"use client";

import { useState } from "react";
import Link from "next/link";
import Image from "next/image";
import { Shield, Lock, ArrowLeft } from "lucide-react";
import { useCartStore } from "@/store/cartStore";
import { formatPrice } from "@/lib/utils";
import toast from "react-hot-toast";

const COUNTRIES = [
  { code: "US", name: "United States" },
  { code: "CA", name: "Canada" },
  { code: "GB", name: "United Kingdom" },
  { code: "AU", name: "Australia" },
];

export default function CheckoutPage() {
  const { items, totalPrice } = useCartStore();
  const subtotal = totalPrice();
  const shipping = subtotal >= 75 ? 0 : 9.99;
  const total = subtotal + shipping;

  const [loading, setLoading] = useState(false);
  const [form, setForm] = useState({
    email: "",
    firstName: "",
    lastName: "",
    phone: "",
    address: "",
    address2: "",
    city: "",
    state: "",
    zip: "",
    country: "US",
  });

  const handleCheckout = async (e: React.FormEvent) => {
    e.preventDefault();
    if (items.length === 0) return;
    setLoading(true);

    try {
      const res = await fetch("/api/checkout", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          items: items.map((item) => ({ id: item.id, quantity: item.quantity })),
          email: form.email,
          shipping: {
            firstName: form.firstName,
            lastName: form.lastName,
            phone: form.phone,
            address: form.address,
            address2: form.address2,
            city: form.city,
            state: form.state,
            zip: form.zip,
            country: form.country,
          },
        }),
      });
      const data = await res.json();
      if (data.url) {
        window.location.href = data.url;
      } else {
        toast.error(data.error ?? "Failed to create checkout session.");
      }
    } catch {
      toast.error("Something went wrong.");
    } finally {
      setLoading(false);
    }
  };

  if (items.length === 0) {
    return (
      <div className="min-h-screen flex items-center justify-center">
        <div className="text-center">
          <p className="text-xl font-bold text-gray-900">Your cart is empty.</p>
          <Link href="/shop" className="btn-primary mt-4">Shop Now</Link>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-gray-50">
      <div className="max-w-6xl mx-auto px-4 sm:px-6 lg:px-8 py-10">
        <Link href="/cart" className="flex items-center gap-2 text-sm text-gray-500 hover:text-primary-600 mb-8 transition-colors">
          <ArrowLeft className="h-4 w-4" /> Back to Cart
        </Link>

