package foo

import (
	"testing"
	"time"

	"github.com/dimonomid/clock"
)

const testTimeLayout = "Jan 2, 2006 at 15:04:05.000"

func TestFoo(t *testing.T) {
	// Create a mocked time, initialized at May 1, 2020 midnight.
	mockedClock := clock.NewMock()
	now, _ := time.Parse(testTimeLayout, "May 1, 2020 at 00:00:00.000")
	mockedClock.Set(now)

	// Create output channel, we'll check later that it receives the numbers we
	// expect.
	out := make(chan int, 1)

	// Create Foo, it will also start the internal goroutine to send numbers
	// to the channel.
	NewFoo(&FooParams{
		Clock: mockedClock,

		Out:      out,
		Interval: 1 * time.Second,
	})

	// Assert that we receive the numbers we expect
	mockedClock.Add(1 * time.Second)
	assertRecvInt(t, out, 0)

	mockedClock.Add(1 * time.Second)
	assertRecvInt(t, out, 1)

	mockedClock.Add(1 * time.Second)
	assertRecvInt(t, out, 2)
}

func assertRecvInt(t *testing.T, ch <-chan int, want int) {
	select {
	case got := <-ch:
		if got != want {
			t.Errorf("wanted %d, got %d", want, got)
		}
	default:
		t.Errorf("wanted %d, got nothing", want)
	}
}