                height: 50,
                top: 10,
            });

        expect(
            domElementLocationService
            .getCenterPointOfElement(
                elementRef,
            ),
        ).toBe(35);

    });
});

describe('getMostCentralElement', () => {
    // tslint:disable-next-line
    test('If there is just one element it returns that element', () => {
        const window = {
            innerHeight: 100,
        } as Window;
        const domElementLocationService =
            initDomElementLocationService(
                window,
            );
        const elementRefOne = {} as ElementRef;
        domElementLocationService.getCenterPointOfElement =
            jest.fn().mockReturnValue(0);

        const result =
            domElementLocationService.getMostCentralElement(
                [
                    elementRefOne,
                ],
            );

        expect(result.mostCentralIndex).toBe(0);
        expect(result.mostCentral).toBe(
            elementRefOne,
        );
    });

    // tslint:disable-next-line
    test('It returns the element with the center point closest to the window center point', () => {
        const window = {
            innerHeight: 100,
        } as Window;
        const domElementLocationService =
            initDomElementLocationService(
                window,
            );
        const elementRefOne = {} as ElementRef;
        const elementRefTwo = {} as ElementRef;
        const elementRefThree = {} as ElementRef;
        domElementLocationService.getCenterPointOfElement =
            jest.fn().mockImplementation((elementRef) => {
                if (elementRef === elementRefOne) {
                    return 0;
                } else if (elementRef === elementRefTwo) {
                    return 50;
                }
                return 100;
            });

        const result =
            domElementLocationService.getMostCentralElement(
                [
                    elementRefOne,
                    elementRefTwo,
                    elementRefThree,
                ],
            );

        expect(result.mostCentralIndex).toBe(1);
        expect(result.mostCentral).toBe(
            elementRefTwo,
        );
    });
});