"use strict";

const cheerio = require("cheerio");
const url = require("url");
const assert = require("assert");
const syncpipe = require("syncpipe");
const htmlEntities = require("html-entities");

const createDatasheet = require("../../shared/create-datasheet");
const assureResponse = require("../../shared/assure-response");
const getUntaggedText = require("../../shared/get-untagged-text");

// ST Microelectronics

function extractID(string) {
	// Quick-and-dirty category ID parsing from category pages
	let match = /"prmisID":"([^"]+)"/.exec(string);

	if (match != null) {
		return match[1];
	} else {
		throw new Error(`ST: prmis ID expected but not found`);
	}
}

module.exports = function ({ session }) {
	return {
		seed: [{
			id: "st:home",
			tags: [ "st:home" ],
			data: {}
		}],
		tags: {
			"st:home": [ "st:findCategories" ],
			"st:category": [ "st:scrapeCategory" ],
			"st:product": [ "st:scrapeProduct", "st:normalizeProduct" ],
		},
		tasks: {
			"st:findCategories": {
				ttl: "15d",
				run: async function ({ createItem }) {
					let response = await session.get("https://www.st.com/content/st_com/en.html");
					assureResponse(response);
			
					let $ = cheerio.load(response.body);
			
					let links = $("#Top_Menu_Products :is(a.st-nav__blockmenu-title, a.st-nav__blockmenu-link)")
						.toArray()
						.map((element) => $(element).attr("href"))
						.map((relativeURL) => url.resolve("https://www.st.com/", relativeURL));
			
					for (let link of links) {
						createItem({
							id: `st:category:${link}`,
							tags: [ "st:category" ],
							data: { url: link }
						});
					}
				}
			},
			"st:scrapeCategory": {
				ttl: "1d",
				taskInterval: "60s",
				version: "2",
				run: async function({ data, createItem }) {
					let response = await session.get(data.url);
					assureResponse(response);
				
					let prmisID = extractID(response.body.toString());
				
					let listingResponse = await session.get(`https://www.st.com/en/documentation/scraper.cxst-ps-grid.html/${encodeURIComponent(prmisID)}.json`, { noDecode: true });
					assureResponse(response);
					let listingBuffer = listingResponse.body;
				
					if (listingBuffer.length > 0) {
						// This is a category that has a product explorer
						let listing = JSON.parse(listingBuffer.toString());
				
						let cellNames = listing.columns.map((column) => {
							let cellName = (column.identifier != null)
								? `${column.identifier}_${column.qualifier_identifier}`
								: `nonstandard:${column.name}:${column.qualifier}`
				
							createItem({
								id: `st:column:${cellName}`,
								tags: [ "st:column" ],
								data: column
							});
				
							return cellName;
						});
				
						for (let row of listing.rows) {
							assert(row.productId != null);
				
							let cellData = syncpipe(row.cells, [
								(_) => _.map((cell, i) => [ cellNames[i], cell.value ]),
								(_) => Object.fromEntries(_)
							]);
				
							createItem({
								id: `st:product:${row.productId}`,
								tags: [ "st:product" ],
								data: {
									... row,
									cells: undefined,
									cellData: cellData
								}
							});
						}
					} else {
						console.warn("Warning: empty response, category does not have product explorer");
					}
				}
			},
			"st:scrapeProduct": {
				ttl: "15d",
				taskInterval: "5s",
				run: async function({ data, createItem, updateData, expireDependents }) {
					if (data.productFolderUrl == null) {
						throw new Error(`No known product page URL`);
					}
			
					let productPageURL = url.resolve("https://www.st.com/", data.productFolderUrl);
			
					let response = await session.get(productPageURL);
					assureResponse(response);
			
					let $ = cheerio.load(response.body);
			
					let datasheetLink = $("a[data-js='datasheetLink']").attr("href");
					let datasheetURL = (datasheetLink != null)
						? url.resolve(productPageURL, datasheetLink)
						: null;
			
					let resources = $(".st-table--resources")
						.find("h3").toArray()
						.map((heading) => {
							let $heading = $(heading);
							let sectionID = $heading.attr("id");
							let sectionTitle = $heading.text().trim();
			
							let $table = $heading.next("table");
			
							let items = $table
								.find("tbody tr").toArray()
								.map((row) => {
									let $row = $(row);
									let $mainView = $row.find(".visible-on-desktop-only");
									let $link = $mainView.find("a.st-link");
			
									return {
										url: url.resolve(productPageURL, $link.attr("href")),
										documentID: $link.find("span.st-font--bold").text().trim(),
										description: $link.find("span:not(.st-font--bold)").text().trim(),
										version: getUntaggedText($link),
										date: $row.find(".visible-on-desktop-only[data-latest-update]").text().trim()
									};
								});
			
							return {
								sectionID: sectionID,
								sectionTitle: sectionTitle,
								items: items
							};
						});
			
					updateData((data) => {
						return {
							... data,
							datasheetLink: datasheetURL,
							resources: resources
						};
					});
			
					expireDependents();
			
					for (let section of resources) {
						for (let resource of section.items) {
							createItem({
								id: `st:resource:${resource.url}`,
								tags: (resource.url === datasheetURL)
									? [ "st:resource", "st:datasheet" ]
									: [ "st_resource" ],
								data: { url: resource.url }
							});
						}
					}
				}
			},
			"st:normalizeProduct": {
				dependsOn: [ "st:scrapeProduct" ],
				version: "8",
				parallelTasks: 50,
				run: async function (api) {
					let { data } = api;
			
					createDatasheet(api, {
						priority: 0.8,
						source: "st",
						manufacturer: "STMicroelectronics",
						productID: data.productId,
						name: data.cellData["XJE010_VT-007"],
						description: htmlEntities.decode(data.cellData["XJE014_VT-007"]),
						url: data.datasheetLink
					});
				}
			},
		}
	};
};