feat: crawler extension

deno.jsonc

@@ -1,7 +1,10 @@
 {
   "name": "@astral/astral",
   "version": "0.4.8",
-  "exports": "./mod.ts",
+  "exports": {
+    ".": "./mod.ts",
+    "./ext/crawler": "./ext/crawler.ts"
+  },
   "tasks": {
     // The task to automatically generate `./src/celestial.ts`
     "bind": "deno run -A ./bindings/_tools/generate/mod.ts && deno fmt",

examples/crawler.ts

@@ -0,0 +1,30 @@
+import { Crawler } from "../ext/crawler.ts";
+
+// Create an instance of the crawler
+const crawler = new Crawler({
+    maxDepth: 2,
+    userAgent:
+        "Mozilla/5.0 (compatible; Crawler4AI/1.0; +https://yourdomain.com/bot)",
+    customHeaders: {
+        "Accept-Language": "en-US,en;q=0.9",
+    },
+    concurrency: 5,
+    outputFormat: "json",
+    mediaTags: true,
+    extractLinks: true,
+    metadata: true,
+    screenshots: true,
+    customScripts: [
+        // Custom JavaScript code as strings
+        'console.log("Custom script executed");',
+    ],
+    sessionManagement: false,
+});
+
+// URLs to crawl
+const urls = [
+    "https://deno.church",
+];
+
+// Start crawling
+await crawler.crawlUrls(urls);

