// ── Player · Rust — the handlers ──────────────────────────────────────────
//
// Two things live here now: the server list as a signed-in caller sees it (phase
// 1's honest placeholder, which must not reshape the list — it calls the same
// model the public tier does so the two cannot drift), and R1's identity link.
//
// ── Every refusal is a sentence, and they are not interchangeable ─────────
//
// The link handler's whole job is turning a discriminated result into the right
// thing to tell a player, and the four wrong answers are wrong in different ways:
//
//   • "that code is unknown or expired" → run `/link` again
//   • "another account holds that Steam id" → run `/unlink` in game, or ask staff
//   • "we could not reach a server" → try again in a minute; the code is fine
//   • "no servers are configured" → nothing the player can do at all
//
// A player told to run `/link` again when the server their code came from was
// merely unreachable will run it again, get another code from the same
// unreachable server, and be told the same thing. That is the failure the
// `unsure` branch exists to prevent.

const core = require('../../core')

const links = require('../../model/links/links.model')
const permissions = require('../../model/permissions/permissions.model')
const servers = require('../../model/servers/servers.model')

const log = core.logger('player')

async function listServers(req, res) {
  try {
    res.json({ servers: await servers.listPublic() })
  } catch (err) {
    log.error('failed to read the server list', { error: err.message })
    res.status(500).json({ message: 'Failed to read the server list' })
  }
}

/** GET /player/rust/links — the Steam accounts the caller holds. */
async function listLinks(req, res) {
  try {
    res.json({ links: await links.listForUser(req.user.id) })
  } catch (err) {
    log.error('failed to read a player’s links', { error: err.message })
    res.status(500).json({ message: 'Failed to read your linked accounts' })
  }
}

/**
 * POST /player/rust/link — redeem a code from `/link` in game.
 *
 * The fleet loop is the model's (D24); this maps its answer onto a status and a
 * sentence. **A refused code is a 400 and an unreachable server is a 503**,
 * because a client that cannot tell them apart cannot tell a player whether to
 * try again or to go and get a new code.
 */
async function confirmLink(req, res) {
  const code = String(req.body.code || '').trim()

  try {
    const result = await links.redeem({ code, userId: req.user.id })

    if (result.ok) {
      // Logged on the player tier too, not only for admin writes: this is the
      // moment a website account starts being able to hold permissions and
      // entitlements in a game, and "when did this account become that Steam id"
      // is a question an operator will eventually need answered.
      await core.activity.log({
        req,
        action: 'rust.account.link',
        detail: { steamId: result.link.steamId, serverId: result.link.serverId },
      })

      return res.json({ linked: true, link: result.link, already: Boolean(result.already) })
    }

    switch (result.reason) {
      case 'taken':
        // Naming the holder is deliberate and it is not a leak: the player is
        // signed in, the account named is one they may well own, and without the
        // name the advice ("sign in as that account, or ask staff") is unusable.
        return res.status(409).json({
          message: result.username
            ? `That Steam account is already linked to ${result.username}. Run /unlink in game to release it.`
            : 'That Steam account is already linked to another website account. Run /unlink in game to release it.',
        })

      case 'unsure':
        return res.status(503).json({
          message:
            'One of the servers could not be reached, so that code could not be checked. ' +
            'Your code is still good — try again in a minute.',
        })

      case 'offline':
        return res.status(503).json({
          message: 'The game servers are unreachable right now — try again in a minute.',
        })

      case 'no-servers':
        return res.status(503).json({ message: 'No Rust servers are configured on this site yet.' })

      default:
        return res.status(400).json({
          message: 'That code is unknown or has expired. Type /link in game for a new one.',
        })
    }
  } catch (err) {
    log.error('failed to confirm a link code', { error: err.message })
    return res.status(500).json({ message: 'Failed to confirm that code' })
  }
}

/**
 * DELETE /player/rust/links/:steamId — release a link the caller holds.
 *
 * Scoped to the caller inside the statement, so "not linked" and "not yours"
 * answer the same 404 — a signed-in stranger must not be able to discover which
 * Steam ids are linked by deleting them one at a time.
 */
async function removeLink(req, res) {
  const { steamId } = req.params

  try {
    const removed = await links.unlinkOwned(steamId, req.user.id)

    if (!removed) return res.status(404).json({ message: 'That account is not linked to you' })

    await core.activity.log({ req, action: 'rust.account.unlink', detail: { steamId } })

    return res.json({ unlinked: true })
  } catch (err) {
    log.error('failed to unlink', { error: err.message })
    return res.status(500).json({ message: 'Failed to unlink that account' })
  }
}

/**
 * GET /player/rust/permissions — what the site has given this player in game.
 *
 * Phase 7 made the website the author of in-game privilege and gave an operator
 * every view of it; this is the other side of that, and it is the first time a
 * player can see what they hold without asking one. Read-only by construction:
 * nothing a player can do here changes a grant, because a grant they could
 * change would not be a grant.
 *
 * The caller's Steam ids come from the link model rather than the permission
 * one, so the two questions stay in the files that own them — and the pushed
 * ledger is keyed by Steam id, which is the whole reason this read needs them.
 */
async function listPermissions(req, res) {
  try {
    const [accounts, serverRows] = await Promise.all([
      links.listForUser(req.user.id),
      servers.listPublic(),
    ])

    const held = await permissions.forPlayer(
      req.user.id,
      accounts.map((account) => account.steamId),
      serverRows,
    )

    res.json({ ...held, accounts: accounts.length })
  } catch (err) {
    log.error('failed to read a player’s entitlements', { error: err.message })
    res.status(500).json({ message: 'Failed to read what you hold in game' })
  }
}

module.exports = { listServers, listLinks, confirmLink, removeLink, listPermissions }