// settings.seeder — the home seeder of last resort (release 21 D4b).
//
// Pure: the type, its defaults, the sanitizer settingsSchema.ts runs it
// through, and the per-field docs SETTINGS.md renders. The seeder itself is
// controller/seeder.ts (`archilyzer seed`); the decision of when to seed is
// lib/lastResortSeeder.ts.
//
// NOT CONFIGURED is `sites: []`, the default: `archilyzer seed` refuses to
// start and `archilyzer doctor` says "seeder not configured".

import type { FieldDocs } from "./fieldDocs";

export type SeederSettings = {
  sites: string[];
  trackers: string[];
  maxUploadKiBps: number;
  maxConnections: number;
  pollSeconds: number;
  standbyAfterSeconds: number;
  bindInterface: string;
};

export const DEFAULT_SEEDER_SETTINGS: SeederSettings = {
  sites: [],
  trackers: [],
  maxUploadKiBps: 0,
  maxConnections: 50,
  pollSeconds: 60,
  standbyAfterSeconds: 600,
  bindInterface: "",
};

export const SEEDER_SETTINGS_FIELD_DOCS: FieldDocs<SeederSettings> = {
  sites:
    "The site ids whose playable torrents the seeder seeds: every channel of each site " +
    "that has a playable manifest (`archilyzer media playable`). Empty = the seeder is " +
    "not configured, and `archilyzer seed` refuses to start.",
  trackers:
    "Announce URLs the seeder announces to and scrapes (wss:// or ws:// for browsers, " +
    "http(s):// or udp:// for desktop clients). Empty = each torrent's own announce list.",
  maxUploadKiBps: "Upload cap across every torrent, KiB/s. 0 = unlimited.",
  maxConnections: "Most peer connections per torrent. Clamped to [1, 500]; default 50.",
  pollSeconds:
    "How often the seeder scrapes the trackers and decides, per torrent, whether to " +
    "seed or stand by. A viewer whose last other seeder leaves mid-stream waits up to " +
    "this long. Clamped to [10, 3600]; default 60.",
  standbyAfterSeconds:
    "Other seeders seen on every poll for this long → the seeder stands by on that " +
    "torrent (stops announcing, closes its peers, keeps the data). The same window, " +
    "with no other seeder seen, brings it back when nobody is waiting; a waiting " +
    "leecher brings it back at once. Clamped to [60, 86400]; default 600.",
  bindInterface:
    "The network interface the seeder must have — the VPN tunnel's (e.g. `wg0`, " +
    "`tun0`). While it is missing the seeder does not start, and stops every torrent " +
    "if it disappears. Empty = not checked (the docker profile `seeder` confines the " +
    "process to the tunnel either way; see docker-compose.seeder.yml).",
};

function clampInt(value: unknown, fallback: number, min: number, max: number): number {
  const n = typeof value === "number" && Number.isFinite(value) ? Math.floor(value) : fallback;
  return Math.min(max, Math.max(min, n));
}

const SITE_ID_RE = /^[a-z0-9][a-z0-9-]*$/;
const TRACKER_RE = /^(wss?|https?|udp):\/\/\S+$/i;
const IFACE_RE = /^[A-Za-z0-9_.:-]{1,32}$/;

function stringList(value: unknown, keep: (s: string) => boolean): string[] {
  if (!Array.isArray(value)) return [];
  const out: string[] = [];
  for (const v of value) {
    if (typeof v !== "string") continue;
    const s = v.trim();
    if (s && keep(s) && !out.includes(s)) out.push(s);
  }
  return out;
}

export function sanitizeSeeder(value: unknown): SeederSettings {
  const d = DEFAULT_SEEDER_SETTINGS;
  const r = (value && typeof value === "object" && !Array.isArray(value) ? value : {}) as Record<string, unknown>;
  const iface = typeof r.bindInterface === "string" ? r.bindInterface.trim() : "";
  return {
    sites: stringList(r.sites, (s) => SITE_ID_RE.test(s)),
    trackers: stringList(r.trackers, (s) => TRACKER_RE.test(s)),
    maxUploadKiBps: clampInt(r.maxUploadKiBps, d.maxUploadKiBps, 0, 10_000_000),
    maxConnections: clampInt(r.maxConnections, d.maxConnections, 1, 500),
    pollSeconds: clampInt(r.pollSeconds, d.pollSeconds, 10, 3600),
    standbyAfterSeconds: clampInt(r.standbyAfterSeconds, d.standbyAfterSeconds, 60, 86_400),
    bindInterface: IFACE_RE.test(iface) ? iface : "",
  };
}

export function seederConfigured(s: SeederSettings): boolean {
  return s.sites.length > 0;
}