// Copyright 2023 EMQ Technologies Co., Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package function

import (
	"fmt"
	"testing"

	"github.com/stretchr/testify/require"

	"github.com/lf-edge/ekuiper/internal/conf"
	kctx "github.com/lf-edge/ekuiper/internal/topo/context"
	"github.com/lf-edge/ekuiper/internal/topo/state"
	"github.com/lf-edge/ekuiper/pkg/api"
)

func TestStrFuncNil(t *testing.T) {
	contextLogger := conf.Log.WithField("rule", "testExec")
	ctx := kctx.WithValue(kctx.Background(), kctx.LoggerKey, contextLogger)
	tempStore, _ := state.CreateStore("mockRule0", api.AtMostOnce)
	fctx := kctx.NewDefaultFuncContext(ctx.WithMeta("mockRule0", "test", tempStore), 2)
	oldBuiltins := builtins
	defer func() {
		builtins = oldBuiltins
	}()
	builtins = map[string]builtinFunc{}
	registerStrFunc()
	for name, function := range builtins {
		switch name {
		case "concat":
			r, b := function.exec(fctx, []interface{}{"1", nil, "2"})
			require.True(t, b, fmt.Sprintf("%v failed", name))
			require.Equal(t, "12", r)
		case "endswith", "regexp_matches", "startswith":
			r, b := function.check([]interface{}{nil})
			require.True(t, b, fmt.Sprintf("%v failed", name))
			require.Equal(t, false, r)
		case "indexof":
			r, b := function.exec(fctx, []interface{}{nil})
			require.True(t, b, fmt.Sprintf("%v failed", name))
			require.Equal(t, -1, r)
		case "length", "numbytes":
			r, b := function.check([]interface{}{nil})
			require.True(t, b, fmt.Sprintf("%v failed", name))
			require.Equal(t, 0, r)
		default:
			r, b := function.check([]interface{}{nil})
			require.True(t, b, fmt.Sprintf("%v failed", name))
			require.Nil(t, r, fmt.Sprintf("%v failed", name))
		}
	}
}