// 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 stdout_test

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/exporters/stdout"
	"go.opentelemetry.io/otel/oteltest"
	"go.opentelemetry.io/otel/sdk/resource"
	tracesdk "go.opentelemetry.io/otel/sdk/trace"
	"go.opentelemetry.io/otel/sdk/trace/tracetest"
	"go.opentelemetry.io/otel/trace"
)

func TestExporter_ExportSpan(t *testing.T) {
	// write to buffer for testing
	var b bytes.Buffer
	ex, err := stdout.NewExporter(stdout.WithWriter(&b), stdout.WithPrettyPrint())
	if err != nil {
		t.Errorf("Error constructing stdout exporter %s", err)
	}

	// setup test span
	now := time.Now()
	traceID, _ := trace.TraceIDFromHex("0102030405060708090a0b0c0d0e0f10")
	spanID, _ := trace.SpanIDFromHex("0102030405060708")
	traceState, _ := oteltest.TraceStateFromKeyValues(attribute.String("key", "val"))
	keyValue := "value"
	doubleValue := 123.456
	resource := resource.NewWithAttributes(attribute.String("rk1", "rv11"))

	ro := tracetest.SpanStubs{
		{
			SpanContext: trace.NewSpanContext(trace.SpanContextConfig{
				TraceID:    traceID,
				SpanID:     spanID,
				TraceState: traceState,
			}),
			Name:      "/foo",
			StartTime: now,
			EndTime:   now,
			Attributes: []attribute.KeyValue{
				attribute.String("key", keyValue),
				attribute.Float64("double", doubleValue),
			},
			Events: []tracesdk.Event{
				{Name: "foo", Attributes: []attribute.KeyValue{attribute.String("key", keyValue)}, Time: now},
				{Name: "bar", Attributes: []attribute.KeyValue{attribute.Float64("double", doubleValue)}, Time: now},
			},
			SpanKind: trace.SpanKindInternal,
			Status: tracesdk.Status{
				Code:        codes.Error,
				Description: "interesting",
			},
			Resource: resource,
		},
	}.Snapshots()
	if err := ex.ExportSpans(context.Background(), ro); err != nil {
		t.Fatal(err)
	}

	expectedSerializedNow, _ := json.Marshal(now)

	got := b.String()
	expectedOutput := `[
	{
		"Name": "/foo",
		"SpanContext": {
			"TraceID": "0102030405060708090a0b0c0d0e0f10",
			"SpanID": "0102030405060708",
			"TraceFlags": "00",
			"TraceState": "key=val",
			"Remote": false
		},
		"Parent": {
			"TraceID": "00000000000000000000000000000000",
			"SpanID": "0000000000000000",
			"TraceFlags": "00",
			"TraceState": "",
			"Remote": false
		},
		"SpanKind": 1,
		"StartTime": ` + string(expectedSerializedNow) + `,
		"EndTime": ` + string(expectedSerializedNow) + `,
		"Attributes": [
			{
				"Key": "key",
				"Value": {
					"Type": "STRING",
					"Value": "value"
				}
			},
			{
				"Key": "double",
				"Value": {
					"Type": "FLOAT64",
					"Value": 123.456
				}
			}
		],
		"Events": [
			{
				"Name": "foo",
				"Attributes": [
					{
						"Key": "key",
						"Value": {
							"Type": "STRING",
							"Value": "value"
						}
					}
				],
				"DroppedAttributeCount": 0,
				"Time": ` + string(expectedSerializedNow) + `
			},
			{
				"Name": "bar",
				"Attributes": [
					{
						"Key": "double",
						"Value": {
							"Type": "FLOAT64",
							"Value": 123.456
						}
					}
				],
				"DroppedAttributeCount": 0,
				"Time": ` + string(expectedSerializedNow) + `
			}
		],
		"Links": null,
		"Status": {
			"Code": "Error",
			"Description": "interesting"
		},
		"DroppedAttributes": 0,
		"DroppedEvents": 0,
		"DroppedLinks": 0,
		"ChildSpanCount": 0,
		"Resource": [
			{
				"Key": "rk1",
				"Value": {
					"Type": "STRING",
					"Value": "rv11"
				}
			}
		],
		"InstrumentationLibrary": {
			"Name": "",
			"Version": ""
		}
	}
]
`
	assert.Equal(t, expectedOutput, got)
}

func TestExporterShutdownHonorsTimeout(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Minute)
	defer cancel()

	e, err := stdout.NewExporter()
	if err != nil {
		t.Fatalf("failed to create exporter: %v", err)
	}

	innerCtx, innerCancel := context.WithTimeout(ctx, time.Nanosecond)
	defer innerCancel()
	<-innerCtx.Done()
	if err := e.Shutdown(innerCtx); err == nil {
		t.Error("expected context DeadlineExceeded error, got nil")
	} else if !errors.Is(err, context.DeadlineExceeded) {
		t.Errorf("expected context DeadlineExceeded error, got %v", err)
	}
}

func TestExporterShutdownHonorsCancel(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Minute)
	defer cancel()

	e, err := stdout.NewExporter()
	if err != nil {
		t.Fatalf("failed to create exporter: %v", err)
	}

	innerCtx, innerCancel := context.WithCancel(ctx)
	innerCancel()
	if err := e.Shutdown(innerCtx); err == nil {
		t.Error("expected context canceled error, got nil")
	} else if !errors.Is(err, context.Canceled) {
		t.Errorf("expected context canceled error, got %v", err)
	}
}

func TestExporterShutdownNoError(t *testing.T) {
	e, err := stdout.NewExporter()
	if err != nil {
		t.Fatalf("failed to create exporter: %v", err)
	}

	if err := e.Shutdown(context.Background()); err != nil {
		t.Errorf("shutdown errored: expected nil, got %v", err)
	}
}