package watchdog_test

import (
	"context"
	"reflect"
	"testing"
	"time"

	"code.uint32.ru/tiny/watchdog"
)

type mockChecker struct {
	name   string
	status watchdog.Status
	err    error
	called bool
}

func (m *mockChecker) Func(_ context.Context) (watchdog.Status, error) {
	m.called = true
	return m.status, m.err
}

func (m *mockChecker) HasBeenCalled() bool {
	return m.called
}

func (m *mockChecker) Check() watchdog.Check {
	return watchdog.Check{
		Name:     m.name,
		Interval: time.Minute,
		Check:    m.Func,
	}
}

func newMockChecker(name string, s watchdog.Status, err error) *mockChecker {
	return &mockChecker{name: name, status: s, err: err}
}

func TestCreateWith_new(t *testing.T) {
	w := new(watchdog.Watchdog)

	if len(w.ListChecks()) != 0 {
		t.Errorf("expected len = 0")
	}
}

func TestNew(t *testing.T) {
	w := watchdog.New()

	if len(w.ListChecks()) != 0 {
		t.Errorf("expected len = 0")
	}

	m1 := newMockChecker("mock", watchdog.StatusOK, nil)
	m2 := newMockChecker("mock2", watchdog.StatusOK, nil)

	w = watchdog.New()
	w.AddChecks(m1.Check(), m2.Check())
	if len(w.ListChecks()) != 2 {
		t.Errorf("expected len = 2")
	}

	w.RemoveChecks("mock")

	if len(w.ListChecks()) != 1 {
		t.Errorf("expected len = 1")
	}

	w.RemoveChecks("mock2")

	if len(w.ListChecks()) != 0 {
		t.Errorf("expected len = 0")
	}

	w = watchdog.New(m1.Check(), m2.Check())
	if len(w.ListChecks()) != 2 {
		t.Errorf("")
	}
}

func TestRunImmediately(t *testing.T) {
	w := new(watchdog.Watchdog)
	out, err := w.RunImmediately(t.Context(), 1)
	if err == nil {
		t.Error("empty instance must return error on RunImmediately")
	}
	if len(out) != 0 {
		t.Errorf("expected zero len slice for empty instance, got %d", len(out))
	}

	m1 := newMockChecker("mock", watchdog.StatusOK, nil)
	m2 := newMockChecker("mock2", watchdog.StatusOK, nil)

	w = watchdog.New(m1.Check(), m2.Check())
	out, _ = w.RunImmediately(t.Context(), 0)
	if len(out) != 2 {
		t.Error("expected result of len 2")
	}

	for _, m := range []*mockChecker{m1, m2} {
		if !m.HasBeenCalled() {
			t.Errorf("mock %s has not been called", m.name)
		}
	}

}

func TestStart(t *testing.T) {
	w := new(watchdog.Watchdog)
	if _, err := w.Start(t.Context(), 0); err == nil {
		t.Error("Start doen't error on empty checks slice")
	}

	m1 := newMockChecker("mock", watchdog.StatusOK, nil)
	m2 := newMockChecker("mock2", watchdog.StatusOK, nil)

	w.AddChecks(m1.Check(), m2.Check())

	out, err := w.Start(t.Context(), 0)
	if err != nil {
		t.Error("Start returns error", err)
	}

	out2, err := w.Start(t.Context(), 0)
	if err != nil {
		t.Error("second call to Start returns error")
	}

	if !reflect.DeepEqual(out, out2) {
		t.Error("returned channels are not equal")
	}

	count := 0
	go func() {
		time.Sleep(time.Second)
		if err := w.Stop(); err != nil {
			t.Error("Stop returned error", err)
		}
	}()

	for res := range out {
		if res.Status != watchdog.StatusOK || res.Error != nil {
			t.Errorf("incorrect status for check %s", res.Name)
		}

		count++
	}

	if count != 2 {
		t.Error("incorrect result count received from chan")
	}

	for _, m := range []*mockChecker{m1, m2} {
		if !m.HasBeenCalled() {
			t.Errorf("mock %s has not been called", m.name)
		}
	}

	if err := w.Stop(); err == nil {
		t.Error("call to stop on stopped instance does not return err")
	}
}

func TestWatchdogObeysContext(t *testing.T) {
	w := new(watchdog.Watchdog)
	m1 := newMockChecker("mock", watchdog.StatusOK, nil)
	m2 := newMockChecker("mock2", watchdog.StatusOK, nil)

	w.AddChecks(m1.Check(), m2.Check())

	ctx, stop := context.WithCancel(t.Context())
	if _, err := w.Start(ctx, 2); err != nil {
		t.Error(err)
	}

	stop()
	// wait for goroutines to finish
	time.Sleep(time.Second)
	if err := w.Stop(); err == nil {
		t.Error("no error calling Stop for stopped instance")
	}
}