Add login page visibility controls

frontend/app/login/page.tsx

@@ -1,19 +1,36 @@
 'use client'
 
 import { useRouter } from 'next/navigation'
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 import { getApiBase, setToken, clearToken } from '../lib/auth'
 import BrandingLogo from '../ui/BrandingLogo'
 
+const DEFAULT_LOGIN_OPTIONS = {
+  showJellyfinLogin: true,
+  showLocalLogin: true,
+  showForgotPassword: true,
+  showSignupLink: true,
+}
+
 export default function LoginPage() {
   const router = useRouter()
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')
   const [error, setError] = useState<string | null>(null)
   const [loading, setLoading] = useState(false)
+  const [loginOptions, setLoginOptions] = useState(DEFAULT_LOGIN_OPTIONS)
+  const primaryMode: 'jellyfin' | 'local' | null = loginOptions.showJellyfinLogin
+    ? 'jellyfin'
+    : loginOptions.showLocalLogin
+      ? 'local'
+      : null
 
   const submit = async (event: React.FormEvent, mode: 'local' | 'jellyfin') => {
     event.preventDefault()
+    if (!primaryMode) {
+      setError('Login is currently disabled. Contact an administrator.')
+      return
+    }
     setError(null)
     setLoading(true)
     try {
@@ -48,12 +65,63 @@ export default function LoginPage() {
     }
   }
 
+  useEffect(() => {
+    let active = true
+    const loadLoginOptions = async () => {
+      try {
+        const baseUrl = getApiBase()
+        const response = await fetch(`${baseUrl}/site/public`)
+        if (!response.ok) {
+          return
+        }
+        const data = await response.json()
+        const login = data?.login ?? {}
+        if (!active) return
+        setLoginOptions({
+          showJellyfinLogin: login.showJellyfinLogin !== false,
+          showLocalLogin: login.showLocalLogin !== false,
+          showForgotPassword: login.showForgotPassword !== false,
+          showSignupLink: login.showSignupLink !== false,
+        })
+      } catch (err) {
+        console.error(err)
+      }
+    }
+    void loadLoginOptions()
+    return () => {
+      active = false
+    }
+  }, [])
+
+  const loginHelpText = (() => {
+    if (loginOptions.showJellyfinLogin && loginOptions.showLocalLogin) {
+      return 'Use your Jellyfin account, or sign in with a local Magent admin account.'
+    }
+    if (loginOptions.showJellyfinLogin) {
+      return 'Use your Jellyfin account to sign in.'
+    }
+    if (loginOptions.showLocalLogin) {
+      return 'Use your local Magent admin account to sign in.'
+    }
+    return 'No sign-in methods are currently available. Contact an administrator.'
+  })()
+
   return (
     <main className="card auth-card">
       <BrandingLogo className="brand-logo brand-logo--login" />
       <h1>Sign in</h1>
-      <p className="lede">Use your Jellyfin account, or sign in with a local Magent admin account.</p>
-      <form onSubmit={(event) => submit(event, 'jellyfin')} className="auth-form">
+      <p className="lede">{loginHelpText}</p>
+      <form
+        onSubmit={(event) => {
+          if (!primaryMode) {
+            event.preventDefault()
+            setError('Login is currently disabled. Contact an administrator.')
+            return
+          }
+          void submit(event, primaryMode)
+        }}
+        className="auth-form"
+      >
         <label>
           Username
           <input
@@ -73,24 +141,35 @@ export default function LoginPage() {
         </label>
         {error && <div className="error-banner">{error}</div>}
         <div className="auth-actions">
-          <button type="submit" disabled={loading}>
-            {loading ? 'Signing in...' : 'Login with Jellyfin account'}
-          </button>
+          {loginOptions.showJellyfinLogin ? (
+            <button type="submit" disabled={loading}>
+              {loading ? 'Signing in...' : 'Login with Jellyfin account'}
+            </button>
+          ) : null}
         </div>
-        <button
-          type="button"
-          className="ghost-button"
-          disabled={loading}
-          onClick={(event) => submit(event, 'local')}
-        >
-          Sign in with Magent account
-        </button>
-        <a className="ghost-button" href="/forgot-password">
-          Forgot password?
-        </a>
-        <a className="ghost-button" href="/signup">
-          Have an invite? Create your account (Jellyfin + Magent)
-        </a>
+        {loginOptions.showLocalLogin ? (
+          <button
+            type="button"
+            className="ghost-button"
+            disabled={loading}
+            onClick={(event) => submit(event, 'local')}
+          >
+            Sign in with Magent account
+          </button>
+        ) : null}
+        {loginOptions.showForgotPassword ? (
+          <a className="ghost-button" href="/forgot-password">
+            Forgot password?
+          </a>
+        ) : null}
+        {loginOptions.showSignupLink ? (
+          <a className="ghost-button" href="/signup">
+            Have an invite? Create your account (Jellyfin + Magent)
+          </a>
+        ) : null}
+        {!loginOptions.showJellyfinLogin && !loginOptions.showLocalLogin ? (
+          <div className="error-banner">Login is currently disabled. Contact an administrator.</div>
+        ) : null}
       </form>
     </main>
   )