// ── Admin · Rust — the handlers ───────────────────────────────────────────
//
// The write side of the module. Three things every handler here owes:
//
//  1. **Never return the token.** Not in a response, not in an error, not in an
//     activity-log detail. It is accepted, encrypted and forgotten.
//  2. **Record the change.** `core.activity.log` writes core's own admin audit
//     row. These handlers edit the credential that reaches a game host; "who
//     changed this" has no second place it is recorded.
//  3. **Answer rather than throw.** An unhandled rejection reaches core's error
//     handler and gets core blamed for a fault in this module.

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

const db = require('../../model/servers/servers.db')
const servers = require('../../model/servers/servers.model')
const sidecar = require('../../sidecarClient')

const log = core.logger('admin')

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

async function putServer(req, res) {
  const { id } = req.params
  const { name, sidecarBaseUrl, sidecarToken, protocol, enabled, sortOrder } = req.body

  try {
    const existing = await db.getServer(id)

    // A NEW server with no token is a row that can never reach its sidecar, and
    // the operator will read the resulting "unreachable" as a network problem.
    // Refusing it up front costs one round trip and saves that hunt. An EXISTING
    // row is a different case: omitting the token is how you say "leave it".
    if (!existing && !sidecarToken) {
      return res.status(400).json({ error: 'A new server needs its sidecar token' })
    }

    await db.upsertServer({
      id,
      name,
      sidecarBaseUrl,
      // `encryptToken` returns null for an empty value, and `upsertServer` reads
      // null as "do not write this column". The two halves of that rule are in
      // different files on purpose: the model decides what a blank means, the SQL
      // decides what null does, and neither has to know the other's reason.
      sidecarTokenEnc: servers.encryptToken(sidecarToken),
      protocol: protocol === undefined ? sidecar.PROTOCOL_VERSION : protocol,
      enabled: enabled === undefined ? true : enabled,
      sortOrder: sortOrder === undefined ? 0 : sortOrder,
    })

    await core.activity.log({
      req,
      action: 'rust.server.save',
      detail: {
        server: id,
        created: !existing,
        sidecarBaseUrl,
        // Whether the credential was rotated, never the credential.
        tokenChanged: Boolean(sidecarToken),
      },
    })

    return res.status(204).end()
  } catch (err) {
    log.error('failed to save a server', { server: id, error: err.message })
    return res.status(500).json({ error: 'Failed to save the server' })
  }
}

async function deleteServer(req, res) {
  const { id } = req.params

  try {
    const existing = await db.getServer(id)
    if (!existing) return res.status(404).json({ error: 'No such server' })

    await db.deleteServer(id)
    await core.activity.log({ req, action: 'rust.server.delete', detail: { server: id } })

    return res.status(204).end()
  } catch (err) {
    log.error('failed to delete a server', { server: id, error: err.message })
    return res.status(500).json({ error: 'Failed to delete the server' })
  }
}

/**
 * Probe one sidecar and report what came back.
 *
 * This is the route that tells a wrong URL from a wrong token from a mismatched
 * protocol, and that distinction is the whole reason it exists: all three present
 * to an operator as "the site says my server is offline", and each has a
 * different fix. The status string from `sidecarClient` is carried through
 * verbatim so the panel can say which.
 */
async function testServer(req, res) {
  const { id } = req.params

  try {
    const row = await db.getServer(id)
    if (!row) return res.status(404).json({ error: 'No such server' })

    const result = await sidecar.health(servers.withToken(row))

    await core.activity.log({
      req,
      action: 'rust.server.test',
      detail: { server: id, ok: result.ok, status: result.status },
    })

    return res.json({
      ok: result.ok,
      status: result.status,
      // `data` is the sidecar's own health document on success and the mismatch
      // detail on a 409. Both are safe to show: neither carries a credential.
      sidecar: result.data || null,
    })
  } catch (err) {
    log.error('failed to probe a sidecar', { server: id, error: err.message })
    return res.status(500).json({ error: 'Failed to probe the sidecar' })
  }
}

module.exports = { listServers, putServer, deleteServer, testServer }