// ── Admin · Rust · Permissions ────────────────────────────────────────────
//
// R2's authoring surface, and this module's first admin page.
//
// **What is on it is decided by what an operator can get wrong**, rather than by
// what the tables contain. Four states are invisible from the game and from a
// list of grants, and every one of them looks exactly like success:
//
//   • a grant against somebody who has linked no Steam account — authored,
//     stored, pushed nowhere;
//   • a permission no loaded plugin has registered — the grant lands silently
//     nowhere, because `GrantUserPermission` no-ops for an unregistered name;
//   • a group member who has never connected — the store has no user record to
//     put in a group yet, and the membership waits for their first connection;
//   • a server whose last sync failed — the site is authoritative and the game
//     has not heard it.
//
// So each of those is a sentence on this page rather than a number in a report.
//
// The screen never writes to a game. Every button here writes to the site and
// the mirror's loop reconciles within seconds — except *Sync now*, which runs
// that pass immediately because an operator who has just changed something
// should not have to trust a timer to find out that a host is unreachable.

import { useCallback, useState } from 'react'

import { ErrorState, Loading, useAsync } from '../../core.js'
import { ago } from '../../lib/format.js'
import api from '../../api.js'

const FLEET = '*'

/** Shared furniture. The kit is nine exports and none of them is a table. */
function Card({ title, subtitle, children, actions }) {
  return (
    <section className="panel" style={{ padding: '16px 18px', marginBottom: 18 }}>
      <header style={{ display: 'flex', alignItems: 'baseline', gap: 12, marginBottom: 12 }}>
        <h2 className="display" style={{ fontSize: '1.05rem', margin: 0, color: 'var(--head)' }}>
          {title}
        </h2>
        {subtitle && (
          <span className="sans dim" style={{ fontSize: '0.76rem' }}>
            {subtitle}
          </span>
        )}
        <span style={{ flex: 1 }} />
        {actions}
      </header>
      {children}
    </section>
  )
}

function Row({ children, muted = false }) {
  return (
    <div
      className="sans"
      style={{
        display: 'flex',
        alignItems: 'center',
        gap: 10,
        padding: '8px 0',
        borderTop: '1px solid var(--line-soft)',
        fontSize: '0.86rem',
        color: muted ? 'var(--ink)' : 'var(--head)',
      }}
    >
      {children}
    </div>
  )
}

function Warn({ children }) {
  return (
    <p className="sans" style={{ color: '#d08a2a', fontSize: '0.78rem', margin: '6px 0 0' }}>
      {children}
    </p>
  )
}

function Scope({ value }) {
  return (
    <span className="sans dim" style={{ fontSize: '0.74rem' }}>
      {value === FLEET ? 'every server' : value}
    </span>
  )
}

/**
 * One server's mirror state.
 *
 * `unresolved` and `pending` are rendered as sentences rather than counts
 * because each is a different problem with a different fix, and both are
 * invisible everywhere else on this page.
 */
function ServerState({ row, onSync, busy }) {
  const report = row.report || {}
  const unresolved = report.unresolved || []
  const pending = report.pending || []

  return (
    <div style={{ padding: '10px 0', borderTop: '1px solid var(--line-soft)' }}>
      <div style={{ display: 'flex', alignItems: 'center', gap: 10 }}>
        <span className="sans" style={{ color: 'var(--head)', fontSize: '0.9rem' }}>
          {row.serverId}
        </span>
        <span
          className="sans"
          style={{ fontSize: '0.76rem', color: row.inSync ? 'var(--ink)' : '#d08a2a' }}
        >
          {row.inSync ? 'in sync' : row.state === 'failed' ? 'out of sync' : 'pending'}
        </span>
        <span className="sans dim" style={{ fontSize: '0.74rem' }}>
          {row.lastOkAt ? `last pushed ${ago(row.lastOkAt)}` : 'never pushed'}
        </span>
        <span style={{ flex: 1 }} />
        <button type="button" className="btn btn-ghost" onClick={() => onSync(row.serverId)} disabled={busy}>
          {busy ? 'Syncing…' : 'Sync now'}
        </button>
      </div>

      {row.error && (
        <p className="sans" style={{ color: '#e05a5a', fontSize: '0.78rem', margin: '4px 0 0' }}>
          {row.error}
        </p>
      )}

      {unresolved.length > 0 && (
        <Warn>
          {unresolved.join(', ')} — no plugin loaded on this server has registered{' '}
          {unresolved.length === 1 ? 'that name' : 'those names'}, so a grant naming{' '}
          {unresolved.length === 1 ? 'it' : 'them'} reaches nobody here. It will land by itself when
          the plugin is back.
        </Warn>
      )}

