// ── Permissions as event rewards (PLAN_REDESIGNS.md §12, D342–D346) ───────
//
// Any permission a server's plugins registered can be a reward — night vision,
// a chat colour, a `/remove` command — with no code written for the perk. Two
// verbs, because core gives an action one risk class (D346):
//
//   rust.perm.lend   until the run ends: a kit reward's lease, one
//                    `rust_perm_run_grants` row per recipient per permission,
//                    withdrawn by the step's revert (`change` / `ledger`)
//   rust.perm.give   for good: a standing `rust_perm_grants` row per website
//                    user per permission, scoped to the step's server, source
//                    `event` (`irreversible` / `none`); staff take it back in
//                    the permission manager
//
// …and the picker both use, `rust.options.permissions`: the enabled servers'
// catalogues, grouped by the plugin that registered each permission.
//
// Nothing here is new machinery. Both write rows the permission mirror already
// pushes, so there is no plugin code, no sidecar code and no protocol change
// (§12.1). The message is D333's notice and rides `perm.sync` like a kit
// reward's.
//
// ── The safety is the author's own "I am sure" (D343) ───────────────────────
//
// No blocklist and no allowlist: the bridge's own `runicgateway.*` permissions
// are in the picker like any other. A required toggle in the step says the
// author meant it, and unticked the dry run and the run refuse, naming what the
// step would have given.

const permDb = require('./model/permissions/permissions.db')
const linksDb = require('./model/links/links.db')
const servers = require('./model/servers/servers.model')
const core = require('./core')
const { serverFor, bounded } = require('./eventLeases')
const { BUDGET_MS } = require('./eventWorld')
const rewards = require('./eventRewards')

const log = core.logger('perm-rewards')

const { MAX_RECIPIENTS, MAX_CHAT, DELIVERIES, MODES, oneOf, checkCount, pickRecipients, peopleOf, usersFor, readTally, entitlementRef } = rewards

/** At most this many permissions in one step (§12.6): a perk bundle, with a price that stays readable. */
const MAX_PERMISSIONS = 10

/** A permission name as Oxide and Carbon store it: lower case, and at most the column's width. */
const PERMISSION_MAX = 128

/** What a for-good grant says it came from, in the permission manager (§12.5). */
const SOURCE = 'event'

const BUDGETS = [
  {
    id: 'rust.permissions',
    label: 'Permissions lent',
    unit: 'permissions',
    description:
      'Permissions an event lends until it ends: one per recipient per permission. A mode that is not a count is priced at the most it could lend.',
  },
  {
    id: 'rust.permissions.kept',
    label: 'Permissions given for good',
    unit: 'permissions',
    description:
      'Permissions an event gives for good: one per recipient per permission. Ending the event does not take them back; staff remove them in the permission manager. A mode that is not a count is priced at the most it could give.',
  },
]

// ── The params both steps check ──────────────────────────────────────────────

/**
 * The picked permissions as a list, checked: lower case, trimmed, each once, at
 * least one and at most MAX_PERMISSIONS. Core hands a `multiple` param over as
 * an array (MODULE_API 1.14.0); a bare value is a list of one.
 */
function checkPermissions(raw) {
  const items = raw === undefined || raw === null || raw === '' ? [] : Array.isArray(raw) ? raw : [raw]
  const out = []
  for (const item of items) {
    const name = String(item === undefined || item === null ? '' : item).trim().toLowerCase()
    if (!name) continue
    if (name.length > PERMISSION_MAX || /\s/.test(name)) return { ok: false, error: `"${item}" is not a permission name` }
    if (!out.includes(name)) out.push(name)
  }
  if (!out.length) return { ok: false, error: 'pick at least one permission' }
  if (out.length > MAX_PERMISSIONS) return { ok: false, error: `a step gives at most ${MAX_PERMISSIONS} permissions, not ${out.length}` }
  return { ok: true, value: out }
}

/** The "I am sure" toggle (D343). Only a real `true` passes; a string is not a tick. */
function checkConfirm(params, permissions) {
  if (params.confirm === true) return { ok: true }
  return { ok: false, error: `Tick "I am sure" to make ${permissions.join(', ')} a reward` }
}

