import { healthUtil, util, types as T } from "../deps.ts";

const API_BASE = "http://kamado-pool.embassy:8080";
const STARTING_GRACE_MS = 20_000;

interface HealthPayload {
  ok: boolean;
  ckpool: boolean;
  bitcoin: boolean;
  submit_gap: number;
  zmq_stale: boolean;
  last_error?: string;
}

async function fetchHealth(effects: T.Effects): Promise<HealthPayload | null> {
  try {
    const res = await effects.fetch(`${API_BASE}/api/health`);
    return await res.json() as HealthPayload;
  } catch {
    return null;
  }
}

export const health: T.ExpectedExports.health = {
  "web": async (effects, duration) => {
    return healthUtil.checkWebUrl(`${API_BASE}/api/health`)(effects, duration);
  },

  "ckpool": async (effects, duration) => {
    if (duration < STARTING_GRACE_MS) return util.errorCode(60, "Stratum server is starting…");
    const h = await fetchHealth(effects);
    if (!h) return util.error("Kamado API is unreachable — service may be down.");
    if (h.ckpool) return util.ok;
    const detail = h.last_error ? ` (${h.last_error})` : "";
    return util.error(`Stratum server is not responding${detail}.`);
  },

  "bitcoin": async (effects, duration) => {
    if (duration < STARTING_GRACE_MS) return util.errorCode(60, "Bitcoin Core connection is starting…");
    const h = await fetchHealth(effects);
    if (!h) return util.error("Kamado API is unreachable — service may be down.");
    if (h.bitcoin) return util.ok;
    const detail = h.last_error ? ` (${h.last_error})` : "";
    return util.error(`Bitcoin Core RPC is unreachable${detail}.`);
  },

  "submit-gap": async (effects, duration) => {
    if (duration < STARTING_GRACE_MS) return util.errorCode(60, "Block submission check is starting…");
    const h = await fetchHealth(effects);
    if (!h) return util.error("Kamado API is unreachable — service may be down.");
    const gap = h.submit_gap ?? 0;
    if (gap === 0) return util.ok;
    return util.error(
      `${gap} block${gap === 1 ? "" : "s"} submitted to bitcoind but not confirmed — check Bitcoin Core logs.`,
    );
  },
};