// Copyright 2018 Google LLC
//
// 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 interpreter

import (
	"testing"
	"time"

	"github.com/google/cel-go/common/types"
	"github.com/google/cel-go/common/types/ref"
)

func TestActivation(t *testing.T) {
	act, err := NewActivation(map[string]any{"a": types.True})
	if err != nil {
		t.Fatalf("Got err: %v, wanted activation", err)
	}
	_, err = NewActivation(act)
	if err != nil {
		t.Fatalf("Got err: %v, wanted activation", err)
	}
	act3, err := NewActivation("")
	if err == nil {
		t.Fatalf("Got %v, wanted err", act3)
	}
}

func TestActivation_Resolve(t *testing.T) {
	activation, _ := NewActivation(map[string]any{"a": types.True})
	if val, found := activation.ResolveName("a"); !found || val != types.True {
		t.Error("Activation failed to resolve 'a'")
	}
}

func TestActivation_ResolveLazy(t *testing.T) {
	var v ref.Val
	now := func() ref.Val {
		if v == nil {
			v = types.DefaultTypeAdapter.NativeToValue(time.Now().Unix())
		}
		return v
	}
	a, _ := NewActivation(map[string]any{
		"now": now,
	})
	first, _ := a.ResolveName("now")
	second, _ := a.ResolveName("now")
	if first != second {
		t.Errorf("Got different second, "+
			"expected same as first: 1:%v 2:%v", first, second)
	}
}

func TestHierarchicalActivation(t *testing.T) {
	// compose a parent with more properties than the child
	parent, _ := NewActivation(map[string]any{
		"a": types.String("world"),
		"b": types.Int(-42),
	})
	// compose the child such that it shadows the parent
	child, _ := NewActivation(map[string]any{
		"a": types.True,
		"c": types.String("universe"),
	})
	combined := NewHierarchicalActivation(parent, child)

	// Resolve the shadowed child value.
	if val, found := combined.ResolveName("a"); !found || val != types.True {
		t.Error("Activation failed to resolve shadow value of 'a'")
	}
	// Resolve the parent only value.
	if val, found := combined.ResolveName("b"); !found || val.(types.Int) != -42 {
		t.Error("Activation failed to resolve parent value of 'b'")
	}
	// Resolve the child only value.
	if val, found := combined.ResolveName("c"); !found || val.(types.String) != "universe" {
		t.Error("Activation failed to resolve child value of 'c'")
	}
}