/**
 * The step's message, checked like a kit reward's (D333): `{ ok, text,
 * delivery }`, text null for a step that tells nobody — the default (§12.6),
 * because a permission's name means nothing to a player and only the author can
 * say what it does. `{permissions}` is the names; measured with them in place.
 */
function permNotice(params, permissions) {
  const text = params.message === undefined || params.message === null ? '' : String(params.message).trim()
  if (!text) return { ok: true, text: null, delivery: null }

  const rawDelivery = params.delivery === undefined || params.delivery === null || params.delivery === '' ? 'chat' : params.delivery
  const delivery = oneOf(rawDelivery, DELIVERIES)
  if (!delivery) return { ok: false, error: `a reward's message goes to chat or to a popup, not to "${rawDelivery}"` }

  const said = sayPermissions(text, permissions)
  if (said.length > MAX_CHAT) {
    return { ok: false, error: `a reward's message is at most ${MAX_CHAT} characters with the permissions in it, not ${said.length}` }
  }
  return { ok: true, text, delivery }
}

const sayPermissions = (text, permissions) => text.replace(/\{permissions\}/g, permissions.join(', '))

/**
 * Every picked permission must be in the server's catalogue (§12.2), and one
 * that is not is refused by name rather than skipped (§12.6): the plugin may be
 * unloaded for the wipe, and a reward that silently gives less than it says is
 * the worse failure. Runs in the dry run too.
 */
async function checkCatalogue(server, permissions) {
  const name = server.name || server.id
  const registered = new Set(
    (await permDb.listCatalogue())
      .filter((row) => row.serverId === server.id)
      .map((row) => String(row.permission).toLowerCase()),
  )
  if (!registered.size) {
    return {
      ok: false,
      error: `${name} has reported no permissions yet — its plugins' permissions arrive with its next permission sync`,
    }
  }
  const missing = permissions.filter((p) => !registered.has(p))
  if (missing.length) {
    return {
      ok: false,
      retry: false,
      error: `${name} has no permission ${missing.join(', ')} — its plugins did not register ${missing.length === 1 ? 'it' : 'them'}`,
    }
  }
  return { ok: true }
}

/**
 * Everything both steps check before touching anything, in the order an author
 * fixes them: the permissions, the toggle, the mode and its count, the message,
 * the server, its catalogue, the bound. `{ ok, permissions, mode, count, notice,
 * server }` or a refusal core reads as permanent.
 */
async function checkStep(params, verb) {
  const permissions = checkPermissions(params.permissions)
  if (!permissions.ok) return { ok: false, retry: false, error: permissions.error }

  const confirm = checkConfirm(params, permissions.value)
  if (!confirm.ok) return { ok: false, retry: false, error: confirm.error }

  const mode = oneOf(params.recipients, MODES)
  if (!mode) return { ok: false, retry: false, error: `recipients is one of ${MODES.join(', ')}, not "${params.recipients}"` }

  const count = checkCount(mode, params.count)
  if (!count.ok) return { ok: false, retry: false, error: count.error }

  const notice = permNotice(params, permissions.value)
  if (!notice.ok) return { ok: false, retry: false, error: notice.error }

  const found = await serverFor(String(params.server || '').trim())
  if (!found.ok) return found
  const server = found.server

  const listed = await checkCatalogue(server, permissions.value)
  if (!listed.ok) return listed

  if ((mode === 'top' || mode === 'random') && count.value > MAX_RECIPIENTS) {
    return { ok: false, retry: false, error: `${server.name || server.id} ${verb} permissions to at most ${MAX_RECIPIENTS} people in one step, not ${count.value}` }
  }

  return { ok: true, permissions: permissions.value, mode, count, notice, server }
}

/**
 * The people a mode picks, as website users (D101, D103): `{ ok, people,
 * missed }`, each person `{ steamId, name, userId }` and each website user once —
 * of two linked accounts that both took part, the earlier in the list, the
 * higher score, is the one. `linked` reads no tally (§2.5).
 */
async function recipientsOf({ server, mode, count, runId, idempotencyKey, verb }) {
  const name = server.name || server.id
  let picked
  let bound = MAX_RECIPIENTS
  let users

  if (mode === 'linked') {
    // One past the bound, so "too many" is a sentence and not a silent cut.
    const linked = await linksDb.linkedOnServer(server.id, bound + 1)
    picked = linked.map((r) => ({ steamId: String(r.steamId), name: r.name ? String(r.name) : String(r.steamId) }))
    users = new Map(linked.map((r) => [String(r.steamId), Number(r.userId)]))
    if (picked.length > bound) {
      return { ok: false, retry: false, error: `${name} has more than ${bound} linked players, and ${verb} permissions to at most ${bound} in one step — reward from a tally instead` }
    }
  } else {
    const tally = await readTally(server, runId)
    if (!tally.ok) return tally

