import { useEffect, useState } from "react";
import { toast } from "react-hot-toast";
import {
  TrashIcon,
  PlusIcon,
  MinusIcon,
  ExclamationCircleIcon,
} from "@heroicons/react/24/solid";
import { ExclamationTriangleIcon } from "@heroicons/react/24/outline";
import { useRouter } from "next/router";

// Helpers
import { 
  createOrUpdateItemCart, 
  deleteItemCart, 
  getCart 
} from "@/core/utils/cart";
import { createSlug } from "@/core/utils/slug";
import apiOdoo from "@/core/utils/apiOdoo";
import currencyFormat from "@/core/utils/currencyFormat";

// Components
import ConfirmAlert from "@/components/elements/ConfirmAlert";
import Image from "@/components/elements/Image";
import Layout from "@/components/layouts/Layout";
import Link from "@/components/elements/Link";
import Alert from "@/components/elements/Alert";
import Spinner from "@/components/elements/Spinner";
import AppBar from "@/components/layouts/AppBar";
import ProgressBar from "@/components/elements/ProgressBar";
import LineDivider from "@/components/elements/LineDivider";

export default function Cart() {
  const router = useRouter();
  const [isLoadingProducts, setIsLoadingProducts] = useState(true);
  const [products, setProducts] = useState([]);
  const [totalPriceBeforeTax, setTotalPriceBeforeTax] = useState(0);
  const [totalTaxAmount, setTotalTaxAmount] = useState(0);
  const [totalDiscountAmount, setTotalDiscountAmount] = useState(0);
  const [deleteConfirmation, setDeleteConfirmation] = useState({
    productId: null,
    show: false
  });

  useEffect(() => {
    const getProducts = async () => {
      let cart = getCart();
      let productIds = Object.keys(cart);
      if (productIds.length > 0) {
        productIds = productIds.join(',');
        let dataProducts = await apiOdoo('GET', `/api/v1/product_variant/${productIds}`);
        dataProducts = dataProducts.map((product) => ({
          ...product,
          quantity: cart[product.id].quantity,
          selected: cart[product.id].selected,
        }));
        setProducts(dataProducts);
      }
      setIsLoadingProducts(false);
    }
    getProducts();
  }, []);

  useEffect(() => {
    for (const product of products) {
      if (product.quantity != '') createOrUpdateItemCart(product.id, product.quantity, product.selected);
    }
    const productsSelected = products.filter((product) => product.selected == true);
    let calculateTotalPriceBeforeTax = 0;
    let calculateTotalTaxAmount = 0;
    let calculateTotalDiscountAmount = 0;
    productsSelected.forEach(product => {
      let priceBeforeTax = product.price.price / 1.11; 
      calculateTotalPriceBeforeTax += priceBeforeTax * product.quantity;
      calculateTotalTaxAmount += (product.price.price - priceBeforeTax) * product.quantity;
      calculateTotalDiscountAmount += (product.price.price - product.price.price_discount) * product.quantity;
    });
    setTotalPriceBeforeTax(calculateTotalPriceBeforeTax);
    setTotalTaxAmount(calculateTotalTaxAmount);
    setTotalDiscountAmount(calculateTotalDiscountAmount);
  }, [products]);

  const getProductsSelected = () => {
    return products.filter((product) => product.selected == true);
  }

  const updateCart = (productId, quantity) => {
    let productIndexToUpdate = products.findIndex((product) => product.id == productId);
    let productsToUpdate = products;
    productsToUpdate[productIndexToUpdate].quantity = quantity;
    setProducts([...productsToUpdate]);
  };

  const blurQuantity = (productId, quantity) => {
    quantity = quantity == ('' || 0) ? 1 : parseInt(quantity);
    if (typeof quantity === 'number') {
      quantity = parseInt(quantity);
      quantity = Math.floor(quantity);
    }
    updateCart(productId, quantity);
  };

  const updateQuantity = (productId, quantity) => {
    quantity = quantity == '' ? '' : parseInt(quantity);
    updateCart(productId, quantity);
  };

  const plusQuantity = (productId) => {
    let productIndexToUpdate = products.findIndex((product) => product.id == productId);
    let quantity = products[productIndexToUpdate].quantity + 1;
    updateCart(productId, quantity);
  }

  const minusQuantity = (productId) => {
    let productIndexToUpdate = products.findIndex((product) => product.id == productId);
    let quantity = products[productIndexToUpdate].quantity - 1;
    updateCart(productId, quantity);
  }

  const showDeleteConfirmation = (productId) => {
    setDeleteConfirmation({
      productId: productId,
      show: true
    });
  }

  const hideDeleteConfirmation = () => {
    setDeleteConfirmation({
      productId: null,
      show: false
    });
  }

  const deleteItem = () => {
    const productId = deleteConfirmation.productId;
    let productIndexToUpdate = products.findIndex((product) => product.id == productId);
    let productsToUpdate = products;
    productsToUpdate.splice(productIndexToUpdate, 1);
    setProducts([...productsToUpdate]);
    deleteItemCart(productId);
    hideDeleteConfirmation();
    toast.success('Berhasil menghapus 1 barang dari keranjang', { duration: 1500 });
  }

  const toggleProductSelected = (productId) => {
    let productIndexToUpdate = products.findIndex((product) => product.id == productId);
    let productsToUpdate = products;
    productsToUpdate[productIndexToUpdate].selected = !productsToUpdate[productIndexToUpdate].selected;
    setProducts([...productsToUpdate]);
  }

  return (
    <>
      <ConfirmAlert 
        title="Hapus barang dari keranjang"
        caption="Apakah anda yakin menghapus barang dari keranjang?"
        show={deleteConfirmation.show}
        onClose={hideDeleteConfirmation}
        onSubmit={deleteItem}
      />

