// ── `/online [server]` — how many, and who, where the caller may see it ─────
//
// The command with the gate. The org lead's rule (2026-09-22) is that nothing
// names who is online by default: the COUNT is public and the NAMES reach the
// server's presence audience (D42, per-server override D45), staff unless an
// operator widened it.
//
// And D127 on top of it: **a caller inside a narrower-than-public audience gets
// the names PRIVATELY.** The answer is posted where the command was run, and a
// moderator's `/online` in a public channel would otherwise hand the roll call to
// everyone reading the channel. Only a server whose audience is `public` posts
// its names in the open.

const c = require('./common')
const events = require('../model/events/events.model')
const visibility = require('../model/visibility/visibility.model')

/** Fifty names, then "and N more" (§32.4 reading 2). */
const LIMIT = 50

// The link nudge, and only when it is TRUE — module-uo's rule. Linking a Discord
// account to a site account earns `signed_in` and nothing above it; `staff` is a
// role an operator grants. So a server that shows names to staff is not a reason
// to tell anybody to link.
function linkNudge(actor, required) {
  if (actor && actor.isLinked) return null
  if (required !== 'signed_in') return null
  return 'Link your Discord account on the site to see who is on — this server shows names to signed-in members.'
}

async function forServer(server, actor, level) {
  const required = await visibility.presenceFor(server.id)
  const visible = visibility.meets(level, required)
  const count = server.online ? server.players : 0

  // Offline, or nobody on: there are no names to decide about, and saying who
  // was on when the server went down would be the presence board's last word
  // presented as now.
  if (!server.online) return { text: `${server.name} is offline.`, url: c.serverUrl(server) }
  if (!visible || count === 0) {
    return {
      title: `${server.name} — ${count} online`,
      url: c.serverUrl(server),
      ...(visible ? {} : { notice: linkNudge(actor, required) }),
    }
  }

  const players = await events.online(server.id)
  const names = players.map((p) => (p.sleeping ? `${p.name || 'Unknown player'} (sleeping)` : p.name || 'Unknown player'))
  return {
    title: `${server.name} — ${players.length} online`,
    url: c.serverUrl(server),
    text: c.fitLines(names, { max: LIMIT, limit: 1900 }),
    // D127. Anything short of `public` is for the caller alone.
    ephemeral: required !== 'public',
  }
}

async function handler({ options, actor }) {
  const now = Date.now()
  const picked = c.pickServer(await c.listServers(now), options && options.server)
  const refusal = c.pickRefusal(picked)
  if (refusal) return refusal

  const level = await c.levelFor(actor)
  if (picked.server) return forServer(picked.server, actor, level)

  // The fleet: counts only, which are public. Names are one server's question,
  // and the closing line offers it only when naming a server would show some.
  const visibleSomewhere = (
    await Promise.all(picked.all.map(async (s) => visibility.meets(level, await visibility.presenceFor(s.id))))
  ).some(Boolean)
  return {
    title: 'Online now',
    url: c.pageUrl('/rust'),
    fields: picked.all.slice(0, 25).map((s) => ({
      name: s.name,
      value: s.online ? `${s.players} online` : 'Offline',
      inline: true,
    })),
    ...(visibleSomewhere ? { text: 'Name a server to see who is on.' } : {}),
  }
}

module.exports = {
  name: 'online',
  description: 'How many are on a Rust server, and who, where this site shows names',
  options: [{ name: 'server', type: 'string', description: 'Server name or id (counts for all when left out)', required: false }],
  // Everyone, deliberately: `linked` would hide the command from the unlinked
  // members the nudge exists to invite. The gate is inside the handler.
  access: 'everyone',
  handler,
}