package observability

import (
	"context"
	"fmt"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
)

type TraceProvider struct{ provider *sdktrace.TracerProvider }

func SetupTracing(ctx context.Context, serviceName, environment, endpoint string) (*TraceProvider, error) {
	res, err := resource.New(ctx, resource.WithAttributes(
		attribute.String("service.name", serviceName),
		attribute.String("deployment.environment.name", environment),
	))
	if err != nil {
		return nil, fmt.Errorf("create telemetry resource: %w", err)
	}
	options := []sdktrace.TracerProviderOption{sdktrace.WithResource(res)}
	if endpoint != "" {
		exporter, err := otlptracegrpc.New(ctx,
			otlptracegrpc.WithEndpoint(endpoint),
			otlptracegrpc.WithInsecure(),
		)
		if err != nil {
			return nil, fmt.Errorf("create OTLP trace exporter: %w", err)
		}
		options = append(options, sdktrace.WithBatcher(exporter))
	}
	provider := sdktrace.NewTracerProvider(options...)
	otel.SetTracerProvider(provider)
	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
		propagation.TraceContext{}, propagation.Baggage{},
	))
	return &TraceProvider{provider: provider}, nil
}

func (p *TraceProvider) Shutdown(ctx context.Context) error {
	if p == nil || p.provider == nil {
		return nil
	}
	return p.provider.Shutdown(ctx)
}