import { DOMParser } from "jsr:@b-fuze/deno-dom";

const downloadDate = new Date();

type ArticleInfo = {
    id: number;
    title: string;
    dateAdded: string;
    author: string;
    tags: string[];
    originalLink: string;
};

type Article = ArticleInfo & {
    body: string;
};

async function downloadArticle(id: number): Promise<Article> {
    const url =
        `https://proletarianrevolution.net/index.php?page=news&type=view&id=${id}`;
    console.log(`Fetching '${url}'...`);
    const contentText = await fetch(url)
        .then((res) => res.text());

    // await Deno.writeTextFile("test_article.html", contentText);
    // const contentText = await Deno.readTextFile("test_article.html");

    const doc = new DOMParser().parseFromString(contentText, "text/html");

    const article = doc.querySelector("article");

    const title = article
        ?.querySelector("h1.screen_title")
        ?.innerText
        .trim()!;

    const dateAdded = article
        ?.querySelector("article ul.meta_details_list")
        ?.children[1]
        .children[0]
        .attributes
        .getNamedItem("datetime")
        ?.value!;

    const author = article
        ?.querySelector("article ul.meta_details_list")
        ?.children[2]
        .children[1]
        .innerText!;

    const tags = [article]
        .map((article) =>
            article?.querySelectorAll(`span[itemprop="keywords"] a`)
        )
        .map((nodeList) => [...nodeList!])
        .map((children) => children.map((aElem) => aElem.innerText))[0];

    const body = article
        ?.querySelector(`div[itemprop="articleBody"]`)
        ?.innerHTML!;

    return { id, title, dateAdded, author, tags, originalLink: url, body };
}

const articleTemplate = await Deno.readTextFile("templates/article.html");

function renderArticle(
    article: Article,
    prevId?: number,
    nextId?: number,
): string {
    return articleTemplate
        .slice()
        .replaceAll("$title", article.title)
        .replaceAll("$dateAddedRaw", article.dateAdded)
        .replaceAll(
            "$dateAdded",
            new Date(article.dateAdded).toUTCString(),
        )
        .replaceAll("$downloadDate", downloadDate.toUTCString())
        .replaceAll("$author", article.author)
        .replaceAll(
            "$tags",
            article.tags.map((tag) =>
                `<a href="categories.html#${tag}"><span class="tag">${tag}</span></a>`
            ).join(
                ", ",
            ),
        )
        .replaceAll("$body", article.body)
        .replaceAll("$originalLink", article.originalLink)
        .replaceAll(
            "$navPrevious",
            prevId ? `<a href="article-${prevId}.html">Previous</a>` : "",
        )
        .replaceAll(
            "$navNext",
            nextId ? `<a href="article-${nextId}.html">Next</a>` : "",
        );
}

const indexTemplate = await Deno.readTextFile("templates/index.html");

function renderIndex(articles: ArticleInfo[]): string {
    return indexTemplate
        .slice()
        .replaceAll("$downloadDate", downloadDate.toUTCString())
        .replaceAll(
            "$articleEntries",
            articles
                .toSorted((a, b) => a.title.localeCompare(b.title))
                .map((article) => `
                <tr>
                    <td>
                        <a href="article-${article.id}.html">
                            ${article.title}
                        </a>
                    </td>
                    <td>${article.author}</td>
                    <td>${new Date(article.dateAdded).toUTCString()}</td>
                    <td>${(
                    article.tags.map((tag) => `
                            <a href="categories.html#${tag}">
                                <span class="tag">${tag}</span>
                            </a>
                        `).join(", ")
                )}</td>
                </tr>
            `).join(""),
        );
}

const categoriesTemplate = await Deno.readTextFile("templates/categories.html");

function renderCategories(articles: ArticleInfo[]): string {
    const categories = articles
        .reduce<Map<string, ArticleInfo[]>>((categories, article) => {
            for (const tag of article.tags) {
                if (!categories.has(tag)) {
                    categories.set(tag, []);
                }
                categories.get(tag)!.push(article);
            }
            return categories;
        }, new Map());

    return categoriesTemplate
        .slice()
        .replaceAll("$downloadDate", downloadDate.toUTCString())
        .replaceAll(
            "$categoryEntries",
            categories
                .entries()
                .toArray()
                .toSorted((a, b) => a[0].localeCompare(b[0]))
                .map(([tag, articles]) => `
                    <div id="${tag}">
                        <h2>${tag}</h2>
                        <ul>${
                    articles
                        .toSorted((a, b) => a.title.localeCompare(b.title))
                        .map((article) => `
                                    <li>
                                        <a href="article-${article.id}.html">
                                            ${article.title}
                                        </a>
                                    </li>
                                `).join("")
                }</ul>
                    </div>
                `).join(""),
        );
}

await Deno.mkdir("build/articles", { recursive: true });

const articlesIdMin = 1;
const articlesIdMax = 87;

const articles: ArticleInfo[] = [];
for (let id = articlesIdMin; id <= articlesIdMax; ++id) {
    const prevId = id > articlesIdMin ? id - 1 : undefined;
    const nextId = id < articlesIdMax ? id + 2 : undefined;

    console.log(`Downloading article ${id}...`);
    const article = await downloadArticle(id);

    if (article.title === "Log in") {
        console.log(`Article ${id} invalid. Skipping!`);
        continue;
    }

    const html = renderArticle(article, prevId, nextId);
    const filepath = `build/articles/article-${id}.html`;
    await Deno.writeTextFile(filepath, html);
    console.log(`Article ${id} written to '${filepath}'!`);

    const { title, dateAdded, author, tags, originalLink } = article;
    articles.push({ id, title, dateAdded, author, tags, originalLink });
}

console.log("Building index...");
const indexHtml = renderIndex(articles);
await Deno.writeTextFile("build/articles/index.html", indexHtml);
console.log("Index written to 'build/articles/index.html'!");
console.log("Building categories...");
const categoriesHtml = renderCategories(articles);
await Deno.writeTextFile("build/articles/categories.html", categoriesHtml);
console.log("Categories written to 'build/articles/categories.html'!");
console.log("Done!");