      {pending.length > 0 && (
        <Warn>
          {pending.length} {pending.length === 1 ? 'membership is' : 'memberships are'} waiting on a
          first connection — this server has never seen those players, so it has no account to put
          in a group yet.
        </Warn>
      )}
    </div>
  )
}

/** A hand edit, with the two answers to it. */
function DriftRow({ row, onAdopt, onRevoke, busy }) {
  const subject = row.username ? `${row.username} (${row.subject})` : row.subject

  return (
    <Row>
      <span style={{ minWidth: 0, flex: 1 }}>
        <strong style={{ fontWeight: 500 }}>{row.object}</strong>{' '}
        <span className="dim" style={{ fontSize: '0.78rem' }}>
          {row.kind === 'group-permission' ? `on group ${row.subject}` : `held by ${subject}`} ·{' '}
          {row.serverId} · seen {ago(row.firstSeen)}
        </span>
      </span>
      <button type="button" className="btn btn-ghost" onClick={() => onAdopt(row)} disabled={busy}>
        Adopt
      </button>
      <button type="button" className="btn btn-ghost" onClick={() => onRevoke(row)} disabled={busy}>
        Revoke
      </button>
    </Row>
  )
}

/**
 * The memberships the game could not place yet, as `steamId:group`.
 *
 * Read out of each server's own report, because it is the only thing that knows:
 * a member who has never connected to a server has no user record there to put
 * in a group (§12.2 rule 4), and from every other angle they look like a member.
 * The server strip says how many; this is what puts it next to the person.
 */
function pendingSet(servers) {
  const pending = new Map()

  for (const server of servers) {
    for (const entry of (server.report && server.report.pending) || []) {
      if (!pending.has(entry)) pending.set(entry, [])
      pending.get(entry).push(server.serverId)
    }
  }

  return pending
}

function GroupCard({ group, catalogue, servers, pending, onChanged, setError }) {
  const [busy, setBusy] = useState(false)
  const [member, setMember] = useState('')
  const [permission, setPermission] = useState('')

  const act = async (fn) => {
    setBusy(true)
    setError('')
    try {
      await fn()
      await onChanged()
    } catch (err) {
      setError(err.message || 'That did not work.')
    } finally {
      setBusy(false)
    }
  }

  const save = (permissions) =>
    act(() =>
      api.adminPermissions.saveGroup(group.name, {
        title: group.title,
        rank: group.rank,
        scope: group.scope,
        permissions,
      }),
    )

  return (
    <Card
      title={group.title || group.name}
      subtitle={<>{group.name} · <Scope value={group.scope} /></>}
      actions={
        <button
          type="button"
          className="btn btn-ghost"
          disabled={busy}
          onClick={() => act(() => api.adminPermissions.deleteGroup(group.name))}
        >
          Delete
        </button>
      }
    >
      <div className="field-label">Permissions</div>
      {group.permissions.length === 0 && (
        <p className="sans dim" style={{ fontSize: '0.8rem', margin: '4px 0' }}>
          This group carries nothing, so being in it does nothing.
        </p>
      )}
      {group.permissions.map((perm) => (
        <Row key={perm}>
          <span style={{ flex: 1 }}>{perm}</span>
          {!catalogue.some((entry) => entry.permission === perm) && (
            <span className="sans" style={{ color: '#d08a2a', fontSize: '0.74rem' }}>
              no server has registered this
            </span>
          )}
          <button
            type="button"
            className="btn btn-ghost"
            disabled={busy}
            onClick={() => save(group.permissions.filter((p) => p !== perm))}
          >
            Remove
          </button>
        </Row>
      ))}

      <form
        style={{ display: 'flex', gap: 8, marginTop: 10 }}
        onSubmit={(event) => {
          event.preventDefault()
          if (!permission.trim()) return
          save([...group.permissions, permission.trim().toLowerCase()])
          setPermission('')
        }}
      >
        <input
          list="rust-permission-names"
          className="input"
          placeholder="kits.vip"
          value={permission}
          onChange={(event) => setPermission(event.target.value)}
          style={{ flex: 1 }}
        />
        <button type="submit" className="btn" disabled={busy}>
          Add permission
        </button>
      </form>

      <div className="field-label" style={{ marginTop: 18 }}>
        Members
      </div>
      {group.members.length === 0 && (
        <p className="sans dim" style={{ fontSize: '0.8rem', margin: '4px 0' }}>
          Nobody is in this group.
        </p>
      )}
      {group.members.map((m) => {
        const waiting = m.accounts
          .map((account) => pending.get(`${account.steamId}:${group.name}`))
          .filter(Boolean)
          .flat()

        return (
        <Row key={m.userId}>
          <span style={{ flex: 1 }}>
            {m.username}
            {m.accounts.length > 0 ? (
              <span className="dim" style={{ fontSize: '0.76rem' }}>
                {' '}
                · {m.accounts.map((a) => a.name || a.steamId).join(', ')}
              </span>
            ) : (
              <span style={{ color: '#d08a2a', fontSize: '0.76rem' }}>
                {' '}
                · has linked no Steam account, so this reaches nobody
              </span>
            )}
            {waiting.length > 0 && (
              <span style={{ color: '#d08a2a', fontSize: '0.76rem' }}>
                {' '}
                · waiting on their first connection to {[...new Set(waiting)].join(', ')}
              </span>
            )}
          </span>
          <button
            type="button"
            className="btn btn-ghost"
            disabled={busy}
            onClick={() => act(() => api.adminPermissions.removeMember(group.name, m.userId))}
          >
            Remove
          </button>
        </Row>
        )
      })}

