// src/services/dectCollectorService.js
//
// Fan-out layer over the DECT relay hub. Callers hand it a list of
// bases (from services/dectDiscovery.js), it dispatches one RPC per
// base in parallel and returns a normalized per-base result array.
//
// Kept intentionally thin: it doesn't render, it doesn't decide what
// to do with warnings, it doesn't touch Meraki. Whoever calls this
// (the /phonestatus follow-up, the /dectstatus command in Phase 2,
// the Jira poller in Phase 3) owns presentation.

import { getDectRelayHub, RelayErrorCodes } from './dectRelayHub.js';
import { parseStatusXml, summarizeBaseHealth } from '../integrations/cisco-dect/statusXml.js';
import { logger } from '../utils/logger.js';

const LOG_SCOPE = 'dect:collector';

const DEFAULT_TIMEOUT_MS = Number(process.env.DECT_COLLECT_TIMEOUT_MS) || 15_000;

/**
 * @typedef  {object}  BaseTarget
 * @property {string}  mac
 * @property {string}  ip
 * @property {string}  name
 */

/**
 * @typedef  {object}       BaseCollectResult
 * @property {BaseTarget}   base
 * @property {boolean}      ok
 * @property {object|null}  data     parsed status object (when ok)
 * @property {object|null}  verdict  { healthy, warnings, info } (when ok)
 * @property {number|null}  elapsedMs
 * @property {object|null}  error    { code, message } (when !ok)
 */

/**
 * Run `collect` against every base in the list, in parallel. One base
 * failing (timeout, offline, bad creds) does NOT fail the batch —
 * that base's entry just has ok:false. Ordering of returned entries
 * matches the input.
 *
 * @param {BaseTarget[]} bases
 * @param {object}       [opts]
 * @param {number}       [opts.timeoutMs]   per-base RPC timeout override
 * @param {object}       [opts.hub]         inject a hub for tests
 * @returns {Promise<BaseCollectResult[]>}
 */
export async function collectAll(bases, opts = {}) {
  const list = Array.isArray(bases) ? bases : [];
  if (list.length === 0) return [];
  const hub = opts.hub || getDectRelayHub();
  const timeoutMs = opts.timeoutMs || DEFAULT_TIMEOUT_MS;

  logger(LOG_SCOPE, `Fanning out collect() to ${list.length} base(s)`, 'debug');

  const results = await Promise.all(list.map((base) => collectOne(hub, base, timeoutMs)));

  const okCount = results.filter((r) => r.ok).length;
  logger(LOG_SCOPE, `Collect finished: ${okCount}/${list.length} succeeded`, 'debug');
  return results;
}

/**
 * Single-base variant. Mostly here for the eventual /dectstatus
 * command's individual "refresh this base" flow — collectAll uses it
 * internally.
 */
/**
 * @typedef {object}       BaseCollectRawResult
 * @property {BaseTarget}   base
 * @property {boolean}      ok
 * @property {string|null}  rawXml
 * @property {number|null}  byteLength
 * @property {object|null}  data
 * @property {object|null}  verdict
 * @property {Array|null}   sectionInventory
 * @property {number|null}  elapsedMs
 * @property {object|null}  error
 */

/**
 * Run `collect-raw` against every base (includes raw XML + inventory).
 *
 * @param {BaseTarget[]} bases
 * @param {object}       [opts]
 * @returns {Promise<BaseCollectRawResult[]>}
 */
export async function collectRawAll(bases, opts = {}) {
  const list = Array.isArray(bases) ? bases : [];
  if (list.length === 0) return [];
  const hub = opts.hub || getDectRelayHub();
  const timeoutMs = opts.timeoutMs || DEFAULT_TIMEOUT_MS;

  logger(LOG_SCOPE, `Fanning out collect-raw() to ${list.length} base(s)`, 'debug');

  const results = await Promise.all(list.map((base) => collectRawOne(hub, base, timeoutMs)));

  const okCount = results.filter((r) => r.ok).length;
  logger(LOG_SCOPE, `Collect-raw finished: ${okCount}/${list.length} succeeded`, 'debug');
  return results;
}

export async function collectRawOne(hub, base, timeoutMs = DEFAULT_TIMEOUT_MS) {
  if (!base?.ip) {
    return {
      base, ok: false, rawXml: null, byteLength: null, data: null, verdict: null,
      sectionInventory: null, elapsedMs: null,
      error: { code: 'NO_IP', message: 'base has no IP address' },
    };
  }
  const started = Date.now();
  try {
    let result;
    let elapsedMs;
    try {
      ({ result, elapsedMs } = await hub.collectRaw(base.ip, { timeoutMs }));
    } catch (err) {
      if (err?.code === 'UNKNOWN_COMMAND' || /unknown command type/i.test(err?.message || '')) {
        ({ result, elapsedMs } = await hub.collectRawLegacy(base.ip, { timeoutMs }));
      } else {
        throw err;
      }
    }