    picked = pickRecipients(peopleOf(tally.data), mode, count, idempotencyKey)
    bound = Number(tally.data.maxRecipients) || bound
    if (picked.length > bound) {
      return { ok: false, retry: false, error: `${picked.length} people qualify, and ${name} ${verb} permissions to at most ${bound} in one step — pick a count-based mode or a higher bar` }
    }
    users = await usersFor(picked.map((p) => p.steamId))
  }

  const people = []
  const byUser = new Set()
  const missed = []
  for (const p of picked) {
    const userId = users.get(p.steamId)
    if (!userId) {
      missed.push(p.name)
      continue
    }
    if (byUser.has(userId)) continue
    byUser.add(userId)
    people.push({ ...p, userId })
  }
  return { ok: true, people, missed }
}

const missedDetail = (missed) =>
  missed.length ? { missed: missed.slice(0, 50), missedCount: missed.length, note: 'missed took part but have linked no website account' } : {}

/** People priced before the tally is read: the count for a count, the bound for every other mode. */
function pricedPeople(p) {
  const mode = oneOf(p.recipients, MODES)
  const n = Math.round(Number(p.count) || 0)
  return mode === 'top' || mode === 'random' ? Math.max(0, n) : MAX_RECIPIENTS
}

/** How many permissions a step names, as its price counts them: at least one, at most the bound. */
function pricedPermissions(p) {
  const checked = checkPermissions(p.permissions)
  return checked.ok ? checked.value.length : 1
}

// ── The params, declared once for both steps (§12.5: "the same params") ─────

const paramsFor = (messageExample) => [
  { name: 'server', type: 'string', required: true, example: 'main', source: 'rust.options.servers',
    description: 'The server the permissions are given on. Each one must be registered there by one of its plugins.' },
  { name: 'permissions', type: 'string', required: true, example: 'nightvision.allowed', source: 'rust.options.permissions',
    multiple: true, max: MAX_PERMISSIONS,
    description: `The permissions, by the plugin that registered them — at most ${MAX_PERMISSIONS}.` },
  { name: 'recipients', type: 'string', required: true, example: 'top', source: 'rust.options.recipientmodes',
    description: 'Who gets them: everyone who scored, the top N, a score of at least X, N drawn at random, the top X per cent — or every linked player of the server, with no tally at all.' },
  { name: 'count', type: 'float', required: false, example: 3,
    description: 'N for top and random, X for a minimum score, the percentage for top per cent. Not used for everyone or linked.' },
  { name: 'message', type: 'string', required: false, example: messageExample,
    description: 'Said once to each player, in game: at once if they are up, otherwise when they next wake on the server. {permissions} is the names. Leave it empty to say nothing — a permission\'s name means little to a player, so say what it does.' },
  { name: 'delivery', type: 'string', required: false, example: 'chat', source: 'rust.options.delivery',
    description: 'Chat, or a popup where the server has PopupNotifications (chat where it has not). Chat if left empty.' },
  { name: 'confirm', type: 'boolean', required: true, example: false,
    description: 'I am sure I want to give these permissions as a reward. Unticked, the step refuses in the dry run and when it runs.' },
]

// ── Until the run ends (§12.4) ───────────────────────────────────────────────

const kitEntitle = rewards.ACTIONS.find((a) => a.id === 'rust.kit.entitle')

const permLend = {
  id: 'rust.perm.lend',
  label: 'Permissions until the event ends',
  description:
    'Lends the permissions you pick to the people a mode picks from this run\'s tally — or every linked player of the server — until the run ends. Waits for them if they are offline. Someone who already held one keeps it when the event ends.',
  // A kit reward's lease with other permissions (D346): the same rows, the same
  // revert, so the same risk. Core reverts it at the end of every run.
  risk: 'change',
  reversible: 'ledger',
  version: 1,
  budgetMs: BUDGET_MS,
  params: paramsFor('You can use /nv until the event ends'),

  cost: (p) => ({ 'rust.permissions': pricedPeople(p) * pricedPermissions(p) }),

  async perform({ runId, stepId, idempotencyKey, params, verify }) {
    const step = await checkStep(params, 'lends')
    if (!step.ok) return step
    if (verify) return { ok: true }

    const { permissions, mode, count, notice, server } = step
    const name = server.name || server.id
    const ref = entitlementRef(server.id, runId, stepId)
    const resource = { kind: 'permission-lease', ref, payload: { serverId: server.id, permissions } }