        <div className="grid grid-cols-1 lg:grid-cols-5 gap-10">
          {/* Form */}
          <div className="lg:col-span-3">
            <div className="bg-white rounded-2xl p-8 shadow-sm">
              <h2 className="text-xl font-bold text-gray-900 mb-6">Shipping Information</h2>
              <form onSubmit={handleCheckout} className="space-y-5">
                <div>
                  <label className="label">Email Address</label>
                  <input
                    type="email"
                    required
                    value={form.email}
                    onChange={(e) => setForm({ ...form, email: e.target.value })}
                    className="input-field"
                    placeholder="you@example.com"
                  />
                </div>
                <div className="grid grid-cols-2 gap-4">
                  <div>
                    <label className="label">First Name</label>
                    <input
                      type="text"
                      required
                      value={form.firstName}
                      onChange={(e) => setForm({ ...form, firstName: e.target.value })}
                      className="input-field"
                    />
                  </div>
                  <div>
                    <label className="label">Last Name</label>
                    <input
                      type="text"
                      required
                      value={form.lastName}
                      onChange={(e) => setForm({ ...form, lastName: e.target.value })}
                      className="input-field"
                    />
                  </div>
                </div>
                <div>
                  <label className="label">Phone Number</label>
                  <input
                    type="tel"
                    required
                    value={form.phone}
                    onChange={(e) => setForm({ ...form, phone: e.target.value })}
                    className="input-field"
                    placeholder="(555) 123-4567"
                  />
                  <p className="text-xs text-gray-400 mt-1">Carriers require a phone number for delivery.</p>
                </div>
                <div>
                  <label className="label">Street Address</label>
                  <input
                    type="text"
                    required
                    value={form.address}
                    onChange={(e) => setForm({ ...form, address: e.target.value })}
                    className="input-field"
                  />
                </div>
                <div>
                  <label className="label">Apartment, suite, etc. (optional)</label>
                  <input
                    type="text"
                    value={form.address2}
                    onChange={(e) => setForm({ ...form, address2: e.target.value })}
                    className="input-field"
                  />
                </div>
                <div className="grid grid-cols-3 gap-4">
                  <div className="col-span-2">
                    <label className="label">City</label>
                    <input
                      type="text"
                      required
                      value={form.city}
                      onChange={(e) => setForm({ ...form, city: e.target.value })}
                      className="input-field"
                    />
                  </div>
                  <div>
                    <label className="label">State</label>
                    <input
                      type="text"
                      required
                      value={form.state}
                      onChange={(e) => setForm({ ...form, state: e.target.value })}
                      className="input-field"
                      placeholder="FL"
                    />
                  </div>
                </div>
                <div className="grid grid-cols-2 gap-4">
                  <div>
                    <label className="label">ZIP Code</label>
                    <input
                      type="text"
                      required
                      value={form.zip}
                      onChange={(e) => setForm({ ...form, zip: e.target.value })}
                      className="input-field"
                    />
                  </div>
                  <div>
                    <label className="label">Country</label>
                    <select
                      value={form.country}
                      onChange={(e) => setForm({ ...form, country: e.target.value })}
                      className="input-field"
                    >
                      {COUNTRIES.map((c) => (
                        <option key={c.code} value={c.code}>{c.name}</option>
                      ))}
                    </select>
                  </div>
                </div>

                <div className="flex items-center gap-2 text-xs text-gray-400 bg-gray-50 rounded-xl p-3 mt-2">
                  <Lock className="h-3.5 w-3.5 shrink-0" />
                  Payment is securely processed by Stripe. We never store your card details.
                </div>

                <button
                  type="submit"
                  disabled={loading}
                  className="btn-primary w-full justify-center py-4 text-base disabled:opacity-70"
                >
                  <Shield className="h-5 w-5" />
                  {loading ? "Redirecting to Stripe..." : `Pay ${formatPrice(total)}`}
                </button>
              </form>
            </div>
          </div>

          {/* Order summary */}
          <div className="lg:col-span-2">
            <div className="bg-white rounded-2xl p-6 shadow-sm">
              <h3 className="font-bold text-gray-900 mb-4">Order Summary</h3>
              <div className="space-y-3 mb-5">
                {items.map((item) => (
                  <div key={item.id} className="flex items-center gap-3">
                    <div className="relative w-12 h-12 rounded-lg overflow-hidden bg-gray-100 shrink-0">
                      <Image src={item.image} alt={item.name} fill className="object-cover" />
                      <span className="absolute -top-1 -right-1 bg-primary-500 text-white text-xs w-4 h-4 rounded-full flex items-center justify-center font-bold">
                        {item.quantity}
                      </span>
                    </div>
                    <div className="flex-1 min-w-0">
                      <p className="text-xs font-medium text-gray-900 truncate">{item.name}</p>
                    </div>
                    <span className="text-sm font-semibold text-gray-900 shrink-0">
                      {formatPrice((item.salePrice ?? item.price) * item.quantity)}
                    </span>
                  </div>
                ))}
              </div>
              <div className="border-t border-gray-100 pt-4 space-y-2 text-sm">
                <div className="flex justify-between text-gray-600">
                  <span>Subtotal</span>
                  <span>{formatPrice(subtotal)}</span>
                </div>
                <div className="flex justify-between text-gray-600">
                  <span>Shipping</span>
                  <span className={shipping === 0 ? "text-green-600" : ""}>{shipping === 0 ? "FREE" : formatPrice(shipping)}</span>
                </div>
                <div className="flex justify-between font-bold text-gray-900 text-base pt-2 border-t border-gray-100">
                  <span>Total</span>
                  <span>{formatPrice(total)}</span>
                </div>
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}