"use strict";

import { ERROR_SERVER, PRODUCT_INFORMATION_NOT_FOUND } from '/js/constants.js';
import { 
    showErrorMessage,
    setBasketLocalStorage,
    getBasketLocalStorage,
    checkingRelevanceValueBasket
} from './utils.js';

/* ================================
   ЗАЩИТА ШАБЛОНА card.html
   ================================ */
(function () {
    const path = window.location.pathname;

    if (path !== '/card.html') return;

    const params = new URLSearchParams(window.location.search);
    const productId = params.get('id');

    if (!productId) {
        const meta = document.createElement('meta');
        meta.name = 'robots';
        meta.content = 'noindex, nofollow';
        document.head.appendChild(meta);

        window.location.replace('/');
    }
})();

/* ================================
   ОСНОВНОЙ КОД
   ================================ */

const wrapper = document.querySelector('.wrapper');
let productsData = [];

// Формирование ссылки фабрики
function formatFabricLink(fabricName) {
    if (!fabricName) return '#';

    const FABRIC_LINKS = {
        'ATLAS CONCORDE': 'atlas-concorde',
        'ITALGRANITI': 'italgraniti',
    };

    const special = FABRIC_LINKS[fabricName.toUpperCase()];
    if (special) return special;

    return fabricName
        .toLowerCase()
        .replace(/\s+/g, '-')
        .replace(/[^a-z0-9-]/g, '');
}

document.addEventListener('DOMContentLoaded', getProducts);

async function getProducts() {
    try {
        if (!productsData.length) {
            const response = await fetch('/data/products.json');

            if (!response.ok) {
                throw new Error(ERROR_SERVER);
            }

            productsData = await response.json();
        }

        loadProductDetails(productsData);

    } catch (error) {
        showErrorMessage(ERROR_SERVER);
        console.error(error);
    }
}

function getParameterFromURL(parameter) {
    const params = new URLSearchParams(window.location.search);
    return params.get(parameter);
}

function loadProductDetails(data) {
    if (!data || !data.length) {
        showErrorMessage(ERROR_SERVER);
        return;
    }

    checkingRelevanceValueBasket(data);

    const productId = Number(getParameterFromURL('id'));

    if (!productId) {
        showErrorMessage(PRODUCT_INFORMATION_NOT_FOUND);
        return;
    }

    const currentProduct = data.find(p => p.id === productId);

    if (!currentProduct) {
        showErrorMessage(PRODUCT_INFORMATION_NOT_FOUND);
        return;
    }

    renderInfoProduct(currentProduct);
}

function renderInfoProduct(product) {
    const { id, img, title, fabric, collection, price, discount, descr, edizm, razmer, type } = product;
    const priceDiscount = price - ((price * discount) / 100);

    setCanonicalForCard(id);
    optimizePageSEO(title, type, fabric, priceDiscount, discount, descr);

    const fabricLink = formatFabricLink(fabric);

    const productHTML = `
        <div class="product" data-product-id="${id}">
            <h1 class="product__title">${title}</h1>
            <h2 class="product__title">${type}</h2>

            <div class="product__meta">
                <div class="product__brand">
                    <span>Производитель:</span>
                    <a href="/${fabricLink}.html">${fabric}</a>
                </div>

                <div class="product__collection">
                    <span>Коллекция:</span>
                    <a href="/collection.html?collection=${encodeURIComponent(collection)}">
                        ${collection}
                    </a>
                </div>
            </div>

            <img src="${img}" alt="${title}">

            <p>${descr}</p>
            <p>Размер: ${razmer}</p>

            <div class="price">
                <del>${price.toFixed(0)} ₽/${edizm}</del>
                <strong>${priceDiscount.toFixed(0)} ₽/${edizm}</strong>
            </div>

            <input type="number" min="0.1" step="0.1" value="1" id="quantity-${id}">
            <button class="product__add-to-cart">Добавить в корзину</button>
        </div>
    `;

    wrapper.insertAdjacentHTML('beforeend', productHTML);
    wrapper.querySelector('.product__add-to-cart')
        .addEventListener('click', () => addToCartHandler(id));
}

/* ================================
   SEO
   ================================ */

function setCanonicalForCard(productId) {
    const baseUrl = `${location.protocol}//${location.host}${location.pathname}`;
    const canonicalUrl = `${baseUrl}?id=${productId}`;

    let link = document.querySelector('link[rel="canonical"]');
    if (!link) {
        link = document.createElement('link');
        link.rel = 'canonical';
        document.head.appendChild(link);
    }

    link.href = canonicalUrl;
}

function optimizePageSEO(title, type, fabric, price, discount, description) {
    document.title = `${type} ${title} от ${fabric} — ${price.toFixed(0)} ₽`;

    let meta = document.querySelector('meta[name="description"]');
    if (!meta) {
        meta = document.createElement('meta');
        meta.name = 'description';
        document.head.appendChild(meta);
    }

    meta.content = `Купить ${type} ${title} от ${fabric}. Цена ${price.toFixed(0)} ₽. ${description.slice(0, 150)}`;

    addSchemaMarkup(title, fabric, price, description);
}

function addSchemaMarkup(title, brand, price, description) {
    const script = document.createElement('script');
    script.type = 'application/ld+json';

    script.textContent = JSON.stringify({
        "@context": "https://schema.org",
        "@type": "Product",
        "name": title,
        "brand": { "@type": "Brand", "name": brand },
        "description": description,
        "offers": {
            "@type": "Offer",
            "price": price,
            "priceCurrency": "RUB"
        }
    });

    document.head.appendChild(script);
}

/* ================================
   КОРЗИНА
   ================================ */

function addToCartHandler(productId) {
    const input = document.querySelector(`#quantity-${productId}`);
    const quantity = parseFloat(input.value);

    if (isNaN(quantity)) return;

    const basket = getBasketLocalStorage();
    const item = basket.find(i => i.id === String(productId));

    if (item) {
        item.quantity += quantity;
    } else {
        basket.push({ id: String(productId), quantity });
    }

    setBasketLocalStorage(basket);
}