"use client";

import { useState } from "react";
import { Button } from "./Button";

interface FormState {
  name: string;
  email: string;
  phone: string;
  message: string;
}

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

export function ContactForm() {
  const [form, setForm] = useState<FormState>({
    name: "",
    email: "",
    phone: "",
    message: "",
  });
  const [errors, setErrors] = useState<FormErrors>({});
  const [submitted, setSubmitted] = useState(false);

  function validate(): FormErrors {
    const newErrors: FormErrors = {};
    if (!form.name.trim()) newErrors.name = "Bitte geben Sie Ihren Namen ein.";
    if (!form.email.trim()) {
      newErrors.email = "Bitte geben Sie Ihre E-Mail-Adresse ein.";
    } else if (!/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(form.email)) {
      newErrors.email = "Bitte geben Sie eine gültige E-Mail-Adresse ein.";
    }
    if (!form.message.trim())
      newErrors.message = "Bitte geben Sie eine Nachricht ein.";
    return newErrors;
  }

  function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    const newErrors = validate();
    setErrors(newErrors);
    if (Object.keys(newErrors).length === 0) {
      setSubmitted(true);
    }
  }

  function handleChange(
    e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement>
  ) {
    const { name, value } = e.target;
    setForm((prev) => ({ ...prev, [name]: value }));
    if (errors[name as keyof FormErrors]) {
      setErrors((prev) => ({ ...prev, [name]: undefined }));
    }
  }

  if (submitted) {
    return (
      <div
        className="border border-success p-8 text-center"
        style={{ borderRadius: "var(--radius-md)" }}
        role="status"
        aria-live="polite"
      >
        <p className="text-lg font-bold mb-2">Vielen Dank für Ihre Nachricht!</p>
        <p className="text-muted">
          Wir werden uns so schnell wie möglich bei Ihnen melden.
        </p>
      </div>
    );
  }

  return (
    <form onSubmit={handleSubmit} noValidate className="space-y-6">
      <div>
        <label htmlFor="contact-name" className="block text-sm font-medium mb-1.5">
          Name <span aria-hidden="true">*</span>
        </label>
        <input
          id="contact-name"
          name="name"
          type="text"
          autoComplete="name"
          aria-required="true"
          aria-invalid={!!errors.name}
          aria-describedby={errors.name ? "name-error" : undefined}
          value={form.name}
          onChange={handleChange}
          className="w-full border border-border px-4 py-3 text-sm bg-background text-foreground transition-colors focus:border-primary focus:outline-none"
          style={{ borderRadius: "var(--radius-sm)" }}
        />
        {errors.name && (
          <p id="name-error" className="mt-1.5 text-sm text-error" role="alert">
            {errors.name}
          </p>
        )}
      </div>

      <div>
        <label htmlFor="contact-email" className="block text-sm font-medium mb-1.5">
          E-Mail <span aria-hidden="true">*</span>
        </label>
        <input
          id="contact-email"
          name="email"
          type="email"
          autoComplete="email"
          aria-required="true"
          aria-invalid={!!errors.email}
          aria-describedby={errors.email ? "email-error" : undefined}
          value={form.email}
          onChange={handleChange}
          className="w-full border border-border px-4 py-3 text-sm bg-background text-foreground transition-colors focus:border-primary focus:outline-none"
          style={{ borderRadius: "var(--radius-sm)" }}
        />
        {errors.email && (
          <p id="email-error" className="mt-1.5 text-sm text-error" role="alert">
            {errors.email}
          </p>
        )}
      </div>

      <div>
        <label htmlFor="contact-phone" className="block text-sm font-medium mb-1.5">
          Telefon
        </label>
        <input
          id="contact-phone"
          name="phone"
          type="tel"
          autoComplete="tel"
          value={form.phone}
          onChange={handleChange}
          className="w-full border border-border px-4 py-3 text-sm bg-background text-foreground transition-colors focus:border-primary focus:outline-none"
          style={{ borderRadius: "var(--radius-sm)" }}
        />
      </div>

      <div>
        <label htmlFor="contact-message" className="block text-sm font-medium mb-1.5">
          Nachricht <span aria-hidden="true">*</span>
        </label>
        <textarea
          id="contact-message"
          name="message"
          rows={5}
          aria-required="true"
          aria-invalid={!!errors.message}
          aria-describedby={errors.message ? "message-error" : undefined}
          value={form.message}
          onChange={handleChange}
          className="w-full border border-border px-4 py-3 text-sm bg-background text-foreground transition-colors focus:border-primary focus:outline-none resize-y"
          style={{ borderRadius: "var(--radius-sm)" }}
        />
        {errors.message && (
          <p id="message-error" className="mt-1.5 text-sm text-error" role="alert">
            {errors.message}
          </p>
        )}
      </div>

      <Button type="submit" variant="primary">
        Nachricht senden
      </Button>
    </form>
  );
}