1 files changed, 60 insertions, 0 deletions
diff --git a/packages/frontend/src/utility/warning-external-website.ts b/packages/frontend/src/utility/warning-external-website.ts
new file mode 100644
index 0000000000..0c9b5ba806
--- /dev/null
+++ b/packages/frontend/src/utility/warning-external-website.ts
@@ -0,0 +1,60 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { instance } from '@/instance.js';
+import { defaultStore } from '@/store.js';
+import * as os from '@/os.js';
+import MkUrlWarningDialog from '@/components/MkUrlWarningDialog.vue';
+
+const isRegExp = /^\/(.+)\/(.*)$/;
+
+function extractHostname(maybeUrl: string): URL | null {
+	try {
+		const url = new URL(maybeUrl);
+		return url.host;
+	} catch {
+		return null;
+	}
+}
+
+export async function warningExternalWebsite(url: string) {
+	const hostname = extractHostname(url);
+
+	if (!hostname) return false;
+
+	const isTrustedByInstance = instance.trustedLinkUrlPatterns.some(expression => {
+		const r = isRegExp.exec(expression);
+
+		if (r) {
+			return new RegExp(r[1], r[2]).test(url);
+		} else if (expression.includes(' ')) {
+			return expression.split(' ').every(keyword => url.includes(keyword));
+		} else {
+			return `.${hostname}`.endsWith(`.${expression}`);
+		}
+	});
+
+	const isTrustedByUser = defaultStore.reactiveState.trustedDomains.value.includes(hostname);
+	const isDisabledByUser = !defaultStore.reactiveState.warnExternalUrl.value;
+
+	if (!isTrustedByInstance && !isTrustedByUser && !isDisabledByUser) {
+		const confirm = await new Promise<{ canceled: boolean }>(resolve => {
+			const { dispose } = os.popup(MkUrlWarningDialog, {
+				url,
+			}, {
+				done: result => {
+					resolve(result ?? { canceled: true });
+				},
+				closed: () => dispose(),
+			});
+		});
+
+		if (confirm.canceled) return false;
+
+		return window.open(url, '_blank', 'nofollow noopener popup=false');
+	}
+
+	return window.open(url, '_blank', 'nofollow noopener popup=false');
+}