use std::{net::SocketAddr, str::FromStr};

use metrics::{Unit, describe_counter, describe_gauge, counter, gauge};

pub fn webhook_received(event_type: &str) {
    counter!("herald_webhooks_received_total", "event_type" => event_type.to_string())
        .increment(1);
}

pub fn webhook_duplicate(event_type: &str) {
    counter!("herald_webhooks_duplicate_total", "event_type" => event_type.to_string())
        .increment(1);
}

pub fn webhook_channel_full(event_type: &str) {
    counter!("herald_webhooks_channel_full_total", "event_type" => event_type.to_string())
        .increment(1);
}

pub fn increment_task_active() {
    gauge!("herald_bot_tasks_active").increment(1.0);
}

pub fn decrement_task_active() {
    gauge!("herald_bot_tasks_active").decrement(1.0);
}

pub fn task_completed(event_type: &str) {
    counter!("herald_bot_tasks_completed_total", "event_type" => event_type.to_string())
        .increment(1);
}

pub fn task_failed(event_type: &str) {
    counter!("herald_bot_tasks_failed_total", "event_type" => event_type.to_string())
        .increment(1);
}

pub fn openrouter_cost_usd(cost: u64) {
    counter!("herald_openrouter_cost_usd_total").increment(cost);
}

pub fn describe() {
    describe_counter!("herald_webhooks_received_total", Unit::Count, "Total webhooks received");
    describe_counter!("herald_webhooks_duplicate_total", Unit::Count, "Webhooks rejected as duplicates");
    describe_counter!("herald_webhooks_channel_full_total", Unit::Count, "Webhooks dropped because the bot channel was full");
    describe_gauge!("herald_bot_tasks_active", Unit::Count, "Bot tasks currently in progress");
    describe_counter!("herald_bot_tasks_completed_total", Unit::Count, "Bot tasks completed successfully");
    describe_counter!("herald_bot_tasks_failed_total", Unit::Count, "Bot tasks that failed");
    describe_counter!("herald_openrouter_cost_usd_total", Unit::Count, "Total OpenRouter cost in USD");
}

pub fn install(bind_addr: &str) -> anyhow::Result<()> {
    describe();

    let builder = metrics_exporter_prometheus::PrometheusBuilder::new();
    builder
        .with_http_listener(SocketAddr::from_str(bind_addr)?)
        .install()?;

    tracing::info!(bind_addr, "Prometheus metrics exporter installed");
    Ok(())
}