// ── Public: shard live data ────────────────────────────────────────────────
//
// Same-origin, token-free read endpoints backed by the data the WS ingest
// pipeline persists (shard_online / shard_events / shard_economy / shard_houses)
// plus a live character round-trip to the sidecar. The browser never sees the
// sidecar URL or token — every sidecar call is server-side (uoLinkClient).
//
// The stored-data endpoints are cheap DB reads. The live /char endpoint hits the
// running shard, so it is briefly cached and degrades gracefully: a 503 (shard
// restarting) surfaces as a retry-able banner rather than an error.

const shardEvents = require('../../../model/shardEvents/shardEvents.model')
const shardState = require('../../../model/shardState/shardState.model')
const shardMarket = require('../../../model/shardMarket/shardMarket.model')
const uoLinkConfig = require('../../../model/uoLinkConfig/uoLinkConfig.model')
const broadcast = require('../../../utils/shardBroadcast')
const visibility = require('../../../utils/shardVisibility')

const log = require('../../../utils/logger')('public-shard')

// GET /public/shard/status — connection state + online count + latest economy.
async function getStatus(req, res) {
  try {
    const config = await uoLinkConfig.getSafe()
    const [online, economy] = await Promise.all([
      shardState.onlineCount(),
      shardState.latestEconomy(),
    ])
    return res.json({
      enabled: config.enabled,
      status: config.status,
      pluginConnected: config.pluginConnected,
      lastEventAt: config.lastEventAt,
      onlineCount: online,
      economy,
    })
  } catch (err) {
    log.error('shard.getStatus', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/feed?kind=&limit= — recent notable events from the log.
//
// This is the stored-history twin of the SSE stream, and it must reach the same
// verdict the stream does about the same event. Two things are therefore resolved
// against the LIVE config rather than the compiled defaults:
//
//   • which kinds this viewer may read at all — `visibleKinds`, not the static
//     PUBLIC_KINDS set (which is fixed at module load, so an admin moving
//     `guilds` to `staff` would gate /guilds while /feed kept serving
//     guild.join to anonymous callers), and
//   • the payload itself, projected per event against ITS OWN kind's feature —
//     the rows are a mix of features, and without this the stored frames were
//     returned verbatim, `acct`/`webId` and all, on an anonymous endpoint.
async function getFeed(req, res) {
  try {
    const config = await visibility.getConfig()
    const level = req.viewerLevel || (await visibility.viewerLevel(req))
    const allowed = new Set(visibility.visibleKinds(level, config))

    const { kind, limit } = req.query
    // No readable kinds ⇒ nothing to serve. Returning early also keeps us clear
    // of `list({ kinds: [] })`, which means "no filter", not "match nothing".
    if (allowed.size === 0) return res.json([])

    let events
    if (kind) {
      if (!allowed.has(kind)) return res.json([])
      events = await shardEvents.list({ kind, limit })
    } else {
      events = await shardEvents.list({ kinds: [...allowed], limit })
    }

    return res.json(
      events.map((ev) => ({
        ...ev,
        payload: visibility.projectFeature(
          visibility.KIND_FEATURE.get(ev.kind),
          ev.payload,
          level,
          config,
        ),
      })),
    )
  } catch (err) {
    log.error('shard.getFeed', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/economy — gold-supply series, oldest → newest.
async function getEconomy(req, res) {
  try {
    return res.json(await shardState.listEconomy(req.query.limit))
  } catch (err) {
    log.error('shard.getEconomy', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/online — players online now whose account is linked to a
// STAFF website user (admin/editor/moderator). Everyone sees that a staff member
// is online (name + serial); their in-game location (map + coordinates) is gated
// on the `presence` feature's `location` field rule, which defaults to `staff`
// — the same admin/moderator set this used to hardcode. Non-staff players are
// never listed.
async function canSeeStaffLocation(req) {
  const config = await visibility.getConfig()
  const required = config.presence?.fields?.location || 'staff'
  const level = req.viewerLevel || (await visibility.viewerLevel(req))
  return visibility.meets(level, required)
}

