package observability

import (
	"context"
	"log/slog"
	"strings"

	"go.opentelemetry.io/otel"
	"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"
	semconv "go.opentelemetry.io/otel/semconv/v1.37.0"
	"go.opentelemetry.io/otel/trace"
)

func NewTracerProvider(ctx context.Context, logger *slog.Logger, serviceName, environment, otlpEndpoint string) (*sdktrace.TracerProvider, error) {
	res, err := resource.New(
		ctx,
		resource.WithAttributes(
			semconv.ServiceName(serviceName),
			semconv.DeploymentEnvironmentName(environment),
		),
	)
	if err != nil {
		return nil, err
	}

	providerOptions := []sdktrace.TracerProviderOption{sdktrace.WithResource(res)}
	endpoint := strings.TrimSpace(otlpEndpoint)
	if endpoint != "" {
		exporter, err := otlptracegrpc.New(
			ctx,
			otlptracegrpc.WithEndpoint(endpoint),
			otlptracegrpc.WithInsecure(),
		)
		if err != nil {
			return nil, err
		}
		providerOptions = append(providerOptions, sdktrace.WithBatcher(exporter))
		logger.Info("otlp tracing exporter enabled", slog.String("endpoint", endpoint))
	} else {
		logger.Info("otlp endpoint not set, traces will not be exported")
	}

	tp := sdktrace.NewTracerProvider(providerOptions...)
	otel.SetTracerProvider(tp)
	otel.SetTextMapPropagator(
		propagation.NewCompositeTextMapPropagator(
			propagation.TraceContext{},
			propagation.Baggage{},
		),
	)
	return tp, nil
}

func NewTracer(tp *sdktrace.TracerProvider, serviceName string) trace.Tracer {
	return tp.Tracer(serviceName)
}