// ── Dangerous Treasures (protocol 14, PLAN_REDESIGNS §14.3.4) ──────────────
//
// nivex's Dangerous Treasures opens a guarded, burning treasure chest somewhere
// on the map. Its events reach this module as three kinds: `dt.started`
// (public), `dt.won` (public) and `dt.ended` (staff's). The chest emptied is
// *Treasure Hunter*'s count, from the tally's `treasuresWon` (D375). A run's step
// opens one (`eventDangerousTreasures.js`).
//
// ── Who may read what ──────────────────────────────────────────────────────
//
// As a world event is read (`worldEvents.js`, D353, D376): the event and its
// grid are public; the winner's name shows only to the operator's presence
// audience, so with presence left at staff a signed-out visitor reads "The
// treasure was won at K12"; Steam ids, the invaders' among them, and the
// position are staff's. How many fought for it is a count, and names nobody.
// The step's key, when a step opened it, is staff's too.

const { gridOf } = require('./worldEvents')

const KINDS = Object.freeze(['dt.started', 'dt.won', 'dt.ended'])

/** DT's three shipped difficulties, as `dtevent <level>` takes them. */
const LEVELS = Object.freeze([
  { value: 0, label: 'Easy' },
  { value: 1, label: 'Medium' },
  { value: 2, label: 'Hard' },
])

const STEAM_ID = /^\d{17}$/

function isKind(kind) {
  return KINDS.includes(kind)
}

/**
 * One `dt.*` frame for one viewer: `{ staff, presence, geometry }`. Passes the
 * envelope, adds `grid`; a win adds `invaderCount`, and `name` for the presence
 * audience. Staff also get `x`, `z`, the step's `key`, the winner's `steamId` and
 * the `invaders`. Any other frame is returned as is.
 */
function shapeFor(frame, { staff = false, presence = false, geometry = null } = {}) {
  if (!frame || !isKind(frame.kind)) return frame

  const out = {}
  for (const key of ['kind', 'type', 't', 'serverId', 'wipeId']) {
    if (frame[key] !== undefined) out[key] = frame[key]
  }

  const grid = gridOf(geometry, frame.x, frame.z)
  if (grid) out.grid = grid

  if (frame.kind === 'dt.won') {
    const invaders = Array.isArray(frame.invaders) ? frame.invaders : []
    const count = Number(frame.invaderCount)
    out.invaderCount = Number.isInteger(count) && count >= 0 ? count : invaders.length
    if ((presence || staff) && typeof frame.name === 'string' && frame.name) out.name = frame.name
    if (staff) {
      if (STEAM_ID.test(String(frame.steamId || ''))) out.steamId = String(frame.steamId)
      out.invaders = invaders.map(String).filter((id) => STEAM_ID.test(id))
    }
  }

  if (staff) {
    for (const key of ['x', 'z', 'key']) {
      if (frame[key] !== undefined) out[key] = frame[key]
    }
  }

  return out
}

/**
 * A server's last report about Dangerous Treasures and its console, from
 * `servers.db.dtReportFor`: `{ dangerousTreasures, consolePlugins }`, each null
 * where the plugin never said (no state yet, or a plugin before protocol 14).
 * `dangerousTreasures` is `{ loaded, version }`.
 */
function reportOf(row) {
  const parse = (value) => {
    if (value === null || value === undefined) return null
    if (typeof value !== 'string') return value
    try {
      return JSON.parse(value)
    } catch {
      return null
    }
  }
  const dt = row ? parse(row.dangerousTreasures) : null
  const probe = row ? parse(row.console) : null
  return {
    dangerousTreasures:
      dt && typeof dt === 'object' ? { loaded: dt.loaded === true, version: typeof dt.version === 'string' ? dt.version : null } : null,
    consolePlugins: probe && typeof probe === 'object' && typeof probe.plugins === 'boolean' ? probe.plugins : null,
  }
}

module.exports = { KINDS, LEVELS, isKind, shapeFor, reportOf }