ext/crawler.ts

@@ -0,0 +1,239 @@
+// deno-lint-ignore-file no-explicit-any
+
+import { type Browser, launch } from "../mod.ts";
+
+/**
+ * This class is used to crawl websites and extract data such as images, videos, links, metadata, etc. for easy to use data for AI models.
+ */
+export class Crawler {
+    #browser?: Browser;
+    #maxDepth: number;
+    #visited: Set<string>;
+    #userAgent: string;
+    #customHeaders: Record<string, string>;
+    #concurrency: number;
+    #outputFormat: "json" | "html" | "markdown";
+    #mediaTags: boolean;
+    #extractLinks: boolean;
+    #metadata: boolean;
+    #screenshots: boolean;
+    #customScripts: string[];
+    #sessionManagement: boolean;
+
+    constructor(options: {
+        maxDepth?: number;
+        userAgent?: string;
+        customHeaders?: Record<string, string>;
+        concurrency?: number;
+        outputFormat?: "json" | "html" | "markdown";
+        mediaTags?: boolean;
+        extractLinks?: boolean;
+        metadata?: boolean;
+        screenshots?: boolean;
+        customScripts?: string[];
+        sessionManagement?: boolean;
+    } = {}) {
+        this.#maxDepth = options.maxDepth || 2;
+        this.#visited = new Set<string>();
+        this.#userAgent = options.userAgent || "Crawler4AI";
+        this.#customHeaders = options.customHeaders || {};
+        this.#concurrency = options.concurrency || 5;
+        this.#outputFormat = options.outputFormat || "json";
+        this.#mediaTags = options.mediaTags !== undefined
+            ? options.mediaTags
+            : true;
+        this.#extractLinks = options.extractLinks !== undefined
+            ? options.extractLinks
+            : true;
+        this.#metadata = options.metadata !== undefined
+            ? options.metadata
+            : true;
+        this.#screenshots = options.screenshots || false;
+        this.#customScripts = options.customScripts || [];
+        this.#sessionManagement = options.sessionManagement || false;
+    }
+
+    /**
+     * Initialize the browser instance
+     */
+    async init() {
+        this.#browser = await launch({
+            headless: true,
+            args: this.#sessionManagement ? [] : ["--incognito"],
+        });
+    }
+
+    async close() {
+        if (this.#browser) {
+            await this.#browser.close();
+        }
+    }
+
+    /**
+     * Crawl multiple URLs
+     */
+    async crawlUrls(urls: string[]) {
+        await this.init();
+
+        const semaphore = new Semaphore(this.#concurrency);
+
+        const crawlPromises = urls.map((url) =>
+            semaphore.acquire()
+                .then(() => this.crawl(url))
+                .finally(() => semaphore.release())
+        );
+
+        await Promise.all(crawlPromises);
+        await this.close();
+    }
+
+    /**
+     * Crawl a single URL
+     */
+    async crawl(url: string, depth: number = 0) {
+        if (depth > this.#maxDepth || this.#visited.has(url)) {
+            return;
+        }
+        this.#visited.add(url);
+
+        const page = await this.#browser!.newPage(url);
+
+        // await page.setExtraHTTPHeaders(this.#customHeaders);
+        // await page.setUserAgent(this.#userAgent);
+
+        await page.evaluate((customScripts: string[]) => {
+            for (const script of customScripts) {
+                const scriptElement = document.createElement("script");
+                scriptElement.text = script;
+                document.body.appendChild(scriptElement);
+            }
+        }, { args: [this.#customScripts] });
+
+        const data = await this.extractData(page, url);
+
+        await this.saveData(url, data);
+
+        if (this.#screenshots) {
+            try {
+                await Deno.stat("screenshots");
+            } catch (error) {
+                if (error instanceof Deno.errors.NotFound) {
+                    await Deno.mkdir("screenshots", { recursive: true });
+                }
+            }
+            const img = await page.screenshot({ format: "png" });
+            await Deno.writeFile(
+                `screenshots/${this.#sanitizeFilename(url)}.png`,
+                img,
+            );
+        }
+
+        if (this.#extractLinks && data.links) {
+            const crawlPromises = data.links.map((link: string) =>
+                this.crawl(link, depth + 1)
+            );
+            await Promise.all(crawlPromises);
+        }
+
+        await page.close();
+    }
+
+    /**
+     * Extract data from the page
+     */
+    async extractData(page: any, _url: string) {
+        const data = await page.evaluate(
+            (mediaTagsEnabled: boolean, metadataEnabled: boolean) => {
+                const data: any = {};
+
+                if (mediaTagsEnabled) {
+                    data.images = Array.from(document.querySelectorAll("img"))
+                        .map((img) => img.src);
+                    data.videos = Array.from(document.querySelectorAll("video"))
+                        .map((video) => video.src);
+                    data.audios = Array.from(document.querySelectorAll("audio"))
+                        .map((audio) => audio.src);
+                }
+
+                if (metadataEnabled) {
+                    data.title = document.title;
+                    data.description =
+                        document.querySelector('meta[name="description"]')
+                            ?.getAttribute("content") || "";
+                    data.keywords =
+                        document.querySelector('meta[name="keywords"]')
+                            ?.getAttribute("content") || "";
+                }
+
+                data.links = Array.from(document.querySelectorAll("a[href]"))
+                    .map((a) => (a as HTMLAnchorElement).href);
+
+                data.html = document.documentElement.outerHTML;
+
+                return data;
+            },
+            this.#mediaTags,
+            this.#metadata,
+        );
+
+        return data;
+    }
+
+    /**
+     * Save the data to a file
+     * The filename is sanitized and saved in the output folder
+     * The data is saved in JSON format
+     */
+    async saveData(url: string, data: any) {
+        const filename = `output/${this.#sanitizeFilename(url)}.json`;
+        try {
+            await Deno.stat("output");
+        } catch (error) {
+            if (error instanceof Deno.errors.NotFound) {
+                await Deno.mkdir("output", { recursive: true });
+            }
+        }
+        await Deno.writeTextFile(filename, JSON.stringify(data, null, 2));
+    }
+
+    #sanitizeFilename(url: string): string {
+        return url.replace(/[^a-z0-9]/gi, "_").toLowerCase();
+    }
+}
+
+/**
+ * Simple semaphore for #concurrency control
+ */
+class Semaphore {
+    #tasks: Array<() => void> = [];
+    #count: number;
+
+    constructor(count: number) {
+        this.#count = count;
+    }
+
+    acquire(): Promise<void> {
+        return new Promise((resolve) => {
+            const task = () => {
+                this.#count--;
+                resolve();
+            };
+
+            if (this.#count > 0) {
+                task();
+            } else {
+                this.#tasks.push(task);
+            }
+        });
+    }
+
+    release() {
+        this.#count++;
+        if (this.#tasks.length > 0) {
+            const task = this.#tasks.shift();
+            if (task) {
+                task();
+            }
+        }
+    }
+}