"use client";

import { useEffect, useState } from "react";
import { Check, CreditCard, ExternalLink, ShieldCheck, Sparkles } from "lucide-react";
import { StripeCardForm } from "@/components/StripeCardForm";

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

export function PremiumView() {
  const [subscription, setSubscription] = useState<Subscription>(null);
  const [billingAvailable, setBillingAvailable] = useState(true);
  const [billingMode, setBillingMode] = useState("stripe-test");
  const [loading, setLoading] = useState(true);
  const [action, setAction] = useState<"checkout" | "portal" | null>(null);
  const [error, setError] = useState("");
  const [cardSetup, setCardSetup] = useState<{ setupIntentId: string } | null>(null);

  useEffect(() => {
    fetch("/api/billing/subscription")
      .then(async (response) => {
        if (response.status === 401) return;
        const result = await response.json() as { subscription?: Subscription; billingAvailable?: boolean; mode?: string; error?: string };
        if (!response.ok) throw new Error(result.error ?? "Unable to load billing.");
        setSubscription(result.subscription ?? null);
        setBillingAvailable(result.billingAvailable !== false);
        setBillingMode(result.mode ?? "stripe-test");
      })
      .catch((caught: unknown) => setError(caught instanceof Error ? caught.message : "Unable to load billing."))
      .finally(() => setLoading(false));
  }, []);

  async function openBilling(endpoint: "checkout" | "portal") {
    setAction(endpoint);
    setError("");
    try {
      const response = await fetch(`/api/billing/${endpoint}`, {
        method: "POST",
        headers: { "content-type": "application/json" },
        body: "{}",
      });
      const result = await response.json() as { url?: string; setupIntentId?: string; error?: string };
      if (!response.ok) throw new Error(result.error ?? "Unable to open Stripe.");
      if (endpoint === "checkout") {
        if (!result.setupIntentId) throw new Error("Stripe did not prepare the test card simulation.");
        setCardSetup({ setupIntentId: result.setupIntentId });
        setAction(null);
      } else {
        if (!result.url) throw new Error("Unable to open Stripe.");
        window.location.assign(result.url);
      }
    } catch (caught) {
      setError(caught instanceof Error ? caught.message : "Unable to open Stripe.");
      setAction(null);
    }
  }

  const active = subscription && ["active", "trialing"].includes(subscription.status);

  return (
    <div className="premium-page">
      <header className="premium-header">
        <div>
          <span className="premium-kicker"><Sparkles size={17} /> LinkedIn Premium</span>
          <h1>More signal for your professional work</h1>
          <p>Advanced discovery and profile tools with secure Stripe Test Mode billing.</p>
        </div>
        <div className="premium-trust"><ShieldCheck size={21} /><span><b>Stripe Test Mode</b> Test values stay in your browser while Stripe binds its standard sandbox card to this account.</span></div>
      </header>

      <section className="premium-plan" aria-labelledby="premium-plan-title">
        <div className="premium-plan-copy">
          <span>Individual plan</span>
          <h2 id="premium-plan-title">Premium Career</h2>
          <p>One subscription for deeper job insights, stronger profile discovery, and focused learning.</p>
          <ul>
            <li><Check size={18} /> Applicant and company insights</li>
            <li><Check size={18} /> Advanced people and job search filters</li>
            <li><Check size={18} /> Full learning library access</li>
            <li><Check size={18} /> Profile discovery analytics</li>
          </ul>
        </div>
        <div className="premium-plan-action">
          <div><strong>$29.99</strong><span>USD / month</span></div>
          {loading ? (
            <button className="button button-primary button-full" disabled>Loading billing…</button>
          ) : !billingAvailable ? (
            <button className="button button-outline button-full" disabled>
              <CreditCard size={18} /> Billing temporarily unavailable
            </button>
          ) : active ? (
            <>
              <div className="subscription-status"><Check size={18} /> {subscription.status === "trialing" ? "Trial active" : "Subscription active"}</div>
              {billingMode === "stripe-test" ? (
                <div className="subscription-status"><ShieldCheck size={18} /> Stripe sandbox payment verified</div>
              ) : (
                <button className="button button-outline button-full" disabled={action === "portal"} onClick={() => openBilling("portal")}>
                  <CreditCard size={18} /> {action === "portal" ? "Opening…" : "Manage subscription"} <ExternalLink size={15} />
                </button>
              )}
            </>
          ) : cardSetup ? (
            <StripeCardForm
              setupIntentId={cardSetup.setupIntentId}
              onCancel={() => setCardSetup(null)}
              onComplete={(nextSubscription) => {
                setSubscription(nextSubscription);
                setCardSetup(null);
                setAction(null);
                setError("");
              }}
            />
          ) : (
            <button className="button button-primary button-full" disabled={action === "checkout"} onClick={() => openBilling("checkout")}>
              <CreditCard size={18} /> {action === "checkout" ? "Preparing secure card form…" : "Add a test card"}
            </button>
          )}
          {!active && billingAvailable && !loading && !cardSetup && <small>No card is attached to this account. Only name, card number, expiration date, and security code are collected.</small>}
          {subscription?.currentPeriodEnd && <small>Current period ends {new Date(subscription.currentPeriodEnd).toLocaleDateString("en-US")}.</small>}
          {subscription?.cancelAtPeriodEnd && <small>Your plan is set to cancel at the end of the current period.</small>}
          {error && <div className="form-error" role="alert">{error}</div>}
        </div>
      </section>
    </div>
  );
}