Facilitate installation of scripts from the repository

This commit includes:
* removal of page_info_server
* running of storage client in popup context
* extraction of some common CSS to a separate file
* extraction of scripts import view to a separate file
* addition of a facility to conveniently clone complex structures from DOM (in DOM_helpers.js)
* addition of hydrilla repo url to default settings
* other minor changes
and of course changes related to the actual installation of scripts from the repo

3 files changed, 94 insertions, 52 deletions

diff --git a/content/activity_info_server.js b/content/activity_info_server.js
index a1384e9..81a25fb 100644
--- a/content/activity_info_server.js
+++ b/content/activity_info_server.js
@@ -11,14 +11,20 @@
  * IMPORTS_START
  * IMPORT listen_for_connection
  * IMPORT CONNECTION_TYPE
- * IMPORT set_repo_query_repos
- * IMPORT set_repo_query_callback
+ * IMPORT repo_query
+ * IMPORT subscribe_repo_query_results
+ * IMPORT unsubscribe_repo_query_results
  * IMPORTS_END
  */
 
 var activities = [];
 var ports = new Set();
 
+function report_activity_oneshot(name, data, port)
+{
+    port.postMessage([name, data]);
+}
+
 function report_activity(name, data)
 {
     const activity = [name, data];
@@ -35,20 +41,23 @@ function report_script(script_data)
 
 function report_settings(settings)
 {
-    const [pattern, settings_data, repos] = settings;
-    set_repo_query_repos(repos);
-
     report_activity("settings", settings);
 }
 
-function report_repo_query_result(result)
+function report_repo_query_action(update, port)
 {
-    report_activity("repo_query_result", result);
+    report_activity_oneshot("repo_query_action", update, port);
 }
 
-function trigger_repo_query()
+function trigger_repo_query(query_specifier)
 {
-    set_repo_query_callback(report_repo_query_result);
+    repo_query(...query_specifier);
+}
+
+function handle_disconnect(port, report_action)
+{
+    ports.delete(port)
+    unsubscribe_repo_query_results(report_action);
 }
 
 function new_connection(port)
@@ -60,13 +69,16 @@ function new_connection(port)
     for (const activity of activities)
 	port.postMessage(activity);
 
+    const report_action = u => report_repo_query_action(u, port);
+    subscribe_repo_query_results(report_action);
+
     /*
      * So far the only thing we expect to receive is repo query order. Once more
      * possibilities arrive, we will need to complicate this listener.
      */
     port.onMessage.addListener(trigger_repo_query);
 
-    port.onDisconnect.addListener(() => ports.delete(port));
+    port.onDisconnect.addListener(() => handle_disconnect(port, report_action));
 }
 
 function start_activity_info_server()
diff --git a/content/main.js b/content/main.js
index 437a32b..8f8375e 100644
--- a/content/main.js
+++ b/content/main.js
@@ -20,7 +20,6 @@
  * IMPORT is_chrome
  * IMPORT is_mozilla
  * IMPORT start_activity_info_server
- * IMPORT set_repo_query_url
  * IMPORTS_END
  */
 
@@ -130,6 +129,4 @@ if (!is_privileged_url(document.URL)) {
     }
 
     start_activity_info_server();
-
-    set_repo_query_url(document.URL);
 }
diff --git a/content/repo_query.js b/content/repo_query.js
index b8c8ed9..3708108 100644
--- a/content/repo_query.js
+++ b/content/repo_query.js
@@ -9,72 +9,105 @@
 /*
  * IMPORTS_START
  * IMPORT make_ajax_request
+ * IMPORT observables
+ * IMPORT TYPE_PREFIX
+ * IMPORT parse_json_with_schema
+ * IMPORT matchers
  * IMPORTS_END
  */
 
-var query_started = false;
+const paths = {
+    [TYPE_PREFIX.PAGE]: "/pattern",
+    [TYPE_PREFIX.BAG]: "/bag",
+    [TYPE_PREFIX.SCRIPT]: "/script",
+    [TYPE_PREFIX.URL]: "/query"
+};
 