    if (!result?.rawXml) {
      return {
        base,
        ok: false,
        rawXml: null,
        byteLength: null,
        data: result?.parsed || null,
        verdict: result?.verdict || null,
        sectionInventory: null,
        elapsedMs: elapsedMs ?? (Date.now() - started),
        error: {
          code: 'AGENT_OUTDATED',
          message: 'Relay agent returned parsed status but not raw XML',
          hint:
            'Redeploy dect-relay-agent on the DC host (separate from the bot container). ' +
            'From the repo root: ./dect-relay-agent/bundle.sh, then install on the DC host ' +
            'and docker compose restart dect-relay-agent. Agent v0.2.0+ supports includeRaw on collect.',
        },
      };
    }

    return {
      base,
      ok: true,
      rawXml: result.rawXml,
      byteLength: result.byteLength ?? null,
      data: result.parsed || null,
      verdict: result.verdict || null,
      sectionInventory: result.sectionInventory || null,
      elapsedMs: elapsedMs ?? (Date.now() - started),
      error: null,
    };
  } catch (err) {
    const code = err?.code || 'UNKNOWN';
    const hint = hintFor(code)
      || (/unknown command type/i.test(err?.message || '')
        ? 'Redeploy dect-relay-agent on the DC host — the bot container does not run the relay agent.'
        : null);
    return {
      base,
      ok: false,
      rawXml: null,
      byteLength: null,
      data: null,
      verdict: null,
      sectionInventory: null,
      elapsedMs: Date.now() - started,
      error: {
        code,
        message: err?.message || String(err),
        hint,
      },
    };
  }
}

export async function collectOne(hub, base, timeoutMs = DEFAULT_TIMEOUT_MS) {
  if (!base?.ip) {
    return {
      base, ok: false, data: null, verdict: null, elapsedMs: null,
      error: { code: 'NO_IP', message: 'base has no IP address' },
    };
  }
  const started = Date.now();
  try {
    let result;
    let elapsedMs;
    try {
      ({ result, elapsedMs } = await hub.collectRaw(base.ip, { timeoutMs }));
    } catch (err) {
      if (err?.code === 'UNKNOWN_COMMAND' || /unknown command type/i.test(err?.message || '')) {
        try {
          ({ result, elapsedMs } = await hub.collectRawLegacy(base.ip, { timeoutMs }));
        } catch {
          ({ result, elapsedMs } = await hub.collect(base.ip, { timeoutMs }));
        }
      } else {
        throw err;
      }
    }

    // Prefer bot-side parsing so handset/RSSI fields stay current even when
    // the DC relay agent ships an older statusXml.js.
    const data = result?.rawXml
      ? parseStatusXml(result.rawXml)
      : (result?.parsed || result || null);

    return {
      base,
      ok: true,
      data,
      verdict: data ? summarizeBaseHealth(data) : (result?.verdict || null),
      elapsedMs: elapsedMs ?? (Date.now() - started),
      error: null,
    };
  } catch (err) {
    // We keep the code+message split so renderers can decide whether
    // to show a hint ("relay is offline" vs "wrong password" are very
    // different remediations).
    const code = err?.code || 'UNKNOWN';
    return {
      base,
      ok: false,
      data: null,
      verdict: null,
      elapsedMs: Date.now() - started,
      error: {
        code,
        message: err?.message || String(err),
        // For NOT_CONNECTED there's no per-base fix — surface a hint.
        hint: hintFor(code),
      },
    };
  }
}

/**
 * Run one of the mutating actions against a base. Same envelope shape
 * as collectOne (ok / error / elapsedMs) so callers can log it
 * uniformly. Actions handled here mirror the CLI script's subcommands.
 *
 * @param {BaseTarget} base
 * @param {string}     action    'reboot' | 'force-reboot' | 'reboot-chain' |
 *                               'force-reboot-chain' | 'factory-reset' |
 *                               'reconfigure-tree'
 * @param {object}     [opts]
 * @param {number}     [opts.timeoutMs]
 * @param {object}     [opts.hub]
 */
export async function execAction(base, action, opts = {}) {
  if (!base?.ip) {
    return {
      base, ok: false, elapsedMs: null,
      error: { code: 'NO_IP', message: 'base has no IP address' },
    };
  }
  const hub = opts.hub || getDectRelayHub();
  const timeoutMs = opts.timeoutMs || DEFAULT_TIMEOUT_MS;
  const started = Date.now();
  try {
    const { result, elapsedMs } = await hub.execAction(base.ip, action, {}, { timeoutMs });
    return {
      base, ok: true, action,
      elapsedMs: elapsedMs ?? (Date.now() - started),
      result: result || null,
      error: null,
    };
  } catch (err) {
    const code = err?.code || 'UNKNOWN';
    return {
      base, ok: false, action,
      elapsedMs: Date.now() - started,
      error: {
        code, message: err?.message || String(err),
        hint: hintFor(code),
      },
    };
  }
}

function hintFor(code) {
  switch (code) {
    case RelayErrorCodes.NOT_CONNECTED:
      return 'DECT relay agent is not connected. Check that dect-relay-agent is running in the data center.';
    case RelayErrorCodes.TIMEOUT:
      return 'Relay accepted the request but the base did not respond in time. The base may be offline, rebooting, or unreachable.';
    case RelayErrorCodes.DISCONNECTED:
      return 'Relay agent disconnected while this command was in flight. Try again in a moment.';
    default:
      return null;
  }
}