//! `hive-github-notify` binary — long-running per-agent **github.com**
//! notification poller. Same delivery path as its Forgejo sibling: unread
//! list, per-thread summary, todo upsert on the harness's in-agent socket,
//! mark read on the source.
//!
//! Takes no arguments. `HYPERHIVE_STATE_DIR` holds the PAT
//! (`github-token`, provisioned from the dashboard credentials tab — see
//! `docs/integrations/github.md`) and `HIVE_AGENT_SOCKET` is the harness's todo socket.
//! Having a PAT *is* the opt-in: with no token the poller logs why and
//! exits 0, so deploying this unit to an agent that never gets one costs a
//! settled process rather than a restart loop.
//!
//! ⚠️ Reading the notification stream needs the **`notifications` scope**
//! on the PAT — a token minted for `gh` + `git push` usually carries `repo`
//! only, which is enough to push and open PRs but not to read (or mark
//! read) notifications. A PAT without it is not fatal: the poller logs the
//! refusal and stays quiet, so the symptom is silence rather than an error.

mod source;

use std::collections::HashMap;
use std::time::Duration;

use hive_forge_notify::notify::{
    POLL_INTERVAL_SECS, TOKEN_RETRY_MAX, TOKEN_RETRY_SECS, poll_once, resolve_own_login,
};
use hive_forge_notify::{HTTP_TIMEOUT_SECS, agent_socket, init_tracing};
use source::GithubSource;
use tracing::{debug, info, warn};

#[tokio::main]
async fn main() {
    init_tracing();

    let socket = agent_socket();
    info!(socket = %socket.display(), "hive-github-notify starting");

    // Returns only when no PAT ever arrives; otherwise loops forever.
    github_loop(hive_forge_notify::state_dir(), socket).await;
}

/// Waits for the PAT to appear: the token is written out of band from the
/// dashboard and takes effect without a rebuild, so an agent that gains a
/// PAT mid-session starts getting notifications on the next tick rather
/// than after a restart. Gives up — returning, so the process exits 0
/// rather than restart-looping — when no PAT ever arrives, which is the
/// common case for an agent that has the unit but no account.
async fn github_loop(state_dir: String, socket: std::path::PathBuf) {
    let token_path = format!("{state_dir}/github-token");
    let mut attempts = 0u32;
    let token = loop {
        match tokio::fs::read_to_string(&token_path).await {
            Ok(t) if !t.trim().is_empty() => break t.trim().to_owned(),
            _ => debug!("forge_notify: no github token at {token_path} yet"),
        }
        attempts += 1;
        if attempts >= TOKEN_RETRY_MAX {
            debug!(
                "forge_notify: no github token after {TOKEN_RETRY_MAX} retries — github disabled"
            );
            return;
        }
        tokio::time::sleep(Duration::from_secs(TOKEN_RETRY_SECS)).await;
    };

    let client = match reqwest::Client::builder()
        .timeout(Duration::from_secs(HTTP_TIMEOUT_SECS))
        .build()
    {
        Ok(c) => c,
        Err(e) => {
            warn!("forge_notify: failed to build github HTTP client: {e}");
            return;
        }
    };

    let source = GithubSource::new(&token);
    let mut own_login = resolve_own_login(&client, &source).await;
    let mut delivered: HashMap<String, String> = HashMap::new();

    // GitHub tells callers how often it is willing to be polled
    // (`X-Poll-Interval`, 60s in practice) and rate-limits those who
    // ignore it. Start at our own cadence and re-arm to whatever the
    // server asks for — never faster than it wants, never slower than we
    // need.
    let mut cadence = POLL_INTERVAL_SECS;
    let mut interval = tokio::time::interval(Duration::from_secs(cadence));
    interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay);
    interval.tick().await;

    info!("forge_notify: github polling started");

    loop {
        interval.tick().await;
        if own_login.is_empty() {
            own_login = resolve_own_login(&client, &source).await;
        }
        let hint = poll_once(&source, &client, &socket, &mut delivered, &own_login).await;
        if let Some(secs) = hint.filter(|s| *s > cadence) {
            debug!(
                secs,
                "forge_notify: github asked for a slower poll — re-arming"
            );
            cadence = secs;
            interval = tokio::time::interval(Duration::from_secs(cadence));
            interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay);
            interval.tick().await;
        }
    }
}