// Copyright Istio 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.

use prometheus_client::encoding::EncodeLabelSet;

use prometheus_client::metrics::family::Family;

use prometheus_client::metrics::gauge::Gauge;

use prometheus_client::registry::Registry;

use crate::version;

pub struct Metrics {}

#[derive(Clone, Hash, Debug, PartialEq, Eq, EncodeLabelSet)]

pub struct IstioBuildLabel {

    component: String,

    tag: String,

}

impl Metrics {

    pub fn new(registry: &mut Registry) -> Self {

        let build_gauge: Family<IstioBuildLabel, Gauge> = Default::default();

        registry.register("build", "Istio component build info", build_gauge.clone());

        let tag = version::BuildInfo::new().istio_version;

        // Note: tag refers to the "Istio version", not the ztunnels own tag (which is an implementation detail to Istio).

        build_gauge

            .get_or_create(&IstioBuildLabel {

                component: "ztunnel".to_string(),

                tag,

            })

            .set(1);

        Self {}

    }

}