import { useEffect, useMemo, useState } from "react";
import { useLocation, useNavigate, Link } from "react-router-dom";
import { useAuthStore } from "../store/authStore";
import InputField from "../components/form/input/InputField";
import TextArea from "../components/form/input/TextArea";
import Label from "../components/form/Label";
import Button from "../components/ui/button/Button";

const PLAN_COPY: Record<string, { name: string; price: string; content: string }> = {
  starter: { name: "Starter", price: "$49/mo", content: "50 content pieces/month" },
  growth: { name: "Growth", price: "$149/mo", content: "200 content pieces/month" },
  scale: { name: "Scale", price: "$349/mo", content: "500 content pieces/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-gray-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-gray-100">
        <div className="flex items-center justify-between">
          <div>
            <p className="text-sm text-gray-500">Confirm your plan</p>
            <h1 className="text-2xl font-semibold text-gray-900">Complete your subscription</h1>
          </div>
          <Link to="/pricing" className="text-sm text-brand-600 hover:text-brand-700">
            Change plan
          </Link>
        </div>

        {plan && (
          <div className="rounded-xl border border-gray-200 bg-gray-50 p-4">
            <h2 className="text-lg font-semibold text-gray-900">{plan.name}</h2>
            <p className="text-gray-700">{plan.price}</p>
            <p className="text-sm text-gray-600">{plan.content}</p>
            <p className="text-xs text-warning-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">
          <InputField
            label="Contact email"
            type="email"
            value={contactEmail}
            onChange={(e) => setContactEmail(e.target.value)}
            placeholder="you@example.com"
          />
          <div>
            <Label className="mb-2">Notes (optional)</Label>
            <TextArea
              value={note}
              onChange={(value) => setNote(value)}
              placeholder="Company name, billing contact, or questions"
              rows={3}
            />
          </div>
        </div>

        <div className="flex items-center justify-between">
          <Link to="/signup" className="text-sm text-gray-600 hover:text-gray-800">
            Prefer the free plan? Start your trial
          </Link>
          <Button
            onClick={() => {
              if (mailtoHref && contactEmail.trim()) {
                window.location.href = mailtoHref;
              }
            }}
            disabled={!contactEmail.trim()}
            variant="primary"
          >
            Request payment instructions
          </Button>
        </div>
        {error && <p className="text-sm text-error-600">{error}</p>}
      </div>
    </div>
  );
}