// Copyright The OpenTelemetry Authors
//
// 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 core_test

import (
	"encoding/json"
	"testing"
	"unsafe"

	"github.com/google/go-cmp/cmp"
	"github.com/stretchr/testify/require"

	"go.opentelemetry.io/otel/api/core"
	"go.opentelemetry.io/otel/api/key"
)

func TestValue(t *testing.T) {
	k := core.Key("test")
	bli := getBitlessInfo(42)
	for _, testcase := range []struct {
		name      string
		value     core.Value
		wantType  core.ValueType
		wantValue interface{}
	}{
		{
			name:      "Key.Bool() correctly returns keys's internal bool value",
			value:     k.Bool(true).Value,
			wantType:  core.BOOL,
			wantValue: true,
		},
		{
			name:      "Key.Int64() correctly returns keys's internal int64 value",
			value:     k.Int64(42).Value,
			wantType:  core.INT64,
			wantValue: int64(42),
		},
		{
			name:      "Key.Uint64() correctly returns keys's internal uint64 value",
			value:     k.Uint64(42).Value,
			wantType:  core.UINT64,
			wantValue: uint64(42),
		},
		{
			name:      "Key.Float64() correctly returns keys's internal float64 value",
			value:     k.Float64(42.1).Value,
			wantType:  core.FLOAT64,
			wantValue: 42.1,
		},
		{
			name:      "Key.Int32() correctly returns keys's internal int32 value",
			value:     k.Int32(42).Value,
			wantType:  core.INT32,
			wantValue: int32(42),
		},
		{
			name:      "Key.Uint32() correctly returns keys's internal uint32 value",
			value:     k.Uint32(42).Value,
			wantType:  core.UINT32,
			wantValue: uint32(42),
		},
		{
			name:      "Key.Float32() correctly returns keys's internal float32 value",
			value:     k.Float32(42.1).Value,
			wantType:  core.FLOAT32,
			wantValue: float32(42.1),
		},
		{
			name:      "Key.String() correctly returns keys's internal string value",
			value:     k.String("foo").Value,
			wantType:  core.STRING,
			wantValue: "foo",
		},
		{
			name:      "Key.Int() correctly returns keys's internal signed integral value",
			value:     k.Int(bli.intValue).Value,
			wantType:  bli.signedType,
			wantValue: bli.signedValue,
		},
		{
			name:      "Key.Uint() correctly returns keys's internal unsigned integral value",
			value:     k.Uint(bli.uintValue).Value,
			wantType:  bli.unsignedType,
			wantValue: bli.unsignedValue,
		},
	} {
		t.Logf("Running test case %s", testcase.name)
		if testcase.value.Type() != testcase.wantType {
			t.Errorf("wrong value type, got %#v, expected %#v", testcase.value.Type(), testcase.wantType)
		}
		got := testcase.value.AsInterface()
		if diff := cmp.Diff(testcase.wantValue, got); diff != "" {
			t.Errorf("+got, -want: %s", diff)
		}
	}
}

type bitlessInfo struct {
	intValue      int
	uintValue     uint
	signedType    core.ValueType
	unsignedType  core.ValueType
	signedValue   interface{}
	unsignedValue interface{}
}

func getBitlessInfo(i int) bitlessInfo {
	if unsafe.Sizeof(i) == 4 {
		return bitlessInfo{
			intValue:      i,
			uintValue:     uint(i),
			signedType:    core.INT32,
			unsignedType:  core.UINT32,
			signedValue:   int32(i),
			unsignedValue: uint32(i),
		}
	}
	return bitlessInfo{
		intValue:      i,
		uintValue:     uint(i),
		signedType:    core.INT64,
		unsignedType:  core.UINT64,
		signedValue:   int64(i),
		unsignedValue: uint64(i),
	}
}

func TestDefined(t *testing.T) {
	for _, testcase := range []struct {
		name string
		k    core.Key
		want bool
	}{
		{
			name: "Key.Defined() returns true when len(v.Name) != 0",
			k:    core.Key("foo"),
			want: true,
		},
		{
			name: "Key.Defined() returns false when len(v.Name) == 0",
			k:    core.Key(""),
			want: false,
		},
	} {
		t.Run(testcase.name, func(t *testing.T) {
			//func (k core.Key) Defined() bool {
			have := testcase.k.Defined()
			if have != testcase.want {
				t.Errorf("Want: %v, but have: %v", testcase.want, have)
			}
		})
	}
}

func TestJSONValue(t *testing.T) {
	var kvs interface{} = [2]core.KeyValue{
		key.String("A", "B"),
		key.Int64("C", 1),
	}

	data, err := json.Marshal(kvs)
	require.NoError(t, err)
	require.Equal(t,
		`[{"Key":"A","Value":{"Type":"STRING","Value":"B"}},{"Key":"C","Value":{"Type":"INT64","Value":1}}]`,
		string(data))
}

func TestEmit(t *testing.T) {
	for _, testcase := range []struct {
		name string
		v    core.Value
		want string
	}{
		{
			name: `test Key.Emit() can emit a string representing self.BOOL`,
			v:    core.Bool(true),
			want: "true",
		},
		{
			name: `test Key.Emit() can emit a string representing self.INT32`,
			v:    core.Int32(42),
			want: "42",
		},
		{
			name: `test Key.Emit() can emit a string representing self.INT64`,
			v:    core.Int64(42),
			want: "42",
		},
		{
			name: `test Key.Emit() can emit a string representing self.UINT32`,
			v:    core.Uint32(42),
			want: "42",
		},
		{
			name: `test Key.Emit() can emit a string representing self.UINT64`,
			v:    core.Uint64(42),
			want: "42",
		},
		{
			name: `test Key.Emit() can emit a string representing self.FLOAT32`,
			v:    core.Float32(42.1),
			want: "42.1",
		},
		{
			name: `test Key.Emit() can emit a string representing self.FLOAT64`,
			v:    core.Float64(42.1),
			want: "42.1",
		},
		{
			name: `test Key.Emit() can emit a string representing self.STRING`,
			v:    core.String("foo"),
			want: "foo",
		},
	} {
		t.Run(testcase.name, func(t *testing.T) {
			//proto: func (v core.Value) Emit() string {
			have := testcase.v.Emit()
			if have != testcase.want {
				t.Errorf("Want: %s, but have: %s", testcase.want, have)
			}
		})
	}
}

func BenchmarkEmitBool(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		n := core.Bool(i%2 == 0)
		_ = n.Emit()
	}
}

func BenchmarkEmitInt64(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		n := core.Int64(int64(i))
		_ = n.Emit()
	}
}

func BenchmarkEmitUInt64(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		n := core.Uint64(uint64(i))
		_ = n.Emit()
	}
}

func BenchmarkEmitFloat64(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		n := core.Float64(float64(i))
		_ = n.Emit()
	}
}

func BenchmarkEmitFloat32(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		n := core.Float32(float32(i))
		_ = n.Emit()
	}
}