import { useEffect, useMemo, useState } from "react";
import { useLocation, useNavigate, Link } from "react-router-dom";
import { useAuthStore } from "../store/authStore";

const PLAN_COPY: Record<string, { name: string; price: string; credits: string }> = {
  starter: { name: "Starter", price: "$89/mo", credits: "1,000 credits/month" },
  growth: { name: "Growth", price: "$139/mo", credits: "2,000 credits/month" },
  scale: { name: "Scale", price: "$229/mo", credits: "4,000 credits/month" },
};

export default function Payment() {
  const location = useLocation();
  const navigate = useNavigate();
  const user = useAuthStore((s) => s.user);
  const [contactEmail, setContactEmail] = useState("");
  const [note, setNote] = useState("");
  const [error, setError] = useState("");

  const planSlug = useMemo(() => new URLSearchParams(location.search).get("plan") || "", [location.search]);
  const plan = useMemo(() => {
    const slugFromAccount = user?.account?.plan?.slug;
    const slug = planSlug || slugFromAccount || "";
    return slug ? PLAN_COPY[slug] : null;
  }, [planSlug, user?.account?.plan?.slug]);
  const mailtoHref = useMemo(() => {
    if (!plan || !contactEmail.trim()) return "";
    const subject = encodeURIComponent(`Payment submitted for ${plan.name}`);
    const body = encodeURIComponent(
      `Plan: ${plan.name}\nAccount: ${user?.account?.slug || user?.account?.id || "-"}\nEmail: ${contactEmail}\nNotes/Reference: ${note || "-"}`
    );
    return `mailto:sales@igny8.com?subject=${subject}&body=${body}`;
  }, [plan, contactEmail, note, user?.account?.slug, user?.account?.id]);

  useEffect(() => {
    if (!plan || !user) {
      navigate("/pricing", { replace: true });
    }
  }, [plan, navigate, user]);

  const handleRequest = (e: React.MouseEvent<HTMLAnchorElement>) => {
    if (!plan) {
      e.preventDefault();
      navigate("/pricing", { replace: true });
      return;
    }
    if (!contactEmail.trim()) {
      e.preventDefault();
      setError("Please enter a contact email.");
      return;
    }
    setError("");
  };

  return (
    <div className="min-h-screen flex items-center justify-center bg-slate-50 px-4 py-16">
      <div className="w-full max-w-3xl bg-white rounded-2xl shadow-lg p-8 space-y-6 border border-slate-100">
        <div className="flex items-center justify-between">
          <div>
            <p className="text-sm text-slate-500">Confirm your plan</p>
            <h1 className="text-2xl font-semibold text-slate-900">Complete your subscription</h1>
          </div>
          <Link to="/pricing" className="text-sm text-blue-600 hover:text-blue-700">
            Change plan
          </Link>
        </div>

        {plan && (
          <div className="rounded-xl border border-slate-200 bg-slate-50 p-4">
            <h2 className="text-lg font-semibold text-slate-900">{plan.name}</h2>
            <p className="text-slate-700">{plan.price}</p>
            <p className="text-sm text-slate-600">{plan.credits}</p>
            <p className="text-xs text-amber-700 mt-2">
              Payment is completed offline (bank transfer). Submit your email and reference below; we will verify and activate your account.
            </p>
          </div>
        )}

        <div className="space-y-4">
          <label className="block text-sm font-medium text-slate-800">
            Contact email
            <input
              type="email"
              value={contactEmail}
              onChange={(e) => setContactEmail(e.target.value)}
              placeholder="you@example.com"
              className="mt-1 w-full rounded-lg border border-slate-300 px-3 py-2 text-slate-900 focus:border-blue-500 focus:outline-none"
            />
          </label>
          <label className="block text-sm font-medium text-slate-800">
            Notes (optional)
            <textarea
              value={note}
              onChange={(e) => setNote(e.target.value)}
              placeholder="Company name, billing contact, or questions"
              className="mt-1 w-full rounded-lg border border-slate-300 px-3 py-2 text-slate-900 focus:border-blue-500 focus:outline-none"
              rows={3}
            />
          </label>
        </div>

        <div className="flex items-center justify-between">
          <Link to="/signup" className="text-sm text-slate-600 hover:text-slate-800">
            Prefer the free plan? Start your trial
          </Link>
          <a
            href={mailtoHref || "#"}
            onClick={handleRequest}
            className={`inline-flex items-center justify-center rounded-lg px-4 py-2 text-sm font-semibold text-white ${
              contactEmail.trim() ? "bg-blue-600 hover:bg-blue-700" : "bg-blue-400 cursor-not-allowed"
            }`}
            aria-disabled={!contactEmail.trim()}
          >
            Request payment instructions
          </a>
        </div>
        {error && <p className="text-sm text-red-600">{error}</p>}
      </div>
    </div>
  );
}

