package etcd_test

import (
	"context"
	"fmt"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"gitoa.ru/go-4devs/config"
	"gitoa.ru/go-4devs/config/provider/etcd"
	"gitoa.ru/go-4devs/config/test"
	"gitoa.ru/go-4devs/config/test/require"
)

func TestProvider(t *testing.T) {
	t.Parallel()

	ctx := context.Background()

	et, err := NewEtcd(ctx)
	require.NoError(t, err)

	provider := etcd.New("fdevs", "config", et)
	read := []test.Read{
		test.NewRead(test.DSN, "db_dsn"),
		test.NewRead(12*time.Minute, "duration"),
		test.NewRead(8080, "port"),
		test.NewRead(true, "maintain"),
		test.NewRead(test.Time("2020-01-02T15:04:05Z"), "start_at"),
		test.NewRead(.064, "percent"),
		test.NewRead(uint(2020), "count"),
		test.NewRead(int64(2021), "int64"),
		test.NewRead(int64(2022), "uint64"),
		test.NewReadConfig("config"),
	}
	test.Run(t, provider, read)
}

func value(cnt int32) string {
	return fmt.Sprintf("test data: %d", cnt)
}

func TestWatcher(t *testing.T) {
	t.Parallel()

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	key := "test_watch"

	et, err := NewEtcd(ctx)
	require.NoError(t, err)

	defer func() {
		_, err = et.KV.Delete(context.Background(), "fdevs/config/test_watch")
		require.NoError(t, err)
	}()

	var cnt, cnt2 int32

	prov := etcd.New("fdevs", "config", et)
	wg := sync.WaitGroup{}
	wg.Add(6)

	watch := func(cnt *int32) config.WatchCallback {
		return func(ctx context.Context, oldVar, newVar config.Value) error {
			switch *cnt {
			case 0:
				assert.Equal(t, value(*cnt), newVar.String())
				assert.Nil(t, oldVar)
			case 1:
				assert.Equal(t, value(*cnt), newVar.String())
				assert.Equal(t, value(*cnt-1), oldVar.String())
			case 2:
				_, perr := newVar.ParseString()
				require.NoError(t, perr)
				assert.Equal(t, "", newVar.String())
				assert.Equal(t, value(*cnt-1), oldVar.String())
			default:
				t.Error("unexpected watch")
				t.Fail()
			}

			wg.Done()
			atomic.AddInt32(cnt, 1)

			return nil
		}
	}

	err = prov.Watch(ctx, watch(&cnt), key)
	err = prov.Watch(ctx, watch(&cnt2), key)
	require.NoError(t, err)

	time.AfterFunc(time.Second, func() {
		_, err = et.KV.Put(ctx, "fdevs/config/test_watch", value(0))
		require.NoError(t, err)
		_, err = et.KV.Put(ctx, "fdevs/config/test_watch", value(1))
		require.NoError(t, err)
		_, err = et.KV.Delete(ctx, "fdevs/config/test_watch")
		require.NoError(t, err)
	})

	time.AfterFunc(time.Second*10, func() {
		assert.Fail(t, "failed watch after 5 sec")
		cancel()
	})

	go func() {
		wg.Wait()
		cancel()
	}()

	<-ctx.Done()
}