import { sequentialize } from '../../../src/misc/sequentialize';
import { throttle } from '../../../src/misc/throttle';

describe('throttle decorator', () => {
    it('should call the function once at a time', async () => {
        const foo = new Foo();
        const promises = [];
        for (let i = 0; i < 10; i++) {
            promises.push(foo.bar(1));
        }
        await Promise.all(promises);

        expect(foo.calls).toBe(10);
    });

    it('should call the function once at a time for each object', async () => {
        const foo = new Foo();
        const foo2 = new Foo();
        const promises = [];
        for (let i = 0; i < 10; i++) {
            promises.push(foo.bar(1));
            promises.push(foo2.bar(1));
        }
        await Promise.all(promises);

        expect(foo.calls).toBe(10);
        expect(foo2.calls).toBe(10);
    });

    it('should call the function limit at a time', async () => {
        const foo = new Foo();
        const promises = [];
        for (let i = 0; i < 10; i++) {
            promises.push(foo.baz(1));
        }
        await Promise.all(promises);

        expect(foo.calls).toBe(10);
    });

    it('should call the function limit at a time for each object', async () => {
        const foo = new Foo();
        const foo2 = new Foo();
        const promises = [];
        for (let i = 0; i < 10; i++) {
            promises.push(foo.baz(1));
            promises.push(foo2.baz(1));
        }
        await Promise.all(promises);

        expect(foo.calls).toBe(10);
        expect(foo2.calls).toBe(10);
    });

    it('should work together with sequentialize', async () => {
        const foo = new Foo();
        const promises = [];
        for (let i = 0; i < 10; i++) {
            promises.push(foo.qux(Math.floor(i / 2) * 2));
        }
        await Promise.all(promises);

        expect(foo.calls).toBe(5);
    });
});

class Foo {
    calls = 0;
    inflight = 0;

    @throttle(1, () => 'bar')
    bar(a: number) {
        this.calls++;
        this.inflight++;
        return new Promise(res => {
            setTimeout(() => {
                expect(this.inflight).toBe(1);
                this.inflight--;
                res(a * 2);
            }, Math.random() * 10);
        });
    }

    @throttle(5, () => 'baz')
    baz(a: number) {
        this.calls++;
        this.inflight++;
        return new Promise(res => {
            setTimeout(() => {
                expect(this.inflight).toBeLessThanOrEqual(5);
                this.inflight--;
                res(a * 3);
            }, Math.random() * 10);
        });
    }

    @sequentialize(args => 'qux' + args[0])
    @throttle(1, () => 'qux')
    qux(a: number) {
        this.calls++;
        this.inflight++;
        return new Promise(res => {
            setTimeout(() => {
                expect(this.inflight).toBe(1);
                this.inflight--;
                res(a * 3);
            }, Math.random() * 10);
        });
    }
}