// 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.

// Example from otlp package: https://pkg.go.dev/go.opentelemetry.io/otel/exporters/otlp?tab=doc#example-package-Insecure
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"google.golang.org/grpc"

	"go.opentelemetry.io/otel/exporters/otlp"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
)

func main() {
	exp, err := otlp.NewExporter(otlp.WithInsecure(),
		otlp.WithGRPCDialOption(grpc.WithBlock()))
	if err != nil {
		log.Fatalf("Failed to create the collector exporter: %v", err)
	}
	defer func() {
		err := exp.Stop()
		if err != nil {
			log.Fatalf("Failed to stop the exporter: %v", err)
		}
	}()

	tp, err := sdktrace.NewProvider(
		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
		sdktrace.WithBatcher(exp, // add following two options to ensure flush
			sdktrace.WithScheduleDelayMillis(5),
			sdktrace.WithMaxExportBatchSize(2),
		))
	if err != nil {
		log.Fatalf("error creating trace provider: %v\n", err)
	}
	tracer := tp.Tracer("test-tracer")

	// Then use the OpenTelemetry tracing library, like we normally would.
	ctx, span := tracer.Start(context.Background(), "CollectorExporter-Example")
	defer span.End()

	for i := 0; i < 10; i++ {
		_, iSpan := tracer.Start(ctx, fmt.Sprintf("Sample-%d", i))
		<-time.After(time.Second)
		iSpan.End()
	}
}