stop using js modules

1 files changed, 149 insertions, 0 deletions

diff --git a/background/page_actions_server.js b/background/page_actions_server.js
new file mode 100644
index 0000000..fbb672e
--- /dev/null
+++ b/background/page_actions_server.js
@@ -0,0 +1,149 @@
+/**
+* Myext serving of page actions to content scripts
+*
+* Copyright (C) 2021 Wojtek Kosior
+*
+* Dual-licensed under:
+*   - 0BSD license
+*   - GPLv3 or (at your option) any later version
+*/
+
+"use strict";
+
+(() => {
+    const get_storage = window.get_storage;
+    const TYPE_PREFIX = window.TYPE_PREFIX;
+    const CONNECTION_TYPE = window.CONNECTION_TYPE;
+    const browser = window.browser;
+    const listen_for_connection = window.listen_for_connection;
+    const url_item = window.url_item;
+    const sha256 = window.sha256;
+
+    var storage;
+    var handler;
+
+    function send_scripts(url, port)
+    {
+	let settings = storage.get(TYPE_PREFIX.PAGE, url_item(url));
+	if (settings === undefined)
+	    return;
+
+	let components = settings.components;
+	let processed_bundles = new Set();
+
+	send_scripts_rec(components, port, processed_bundles);
+    }
+
+    // TODO: parallelize script fetching
+    async function send_scripts_rec(components, port, processed_bundles)
+    {
+	for (let [prefix, name] of components) {
+	    if (prefix === TYPE_PREFIX.BUNDLE) {
+		if (processed_bundles.has(name)) {
+		    console.log(`preventing recursive inclusion of bundle ${name}`);
+		    continue;
+		}
+
+		var bundle = storage.get(TYPE_PREFIX.BUNDLE, name);
+
+		if (bundle === undefined) {
+		    console.log(`no bundle in storage for key ${name}`);
+		    continue;
+		}
+
+		processed_bundles.add(name);
+		await send_scripts_rec(bundle, port, processed_bundles);
+		processed_bundles.delete(name);
+	    } else {
+		let script_text = await get_script_text(name);
+		if (script_text === undefined)
+		    continue;
+
+		port.postMessage({inject : [script_text]});
+	    }
+	}
+    }
+
+    async function get_script_text(script_name)
+    {
+	try {
+	    let script_data = storage.get(TYPE_PREFIX.SCRIPT, script_name);
+	    if (script_data === undefined) {
+		console.log(`missing data for ${script_name}`);
+		return;
+	    }
+	    let script_text = script_data.text;
+	    if (!script_text)
+		script_text = await fetch_remote_script(script_data);
+	    return script_text;
+	} catch (e) {
+	    console.log(e);
+	}
+    }
+
+    function ajax_callback()
+    {
+	if (this.readyState == 4)
+	    this.resolve_callback(this);
+    }
+
+    function initiate_ajax_request(resolve, method, url)
+    {
+	var xhttp = new XMLHttpRequest();
+	xhttp.resolve_callback = resolve;
+	xhttp.onreadystatechange = ajax_callback;
+	xhttp.open(method, url, true);
+	xhttp.send();
+    }
+
+    function make_ajax_request(method, url)
+    {
+	return new Promise((resolve, reject) =>
+			   initiate_ajax_request(resolve, method, url));
+    }
+
+    async function fetch_remote_script(script_data)
+    {
+	try {
+	    let xhttp = await make_ajax_request("GET", script_data.url);
+	    if (xhttp.status === 200) {
+		let computed_hash = sha256(xhttp.responseText);
+		if (computed_hash !== script_data.hash) {
+		    console.log(`Bad hash for ${script_data.url}\n    got ${computed_hash} instead of ${script_data.hash}`);
+		    return;
+		}
+		return xhttp.responseText;
+	    } else {
+		console.log("script not fetched: " + script_data.url);
+		return;
+	    }
+	} catch (e) {
+	    console.log(e);
+	}
+    }
+
+    function handle_message(port, message, handler)
+    {
+	port.onMessage.removeListener(handler[0]);
+	let url = message.url;
+	console.log({url});
+	send_scripts(url, port);
+    }
+
+    function new_connection(port)
+    {
+	console.log("new page actions connection!");
+	let handler = [];
+	handler.push(m => handle_message(port, m, handler));
+	port.onMessage.addListener(handler[0]);
+    }
+
+    async function start()
+    {
+	storage = await get_storage();
+
+	listen_for_connection(CONNECTION_TYPE.PAGE_ACTIONS, new_connection);
+    }
+
+    window.start_page_actions_server = start;
+})();