/**
 * Used temporarily until I get access to Amazon Product API.
 */

import cheerio, { type CheerioAPI } from 'cheerio';
import { type AmazonProductDetails } from '../old-data/products/amazon-product-details';
import { type ProductAttribute } from '../old-data/products/product-attribute';
import { parseNumberFromSelector } from './utils';

/**
 * CSS selectors for the product details. Feel free to figure out different variations of these selectors.
 */
const SELECTORS = {
    TITLE: 'span#productTitle',
    PRICE: 'span.priceToPay',
    // LIST_PRICE: 'span.basisPrice .a-offscreen',
    FEATURE_BULLETS: '#feature-bullets li span.a-list-item',
    DESCRIPTION: '#productDescription',
    REVIEW_RATING: '#acrPopover a > span',
    REVIEW_COUNT: '#acrCustomerReviewText',
    IMAGES: '#altImages .item img',
    PRODUCT_ATTRIBUTE_ROWS: '#productOverview_feature_div tr',
    ATTRIBUTES_LABEL: 'td:nth-of-type(1) span',
    ATTRIBUTES_VALUE: 'td:nth-of-type(2) span',
} as const;

/**
 * Extracts the product image URLs from the given Cheerio object.
 * - We have to iterate over the image elements and extract the `src` attribute.
 */
const extractImageUrls = ($: CheerioAPI): string[] => {
    const imageUrls = $(SELECTORS.IMAGES)
        .map((_, imageEl) => $(imageEl).attr('src'))
        .get(); // `get()` - Retrieve all elements matched by the Cheerio object, as an array. Removes `undefined` values.

    return imageUrls;
};

/**
 * Extracts the product attributes from the given Cheerio object.
 * - We have to iterate over the attribute rows and extract both label and value for each row.
 */
const extractProductAttributes = ($: CheerioAPI): ProductAttribute[] => {
    const attributeRowEls = $(SELECTORS.PRODUCT_ATTRIBUTE_ROWS).get();

    const attributeRows = attributeRowEls.map((rowEl) => {
        const label = $(rowEl).find(SELECTORS.ATTRIBUTES_LABEL).text();
        const value = $(rowEl).find(SELECTORS.ATTRIBUTES_VALUE).text();

        return { label, value };
    });

    return attributeRows;
};

/**
 * Extracts the feature bullets from the given Cheerio object.
 * - We have to iterate over the li elements and extract the text.
 */
const extractFeatureBullets = ($: CheerioAPI): string[] => {
    const featureBullets = $(SELECTORS.FEATURE_BULLETS)
        .map((_, featureBulletEl) => $(featureBulletEl).text().trim())
        .get(); // `get()` - Retrieve all elements matched by the Cheerio object, as an array. Removes `undefined` values.
    return featureBullets;
};

/**
 * Scrapes the product details from the given Cheerio object.
 */
export const extractProductDetails = ($: CheerioAPI): AmazonProductDetails => {
    const title = $(SELECTORS.TITLE).text().trim();
    const description = $(SELECTORS.DESCRIPTION).text()!.trim();

    const price = parseNumberFromSelector($, SELECTORS.PRICE);
    // const listPrice = parseNumberFromSelector($, SELECTORS.LIST_PRICE);
    const reviewRating = parseNumberFromSelector($, SELECTORS.REVIEW_RATING);
    const reviewCount = parseNumberFromSelector($, SELECTORS.REVIEW_COUNT);

    const imageUrls = extractImageUrls($);
    const attributes = extractProductAttributes($);
    const featureBullets = extractFeatureBullets($);

    return { title, description, featureBullets, price, /*listPrice,*/ reviewCount, reviewRating, imageUrls, attributes };
};