use std::{collections::BTreeSet, fs, path::PathBuf};

fn repo_root() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .parent()
        .and_then(|p| p.parent())
        .expect("api crate should live under repo root")
        .to_path_buf()
}

#[test]
fn loki_and_tempo_s3_config_variants_are_syntactically_valid() {
    let root = repo_root();

    for file in [
        root.join("observability/loki/config.s3.yml"),
        root.join("observability/tempo/config.s3.yml"),
    ] {
        let raw = fs::read_to_string(&file).unwrap_or_else(|e| panic!("{file:?}: {e}"));
        let _: serde_yaml::Value =
            serde_yaml::from_str(&raw).unwrap_or_else(|e| panic!("{file:?}: {e}"));
    }
}

#[test]
fn grafana_provisioning_files_are_syntactically_valid() {
    let root = repo_root();

    let datasources = fs::read_to_string(
        root.join("observability/grafana/provisioning/datasources/datasources.yml"),
    )
    .expect("missing grafana datasources provisioning file");
    let dashboards = fs::read_to_string(
        root.join("observability/grafana/provisioning/dashboards/dashboards.yml"),
    )
    .expect("missing grafana dashboards provisioning file");

    let _datasources_yaml: serde_yaml::Value =
        serde_yaml::from_str(&datasources).expect("invalid grafana datasources yaml");
    let _dashboards_yaml: serde_yaml::Value =
        serde_yaml::from_str(&dashboards).expect("invalid grafana dashboards yaml");
}

#[test]
fn grafana_dashboards_are_syntactically_valid_json() {
    let root = repo_root();
    let dashboards_dir = root.join("observability/grafana/dashboards");

    let mut found = 0usize;
    for entry in fs::read_dir(&dashboards_dir).expect("missing dashboards dir") {
        let entry = entry.expect("failed to read dashboards dir entry");
        let path = entry.path();
        if path.extension().and_then(|e| e.to_str()) != Some("json") {
            continue;
        }
        found += 1;
        let raw = fs::read_to_string(&path).expect("failed to read dashboard json");
        let _: serde_json::Value =
            serde_json::from_str(&raw).unwrap_or_else(|e| panic!("{path:?}: {e}"));
    }

    assert!(found > 0, "expected at least one dashboard json file");
}

#[test]
fn vmagent_config_parses_and_includes_required_jobs() {
    let root = repo_root();
    let scrape = fs::read_to_string(root.join("observability/vmagent/scrape.yml"))
        .expect("missing vmagent scrape config");

    let value: serde_yaml::Value =
        serde_yaml::from_str(&scrape).expect("invalid vmagent scrape yaml");

    let mut job_names = BTreeSet::<String>::new();
    if let Some(scrape_configs) = value.get("scrape_configs").and_then(|v| v.as_sequence()) {
        for cfg in scrape_configs {
            if let Some(job) = cfg.get("job_name").and_then(|v| v.as_str()) {
                job_names.insert(job.to_string());
            }
        }
    }

    for required in ["victoria-metrics", "vmagent", "control-api"] {
        assert!(
            job_names.contains(required),
            "vmagent scrape config missing required job_name={required}"
        );
    }
}