      <Layout>
        <AppBar title="Keranjang Saya" />

        {isLoadingProducts && (
          <div className="flex justify-center items-center gap-x-3 mt-14">
            <Spinner className="w-10 text-gray_r-8 fill-gray_r-12" />
          </div>
        ) }

        { !isLoadingProducts && products.length == 0 && (
          <div className="text-center mt-14">
            <ExclamationTriangleIcon className="w-12 mx-auto"/>
            <p className="mt-2 h2">Keranjang belanja anda masih kosong.</p>
            <Link href="/" className="btn-yellow text-gray_r-12 mx-auto mt-4">Mulai Belanja</Link>
          </div>
        ) }

        { !isLoadingProducts && products.length > 0 && (
          <>
            <ProgressBar 
              current={1}
              labels={['Keranjang', 'Pembayaran', 'Selesai']}
            />

            <LineDivider />

            <div className="p-4">
              <Alert type="warning" className="text-caption-2 flex gap-x-3 items-center">
                <div>
                  <ExclamationCircleIcon className="w-8 text-yellow_r-11"/>
                </div>
                <span>Mohon dicek kembali & pastikan pesanan kamu sudah sesuai dengan yang kamu butuhkan. Atau bisa hubungi kami.</span>
              </Alert>
            </div>

            <LineDivider />

            <div className="p-4 flex flex-col gap-y-6">
              <div className="flex justify-between items-center">
                <h2>Daftar Produk Belanja</h2>
                <Link href="/" className="text-caption-1">Cari Produk Lain</Link>
              </div>
              {products.map((product, index) => (
                <div className="flex gap-x-3" key={index}>
                  <div className="w-4/12 flex items-center gap-x-2" onClick={() => toggleProductSelected(product.id)}>
                    <button 
                      className={'p-2 rounded border-2 ' + (product.selected ? 'border-yellow_r-9 bg-yellow_r-9' : 'border-gray_r-12')} 
                    ></button>
                    <Image
                      src={product.parent.image} 
                      alt={product.parent.name} 
                      className="object-contain object-center border border-gray_r-6 h-32 w-full rounded-md"
                    />
                  </div>
                  <div className="w-8/12 flex flex-col">
                    <Link href={'/shop/product/' + createSlug(product.parent.name, product.parent.id)} className="product-card__title wrap-line-ellipsis-2">
                      {product.parent.name}
                    </Link>
                    <p className="text-caption-2 text-gray_r-11 mt-1">
                      {product.code || '-'}
                      {product.attributes.length > 0 ? ` | ${product.attributes.join(', ')}` : ''}
                    </p>
                    <div className="flex flex-wrap gap-x-1 items-center mb-2 mt-auto">
                      <p className="text-caption-2 text-gray_r-12">{currencyFormat(product.price.price_discount)}</p>
                      {product.price.discount_percentage > 0 && (
                        <>
                          <span className="badge-red">{product.price.discount_percentage}%</span>
                          <p className="text-caption-2 text-gray_r-11 line-through">{currencyFormat(product.price.price)}</p>
                        </>
                      )}
                    </div>
                    <div className="flex items-center">
                      <p className="mr-auto text-caption-2 text-gray_r-12 font-bold">{currencyFormat(product.quantity * product.price.price_discount)}</p>
                      <div className="flex gap-x-2 items-center">
                        <button 
                          className="btn-red p-2 rounded"
                          onClick={() => showDeleteConfirmation(product.id)}
                        >
                          <TrashIcon className="text-red_r-11 w-3"/>
                        </button>
                        <button 
                          className="btn-light p-2 rounded" 
                          disabled={product.quantity == 1} 
                          onClick={() => minusQuantity(product.id)}
                        >
                          <MinusIcon className={'text-gray_r-12 w-3' + (product.quantity == 1 ? ' text-gray_r-11' : '')}/>
                        </button>
                        <input 
                          type="number" 
                          className="bg-transparent border-none w-6 text-center outline-none" 
                          onBlur={(e) => blurQuantity(product.id, e.target.value)} 
                          onChange={(e) => updateQuantity(product.id, e.target.value)} 
                          value={product.quantity} 
                        />
                        <button className="btn-light p-2 rounded" onClick={() => plusQuantity(product.id)}>
                          <PlusIcon className="text-gray_r-12 w-3"/>
                        </button>
                      </div>
                    </div>
                  </div>
                </div>
              ))}
            </div>

            <div className="p-4 bg-gray_r-1 sticky bottom-0 border-t-4 border-gray_r-4">
              <div className="flex">
                <p>Total</p>
                <p className="text-gray_r-11 ml-1">{getProductsSelected().length > 0 && (
                  <>({ getProductsSelected().length } Barang)</>
                )}</p>
                <p className="font-semibold text-red_r-11 ml-auto">{currencyFormat(totalPriceBeforeTax + totalTaxAmount - totalDiscountAmount)}</p>
              </div>
              
              <div className="flex gap-x-3 mt-4">
                <button 
                  className="flex-1 btn-light"
                  disabled={getProductsSelected().length == 0}
                  onClick={() => router.push('/shop/quotation')}
                >
                  Quotation {getProductsSelected().length > 0 && `(${getProductsSelected().length})`}
                </button>
                <button 
                  className="flex-1 btn-yellow"
                  disabled={getProductsSelected().length == 0}
                  onClick={() => router.push('/shop/checkout')}
                >
                  Checkout {getProductsSelected().length > 0 && `(${getProductsSelected().length})`}
                </button>
              </div>
            </div>
          </>
        ) }
      </Layout>
    </>
  );
}