async function getOnline(req, res) {
  try {
    const rows = await shardState.listOnlineLinked()
    const showLocation = await canSeeStaffLocation(req)
    return res.json(
      rows.map((r) => {
        const entry = { serial: r.serial, name: r.name }
        if (showLocation) {
          entry.map = r.map
          entry.x = r.x
          entry.y = r.y
          entry.z = r.z
        }
        return entry
      }),
    )
  } catch (err) {
    log.error('shard.getOnline', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/idoc — houses currently in danger (stage IDOC).
//
// Projected: shapeHouse flattens the owner actor into `ownerSerial`/`ownerAcct`/
// `ownerName`, so this endpoint used to hand an anonymous caller the house
// owner's GAME ACCOUNT NAME. The public IDOC board only ever needed name, region
// and location — which is all that survives projection below `staff`.
async function getIdoc(req, res) {
  try {
    return res.json(await visibility.project('houses', await shardState.listIdoc(), req))
  } catch (err) {
    log.error('shard.getIdoc', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/champs — the current champion-spawn board (all categories).
// Served from our own store; live deltas (champ.update / champ.remove) arrive on
// the public SSE stream so the page can update in place.
async function getChamps(req, res) {
  try {
    return res.json(await visibility.project('champs', await shardState.listChamps(), req))
  } catch (err) {
    log.error('shard.getChamps', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/guilds — the current guild board. Served from our store;
// live via guild.update / guild.remove / guild.join on the public SSE stream.
//
// Projected: the stored payload is the raw guild.update frame, whose `leader`
// actor carries `acct` and `webId`. Those are admin-only and were previously
// returned verbatim to anonymous callers.
async function getGuilds(req, res) {
  try {
    return res.json(await visibility.project('guilds', await shardState.listGuilds(), req))
  } catch (err) {
    log.error('shard.getGuilds', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/governors — the current town-governor board (empty on shards
// without City Loyalty). Live via city.update on the public SSE stream. Projected
// for the same reason as getGuilds: `governor` / `governorElect` are actors.
async function getGovernors(req, res) {
  try {
    return res.json(await visibility.project('governors', await shardState.listGovernors(), req))
  } catch (err) {
    log.error('shard.getGovernors', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/governors/:city/history — the term ledger for one city
// (look-back: "who were all the governors of Britain?"), newest first.
async function getGovernorHistory(req, res) {
  try {
    const terms = await shardState.listGovernorHistory(req.params.city, req.query.limit)
    return res.json(await visibility.project('governors', terms, req))
  } catch (err) {
    log.error('shard.getGovernorHistory', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/presence — the online-population aggregate (count + per-facet
// + per-region). Live via presence.online on the public SSE stream.
async function getPresence(req, res) {
  try {
    return res.json(await visibility.project('presence', await shardState.latestPresence(), req))
  } catch (err) {
    log.error('shard.getPresence', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/houses — PUBLIC view: only houses in danger (IDOC), and only
// their location (name + region + map/coords). Owner, price, co-owners and decay
// detail are staff-only (see admin GET /admin/shard/houses). Live via house.decay
// on the public SSE stream. This is the "where are the falling houses" board.
async function getHouses(req, res) {
  try {
    const idoc = await shardState.listIdoc()
    const publicHouses = idoc.map((h) => ({
      serial: h.serial,
      name: h.name,
      region: h.region,
      map: h.map,
      x: h.x,
      y: h.y,
      z: h.z,
      isIdoc: true,
    }))
    // Already a hand-picked safe subset; projected anyway so an admin who
    // tightens a `houses` field rule sees it honoured on every houses surface
    // rather than on some of them.
    return res.json(await visibility.project('houses', publicHouses, req))
  } catch (err) {
    log.error('shard.getHouses', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/ruleset — the shard's published ruleset (Protocol 3.0):
// expansion, which optional systems are on, skill/stat caps, account and house
// limits, champion scroll rules, the save/restart schedule. Served from our own
// store, so it renders while the shard is down; live via world.ruleset on the
// public SSE stream.
//
// `null` means the shard has never published one (an old plugin, or
// Bridge.RulesetEnabled=false) — a real answer, distinct from a published
// ruleset, and the page says so rather than rendering an empty one.
//
// Projected like every other shard read (§3.6.1's rule: a read path that returns
// shard data and does not call projectFeature is a bug). The `connect` string is
// the one configurable field — an operator who published a connect address may
// still want it behind a login.
async function getRuleset(req, res) {
  try {
    const ruleset = await shardState.getRuleset()
    if (!ruleset) return res.json(null)
    return res.json(await visibility.project('ruleset', ruleset, req))
  } catch (err) {
    log.error('shard.getRuleset', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// The shard keys boards by its own PointsType enum name (QueensLoyalty,
// CleanUpBritannia, …). Constrain the path param to that shape before it reaches
// the model: the column is VARCHAR(48), and an unbounded string here is a needless
// query on a value that can only ever be an identifier.
const SYSTEM_RE = /^[A-Za-z][A-Za-z0-9_]{0,47}$/