      <form
        style={{ display: 'flex', gap: 8, marginTop: 10 }}
        onSubmit={(event) => {
          event.preventDefault()
          if (!member.trim()) return
          act(() => api.adminPermissions.addMember(group.name, member.trim()))
          setMember('')
        }}
      >
        <input
          className="input"
          placeholder="website username"
          value={member}
          onChange={(event) => setMember(event.target.value)}
          style={{ flex: 1 }}
        />
        <button type="submit" className="btn" disabled={busy}>
          Add member
        </button>
      </form>

      {servers.length > 1 && group.scope !== FLEET && (
        <p className="sans dim" style={{ fontSize: '0.74rem', margin: '10px 0 0' }}>
          This group exists on {group.scope} only. The other servers never receive it.
        </p>
      )}
    </Card>
  )
}

export default function Permissions() {
  const [reloads, setReloads] = useState(0)
  const [busy, setBusy] = useState(false)
  const [error, setError] = useState('')
  const [form, setForm] = useState({ name: '', title: '', scope: FLEET })
  const [grant, setGrant] = useState({ username: '', permission: '', scope: FLEET })

  const { data, error: loadError } = useAsync(() => api.adminPermissions.overview(), [reloads])
  const reload = useCallback(() => setReloads((n) => n + 1), [])

  const act = async (fn) => {
    setBusy(true)
    setError('')
    try {
      await fn()
      reload()
    } catch (err) {
      setError(err.message || 'That did not work.')
    } finally {
      setBusy(false)
    }
  }

  if (loadError) return <ErrorState error={loadError} />
  if (!data) return <Loading />

  const servers = data.servers || []

  return (
    <div style={{ maxWidth: 900 }}>
      {/* No heading of our own: core's admin chrome already draws the route's
          title above the page, and a second one is the same words twice. */}
      <p className="sans dim" style={{ fontSize: '0.82rem', marginTop: 0 }}>
        This site is the author of record. Groups and grants written here are pushed into each
        server’s own permission store, so every plugin that checks a permission honours them — and a
        wipe does not lose them, because they are re-pushed when the server comes back.
      </p>

      {/* The option source, shared by both forms. A datalist rather than a select:
          a name that no server has registered is still authorable — the plugin
          may simply not be loaded right now — and the warning beside it is the
          honest treatment, where a closed list would be a refusal. */}
      <datalist id="rust-permission-names">
        {(data.catalogue || []).map((entry) => (
          <option key={entry.permission} value={entry.permission} />
        ))}
      </datalist>

      {error && (
        <p className="sans" style={{ color: '#e05a5a', fontSize: '0.84rem' }}>
          {error}
        </p>
      )}

      <Card
        title="Servers"
        subtitle={`${servers.length} configured`}
        actions={
          <button type="button" className="btn btn-ghost" disabled={busy} onClick={() => act(() => api.adminPermissions.sync())}>
            Sync all
          </button>
        }
      >
        {servers.length === 0 && (
          <p className="sans dim" style={{ fontSize: '0.82rem', margin: 0 }}>
            No servers are configured yet, so nothing written here reaches a game.
          </p>
        )}
        {servers.map((row) => (
          <ServerState
            key={row.serverId}
            row={row}
            busy={busy}
            onSync={(id) => act(() => api.adminPermissions.sync(id))}
          />
        ))}
      </Card>

      {(data.drift || []).length > 0 && (
        <Card
          title="Changed in game"
          subtitle="granted at a console, not by this site"
        >
          <p className="sans dim" style={{ fontSize: '0.8rem', marginTop: 0 }}>
            Nothing here is undone automatically. <strong>Adopt</strong> records it as the site’s
            own, so it survives the next wipe; <strong>Revoke</strong> removes it from the game on
            the next sync.
          </p>
          {data.drift.map((row) => (
            <DriftRow
              key={row.id}
              row={row}
              busy={busy}
              onAdopt={(d) => act(() => api.adminPermissions.adoptDrift(d.id))}
              onRevoke={(d) => act(() => api.adminPermissions.revokeDrift(d.id))}
            />
          ))}
        </Card>
      )}

