"use client";

import { FormEvent, useState } from "react";
import { CreditCard, LockKeyhole } from "lucide-react";

type Subscription = {
  status: string;
  currentPeriodEnd: string | null;
  cancelAtPeriodEnd: boolean;
};

type Props = {
  setupIntentId: string;
  onComplete: (subscription: Subscription) => void;
  onCancel: () => void;
};

export function StripeCardForm({ setupIntentId, onComplete, onCancel }: Props) {
  const [cardholderName, setCardholderName] = useState("");
  const [cardNumber, setCardNumber] = useState("");
  const [expiration, setExpiration] = useState("");
  const [securityCode, setSecurityCode] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState("");

  async function submit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    const name = cardholderName.trim();
    if (!name) {
      setError("Enter the cardholder name.");
      return;
    }
    if (!/^\d{12,19}$/u.test(cardNumber.replace(/\s/gu, ""))) {
      setError("Enter a card number for the test simulation.");
      return;
    }
    if (!/^(0[1-9]|1[0-2])\s*\/\s*\d{2}$/u.test(expiration)) {
      setError("Enter the expiration date as MM / YY.");
      return;
    }
    if (!/^\d{3,4}$/u.test(securityCode)) {
      setError("Enter a 3 or 4 digit security code.");
      return;
    }
    setSubmitting(true);
    setError("");
    try {
      const response = await fetch("/api/billing/complete", {
        method: "POST",
        headers: { "content-type": "application/json" },
        body: JSON.stringify({ setupIntentId }),
      });
      const result = await response.json() as { subscription?: Subscription; error?: string };
      if (!response.ok || !result.subscription) throw new Error(result.error ?? "Unable to activate Premium.");
      onComplete(result.subscription);
    } catch (caught) {
      setError(caught instanceof Error ? caught.message : "Unable to verify this card.");
      setSubmitting(false);
    }
  }

  return (
    <form className="stripe-card-form" onSubmit={submit}>
      <div className="stripe-card-heading">
        <CreditCard size={19} />
        <div><b>Add a card</b><small>Stripe Test Mode</small></div>
      </div>
      <label className="stripe-card-label">
        <span>Cardholder name</span>
        <input
          autoComplete="cc-name"
          maxLength={100}
          value={cardholderName}
          onChange={(event) => setCardholderName(event.target.value)}
          placeholder="Name on card"
          required
        />
      </label>
      <label className="stripe-card-label">
        <span>Card number</span>
        <input
          autoComplete="off"
          inputMode="numeric"
          maxLength={23}
          value={cardNumber}
          onChange={(event) => setCardNumber(event.target.value.replace(/[^\d ]/gu, ""))}
          placeholder="1234 5678 9012 3456"
          required
        />
      </label>
      <div className="stripe-card-row">
        <label className="stripe-card-label">
          <span>Expiration date</span>
          <input
            autoComplete="off"
            inputMode="numeric"
            maxLength={7}
            value={expiration}
            onChange={(event) => setExpiration(event.target.value.replace(/[^\d /]/gu, ""))}
            placeholder="MM / YY"
            required
          />
        </label>
        <label className="stripe-card-label">
          <span>Security code</span>
          <input
            autoComplete="off"
            inputMode="numeric"
            maxLength={4}
            value={securityCode}
            onChange={(event) => setSecurityCode(event.target.value.replace(/\D/gu, ""))}
            placeholder="CVC"
            required
          />
        </label>
      </div>
      <p className="stripe-card-security"><LockKeyhole size={15} /> Test values stay in this browser and are never stored. Stripe receives its standard sandbox card token.</p>
      {error && <div className="form-error" role="alert">{error}</div>}
      <button className="button button-primary button-full" disabled={submitting} type="submit">
        <CreditCard size={18} /> {submitting ? "Verifying with Stripe…" : "Add card and subscribe"}
      </button>
      <button className="stripe-card-cancel" disabled={submitting} onClick={onCancel} type="button">Cancel</button>
    </form>
  );
}