// GET /public/shard/points — every points/loyalty leaderboard the shard publishes.
// Served from our own store, so the page renders while the shard is down — which
// matters more here than for live state: these are standings accumulated over
// months, and blanking them during a restart would look like a data loss.
async function getPointsBoards(req, res) {
  try {
    const boards = await shardState.listPointsBoards()
    return res.json(await visibility.project('leaderboards', boards, req))
  } catch (err) {
    log.error('shard.getPointsBoards', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/points/:system — one system's board.
//
// 404 for a system the shard has never published, matching the sidecar: "no such
// board" and "a board nobody is on yet" are different answers.
async function getPointsBoard(req, res) {
  const { system } = req.params
  if (!SYSTEM_RE.test(system)) return res.status(400).json({ message: 'Invalid points system.' })
  try {
    const board = await shardState.getPointsBoard(system)
    if (!board) return res.status(404).json({ message: 'Unknown points system.' })
    return res.json(await visibility.project('leaderboards', board, req))
  } catch (err) {
    log.error('shard.getPointsBoard', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// ── Marketplace (Protocol 3.0 vendor.listing) ──────────────────────────────
//
// The shard-wide player-vendor index. Served entirely from our own tables — the
// sidecar is never touched on this path — so shops stay browsable while the shard
// is down, labelled with how stale they may be.
//
// The staleness label is not decoration. The shard sweeps vendors round-robin, so
// a shop can legitimately be a full cycle behind; a page that implied live prices
// would send people to a vendor whose item sold twenty minutes ago.

// The serial spelling the bridge uses everywhere: "0x" and hex. Constrained
// before it reaches the model, like SYSTEM_RE above.
const SERIAL_RE = /^0x[0-9A-Fa-f]{1,16}$/

const intParam = (value) => {
  const n = Number.parseInt(value, 10)
  return Number.isFinite(n) ? n : undefined
}

// GET /public/shard/market — search the index.
//
// Returns LISTINGS, not vendors: "who sells a vanquishing kryss and for how much"
// is the question, and a vendor-shaped result would make every caller flatten the
// shops back out.
async function getMarket(req, res) {
  try {
    const page = await shardMarket.search({
      q: typeof req.query.q === 'string' ? req.query.q : '',
      minPrice: intParam(req.query.minPrice),
      maxPrice: intParam(req.query.maxPrice),
      itemId: intParam(req.query.itemId),
      map: typeof req.query.map === 'string' ? req.query.map : '',
      region: typeof req.query.region === 'string' ? req.query.region : '',
      sort: typeof req.query.sort === 'string' ? req.query.sort : 'price_asc',
      limit: intParam(req.query.limit) ?? 50,
      offset: intParam(req.query.offset) ?? 0,
    })
    return res.json(await visibility.project('market', page, req))
  } catch (err) {
    log.error('shard.getMarket', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/market/meta — index size, staleness, and the filter options
// (which facets and regions actually hold vendors). Separate from the search so
// the page can build its filters without running a query it will throw away.
async function getMarketMeta(req, res) {
  try {
    return res.json(await visibility.project('market', await shardMarket.meta(), req))
  } catch (err) {
    log.error('shard.getMarketMeta', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/market/vendors/:serial — one shop and its listings.
//
// 404 for a serial the index has never seen, which also covers a vendor that has
// since been dismissed or hidden: to an anonymous caller "no such shop" is the
// only honest answer, and distinguishing the two would leak that a vendor exists
// but was hidden.
async function getMarketVendor(req, res) {
  const { serial } = req.params
  if (!SERIAL_RE.test(serial)) return res.status(400).json({ message: 'Invalid vendor serial.' })
  try {
    const vendor = await shardMarket.getVendor(serial, {
      limit: intParam(req.query.limit) ?? 250,
      offset: intParam(req.query.offset) ?? 0,
    })
    if (!vendor) return res.status(404).json({ message: 'Unknown vendor.' })
    return res.json(await visibility.project('market', vendor, req))
  } catch (err) {
    log.error('shard.getMarketVendor', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/features — the shard features THIS caller can actually see,
// so the SPA (and the Android client) can hide nav entries instead of rendering
// links that 403. Deliberately reports only what the viewer may reach: the list
// itself must not disclose the existence of a feature they're gated out of.
async function getFeatures(req, res) {
  try {
    const config = await visibility.getConfig()
    const level = await visibility.viewerLevel(req)
    return res.json({ level, features: visibility.visibleFeatures(level, config) })
  } catch (err) {
    log.error('shard.getFeatures', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// GET /public/shard/stream — live-event SSE channel. What arrives depends on the
// caller's audience rung, resolved once at subscribe time; see shardBroadcast.js.
function stream(req, res) {
  return broadcast.subscribe(req, res, 'public')
}

module.exports = {
  getStatus,
  getFeed,
  getEconomy,
  getOnline,
  getIdoc,
  getChamps,
  getGuilds,
  getGovernors,
  getGovernorHistory,
  getPresence,
  getHouses,
  getRuleset,
  getPointsBoards,
  getPointsBoard,
  getMarket,
  getMarketMeta,
  getMarketVendor,
  getFeatures,
  stream,
}