      <Card title="Direct grants" subtitle="one person, one permission">
        {(data.grants || []).length === 0 && (
          <p className="sans dim" style={{ fontSize: '0.82rem', margin: 0 }}>
            Nobody holds a permission of their own yet.
          </p>
        )}
        {(data.grants || []).map((row) => (
          <Row key={row.id}>
            <span style={{ flex: 1 }}>
              {row.username} · <strong style={{ fontWeight: 500 }}>{row.permission}</strong>{' '}
              <Scope value={row.scope} />
              {row.accounts.length === 0 && (
                <span style={{ color: '#d08a2a', fontSize: '0.76rem' }}>
                  {' '}
                  · has linked no Steam account, so this reaches nobody
                </span>
              )}
              {/* The same warning the group's permission list carries, and it
                  matters more here: a grant naming a permission nothing has
                  registered is the failure the plugin's pre-check exists for,
                  and it is invisible on this row without it. */}
              {!(data.catalogue || []).some((entry) => entry.permission === row.permission) && (
                <span style={{ color: '#d08a2a', fontSize: '0.76rem' }}>
                  {' '}
                  · no server has registered this permission
                </span>
              )}
              {row.source !== 'admin' && (
                <span className="dim" style={{ fontSize: '0.74rem' }}> · {row.source}</span>
              )}
            </span>
            <button
              type="button"
              className="btn btn-ghost"
              disabled={busy}
              onClick={() => act(() => api.adminPermissions.revoke(row.id))}
            >
              Remove
            </button>
          </Row>
        ))}

        <form
          style={{ display: 'flex', gap: 8, marginTop: 12, flexWrap: 'wrap' }}
          onSubmit={(event) => {
            event.preventDefault()
            if (!grant.username.trim() || !grant.permission.trim()) return
            act(() =>
              api.adminPermissions.grant({
                username: grant.username.trim(),
                permission: grant.permission.trim().toLowerCase(),
                scope: grant.scope,
              }),
            )
            setGrant({ username: '', permission: '', scope: FLEET })
          }}
        >
          <input
            className="input"
            placeholder="website username"
            value={grant.username}
            onChange={(event) => setGrant({ ...grant, username: event.target.value })}
            style={{ flex: '1 1 160px' }}
          />
          <input
            list="rust-permission-names"
            className="input"
            placeholder="kits.vip"
            value={grant.permission}
            onChange={(event) => setGrant({ ...grant, permission: event.target.value })}
            style={{ flex: '1 1 160px' }}
          />
          <select
            className="input"
            value={grant.scope}
            onChange={(event) => setGrant({ ...grant, scope: event.target.value })}
          >
            <option value={FLEET}>every server</option>
            {servers.map((row) => (
              <option key={row.serverId} value={row.serverId}>
                {row.serverId}
              </option>
            ))}
          </select>
          <button type="submit" className="btn" disabled={busy}>
            Grant
          </button>
        </form>
      </Card>

      {(data.groups || []).map((group) => (
        <GroupCard
          key={group.name}
          group={group}
          catalogue={data.catalogue || []}
          servers={servers}
          pending={pendingSet(servers)}
          onChanged={reload}
          setError={setError}
        />
      ))}

      <Card title="New group">
        <form
          style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}
          onSubmit={(event) => {
            event.preventDefault()
            if (!form.name.trim()) return
            act(() =>
              api.adminPermissions.saveGroup(form.name.trim().toLowerCase(), {
                title: form.title.trim() || form.name.trim(),
                scope: form.scope,
                permissions: [],
              }),
            )
            setForm({ name: '', title: '', scope: FLEET })
          }}
        >
          <input
            className="input"
            placeholder="vip"
            value={form.name}
            onChange={(event) => setForm({ ...form, name: event.target.value })}
            style={{ flex: '1 1 140px' }}
          />
          <input
            className="input"
            placeholder="VIP"
            value={form.title}
            onChange={(event) => setForm({ ...form, title: event.target.value })}
            style={{ flex: '1 1 140px' }}
          />
          <select
            className="input"
            value={form.scope}
            onChange={(event) => setForm({ ...form, scope: event.target.value })}
          >
            <option value={FLEET}>every server</option>
            {servers.map((row) => (
              <option key={row.serverId} value={row.serverId}>
                {row.serverId}
              </option>
            ))}
          </select>
          <button type="submit" className="btn" disabled={busy}>
            Create
          </button>
        </form>
        <p className="sans dim" style={{ fontSize: '0.74rem', margin: '10px 0 0' }}>
          A group is created in each in-scope game as a real group, so plugins that read group
          membership see it. A member who has never connected to a server joins it there on their
          first connection — a direct grant reaches them straight away, which is the difference
          worth knowing when somebody is waiting.
        </p>
      </Card>
    </div>
  )
}