redirect dynamically via injected content script instead of checking

each request

src/entrypoints/background/index.ts

@@ -4,19 +4,54 @@ import { HostSettings, UrlReferer } from '@/lib/settings';
 
 export default defineBackground(() => {
 	browser.runtime.onMessage.addListener(async (message, sender) => {
-		const messageType = message.type as BackgroundMessageType;
-		const messageData = message.data as BackgroundMessageData<typeof messageType>;
+		const type = message.type as BackgroundMessageType;
+		let data = message.data;
 
 		let response;
-		switch (messageType) {
-			case BackgroundMessageType.Ff2mpv:
-				await browser.runtime.sendNativeMessage('ff2mpv', { url: messageData!.url });
+
+		switch (type) {
+			case BackgroundMessageType.Ff2mpv: {
+				data = data as BackgroundMessageData<typeof type>;
+
+				await browser.runtime.sendNativeMessage('ff2mpv', { url: data.url });
 				break;
-			case BackgroundMessageType.RequestTabUrl:
+			}
+			case BackgroundMessageType.RequestTabUrl: {
 				response = sender.tab?.url ?? null;
 				break;
+			}
+			case BackgroundMessageType.RegisterContentScript: {
+				// requires "dynamic" host permissions, which is only available in mv2
+				if (import.meta.env.MANIFEST_VERSION === 3) break;
+
+				data = data as BackgroundMessageData<typeof type>;
+
+				const contentScript: Browser.scripting.RegisteredContentScript = {
+					id: 'temporary-hosts',
+					js: ['content-scripts/content.js'],
+					matches: [`*://${data.domain}/*`],
+					persistAcrossSessions: false,
+					allFrames: true,
+					runAt: 'document_end'
+				};
+
+				const contentScripts = await browser.scripting.getRegisteredContentScripts({ ids: [contentScript.id] });
+				if (contentScripts.length !== 0) {
+					const registeredContentScript = contentScripts[0];
+
+					// do not double register for same domain
+					if (registeredContentScript.matches!.indexOf(contentScript.matches![0]) !== -1) break;
+
+					contentScript.matches!.push(...contentScripts[0].matches!);
+					await browser.scripting.updateContentScripts([contentScript]);
+				} else {
+					await browser.scripting.registerContentScripts([contentScript]);
+				}
+
+				break;
+			}
 			default:
-				return;
+				break;
 		}
 
 		return response;

src/entrypoints/content/index.ts

@@ -3,11 +3,7 @@ import { getHost, HostMatchType, hosts, type HostMatch } from '@/lib/host';
 import { FF2MPVSettings, PerDomainSettings } from '@/lib/settings';
 
 export default defineContentScript({
-	matches: [
-		...Object.values(hosts).flatMap((h) => h.domains.map((d) => `*://${d}/*`)),
-		// only mv2 allows to match all urls
-		...(import.meta.env.MANIFEST_VERSION === 2 ? ['<all_urls>'] : [])
-	],
+	matches: [...Object.values(hosts).flatMap((h) => h.domains.map((d) => `*://${d}/*`))],
 	allFrames: true,
 	runAt: 'document_end',
 	main