    // As a kit reward's: the rows ARE the lease, and a repeated key finds them.
    const existing = await permDb.listRunGrantsForStep(runId, stepId)
    if (existing.length) {
      return {
        ok: true,
        resources: [resource],
        detail: { repeat: true, lent: new Set(existing.map((r) => r.userId)).size, note: 'answered from the first attempt; nothing new was lent' },
      }
    }

    const picked = await recipientsOf({ server, mode, count: count.value, runId, idempotencyKey, verb: 'lends' })
    if (!picked.ok) return picked

    // One row per recipient per permission; the message on the first only, so
    // each person is told once (the notice key is per run, step and user).
    const said = notice.text ? sayPermissions(notice.text, permissions) : null
    const rows = []
    for (const p of picked.people) {
      permissions.forEach((permission, i) => {
        rows.push({
          runId,
          stepId,
          idemKey: idempotencyKey,
          userId: p.userId,
          serverId: server.id,
          steamId: p.steamId,
          permission,
          kit: '',
          credit: false,
          ...(said && i === 0 ? { notice: said, noticeDelivery: notice.delivery } : {}),
        })
      })
    }

    await permDb.insertRunGrants(rows)
    await permDb.markDirty(server.id)

    log.info('permissions lent', { server: server.id, run: runId, step: stepId, permissions, mode, people: picked.people.length, missed: picked.missed.length })

    return {
      ok: true,
      resources: [resource],
      detail: {
        server: name,
        permissions,
        mode,
        ...(count.value === null ? {} : { count: count.value }),
        lent: picked.people.length,
        ...(said && picked.people.length ? { told: `${picked.people.length} will be told in game, by ${notice.delivery}` } : {}),
        ...missedDetail(picked.missed),
      },
    }
  },

  // The lease ends as a kit reward's does: the step's rows go and the next sync
  // revokes what nobody else grants. A player who already held a permission
  // keeps it, because the push reads the union (§12.1).
  revert: (ctx) => kitEntitle.revert(ctx),
  reconcile: (ctx) => kitEntitle.reconcile(ctx),
}

// ── For good (§12.5) ─────────────────────────────────────────────────────────

/** What a for-good grant's note says, in the permission manager. */
const grantNote = (runId, stepId) => `event run ${runId}, step ${stepId}`

const permGive = {
  id: 'rust.perm.give',
  label: 'Permissions for good',
  description:
    'Gives the permissions you pick to the people a mode picks, for good. Ending or cancelling the event does not take them back; staff remove them in the permission manager.',
  // Irreversible, as `rust.coins.pay` is (D335, D346): core reverts a ledgered
  // step at the end of EVERY run, so a ledger here would take the gift back.
  risk: 'irreversible',
  reversible: 'none',
  version: 1,
  budgetMs: BUDGET_MS,
  params: paramsFor('You can use /nv from now on'),

  cost: (p) => ({ 'rust.permissions.kept': pricedPeople(p) * pricedPermissions(p) }),

  async perform({ runId, stepId, idempotencyKey, params, verify }) {
    const step = await checkStep(params, 'gives')
    if (!step.ok) return step
    if (verify) return { ok: true }

    const { permissions, mode, count, notice, server } = step
    const name = server.name || server.id

    const picked = await recipientsOf({ server, mode, count: count.value, runId, idempotencyKey, verb: 'gives' })
    if (!picked.ok) return picked

    // A grant already there is left alone (§12.5). One this step's own first
    // attempt wrote carries its note, and is counted as given, not as held: a
    // retry after a lost answer reads the same as the attempt that landed.
    const note = grantNote(runId, stepId)
    const held = await permDb.listGrantsForUsers(picked.people.map((p) => p.userId), server.id)
    const heldBy = new Map(held.map((g) => [`${g.userId}:${String(g.permission).toLowerCase()}`, g]))

    const rows = []
    let alreadyHeld = 0
    let repeated = 0
    for (const p of picked.people) {
      for (const permission of permissions) {
        const there = heldBy.get(`${p.userId}:${permission}`)
        if (there) {
          if (there.source === SOURCE && there.note === note) repeated++
          else alreadyHeld++
          continue
        }
        rows.push({ userId: p.userId, permission, scope: server.id, source: SOURCE, note })
      }
    }

    const inserted = await permDb.insertGrants(rows)

