//! In-process Arti onion-service helpers (no C-tor).

use std::sync::Arc;
use std::time::{Duration, Instant};

use arti_client::config::TorClientConfigBuilder;
use arti_client::{TorClient, TorClientConfig};
use futures::StreamExt;
use safelog::DisplayRedacted;
use tor_hsservice::status::State;
use tor_hsservice::{HsNickname, OnionServiceConfig, RunningOnionService};
use tor_rtcompat::PreferredRuntime;

pub const HS_PORT: u16 = 80;
/// HsDir descriptor upload often stays Bootstrapping past 3 minutes.
pub const PUBLISH_WAIT: Duration = Duration::from_secs(360);
/// Consensus default `cbtmintimeout` is 10ms; learned CBT can drop to ~1s.
/// 4-hop vanguard HS circuits need more than 10s on a slow net.
pub const CBT_MIN_TIMEOUT_MS: i32 = 20_000;
/// Consensus `cbtinitialtimeout` can be ~2s; match the min floor.
pub const CBT_INITIAL_TIMEOUT_MS: i32 = CBT_MIN_TIMEOUT_MS;
/// OnionWire never uses exit ports. Default 80/443 preemptive circuits
/// compete with IPT + HsDir builds during publish.
pub const PREEMPTIVE_PREDICTED_PORTS: &[u16] = &[];

const PROBE_EVERY: Duration = Duration::from_secs(15);
const PROBE_TIMEOUT: Duration = Duration::from_secs(12);

pub type Client = Arc<TorClient<PreferredRuntime>>;

pub fn client_config(state_dir: &std::path::Path, cache_dir: &std::path::Path) -> TorClientConfig {
    std::fs::create_dir_all(state_dir).expect("state dir");
    std::fs::create_dir_all(cache_dir).expect("cache dir");
    let mut builder = TorClientConfigBuilder::from_directories(state_dir, cache_dir);
    builder.storage().permissions().dangerously_trust_everyone();
    builder
        .override_net_params()
        .insert("cbtmintimeout".to_string(), CBT_MIN_TIMEOUT_MS);
    builder
        .override_net_params()
        .insert("cbtinitialtimeout".to_string(), CBT_INITIAL_TIMEOUT_MS);
    builder
        .preemptive_circuits()
        .set_initial_predicted_ports(PREEMPTIVE_PREDICTED_PORTS.to_vec());
    builder.build().expect("TorClientConfig")
}

pub async fn bootstrapped(
    state_dir: &std::path::Path,
    cache_dir: &std::path::Path,
) -> Result<Client, String> {
    let cfg = client_config(state_dir, cache_dir);
    TorClient::create_bootstrapped(cfg)
        .await
        .map_err(|e| format!("Arti bootstrap failed — fail closed, no C-tor fallback: {e}"))
}

pub fn hs_config(nickname: &str) -> Result<OnionServiceConfig, String> {
    let nickname = HsNickname::new(nickname.to_string()).map_err(|e| format!("HsNickname: {e}"))?;
    OnionServiceConfig::builder()
        .nickname(nickname)
        .build()
        .map_err(|e| format!("OnionServiceConfig: {e}"))
}

pub fn onion_string(svc: &RunningOnionService) -> Result<String, String> {
    let id = svc
        .onion_address()
        .ok_or_else(|| "onion identity missing from keystore".to_string())?;
    Ok(id.display_unredacted().to_string())
}

/// Combined Arti status stays Bootstrapping through a 5 min HsDir upload
/// round. A successful connect means some HsDir already has the descriptor.
pub fn hs_is_ready(state: State, probe_ok: bool) -> bool {
    match state {
        State::Broken | State::Shutdown => false,
        State::Running | State::DegradedReachable => true,
        _ => probe_ok,
    }
}

pub async fn wait_until_published(
    client: &Client,
    svc: &RunningOnionService,
    onion: &str,
    label: &str,
) -> Result<(), String> {
    let deadline = Instant::now() + PUBLISH_WAIT;
    let mut events = svc.status_events();
    let mut next_probe = Instant::now() + PROBE_EVERY;
    loop {
        let st = svc.status();
        let state = st.state();
        eprintln!("{label} hs status: {state:?}");
        if hs_is_ready(state, false) {
            return Ok(());
        }
        if matches!(state, State::Broken) {
            return Err(format!(
                "{label}: onion service broken: {:?}",
                st.current_problem()
            ));
        }
        if Instant::now() >= deadline {
            return Err(format!(
                "{label}: onion service did not publish within {}s: {state:?}",
                PUBLISH_WAIT.as_secs(),
            ));
        }
        let now = Instant::now();
        if now >= next_probe {
            eprintln!("{label} probing reachability");
            let probe_ok = tokio::time::timeout(PROBE_TIMEOUT, client.connect((onion, HS_PORT)))
                .await
                .ok()
                .and_then(Result::ok)
                .is_some();
            if probe_ok {
                eprintln!("{label} hs reachable while status {state:?}");
            }
            if hs_is_ready(state, probe_ok) {
                return Ok(());
            }
            next_probe = Instant::now() + PROBE_EVERY;
            continue;
        }
        tokio::select! {
            _ = events.next() => {}
            _ = tokio::time::sleep(Duration::from_secs(2)) => {}
        }
    }
}