Inverted newsletter band

'use client'

import { useState, type FormEvent } from 'react'
import { Container } from '@/components/ui/layout'
import { Button } from '@/components/ui/button'
import { Field } from '@/components/ui/field'
import { Input } from '@/components/ui/input'

/**
 * Inverted newsletter band
 *
 * A full-bleed dark band used as page punctuation. Because the surrounding
 * surface is inverted, the input keeps its own light surface rather than
 * inheriting — a transparent field on a dark band is where contrast failures
 * usually appear.
 */
export default function InvertedBandNewsletter() {
  const [email, setEmail] = useState('')
  const [error, setError] = useState<string | null>(null)
  const [done, setDone] = useState(false)

  const submit = (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    const value = email.trim()
    if (!value) return setError('Enter an email address.')
    if (!/^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/.test(value)) {
      return setError('Enter a valid email address, for example name@company.com.')
    }
    setError(null)
    setDone(true)
  }

  return (
    <section className="bg-surface-inverse py-section text-ink-inverse">
      <Container size="narrow" className="text-center">
        <h2 className="display-type text-2xl leading-tight font-semibold sm:text-3xl">
          Release notes, roughly monthly.
        </h2>
        <p className="mx-auto mt-3 max-w-md text-md opacity-80">
          Written by the people who made the change, not by marketing.
        </p>

        {done ? (
          <p
            role="status"
            className="mx-auto mt-8 max-w-md rounded-lg border border-white/20 bg-white/10 px-4 py-3 text-sm"
          >
            Subscribed. This is a template demo — no submission was sent.
          </p>
        ) : (
          <form
            onSubmit={submit}
            noValidate
            className="mx-auto mt-8 flex max-w-md flex-col gap-3 sm:flex-row sm:items-start"
          >
            <Field
              name="newsletter-inverted"
              label="Email address"
              hideLabel
              error={error}
              className="flex-1 text-left [&_p]:text-danger"
            >
              {(field) => (
                <Input
                  {...field}
                  type="email"
                  autoComplete="email"
                  placeholder="you@company.com"
                  value={email}
                  onChange={(event) => {
                    setEmail(event.target.value)
                    if (error) setError(null)
                  }}
                />
              )}
            </Field>
            <Button type="submit" variant="secondary" className="shrink-0">
              Subscribe
            </Button>
          </form>
        )}

        <p className="mt-4 text-xs opacity-60">One click to unsubscribe. No tracking pixels.</p>
      </Container>
    </section>
  )
}

import type { ReactNode } from 'react'
import { AlertCircle, CheckCircle2 } from 'lucide-react'
import { cn } from '@/lib/cn'

/**
 * Field
 *
 * The accessibility contract for every form control in Foundry lives here, in
 * one place, rather than being re-implemented per input.
 *
 * Ids are derived deterministically from `name` instead of `useId`, for two
 * reasons: the component stays renderable from a Server Component (no hooks),
 * and the markup is byte-identical between server and client, so a form works
 * before hydration — see `/docs/accessibility`.
 *
 * The render prop hands back the exact wiring a control needs, which makes it
 * impossible to forget `aria-describedby` on a field that has help text.
 */
export interface FieldRenderProps {
  id: string
  name: string
  'aria-describedby': string | undefined
  'aria-invalid': true | undefined
  'aria-required': true | undefined
  required: boolean
  invalid: boolean
}

export interface FieldProps {
  name: string
  label: ReactNode
  hint?: ReactNode
  /** Validation failure. Presence flips the field into its invalid state. */
  error?: string | null
  /** Confirmation message shown once a value has validated. */
  success?: string | null
  required?: boolean
  /** Marks the field "Optional" instead of marking required fields. */
  showOptional?: boolean
  /** Visually hides the label while keeping it available to screen readers. */
  hideLabel?: boolean
  className?: string
  /** Disambiguates ids when the same field name appears twice on one page. */
  idPrefix?: string
  children: (props: FieldRenderProps) => ReactNode
}

export function Field({
  name,
  label,
  hint,
  error,
  success,
  required = false,
  showOptional = false,
  hideLabel = false,
  className,
  idPrefix = 'field',
  children,
}: FieldProps) {
  const id = `${idPrefix}-${name}`
  const hintId = hint ? `${id}-hint` : undefined
  const errorId = error ? `${id}-error` : undefined
  const successId = success && !error ? `${id}-success` : undefined
  const describedBy = [hintId, errorId, successId].filter(Boolean).join(' ') || undefined

  return (
    <div className={cn('flex flex-col gap-1.5', className)}>
      <label
        htmlFor={id}
        className={cn(
          'flex items-baseline gap-1.5 text-sm font-medium text-ink',
          hideLabel && 'sr-only',
        )}
      >
        <span>{label}</span>
        {required && !showOptional ? (
          <span className="text-danger" aria-hidden="true">
            *
          </span>
        ) : null}
        {showOptional && !required ? (
          <span className="text-xs font-normal text-ink-subtle">Optional</span>
        ) : null}
      </label>

      {hint ? (
        <p id={hintId} className="text-xs leading-normal text-ink-muted">
          {hint}
        </p>
      ) : null}

      {children({
        id,
        name,
        'aria-describedby': describedBy,
        'aria-invalid': error ? true : undefined,
        'aria-required': required || undefined,
        required,
        invalid: Boolean(error),
      })}

      {error ? (
        <p id={errorId} className="flex items-start gap-1.5 text-xs font-medium text-danger">
          <AlertCircle className="mt-px size-3.5 shrink-0" aria-hidden="true" />
          <span>{error}</span>
        </p>
      ) : null}

      {success && !error ? (
        <p id={successId} className="flex items-start gap-1.5 text-xs font-medium text-success">
          <CheckCircle2 className="mt-px size-3.5 shrink-0" aria-hidden="true" />
          <span>{success}</span>
        </p>
      ) : null}
    </div>
  )
}

/** Groups related controls (radios, checkboxes) with a shared legend. */
export interface FieldsetProps {
  legend: ReactNode
  hint?: ReactNode
  error?: string | null
  name: string
  required?: boolean
  className?: string
  children: ReactNode
  idPrefix?: string
}

export function Fieldset({
  legend,
  hint,
  error,
  name,
  required = false,
  className,
  children,
  idPrefix = 'group',
}: FieldsetProps) {
  const id = `${idPrefix}-${name}`
  const hintId = hint ? `${id}-hint` : undefined
  const errorId = error ? `${id}-error` : undefined
  const describedBy = [hintId, errorId].filter(Boolean).join(' ') || undefined

  return (
    <fieldset
      className={cn('flex min-w-0 flex-col gap-2', className)}
      aria-describedby={describedBy}
      aria-invalid={error ? true : undefined}
      aria-required={required || undefined}
    >
      <legend className="flex items-baseline gap-1.5 text-sm font-medium text-ink">
        <span>{legend}</span>
        {required ? (
          <span className="text-danger" aria-hidden="true">
            *
          </span>
        ) : null}
      </legend>
      {hint ? (
        <p id={hintId} className="text-xs text-ink-muted">
          {hint}
        </p>
      ) : null}
      {children}
      {error ? (
        <p id={errorId} className="flex items-start gap-1.5 text-xs font-medium text-danger">
          <AlertCircle className="mt-px size-3.5 shrink-0" aria-hidden="true" />
          <span>{error}</span>
        </p>
      ) : null}
    </fieldset>
  )
}