use std::time::Duration;

use axum_otel_metrics::{HttpMetricsLayer, HttpMetricsLayerBuilder};
use opentelemetry::global;
use opentelemetry_otlp::MetricExporter;
use opentelemetry_sdk::metrics::{PeriodicReader, SdkMeterProvider, Temporality};

const EXPORT_INTERVAL: Duration = Duration::from_secs(30);

pub fn init_meter_provider() -> Result<SdkMeterProvider, String> {
    let exporter = MetricExporter::builder()
        .with_http()
        .with_temporality(Temporality::default())
        .build()
        .map_err(|e| e.to_string())?;

    let reader = PeriodicReader::builder(exporter)
        .with_interval(EXPORT_INTERVAL)
        .build();

    let provider = SdkMeterProvider::builder().with_reader(reader).build();
    global::set_meter_provider(provider.clone());
    Ok(provider)
}

pub fn metrics_layer() -> HttpMetricsLayer {
    HttpMetricsLayerBuilder::new().build()
}