/**
 * ContactForm.tsx
 * ---------------------------------------------------------------------------
 * Accessible contact form island. Posts to /api/contact, which either sends an
 * email via SMTP or fires a webhook. Manages idle / submitting / success / error
 * states, does lightweight client validation, and includes a honeypot field for
 * crude spam defense (the server also rate-limits).
 *
 * The form is keyboard-accessible, labels every field, and announces status
 * changes via an aria-live region.
 */
import { useState, type FormEvent } from 'react';

type Status = 'idle' | 'submitting' | 'success' | 'error';

interface FieldErrors {
  name?: string;
  email?: string;
  message?: string;
}

const EMAIL_RE = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;

export default function ContactForm() {
  const [status, setStatus] = useState<Status>('idle');
  const [errors, setErrors] = useState<FieldErrors>({});
  const [errorMsg, setErrorMsg] = useState<string>('');

  function validate(values: { name: string; email: string; message: string }): FieldErrors {
    const e: FieldErrors = {};
    if (!values.name.trim()) e.name = 'Please enter your name.';
    if (!values.email.trim()) e.email = 'Please enter your email.';
    else if (!EMAIL_RE.test(values.email)) e.email = 'That email address looks off.';
    if (!values.message.trim()) e.message = 'Please enter a message.';
    else if (values.message.trim().length < 10) e.message = 'A little more detail, please (10+ characters).';
    return e;
  }

  async function onSubmit(ev: FormEvent<HTMLFormElement>) {
    ev.preventDefault();
    const form = ev.currentTarget;
    const data = new FormData(form);
    const values = {
      name: String(data.get('name') ?? '').trim(),
      email: String(data.get('email') ?? '').trim(),
      message: String(data.get('message') ?? '').trim(),
      // Honeypot: bots fill this, humans never see it.
      company: String(data.get('company') ?? ''),
    };

    const found = validate(values);
    setErrors(found);
    if (Object.keys(found).length > 0) return;

    setStatus('submitting');
    setErrorMsg('');
    try {
      const res = await fetch('/api/contact', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(values),
      });
      const body = await res.json().catch(() => ({}));
      if (!res.ok) {
        throw new Error(body.error || 'Something went wrong. Please try again.');
      }
      setStatus('success');
      form.reset();
    } catch (err) {
      setStatus('error');
      setErrorMsg(err instanceof Error ? err.message : 'Something went wrong. Please try again.');
    }
  }

  const inputBase =
    'w-full rounded-lg border bg-transparent px-3 py-2.5 text-sm outline-none transition-colors focus:border-[var(--color-accent)]';
  const labelBase = 'mb-1.5 block font-sans text-sm font-medium';

  if (status === 'success') {
    return (
      <div
        className="flex flex-col items-center gap-3 rounded-xl border p-8 text-center"
        style={{ borderColor: 'var(--color-accent)', background: 'color-mix(in srgb, var(--color-accent) 8%, transparent)' }}
      >
        <span
          className="inline-flex h-12 w-12 items-center justify-center rounded-full"
          style={{ background: 'var(--color-accent)', color: 'var(--color-accent-contrast)' }}
          aria-hidden="true"
        >
          <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="3" strokeLinecap="round" strokeLinejoin="round">
            <path d="M20 6L9 17l-5-5" />
          </svg>
        </span>
        <h3 className="font-sans text-lg font-semibold" style={{ color: 'var(--color-text)' }}>
          Message sent.
        </h3>
        <p className="text-sm" style={{ color: 'var(--color-text-muted)' }}>
          Thanks for reaching out. I will get back to you soon.
        </p>
        <button
          type="button"
          onClick={() => setStatus('idle')}
          className="btn btn-secondary mt-2"
        >
          Send another
        </button>
      </div>
    );
  }

  return (
    <form onSubmit={onSubmit} noValidate className="flex flex-col gap-5">
      {/* Honeypot: visually hidden, not aria-hidden so screen readers can skip it. */}
      <div style={{ position: 'absolute', left: '-9999px', top: 'auto', width: 1, height: 1, overflow: 'hidden' }} aria-hidden="true">
        <label htmlFor="company">Company (leave blank)</label>
        <input id="company" name="company" type="text" tabIndex={-1} autoComplete="off" />
      </div>

      <div className="flex flex-col">
        <label htmlFor="name" className={labelBase} style={{ color: 'var(--color-text)' }}>Name</label>
        <input
          id="name"
          name="name"
          type="text"
          autoComplete="name"
          className={inputBase}
          style={{
            borderColor: errors.name ? 'var(--color-accent)' : 'var(--color-border)',
            color: 'var(--color-text)',
          }}
          aria-invalid={Boolean(errors.name)}
          aria-describedby={errors.name ? 'name-error' : undefined}
        />
        {errors.name && <p id="name-error" className="mt-1 text-xs" style={{ color: 'var(--color-accent)' }}>{errors.name}</p>}
      </div>

      <div className="flex flex-col">
        <label htmlFor="email" className={labelBase} style={{ color: 'var(--color-text)' }}>Email</label>
        <input
          id="email"
          name="email"
          type="email"
          autoComplete="email"
          className={inputBase}
          style={{
            borderColor: errors.email ? 'var(--color-accent)' : 'var(--color-border)',
            color: 'var(--color-text)',
          }}
          aria-invalid={Boolean(errors.email)}
          aria-describedby={errors.email ? 'email-error' : undefined}
        />
        {errors.email && <p id="email-error" className="mt-1 text-xs" style={{ color: 'var(--color-accent)' }}>{errors.email}</p>}
      </div>

      <div className="flex flex-col">
        <label htmlFor="message" className={labelBase} style={{ color: 'var(--color-text)' }}>Message</label>
        <textarea
          id="message"
          name="message"
          rows={5}
          className={inputBase}
          style={{
            borderColor: errors.message ? 'var(--color-accent)' : 'var(--color-border)',
            color: 'var(--color-text)',
            resize: 'vertical',
          }}
          aria-invalid={Boolean(errors.message)}
          aria-describedby={errors.message ? 'message-error' : undefined}
        />
        {errors.message && <p id="message-error" className="mt-1 text-xs" style={{ color: 'var(--color-accent)' }}>{errors.message}</p>}
      </div>

      {status === 'error' && (
        <p className="rounded-lg p-3 text-sm" style={{ background: 'color-mix(in srgb, var(--color-accent) 12%, transparent)', color: 'var(--color-accent)' }}>
          {errorMsg}
        </p>
      )}

      <button
        type="submit"
        disabled={status === 'submitting'}
        className="btn btn-primary self-start disabled:cursor-not-allowed disabled:opacity-60"
      >
        {status === 'submitting' ? 'Sending…' : 'Send message'}
      </button>

      {/* Screen-reader status announcements. */}
      <p className="sr-only" role="status" aria-live="polite">
        {status === 'submitting' ? 'Sending your message.' : ''}
      </p>
    </form>
  );
}