    // The message rides a notice-only row (§12.5): no permission, no kit, no
    // credit, so the push grants nothing for it and tells it once. Nothing
    // reverts this step, so the row stays — a sentence that has been said.
    const said = notice.text ? sayPermissions(notice.text, permissions) : null
    if (said && picked.people.length) {
      await permDb.insertRunGrants(picked.people.map((p) => ({
        runId,
        stepId,
        idemKey: idempotencyKey,
        userId: p.userId,
        serverId: server.id,
        steamId: p.steamId,
        permission: '',
        kit: '',
        credit: false,
        notice: said,
        noticeDelivery: notice.delivery,
      })))
    }

    if (inserted || said) await permDb.markDirty(server.id)

    log.info('permissions given', { server: server.id, run: runId, step: stepId, permissions, mode, people: picked.people.length, given: inserted, alreadyHeld, repeated })

    return {
      ok: true,
      detail: {
        server: name,
        permissions,
        mode,
        ...(count.value === null ? {} : { count: count.value }),
        people: picked.people.length,
        given: inserted + repeated,
        ...(alreadyHeld ? { alreadyHeld, alreadyHeldNote: 'already held: the grant was there before, and is left as it was' } : {}),
        ...(repeated ? { repeat: true, repeatNote: 'answered from the first attempt; nothing was given twice' } : {}),
        ...(said && picked.people.length ? { told: `${picked.people.length} will be told in game, by ${notice.delivery}` } : {}),
        ...missedDetail(picked.missed),
      },
    }
  },
}

// ── The picker (§12.2) ───────────────────────────────────────────────────────

/** A permission's group: the plugin that registered it, or its prefix, saying so (the permission manager's rule). */
function groupOf(permission, owner) {
  if (owner) return owner
  const prefix = permission.includes('.') ? permission.slice(0, permission.indexOf('.')) : permission
  return `${prefix} (not registered by a plugin)`
}

/**
 * The picker's rows from the catalogue and the enabled servers. Pure, so the
 * rule is testable without a database: each permission once, grouped by its
 * plugin, sorted by group and then permission without case, and a permission not
 * on every enabled server says where it is (`note`, MODULE_API 1.13.0).
 */
function permissionRows(catalogue, enabled) {
  const names = new Map(enabled.map((s) => [s.id, s.name || s.id]))
  const byPermission = new Map()
  for (const row of catalogue) {
    if (!names.has(row.serverId)) continue
    const permission = String(row.permission || '').trim()
    if (!permission) continue
    const key = permission.toLowerCase()
    if (!byPermission.has(key)) byPermission.set(key, { permission, owner: null, on: new Set() })
    const entry = byPermission.get(key)
    if (!entry.owner && row.owner) entry.owner = String(row.owner)
    entry.on.add(row.serverId)
  }

  const rows = [...byPermission.values()].map((e) => {
    const group = groupOf(e.permission, e.owner)
    const row = { value: e.permission, label: e.permission, group }
    if (e.on.size < names.size) {
      const where = enabled.filter((s) => e.on.has(s.id)).map((s) => names.get(s.id))
      row.note = `Only on ${where.join(', ')}`
    }
    return row
  })

  const fold = (s) => s.toLowerCase()
  rows.sort((a, b) => fold(a.group).localeCompare(fold(b.group)) || fold(a.value).localeCompare(fold(b.value)))
  return rows
}

const OPTION_SOURCES = [
  {
    id: 'rust.options.permissions',
    label: 'Permissions',
    description: "Every permission the enabled servers' plugins registered, grouped by plugin; one missing from a server says where it is.",
    async resolve() {
      const [catalogue, enabled] = await Promise.all([permDb.listCatalogue(), servers.listForPolling()])
      return bounded(permissionRows(catalogue, enabled), 'rust.options.permissions')
    },
  },
]

const ACTIONS = [permLend, permGive]

module.exports = {
  MAX_PERMISSIONS,
  SOURCE,
  BUDGETS,
  ACTIONS,
  OPTION_SOURCES,
  checkPermissions,
  checkConfirm,
  permNotice,
  permissionRows,
  grantNote,
}