-var url = undefined;
-var repos = undefined;
-var callback = undefined;
+const queried_items = new Map();
+const observable = observables.make();
 
-async function query(repo)
+function repo_query(prefix, item, repo_urls)
 {
-    const [repo_url, data] = repo;
+    const key = prefix + item;
 
-    let response = "Query failed";
-    const query_url = `${repo_url}/query?n=${encodeURIComponent(url)}`;
+    const results = queried_items.get(key) || {};
+    queried_items.set(key, results);
 
-    try {
-	let xhttp = await make_ajax_request("GET", query_url);
-	if (xhttp.status === 200)
-	    response = xhttp.responseText;
-	console.log(xhttp);
-    } catch (e) {
-	console.log(e);
-    }
+    for (const repo_url of repo_urls)
+	perform_query_against(key, repo_url, results);
+}
 
-    callback([repo_url, response]);
+const page_schema = {
+    pattern: matchers.nonempty_string,
+    payload: ["optional", matchers.component, "default", undefined]
+};
+const bag_schema = {
+    name: matchers.nonempty_string,
+    components: ["optional", [matchers.component, "repeat"], "default", []]
+};
+const script_schema = {
+    name: matchers.nonempty_string,
+    location: matchers.nonempty_string,
+    sha256: matchers.sha256,
+};
+const search_result_schema = [page_schema, "repeat"];
+
+const schemas = {
+    [TYPE_PREFIX.PAGE]: page_schema,
+    [TYPE_PREFIX.BAG]: bag_schema,
+    [TYPE_PREFIX.SCRIPT]: script_schema,
+    [TYPE_PREFIX.URL]: search_result_schema
 }
 
-function start_query()
+async function perform_query_against(key, repo_url, results)
 {
-    if (query_started || !url || !repos || !callback)
+    if (results[repo_url] !== undefined)
 	return;
 
-    query_started = true;
+    const prefix = key[0];
+    const item = key.substring(1);
+    const result = {state: "started"};
+    results[repo_url] = result;
 
-    console.log(`about to query ${url} from ${repos}`);
+    const broadcast_msg = {prefix, item, results: {[repo_url]: result}};
+    observables.broadcast(observable, broadcast_msg);
 
-    for (const repo of repos)
-	query(repo);
-}
+    let state = "connection_error";
+    const query_url =
+	  `${repo_url}${paths[prefix]}?n=${encodeURIComponent(item)}`;
 
-function set_repo_query_url(_url)
-{
-    url = _url;
+    try {
+	let xhttp = await make_ajax_request("GET", query_url);
+	if (xhttp.status === 200) {
+	    state = "parse_error";
+	    result.response =
+		parse_json_with_schema(schemas[prefix], xhttp.responseText);
+	    state = "completed";
+	}
+    } catch (e) {
+	console.log(e);
+    }
 
-    start_query();
+    result.state = state;
+    observables.broadcast(observable, broadcast_msg);
 }
 
-function set_repo_query_repos(_repos)
+function subscribe_repo_query_results(cb)
 {
-    repos = _repos;
-
-    start_query();
+    observables.subscribe(observable, cb);
+    for (const [key, results] of queried_items.entries())
+	cb({prefix: key[0], item: key.substring(1), results});
 }
 
-function set_repo_query_callback(_callback)
+function unsubscribe_repo_query_results(cb)
 {
-    callback = _callback;
-
-    start_query();
+    observables.unsubscribe(observable, cb);
 }
 
 /*
  * EXPORTS_START
- * EXPORT set_repo_query_url
- * EXPORT set_repo_query_repos
- * EXPORT set_repo_query_callback
+ * EXPORT repo_query
+ * EXPORT subscribe_repo_query_results
+ * EXPORT unsubscribe_repo_query_results
  * EXPORTS_END
  */